The team from China gathered the largest number of medals and earned top honors.
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Saturday, July 21, 2007
Friday, July 20, 2007
MIT Physicists Get Ultra-Sharp Glimpse of Electrons
This is another one of those cool experiments that sounds obvious, but amazingly difficult to make a direct observation. The energy state of electrons confined in 2D has been observed with amazing accuracy.
Here's the exact citation to this work:
O. E. Dial et al., Nature v.448, p.176 (2007).
Properties of electrons in 2D is quite important because many exotic systems are thought to be 2D. This includes the yet-unsolved high-Tc superconductors, where the charge carriers are believed to be in the Cu-O planes.
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The new spectroscopy technique measures electron energy levels with 1,000 times greater resolution than previous methods, an advance that has "tremendous power to tell you what the electrons are doing," said MIT physics professor Ray Ashoori, author of a paper on the work published in the July 12 issue of Nature. This technique has already revealed some surprising behavior, and the researchers believe it will shed new light on many physical phenomena involving electrons.
Here's the exact citation to this work:
O. E. Dial et al., Nature v.448, p.176 (2007).
Properties of electrons in 2D is quite important because many exotic systems are thought to be 2D. This includes the yet-unsolved high-Tc superconductors, where the charge carriers are believed to be in the Cu-O planes.
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Thursday, July 19, 2007
Tips for Choosing a Research Adviser
In Chapter 10 from my essay So You Want To Be A Physicist, I spent some time on a very important aspect of one's graduate program - choosing a research adviser. One important factor that I emphasized is the question on whether you can get along with the person that you are choosing.
Looks like I'm not the only one who feels this way. In the latest issue of Science's Careers section, there is an article on choosing a research adviser that highlights the same issue.
Read the whole article. It has several very good suggestions on what one should do in choosing an adviser.
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3. But most importantly (at least in my book), can you get along with this person. I have seen way too many sad situations where the mentor and the student are simply either miscommunicating with each other, do not understand each other, or simply cannot get along. This will make for a hellish experience and I have never seen anything good coming out of such a thing.
Looks like I'm not the only one who feels this way. In the latest issue of Science's Careers section, there is an article on choosing a research adviser that highlights the same issue.
It's both legitimate and wise--indeed, essential--for aspiring scientists to evaluate a prospective adviser before committing to spending the next 4 or 5 years in her research lab. A hasty decision can mean years of dissatisfaction, and poor advisory relationships are a major reason why students drop out of graduate school. Signing on with an adviser who isn't a good fit, or who isn't sufficiently attentive to the development of students' technical and professional skills, can also hinder your chances of landing choice jobs.
Read the whole article. It has several very good suggestions on what one should do in choosing an adviser.
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The Hottest Field in Physics Is Ultracold?
That is certainly what this Wired article seems to imply. People working in this field certainly think it is a very "hot" area of study. People working in nanoscience might have a strong argument with them, though. Certainly, in terms of funding, nanoscience and nanotechnology seems to be getting a lot of funding.
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Wednesday, July 18, 2007
Nature Insight: The Large Hadron Collider
The new issue of Nature (19 July 2007) has an extensive special section on the LHC. So don't miss it if you have a subscription or access to it. If you don't, there are two articles that are available for free from this website, so you can still read a little bit on it. But get the whole coverage if you can.
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Relativity For the Questioning Mind
Let get this out of the way, shall we? I'm a fan of Dan Styer almost as much as I'm a fan of Bob Park. Styer is a professor at Oberlin College and has written some of the most sensible (in my opinion) articles and papers on physics that I've ever read. You may go to his webpage and check out his publication list and also his school notes/handouts.
Anyway, he is either finished, or about to complete his text on relativity called Relativity For The Questioning Mind. I've read a few chapters of it and think that this is a wonderful introduction to Special Relativity to either beginning students, or the general public that want to have a rigorous, non-superficial account of this important part of physics, but without the mathematical gymnastics. Don't get me wrong, there's some mathematics there, because you do need some to make this clear and rigorous, but the way it is presented, one can follow easily the mathematics (assuming one has at least basic algebra, trig, and geometry).
So I quite highly recommend this text if you want a good intro text on Special Relativity. It is a bonus that he's making this freely available. It just reflects on how much he cares about the teaching of physics.
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Anyway, he is either finished, or about to complete his text on relativity called Relativity For The Questioning Mind. I've read a few chapters of it and think that this is a wonderful introduction to Special Relativity to either beginning students, or the general public that want to have a rigorous, non-superficial account of this important part of physics, but without the mathematical gymnastics. Don't get me wrong, there's some mathematics there, because you do need some to make this clear and rigorous, but the way it is presented, one can follow easily the mathematics (assuming one has at least basic algebra, trig, and geometry).
So I quite highly recommend this text if you want a good intro text on Special Relativity. It is a bonus that he's making this freely available. It just reflects on how much he cares about the teaching of physics.
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Tuesday, July 17, 2007
Using the ‘Beauties of Physics’ to Conquer Science Illiteracy
I mentioned earlier that in dealing with politicians and the general public, a scientist has to be shallow, perky, and superficial to capture the public's attention. A presentation full of facts and content alone will not cut it.
This interview describes Eric Mazur at Harvard in his attempt at tackling the physics illiteracy, especially among none-science students. His method is trying to convey the "beauty" that is inherent in physics.
Still, after reading this, I'm not sure if the way it has been described involves the appreciation of the "beauty" in physics, or more of simply presenting physics in ways that students can actually see the applications and relevance in their lives. I think many instructors and high school teachers have tried doing that. So, not sure if this has anything to do with the "beauty" of the subject matter.
Zz.
This interview describes Eric Mazur at Harvard in his attempt at tackling the physics illiteracy, especially among none-science students. His method is trying to convey the "beauty" that is inherent in physics.
Still, after reading this, I'm not sure if the way it has been described involves the appreciation of the "beauty" in physics, or more of simply presenting physics in ways that students can actually see the applications and relevance in their lives. I think many instructors and high school teachers have tried doing that. So, not sure if this has anything to do with the "beauty" of the subject matter.
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Monday, July 16, 2007
First "Heat Transistor" Unveiled
OK, here's another one that's so cool! :) First we had a single-electron refrigerator. Now we have the world's first heat transistor.
Very, very clever!
Physicists in Finland and Italy claim to have built the world’s first "heat transistor" in which the flow of heat between two electrodes is controlled by a voltage applied to a third lead. The flow can be increased, decreased or even switched off by changing the voltage -- in much the same way as electrical current is controlled in a conventional transistor.
Very, very clever!
50 Years in Space: An International Aerospace Conference Celebrating 50 Years of Space Technology
This is a news report on the upcoming conference celebrating the 50th anniversary of space exploration. It will be held at CalTech in Pasadena, CA.
It's 50 years already?
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It's 50 years already?
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More Evidence of Drop in Physics Enrollment in Australia
The situation in Australia now looks to be grim. The drop in the number of students studying physics and mathematics is reconfirmed in the report from South Australia.
Interestingly enough, the report appears to come up with the source of the drop in enrollment in physics.
That is a universal concern. Certainly many students are influenced greatly of what they will study later on based on how well the subject is introduced to them in high/secondary schools. Qualified and enthusiastic physics teachers are such a valuable commodity.
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The number of students completing key Year 12 courses - including physics and maths - is dramatically declining, according to latest figures from the Senior Secondary Assessment Board of South Australia.
In physics alone, completions last year sank below 2000 - 600 fewer than a decade ago - during a period when the number of students completing their high school certificate increased from 9000 to 12,000.
Interestingly enough, the report appears to come up with the source of the drop in enrollment in physics.
University of Adelaide senior physics lecturer Dr Rodney Crewther blamed the decline on low numbers of qualified science teachers.
That is a universal concern. Certainly many students are influenced greatly of what they will study later on based on how well the subject is introduced to them in high/secondary schools. Qualified and enthusiastic physics teachers are such a valuable commodity.
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Sunday, July 15, 2007
Capturing a Piece of Cosmic Ray
I mentioned earlier about the Auger Observatory project and how we are involved in it indirectly via the AirFly collaboration. This news article reports on the effort to gain support from farmers and also monetary support from governments to build what is known as "Auger North". This will be a large number of detectors in the plains of Colorado to compliment with the already built detectors on the pampas of Argentina.
Hope they don't have the same problem of the cows rubbing against the detector tanks as they have for the ones in Argentina. I thought that was hysterically funny.
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Hope they don't have the same problem of the cows rubbing against the detector tanks as they have for the ones in Argentina. I thought that was hysterically funny.
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Environmental Math in the Ethanol Equation
This is one example where one MUST not simply rely on superficial information or sound bites, but learn a bit deeper into it. The push for ethanol as an alternative energy use sounds fine and dandy on the surface, but after one looks at it more, it isn't as attractive as it is made up to be. This article argue that it actually costs more, in terms of energy and also in terms of other issues, to use ethanol within our current system.
Similar arguments appear to hold true for the use of hydrogen. This is where the lack of knowledge not only leads to ignorance, but also leads to being deceived into accepting something that may actually be worse than the problem that we are trying to solve.
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Similar arguments appear to hold true for the use of hydrogen. This is where the lack of knowledge not only leads to ignorance, but also leads to being deceived into accepting something that may actually be worse than the problem that we are trying to solve.
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Brian May Finally Completes His PhD Thesis
Brian May, a member of the rock group Queen, finally completes his Ph.D thesis in Astronomy at the age of 59.
I guess it helps that the group is no longer active after the death of Freddy Mercury that he could spend time to complete degree requirements.
Still, congratulations. Not that he needs the degree for a job or anything... :)
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I guess it helps that the group is no longer active after the death of Freddy Mercury that he could spend time to complete degree requirements.
Still, congratulations. Not that he needs the degree for a job or anything... :)
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Saturday, July 14, 2007
Follow-up To "Hollywood Blockbusters: Unlimited Fun but Limited Science Literacy"
It seems that the preprint is getting quite a bit of publicity. Phillip Ball at Nature wrote a rather relevant "blog" on it.
While the preprint was a rather entertaining read, I rather agree with Ball on this, i.e. the bastardization of physics in Hollywood movies isn't a big deal and has no lasting impact to cause scientific illiteracy on the general public.
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Should we endorse the violations of physics routinely perpetrated by Hollywood? Efthimiou and Llewellyn clearly think not. I would argue that you might as well complain about 'errors' in the Greek myths or fairy tales, or Warner Brothers cartoons.
While the preprint was a rather entertaining read, I rather agree with Ball on this, i.e. the bastardization of physics in Hollywood movies isn't a big deal and has no lasting impact to cause scientific illiteracy on the general public.
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Friday, July 13, 2007
The Physics of Baseball Feats
I thought I posted something on the physics of baseball, but I guess I didn't. Here's something close to it. It is a conversation between a physicist, a baseball coach, and a physics teacher on what it takes to accomplish some of the more amazing feats in baseball.
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The Scientific Method
The issue on whether there is such a thing as a single "Scientific Method" has been debated in many circles. For most practicing physicist, this issue seldom comes up, because how we investigate something just seems like second nature to many of us. But for the general public (and certainly to philosophers and sociologists), the concept of the scientific method seem to be of great interest. This is especially true when scientists try to argue on why such-and-such can't be considered as science, or why a certain set of "knowledge" is flawed due to its non-scientific methodology. It is why, for example, Intelligent Design isn't considered as science, and why astrology is a pseudoscience. While scientists usually can distinguish the difference between science and non-science, the general public (y'know, the one where half of them did not know that the earth revolves around the sun) often can't. So it is actually quite important if some sort of an explanation on the scientific method and how we arrive at our knowledge are presented.
Brian Jennings at TRIUMPH tries to do just that. I've only skimmed through the article rather fast, so I can't exactly endorse everything that is said here. But from what I've read, it is certainly quite informative and entertaining, at least. You might find a few interesting things to read about in this preprint.
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Brian Jennings at TRIUMPH tries to do just that. I've only skimmed through the article rather fast, so I can't exactly endorse everything that is said here. But from what I've read, it is certainly quite informative and entertaining, at least. You might find a few interesting things to read about in this preprint.
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Physics Genius Turns Ecoterrorist
Whether you believe he was rightly or wrongly convicted, this is still a sad story and a waste of talent. This news report describes the bizzare episode in Billy Cottrell's life that eventually led to his incarceration. It is only with the help of prominent physicists, including Stephen Hawking, that he's receiving at least a slightly better condition.
Still, during what could be the most productive part of one's career, he will not be able to do what he is best at, physics.
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Still, during what could be the most productive part of one's career, he will not be able to do what he is best at, physics.
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Thursday, July 12, 2007
Should the Bohr Model be Taught in Schools?
This preprint explores this question. More specifically, it studies the students' knowledge of the atom after being taught both the Bohr Model and the Schrodinger's model.
Abstract: Some education researchers have claimed that we should not teach the Bohr model of the atom because it inhibits students' ability to learn the true quantum nature of electrons in atoms. Although the evidence for this claim is weak, many have accepted it. This claim has implications for how to present atoms in classes ranging from elementary school to graduate school. We present results from a study designed to test this claim by developing curriculum on models of the atom, including the Bohr and Schrodinger models. We examine student descriptions of atoms on final exams in transformed modern physics classes using various versions of this curriculum. We find that if the curriculum does not include sufficient connections between different models, many students still have a Bohr-like view of atoms, rather than a more accurate Schrodinger model. However, with an improved curriculum designed to develop model-building skills and with better integration between different models, it is possible to get nearly all students to describe atoms using the Schrodinger model. In comparing our results with previous research, we find that comparing and contrasting different models is a key feature of curriculum that helps students move beyond the Bohr model and adopt Schrodinger's view of the atom. We find that understanding the reasons for the development of models is much more difficult for students than understanding the features of the models. We present new interactive computer simulations designed to help students build models of the atom more effectively.
I think the Bohr model should be taught if nothing else, for historical context. However, as the authors have pointed out, it isn't the subject matter that is the source of the problem here, it is HOW they are taught, and how these models are integrated into the teaching of the material. I think many instructors do not emphasize clearly enough that the Bohr model is valid only in the historical sense. More important than the actual understanding of what a Bohr model is, is the story on how physics develops. It clearly shows an example on how we develop our understanding of something new, where we try out an initial model that may nor may not be accurate, but somehow manages to agree roughly with experiment. It is only upon refinement after refinement that we arrive at some degree of a valid description of a phenomenon. The Bohr model is invaluable in this historical perspective.
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Abstract: Some education researchers have claimed that we should not teach the Bohr model of the atom because it inhibits students' ability to learn the true quantum nature of electrons in atoms. Although the evidence for this claim is weak, many have accepted it. This claim has implications for how to present atoms in classes ranging from elementary school to graduate school. We present results from a study designed to test this claim by developing curriculum on models of the atom, including the Bohr and Schrodinger models. We examine student descriptions of atoms on final exams in transformed modern physics classes using various versions of this curriculum. We find that if the curriculum does not include sufficient connections between different models, many students still have a Bohr-like view of atoms, rather than a more accurate Schrodinger model. However, with an improved curriculum designed to develop model-building skills and with better integration between different models, it is possible to get nearly all students to describe atoms using the Schrodinger model. In comparing our results with previous research, we find that comparing and contrasting different models is a key feature of curriculum that helps students move beyond the Bohr model and adopt Schrodinger's view of the atom. We find that understanding the reasons for the development of models is much more difficult for students than understanding the features of the models. We present new interactive computer simulations designed to help students build models of the atom more effectively.
I think the Bohr model should be taught if nothing else, for historical context. However, as the authors have pointed out, it isn't the subject matter that is the source of the problem here, it is HOW they are taught, and how these models are integrated into the teaching of the material. I think many instructors do not emphasize clearly enough that the Bohr model is valid only in the historical sense. More important than the actual understanding of what a Bohr model is, is the story on how physics develops. It clearly shows an example on how we develop our understanding of something new, where we try out an initial model that may nor may not be accurate, but somehow manages to agree roughly with experiment. It is only upon refinement after refinement that we arrive at some degree of a valid description of a phenomenon. The Bohr model is invaluable in this historical perspective.
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Wednesday, July 11, 2007
Galaxy Zoo
Here's another distributed computing project for your idle computer. The Galaxy Zoo project, based at University of Oxford, is seeking you and your computer to analyze the million of images from Sloan Digital Sky survey. This project is being launched TODAY.
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Belief and Knowledge—A Plea About Language (Follow-up)
I highlighted this terrific essay by Helen Quinn a few months ago. All I said was that you MUST read this, especially if you are a scientist. And if you are not, then you should read this because it tells you why you should not simply look up in a dictionary the meanings of the words scientists use, because these words cannot convey the true intentions of how they are used in science.
In the July 2007 issue of Physics Today, this essay received several letters. These letters also make for very enlightening reading. So don't miss them.
In the July 2007 issue of Physics Today, this essay received several letters. These letters also make for very enlightening reading. So don't miss them.
Faust In Copenhagen
We seem to be having a lot of stuff on Bohr lately. In addition to the short news article on Bohr that I pointed to yesterday, there is a book review by John Rigden appearing today. Written by physicist Gino Segre, the book is titled "Faust in Copenhagen".
The book describes the situation in Denmark in the 1920's as many talented physicists descended upon the institute that Bohr has built. In many aspects, it sounds like an entertaining description of who these people are, rather than describing just their accomplishments.
I've always enjoyed Rigden essays before this, especially the ones that have appeared on Physics Today. In this review, he seems to also include a lot of his opinion on Bohr, and how later in Bohr's life, he seemed to be more of someone who tried to hinder a lot of progress within quantum mechanics. Whether this is true or not, I'm sure, is debatable. However, I do buy into what he said here:
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The book describes the situation in Denmark in the 1920's as many talented physicists descended upon the institute that Bohr has built. In many aspects, it sounds like an entertaining description of who these people are, rather than describing just their accomplishments.
I've always enjoyed Rigden essays before this, especially the ones that have appeared on Physics Today. In this review, he seems to also include a lot of his opinion on Bohr, and how later in Bohr's life, he seemed to be more of someone who tried to hinder a lot of progress within quantum mechanics. Whether this is true or not, I'm sure, is debatable. However, I do buy into what he said here:
Bohr contributed nothing to the powerful formalism of quantum mechanics. He did, however, provide the Copenhagen interpretation of quantum mechanics, including the Principle of Complementarity in 1927. Again, I take issue with Mr. Segrè when he writes, "The Bohr interpretation still stands [today], as solidly as ever." The Copenhagen interpretation never did stand solidly: Pauli, Heisenberg, and Dirac tolerated it; contemporary physicists pay no attention to it.
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Tuesday, July 10, 2007
Design Selected for DUSEL
This just in. The National Science Foundation (NSF) has just announced that the design proposed by the team from University of California-Berkeley has been selected for a Deep Underground Science and Engineering Laboratory (DUSEL). This underground laboratory is proposed to be built at the Homestake mine in South Dakota.
One can only hope that this is not going to be another one that get supported in the beginning, but left dangling in the middle.
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Edit: Yowzah! I can't believe the amount of grief I got due to my typo of "Homestake" into "Homestead".
A 22-member panel of external experts, all screened for conflicts of interest, exhaustively merit-reviewed proposals from four teams and unanimously determined that the Homestake proposal offered the greatest potential for developing a DUSEL, and NSF concurred with the panel's recommendation. The agency's selection of the Homestake proposal provides funding only for design work. Any decision to construct and operate a DUSEL would entail a sequence of approvals by NSF and the National Science Board; funding would then have to be requested by the Administration and approved by Congress.
One can only hope that this is not going to be another one that get supported in the beginning, but left dangling in the middle.
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Edit: Yowzah! I can't believe the amount of grief I got due to my typo of "Homestake" into "Homestead".
Hollywood Blockbusters: Unlimited Fun but Limited Science Literacy
OK, this article is just PLAIN FUN! In fact, it can easily be a very good way to get kids to think about physics by pointing out what is wrong with a particular movie scene. I particularly like the fact that they got actual snap shots of the movie scene and show in detail why these things are not physically possible.
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He Bore Down On The Atom
Maybe the titled should have read "He Bohr Down on the Atom". :)
[insert groan here]
I'm not sure what was the impetus for this article, but it gives an account of Niels Bohr's life and accomplishments. I can't vouch for the accuracy of it, and you can certainly find a more detailed biography of Bohr in many other books. Still, if you no knowing about Bohr and can't tell the difference between him and a "bore", then this might be a good place to start.
Edit: I should have pointed this out in the first place. Since we are talking about Bohr, his life story, and his accomplishments, I would like to point out that the AIP has a very good website on the Niels Bohr Library and Archives. This should supplement what you read in that news article.
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[insert groan here]
I'm not sure what was the impetus for this article, but it gives an account of Niels Bohr's life and accomplishments. I can't vouch for the accuracy of it, and you can certainly find a more detailed biography of Bohr in many other books. Still, if you no knowing about Bohr and can't tell the difference between him and a "bore", then this might be a good place to start.
Edit: I should have pointed this out in the first place. Since we are talking about Bohr, his life story, and his accomplishments, I would like to point out that the AIP has a very good website on the Niels Bohr Library and Archives. This should supplement what you read in that news article.
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Fictitious Forces
Here's an explanation of "fictitious forces", given by no less than 2004 Nobel laureate David Politzer.
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Monday, July 09, 2007
More Jobs For Physicists In The Financial Sector?
Are banks and brokerage houses looking for more mathematics and physics graduates? You be the judge for yourself from this article.
What if you have a physics degree, and then you get an MBA? That is almost as desirable as, let's see, a physics degree and a law degree!
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As markets get more sophisticated through such products as derivatives, executives are seeking people with math and physics degrees more than business administration graduates, Dence said. India, China, Russia and France have the highest average physics scores, pointing to where the search for talent may lead firms in the future, according to the study.
What if you have a physics degree, and then you get an MBA? That is almost as desirable as, let's see, a physics degree and a law degree!
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Fewer Students Studying Science and Mathematics in Australia
Having highlighted the problems with attracting students to study physics in the US and UK, it looks like the problem is similarly being faced in Australia.
Luckily, here in the US, there seems to be a turn of events, with many places reporting an increase in enrollment in physics classes. Still, this issue of the decline in interest in physics and math should be dealt with as a long-term problem.
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A report commissioned by the Australian Council of Deans of Science finds that the proportion of students taking physics subjects is now only two-thirds of what it was in 1989.
The picture for chemistry is also gloomy and for maths it is worse: enrolments in maths fell from 7520 in 1989 to 4988 in 2005.
The decline has occurred against massive growth in higher education with student numbers doubling over the same period.
Luckily, here in the US, there seems to be a turn of events, with many places reporting an increase in enrollment in physics classes. Still, this issue of the decline in interest in physics and math should be dealt with as a long-term problem.
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A Review of A Different Universe
Better late than never, I suppose.
This writer reviews Robert Laughlin's "A Different Universe (Reinventing Physics from the Bottom Down". I've recommended this book a few times and even highlighted a recent announcement of a talk given by Laughlin on this topic. It's not that this book is outstanding or full of thrilling accounts. It is just that it is covering an area that most people are not aware of, or are totally ignorant on. It presents a different perspective than those of high energy/particle physicists that seem to get a lot more publicity. Yet, a significant portion of practicing physicists, especially those in Condensed matter, disagree with such a view of our world, and this view hasn't been heard much. That is why this book is a must read.
It is interesting that this writer, at the end of the review, wrote this:
He's referring to Laughlin's "test" in which he gave his first year graduate student a problem to "derive" superconductivity starting with the interactions of each individual particles. What did that prove? It proves to the student in the most direct fashion that superconductivity cannot be derived that way. When taken apart at the individual interactions level, you do not get superconductivity because this is a collective, emergent phenomenon. Reducing it to the individual, reductionist level will NEVER tell you that at the many-body level, you such a phenomenon will emerge. Students who tried to do this and fail will learn very quickly the message being sent here. Now, not knowing the circumstances of the exam, we can only make speculation here. But if I were the one giving the exam, it would certainly be a question that is "open-ended", meaning it doesn't have a right answer. I can certainly see myself giving credit for what was done by the student, even if he/she didn't get to solve it, simply because there is no solution! So no, this isn't as "cruel" or pointless as one would imagine. And having met Laughlin a few times, I can't believe that he would not have done something similar here.
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This writer reviews Robert Laughlin's "A Different Universe (Reinventing Physics from the Bottom Down". I've recommended this book a few times and even highlighted a recent announcement of a talk given by Laughlin on this topic. It's not that this book is outstanding or full of thrilling accounts. It is just that it is covering an area that most people are not aware of, or are totally ignorant on. It presents a different perspective than those of high energy/particle physicists that seem to get a lot more publicity. Yet, a significant portion of practicing physicists, especially those in Condensed matter, disagree with such a view of our world, and this view hasn't been heard much. That is why this book is a must read.
It is interesting that this writer, at the end of the review, wrote this:
Twice he uses the phrase "intellectually mugged" to describe how students and even his own son sometimes go away from discussions with him feeling battered. He even admits to once setting a physics exam question so difficult that not one student could solve it. What did that prove?
He's referring to Laughlin's "test" in which he gave his first year graduate student a problem to "derive" superconductivity starting with the interactions of each individual particles. What did that prove? It proves to the student in the most direct fashion that superconductivity cannot be derived that way. When taken apart at the individual interactions level, you do not get superconductivity because this is a collective, emergent phenomenon. Reducing it to the individual, reductionist level will NEVER tell you that at the many-body level, you such a phenomenon will emerge. Students who tried to do this and fail will learn very quickly the message being sent here. Now, not knowing the circumstances of the exam, we can only make speculation here. But if I were the one giving the exam, it would certainly be a question that is "open-ended", meaning it doesn't have a right answer. I can certainly see myself giving credit for what was done by the student, even if he/she didn't get to solve it, simply because there is no solution! So no, this isn't as "cruel" or pointless as one would imagine. And having met Laughlin a few times, I can't believe that he would not have done something similar here.
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Neutrino Summer School
This is a news report on the first Neutrino Summer School at Fermilab.
With the Tevatron winding down, Fermilab's sole future funded projects center on various neutrino and astrophysics experiments, including Veritas, MINOS, and the upcoming NOvA. Having a neutrino summer school isn't such a bad idea.
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With the Tevatron winding down, Fermilab's sole future funded projects center on various neutrino and astrophysics experiments, including Veritas, MINOS, and the upcoming NOvA. Having a neutrino summer school isn't such a bad idea.
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Sunday, July 08, 2007
Surprise! More Bastardization of Quantum Mechanics!
If you have followed this blog for a considerable period of time, you know that one of my pet peeve is the use, either directly or via analogy, of various principle in physics in wrong, hilarious, and even puzzling ways. It ranges from an outright bastardization of quantum mechanics, to the intention of using it in a rather amusing fashion.
This news article tries to be the latter. It is applying the Heisenberg Uncertainty Principle to the political campaigning process.
Let's do some nit-picking, shall we? :)
The HUP is about two non-commuting observables. In other words, if you make a well-defined measurement of one observable, the other non-commuting observable cannot be predicted with arbitrarily high accuracy. It has NOTHING to do with the knowledge about ANY measurement later on. This is an issue of TIME EVOLUTION, not HUP. If you have determined the measurement of something, then you have already "collapsed" the system into that state, and any variation later on in that value is dependent on the time evolution property of that system, not the HUP. So for this article to say that just because we know the candidates stand now will make us know about where things are in the end isn't a correct application of the HUP. You need to define, first of all, the pair of non-commuting observables in such a scenario. And unless you have learned QM, you will not no clue on what is meant by "non-commuting" observable.
Besides, who said that QM principles can be extrapolated to human activities in the first place? People who do this don't seem to realize that such extrapolation has never been shown to be valid. So what is the justification of applying such QM description to social/political systems? Zilch.
Zz.
This news article tries to be the latter. It is applying the Heisenberg Uncertainty Principle to the political campaigning process.
The absurdly early start of this primary season has a lot more to do with entertaining bored political elites than with persuading actual primary voters.
It is reminiscent of the Heisenberg uncertainty principle we all heard about in high school physics class. Professor Werner Heisenberg postulated that “the more precisely the position is determined, the less precisely the momentum is known.”
Applied to the presidential race, this suggests that the more we measure how the candidates stand now, the less we may know about where things are going to end up – because the measurement itself can render the findings inaccurate.
Let's do some nit-picking, shall we? :)
The HUP is about two non-commuting observables. In other words, if you make a well-defined measurement of one observable, the other non-commuting observable cannot be predicted with arbitrarily high accuracy. It has NOTHING to do with the knowledge about ANY measurement later on. This is an issue of TIME EVOLUTION, not HUP. If you have determined the measurement of something, then you have already "collapsed" the system into that state, and any variation later on in that value is dependent on the time evolution property of that system, not the HUP. So for this article to say that just because we know the candidates stand now will make us know about where things are in the end isn't a correct application of the HUP. You need to define, first of all, the pair of non-commuting observables in such a scenario. And unless you have learned QM, you will not no clue on what is meant by "non-commuting" observable.
Besides, who said that QM principles can be extrapolated to human activities in the first place? People who do this don't seem to realize that such extrapolation has never been shown to be valid. So what is the justification of applying such QM description to social/political systems? Zilch.
Zz.
Teacher Learns New Ways To Teach Physics
Middle school general science teachers do need help in effectively teaching physics, especially since most of them did not major or have any expertise in physics. One such teacher did get the help that she needed.
Wish they could have more of these so that everyone could get the necessary training and resources.
Zz.
Wish they could have more of these so that everyone could get the necessary training and resources.
Zz.
Friday, July 06, 2007
Symmetry Breaking on a Supercomputer
This article is a month old, but better late than never.
One of the points that I've always tried to get across is that fields such as condensed matter physics, which many physicists who study "fundamental" issues look down upon, can and have made significant contribution to the fundamental issues in physics. This article on spontaneous symmetry breaking in lattice QCD is one such example.
This is not the first such case, and in fact, not the only time the Nambu et al. work has inspired a development in something fundamental. Peter Higgs made the same leap using Nambu's work and later on, took up Phil Anderson's work on Goldstone boson to come up with what we now called the Higgs mechanism.
There you go. These are clear proofs that many of the fundamental ideas and principles of world can come from a field of study that deals with materials and many-body interactions. So kids, you don't have to be string theorists, astrophysicists, or study high-energy physics to make significant contributions to our basic understanding of the universe.
Zz.
One of the points that I've always tried to get across is that fields such as condensed matter physics, which many physicists who study "fundamental" issues look down upon, can and have made significant contribution to the fundamental issues in physics. This article on spontaneous symmetry breaking in lattice QCD is one such example.
Chiral symmetry distinguishes right-hand spinning quarks from left-handed and is exact only if the quarks move at c and are therefore massless. In 1961 Yoichiro Nambu and Giovanni Jona-Lasinio proposed the idea of SCSB, inspired by the Bardeen–Cooper–Schrieffer mechanism of superconductivity in which spin-up and spin-down electrons pair up and condense into a lower energy level. In QCD a quark and an antiquark pair up, leading to a vacuum full of condensed quark–antiquark pairs. The result is that chiral symmetry is broken, so that the quarks – and the particles they form – acquire masses.
This is not the first such case, and in fact, not the only time the Nambu et al. work has inspired a development in something fundamental. Peter Higgs made the same leap using Nambu's work and later on, took up Phil Anderson's work on Goldstone boson to come up with what we now called the Higgs mechanism.
"When I moved back to Edinburgh in October 1960 I was not sure where I was going next," he recalls. That all changed the following year when he read a paper by Yoichiro Nambu that based a theory of elementary particles on an analogy with the BCS theory of superconductivity. "This is where the idea of a spontaneously broken symmetry being the way in which the mass of particles could be generated first arose," says Higgs. "Although my name gets thrown around in this context, it was Nambu who showed how fermion masses would be generated in a way that was analogous to the formation of the energy gap in a superconductor."
There was, however, a problem with the Nambu approach. Although the spontaneous breaking of symmetry generated particles with mass, Jeffrey Goldstone, Salam and Steven Weinberg had shown that it also generated a particle known as a Goldstone boson that had no mass. This was bad news because no such particle was known to exist.
Once more help arrived from the condensed-matter community when, in 1963, Phil Anderson pointed out that the equivalent of a Goldstone boson in a superconductor could become massive due to its electromagnetic interactions. But did Anderson's argument apply in the relativistic case? No, said a paper by Walter Gilbert in an issue of Physical Review Letters that arrived in Edinburgh the middle of July. Yes, said Higgs, after thinking about it over the weekend.
There you go. These are clear proofs that many of the fundamental ideas and principles of world can come from a field of study that deals with materials and many-body interactions. So kids, you don't have to be string theorists, astrophysicists, or study high-energy physics to make significant contributions to our basic understanding of the universe.
Zz.
The Importance of Undergraduate Research
ScienceCareers has a very good article on the importance of undergraduate research work, especially if one is looking to enroll in one of the competitive schools for graduate work. So if you are an undergraduate science major, you might want to read this.
I've emphasized the importance of this to physics majors in my So You Want To Be A Physicist essay. Such research work will tend to distinguish you from other graduate school applicants. It is certainly a very important item in your resume that can easily work in your favor. So it is something I strongly recommend on doing as an undergraduate.
Zz.
I've emphasized the importance of this to physics majors in my So You Want To Be A Physicist essay. Such research work will tend to distinguish you from other graduate school applicants. It is certainly a very important item in your resume that can easily work in your favor. So it is something I strongly recommend on doing as an undergraduate.
Zz.
Kobayashi and Maskawa Win the EPS High Energy and Particle Physics Prize
Press release from the KEK:
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The prestigious European Physical Society High Energy and Particle Physics Prize was awarded for 2007 to Makoto Kobayashi and Toshihide Maskawa for "the proposal of a successful mechanism for CP violation in the Standard Model, predicting the existence of a third family of quarks". Kobayashi is a professor emeritus of KEK and the former Director of the Institute of Particle and Nuclear Studies, the High Energy Accelerator Research Organization (KEK), Japan.
Kobayashi, together with Maskawa, proposed six types of quarks and their mixing matrix for the weak interaction in 1973. Later in 1995, the sixth quark was discovered, and in 2001, KEK and SLAC confirmed the CP violation using B mesons at their B-factory experiments Belle and BaBar.
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U.S. Theoretical Physicists Organize To Stem "Outsourcing"
Outsourcing? Of theoretical physics? Who would have thunk?
It seems that there is an organized effort to stop this "outsourcing" of theoretical high energy physics, a field of study that, from my perspective, has been hit the hardest in the US in terms of neglect of funding.
Esoteric fields such as high energy physics have always been difficult to "justify" in terms of cost and benefits. Certainly for theoretical high energy, while it doesn't cost as much as the experimental side with the building of multi-million dollar (even billions) facilities, it is more challenging to argue for more funding other than to support and analyze the output of current high energy physics facility such as the upcoming LHC.
But strangely enough, and especially to the general public, such field of study is more "sexy". News about high energy experiment and particle physics facility fills the newspapers very often, whereas advances in material science/condensed matter seldom get that kind of publicity. Yet, the latter has an easier task of justifying its existence and its funding due to the direct impact on human activities and well-being.
So go figure.
Zz.
It seems that there is an organized effort to stop this "outsourcing" of theoretical high energy physics, a field of study that, from my perspective, has been hit the hardest in the US in terms of neglect of funding.
Esoteric fields such as high energy physics have always been difficult to "justify" in terms of cost and benefits. Certainly for theoretical high energy, while it doesn't cost as much as the experimental side with the building of multi-million dollar (even billions) facilities, it is more challenging to argue for more funding other than to support and analyze the output of current high energy physics facility such as the upcoming LHC.
But strangely enough, and especially to the general public, such field of study is more "sexy". News about high energy experiment and particle physics facility fills the newspapers very often, whereas advances in material science/condensed matter seldom get that kind of publicity. Yet, the latter has an easier task of justifying its existence and its funding due to the direct impact on human activities and well-being.
So go figure.
Zz.
Thursday, July 05, 2007
Physics.org
I'm adding a new website to favorite Physics links of this blog. Physics.org is run by the UK's Institute of Physics. It looks like it is a very well-done website with lots of info, especially for the general public and young students.
Zz.
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Orbo Goes Under
Sigh... when will these people ever learn!
The scheduled "demonstration" of the so-called perpetual motion device in Ireland didn't work. It seems that just when it is to be viewed by the public, it broke down and won't work. Humm... maybe it is a quantum object where the very act of viewing it changes its behavior to fit what we think perpetual motion machine should be - a heap of trash.
Unless they get a bunch of well-known and respecting physicists and engineers to scrutinize this machine, nothing they can do will convince those who matter the most to accept such a claim. They can advertise as much as they want in the Economist and other media. But until they can convince the true and knowledgeable skeptics, this thing will go down into oblivion like other so-called perpetual machines before it.
Zz.
The scheduled "demonstration" of the so-called perpetual motion device in Ireland didn't work. It seems that just when it is to be viewed by the public, it broke down and won't work. Humm... maybe it is a quantum object where the very act of viewing it changes its behavior to fit what we think perpetual motion machine should be - a heap of trash.
Unless they get a bunch of well-known and respecting physicists and engineers to scrutinize this machine, nothing they can do will convince those who matter the most to accept such a claim. They can advertise as much as they want in the Economist and other media. But until they can convince the true and knowledgeable skeptics, this thing will go down into oblivion like other so-called perpetual machines before it.
Zz.
Wednesday, July 04, 2007
No Access of Ultra-High Energy Cosmic Rays
This weeks seems to be the week of falsifying previous observations. First we had the crashing down of a possible observation of axions, which is now no longer reproducible and might not be there, at least not at that energy range. Now comes word that the earlier observation of ultra-high energy cosmic rays may not even be there (link open for free only for a limited time).
The latest results came from the Auger Observatory project, which I'm involved with indirectly via the AirFly collaboration.
Zz.
Really energetic particles should hit Earth only very rarely. After all, the number of cosmic rays pelting Earth decreases steadily as the energy of the rays increases. Above a specific energy, the rate ought to drop even faster. For example, if the rays consist mainly of protons, then at such tremendous energies they ought to break into other subatomic particles when they collide with photons in the afterglow of the big bang, the cosmic microwave background. That effect is known as the GZK cutoff and it should limit the energy of cosmic rays to about 1018 electron volts, a million times the energy achieved with particle accelerators. But from 1990 to 2004, physicists working with the Akeno Giant Air Shower Array (AGASA) west of Tokyo spotted roughly a dozen particles with energies 100 times higher (Science, 14 August 1998, p. 891). That excess puzzled physicists, both because they could not explain how the rays got past the GZK cutoff or how they could gain so much energy in the first place.
The latest results came from the Auger Observatory project, which I'm involved with indirectly via the AirFly collaboration.
Now, a new gigantic cosmic ray detector that employs both techniques has settled the issue. The almost-completed Pierre Auger Observatory on the plains of the Pampa Amarilla in western Argentina comprises more than 1200 ground detectors and 24 telescopes and covers an area of 300 square kilometers (Science, 21 June 2002, p. 2134). And the array has already collected enough data to rule out an excess in cosmic rays above 10^20 eV. "If the AGASA had been correct, then we should have seen 30 events [at or above 10^20 eV], and we see two," says Alan Watson, a physicist from the University of Leeds, U.K., and spokesperson for the Auger collaboration. The team will present its results here this week at the 30th International Cosmic Ray Conference.
Zz.
Tuesday, July 03, 2007
Wave-Particle Duality
I see this issue being discussed very often on the 'net. Other than questions about relativity and the constancy of the speed of light, this issue of wave-particle duality is the most talked about in many public forums. I suppose that is highly understandable since this is one of the most puzzling aspect of what we have observed of our world. Unfortunately, I think there's quite a number of misconception regarding this issue of "duality", almost as much as the misconception about the Heisenberg Uncertainy Principle.
To be able to discussion this wave-particle duality, we must first examine what we mean by "wave", "particle" and "duality". Only after we fully understand what it is that we are talking about can we then search for what the combination of these words mean. Inevitably, when we talk about wave and particle, we are applying our classical understanding of what they are. A wave is simply an "oscillation" of something. We are familiar with water waves, etc. These waves then to "spread out", and most of us who have seen demonstration using ripple tanks, understands what waves are, and how they behave. Often, the phenomena of diffraction, interferences, etc. are attributed to properties of waves.
Particles, on the other hand, usually means an object that has a definite size and boundary in real, physical space. A ping-pong ball is a sphere with some radius. Beyond that radius, there's no more ping-pong ball. So the ball has a definite boundary in real space. We tend to define particles that way, i.e. they are discrete objects with definite size and shape that have finite extent in space.
So if you look at the definition and our understanding of waves and particles, we can clearly see that an entity cannot be both. The wave definition is simply incompatible with the particle definition, and vice versa. This brings us to the issue of duality. When we observe the behavior of light, electrons, neutrons, protons, buckyballs, etc. exhibiting both wave-like and particle-like behavior, we then use the term "duality" to describe such puzzling observation. Why? Because we have to "switch gears" when we talk about wave and particles. We use one type of description/formalism when we talk about the wave-like picture, and then we change our description/formalism to talk about the particle-like picture. Thus, the duality.
But here's something that most people who haven't studied physics are not aware of. In quantum mechanics, there is no such switching of gears! There is only one consistent description of the behavior of light, electron, protons, neutrons, etc.. QM doesn't have to drop one formalism and adopt another when light behaves as "particles" and then exhibit wave-like properties. All of these observations are consistently described using one, single formalism! And usually, when we have such an ability, we do not consider this as a "duality". So in QM, there is no such thing as a wave-particle duality!
I'm sure this might come as a surprise, because the phrase "wave-particle duality" came about mainly due to QM and in the context of quantum behavior. However, one only needs to satisfy oneself that this duality doesn't exist by simply browsing through any undergraduate QM text. This duality is even hardly mentioned since it is utterly irrelevant. You certainly do not see such a thing being an issue in physics research papers other than papers that deal with pedagogical issues of quantum mechanincs.
So if there's no such thing as duality of wave and particles in QM, why is it still being used, especially when physicists talk about such a thing in the context of popular science? For better or for worse, physicists have to convey things to the public in ways that the public can understand! What a wave is, and what a particle is, are both well-known concepts. So we tend to talk about "wave-particle duality" to convey the message that these quantum objects can mimic those behaviors. However, most tend to skip the fact that these seemingly incompatible behavior can come out of just consistent formalism without the need to switch to a different one.
As I've mentioned before, QM has to be understood starting with the mathematical formalism. It is the ONLY thing that connects it to the rest of what we have already understood.
Zz.
To be able to discussion this wave-particle duality, we must first examine what we mean by "wave", "particle" and "duality". Only after we fully understand what it is that we are talking about can we then search for what the combination of these words mean. Inevitably, when we talk about wave and particle, we are applying our classical understanding of what they are. A wave is simply an "oscillation" of something. We are familiar with water waves, etc. These waves then to "spread out", and most of us who have seen demonstration using ripple tanks, understands what waves are, and how they behave. Often, the phenomena of diffraction, interferences, etc. are attributed to properties of waves.
Particles, on the other hand, usually means an object that has a definite size and boundary in real, physical space. A ping-pong ball is a sphere with some radius. Beyond that radius, there's no more ping-pong ball. So the ball has a definite boundary in real space. We tend to define particles that way, i.e. they are discrete objects with definite size and shape that have finite extent in space.
So if you look at the definition and our understanding of waves and particles, we can clearly see that an entity cannot be both. The wave definition is simply incompatible with the particle definition, and vice versa. This brings us to the issue of duality. When we observe the behavior of light, electrons, neutrons, protons, buckyballs, etc. exhibiting both wave-like and particle-like behavior, we then use the term "duality" to describe such puzzling observation. Why? Because we have to "switch gears" when we talk about wave and particles. We use one type of description/formalism when we talk about the wave-like picture, and then we change our description/formalism to talk about the particle-like picture. Thus, the duality.
But here's something that most people who haven't studied physics are not aware of. In quantum mechanics, there is no such switching of gears! There is only one consistent description of the behavior of light, electron, protons, neutrons, etc.. QM doesn't have to drop one formalism and adopt another when light behaves as "particles" and then exhibit wave-like properties. All of these observations are consistently described using one, single formalism! And usually, when we have such an ability, we do not consider this as a "duality". So in QM, there is no such thing as a wave-particle duality!
I'm sure this might come as a surprise, because the phrase "wave-particle duality" came about mainly due to QM and in the context of quantum behavior. However, one only needs to satisfy oneself that this duality doesn't exist by simply browsing through any undergraduate QM text. This duality is even hardly mentioned since it is utterly irrelevant. You certainly do not see such a thing being an issue in physics research papers other than papers that deal with pedagogical issues of quantum mechanincs.
So if there's no such thing as duality of wave and particles in QM, why is it still being used, especially when physicists talk about such a thing in the context of popular science? For better or for worse, physicists have to convey things to the public in ways that the public can understand! What a wave is, and what a particle is, are both well-known concepts. So we tend to talk about "wave-particle duality" to convey the message that these quantum objects can mimic those behaviors. However, most tend to skip the fact that these seemingly incompatible behavior can come out of just consistent formalism without the need to switch to a different one.
As I've mentioned before, QM has to be understood starting with the mathematical formalism. It is the ONLY thing that connects it to the rest of what we have already understood.
Zz.
Monday, July 02, 2007
No Axions Here
Welp, there goes the evidence for the detection of axions. The PVLAS group in Italy that originally made the claim of detecting these particles has not been able to reproduce the measurement (link accessible via free registration).
I think there are still groups that will further test the PVLAS result, or explore another way to see if they can detect these axions. I wish them all the luck in the world.
Zz.
Now, the PVLAS team has repeated the original experiment at two different magnetic field strengths. While the rotation was again observed at the original field of 5.5 T, no effect was seen at 2.3 T – leading the team to conclude that the rotation is an instrumental effect related to the magnetic field strength.
The latest news from Italy should come as a relief to physicists who believe that axions could make up dark matter. This is because the PVLAS axion appeared to couple too strongly to light to be a suitable candidate for dark matter.
The null result also puts PVLAS line with an experiment at CERN called CAST, which has been trying to convert solar photons into axions in a 10-m long test magnet. CAST has found no evidence for axions at the coupling strength implied by the 2006 PVLAS result.
I think there are still groups that will further test the PVLAS result, or explore another way to see if they can detect these axions. I wish them all the luck in the world.
Zz.
Sunday, July 01, 2007
Physics On Tour
Looks like the Institute of Physics in the UK are also pursuing a similar strategy with what is being done here in the US. The IoP will be touring various summer festivals in the UK to introduce the public to physics with various fun demonstrations.
With the UK having its issues on science and science education, any effort like this can only help.
Zz.
With the UK having its issues on science and science education, any effort like this can only help.
Zz.
Saturday, June 30, 2007
The Discovery of the Electron
This is a good website at the American Institute of Physics (AIP) on the history of the discovery of the electron. It is a very good review even for people (such as physicists) who think they already know the important points in this history.
Zz.
Zz.
Friday, June 29, 2007
PAC Day 5
My "reporters" at the 2007 Particle Accelerator Conference haven't been reporting as frequently as I would like, so news and information coming out of it has been sparse. If I had gone, I'd probably had reported a lot more stuff and "gossips". :)
We finally got a short and brief message from Reporter 3
Reporter 3: Scientific progress is mostly incremental. So, PAC did not have any major breakthrough. SNS (Spallation Neutron Source) is producing some beam since 2006, but still ramping up (for another couple of years). Laser plasma acceleration did not achieve any extraordinary progress recently (i.e. since their last report/papers). Barry Barish declared that he is aware of Orbach's time horizon for the ILC (2020s), but chooses to develop a parallel "technical timeline".
So that's it. Today is the final technical day for PAC07. Tomorrow is mostly tours of Oak Ridge lab and the surrounding area. Most attendees would probably start leaving today and tomorrow.
Zz.
We finally got a short and brief message from Reporter 3
Reporter 3: Scientific progress is mostly incremental. So, PAC did not have any major breakthrough. SNS (Spallation Neutron Source) is producing some beam since 2006, but still ramping up (for another couple of years). Laser plasma acceleration did not achieve any extraordinary progress recently (i.e. since their last report/papers). Barry Barish declared that he is aware of Orbach's time horizon for the ILC (2020s), but chooses to develop a parallel "technical timeline".
So that's it. Today is the final technical day for PAC07. Tomorrow is mostly tours of Oak Ridge lab and the surrounding area. Most attendees would probably start leaving today and tomorrow.
Zz.
Farewell HERA
The US is not the only country that is phasing out its high energy experiments. HERA at DESY in Germany is also about to be shut down after a long and wonderfully productive service.
It is a bit sad to see many of these wonderful and historically significant facilities go. This is not uncommon, because many facilities throughout history became obsolete, being replaced by bigger, better, and more powerful facilities.
Zz.
In the H1 and ZEUS experiments, electrons and quark-filled protons were brought to collision. The electron acts as a pointlike probe that scans the proton. With a resolution of 10-18 meters, corresponding to a thousandth of the proton diameter, HERA is the best electron microscope in the world. With these electron-proton collisions, it is possible to measure the structure of the proton and the strong force acting within it very precisely. One special feature of HERA collisions is the fact that the electrons do not influence the measurements because they react to other forces than the quarks in the proton. The HERA measurements for the first time confirmed the nature of the strong force, as it was predicted 20 years ago by the physicists Davis Gross, David Politzer and Frank Wilczek. For this discovery they were awarded with the Nobel Prize in 2004.
It is a bit sad to see many of these wonderful and historically significant facilities go. This is not uncommon, because many facilities throughout history became obsolete, being replaced by bigger, better, and more powerful facilities.
Zz.
Thursday, June 28, 2007
More Verification of Special Relativity Postulate
The isotropy of the speed of light seems to be a very popular question, both among serious researcher, especially those working in String Theory, and among crackpots who unknowingly are benefiting from SR but still "don't believe" in it.
A new experimental report has now improved upon the validity of the isotropy of the speed of light, as reported on PhysicsWeb (link requires a free registration).
The preprint for this work can be found on ArXiv here. They have successfully ruled out the influence of the changes in the apparatus as the possible source of the isotropy in the speed of light.
Zz.
A new experimental report has now improved upon the validity of the isotropy of the speed of light, as reported on PhysicsWeb (link requires a free registration).
Simultaneous tests of Einstein’s special theory of relativity performed in Europe and Australia have allowed physicists to conclude that the speed of light is constant in all directions, without having to make an important assumption that had limited the validity of previous tests. The researchers performed two different types of Michelson-Morley experiment -- one on each continent -- which allowed them to rule out, for the first time, violations of Einstein’s theory that could affect the physical properties of the experimental equipment and change the outcome of the measurement.
The preprint for this work can be found on ArXiv here. They have successfully ruled out the influence of the changes in the apparatus as the possible source of the isotropy in the speed of light.
Zz.
Physicists Protest at GCSE Change
The problem with the teaching of physics and the quality of physics education in the UK appear to continue. I've mentioned earlier a piece by Harry Kroto on the wrecking of British Science. Now comes word of a protest by many physicists, especially physics teachers, that the new GCSE requirement (that's like a high school "evaluation exams" for people who aren't sure that it is) is dumbing down the physics curriculum in the UK.
It sounds like they're training the kids to be POLITICIANS, where you can get by with bells and whistles, but with very little substance. After all, this is how you get to seduce most of the general public, by being perky, shallow, and superficial. That is fine if that is what they intend to be, but to pretend that this is how someone who wants to understand physics should do is hilarious. Who designed such a thing, politicians?
However, in an earlier report that I posted here as well, I thought they're dropping this "dumbed down" GCSC standards? Can someone from the UK who is familiar with this post a comment/update on what's going on?
Zz.
"In this course, pupils debate topics like global warming and nuclear power. Debate drives science, but pupils do not learn meaningful information about the topics they debate. Scientific argument is based on quantifiable evidence.
"The person with the better evidence, not the better rhetoric or talking points, wins. But my pupils now discuss the benefits and drawbacks of nuclear power plants, without any real understanding of how they work or what radiation is.
"The result is a fiasco that will destroy physics in England," he argues.
It sounds like they're training the kids to be POLITICIANS, where you can get by with bells and whistles, but with very little substance. After all, this is how you get to seduce most of the general public, by being perky, shallow, and superficial. That is fine if that is what they intend to be, but to pretend that this is how someone who wants to understand physics should do is hilarious. Who designed such a thing, politicians?
However, in an earlier report that I posted here as well, I thought they're dropping this "dumbed down" GCSC standards? Can someone from the UK who is familiar with this post a comment/update on what's going on?
Zz.
Wednesday, June 27, 2007
Principles of Charge Particle Acceleration
Want a free book on the basics of particle accelerator and beam dynamics? Check out Stan Humphries book available free online.
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Tuesday, June 26, 2007
He Had Firm Grasp Of Physics
Er... Yahoo Finance has an article on the life and times of Enrico Fermi in its investor's daily business section? Who would have thunk? :)
Still, it's a very good and brief summary of who Fermi was and why he is such a giant in the field of physics. But here's a very comment editorial about Fermi's "popularity" among the general public:
All I can say is, speak for yourself.
Every physics major in the world knows the name "Fermi", or at least I hope they do or else they're missing a huge chunk of their education. He may be a relative unknown to the general public, but then again, that can be said about most physicists that remain anonymous to the public, no matter how huge of a contribution they have made. I highlighted the significant contribution of John Bardeen that is even MORE obscure to most people (and to a lot of physicists as well) than Fermi. Yet, Bardeen is the only person thus far to win the Nobel Prize in physics TWICE. So not being known to the general public is more of the norm than the exception, which isn't saying much since this is the same "general public" where half of them do not know that the earth revolves around the sun. So we're not talking about a group of people with a great deal of scientific literacy here.
One part of the article that I rather like was the quote attributed to Fermi at the end of the article. It says:
I love that! This is exactly what practicing scientists do, and it is something most crackpots do not realize when they argue that all we do is simply to uphold what is already valid. Most of us study things that are either new, unexplained, or simply puzzling. That's what we are employed to do as scientists and it is how we contribute to the body of knowledge - by adding to it. And by golly, do we try to make a "discovery"!
Zz.
Still, it's a very good and brief summary of who Fermi was and why he is such a giant in the field of physics. But here's a very comment editorial about Fermi's "popularity" among the general public:
He is the namesake of the Fermi Institute on the campus of the University of Chicago, the Enrico Fermi Award given by the Energy Department, Fermilabs in Illinois and a street in Rome.
Time magazine selected Fermi as one of the 100 most influential people of the 20th century. He won the Nobel Prize in physics.
So why isn't he a household name?
Despite the peer recognition and scores of accolades he received, he still is relatively unknown.
All I can say is, speak for yourself.
Every physics major in the world knows the name "Fermi", or at least I hope they do or else they're missing a huge chunk of their education. He may be a relative unknown to the general public, but then again, that can be said about most physicists that remain anonymous to the public, no matter how huge of a contribution they have made. I highlighted the significant contribution of John Bardeen that is even MORE obscure to most people (and to a lot of physicists as well) than Fermi. Yet, Bardeen is the only person thus far to win the Nobel Prize in physics TWICE. So not being known to the general public is more of the norm than the exception, which isn't saying much since this is the same "general public" where half of them do not know that the earth revolves around the sun. So we're not talking about a group of people with a great deal of scientific literacy here.
One part of the article that I rather like was the quote attributed to Fermi at the end of the article. It says:
"There are two possible outcomes," Fermi said about experimentation. "If the result confirms the hypothesis, then you've made a measurement. If the result is contrary to the hypothesis, then you've made a discovery."
I love that! This is exactly what practicing scientists do, and it is something most crackpots do not realize when they argue that all we do is simply to uphold what is already valid. Most of us study things that are either new, unexplained, or simply puzzling. That's what we are employed to do as scientists and it is how we contribute to the body of knowledge - by adding to it. And by golly, do we try to make a "discovery"!
Zz.
Operation Stargate, The CIA and Psychic Spies
This is highly interesting.
This link points to an article about a rather dubious research project funded by the US military on psychic remote viewing. The "reporter" here seems to claim of only "reporting" the facts that such research work has been done. In reading this piece, as expected, there is a clear learning towards stating this unverified claims to be "facts".
But that is not the reason why I highlighted this article. Scroll down and read the exchange between her and a reader, Shawn Bishop, who happens to be a physicist. I could have sworn that he sounded like me because this would almost be the same thing that I would have blasted back at this reporter. The exchange and comments are quite entertaining to read, and for me, more interesting than the article itself.
Note that Bob Park has covered this way back when. I find that this reporter didn't get a well-balanced view of this project. She could have at least contacted Bob Park and get his opinion on this whole thing, rather than simply getting one view from someone who came out of the project itself. So I would certainly agree with Shawn Bishop that this is a very poorly done coverage of this topic.
Besides, these psychic stuff definitely qualifies as one of the criteria for Voodoo Science if we apply it to what has been outlined by Park:
Zz.
This link points to an article about a rather dubious research project funded by the US military on psychic remote viewing. The "reporter" here seems to claim of only "reporting" the facts that such research work has been done. In reading this piece, as expected, there is a clear learning towards stating this unverified claims to be "facts".
But that is not the reason why I highlighted this article. Scroll down and read the exchange between her and a reader, Shawn Bishop, who happens to be a physicist. I could have sworn that he sounded like me because this would almost be the same thing that I would have blasted back at this reporter. The exchange and comments are quite entertaining to read, and for me, more interesting than the article itself.
Note that Bob Park has covered this way back when. I find that this reporter didn't get a well-balanced view of this project. She could have at least contacted Bob Park and get his opinion on this whole thing, rather than simply getting one view from someone who came out of the project itself. So I would certainly agree with Shawn Bishop that this is a very poorly done coverage of this topic.
Besides, these psychic stuff definitely qualifies as one of the criteria for Voodoo Science if we apply it to what has been outlined by Park:
3) An effect is always at the very limit of detection. All scientific measurements must contend with some level of background noise or statistical fluctuation. Normally, the noise problem can be reduced by shortening distances and increasing the flux. If the signal-to-noise ratio cannot be improved, even in principle, the effect is probably not real and the work is not science.
The most egregious examples are all in parapsychology. Indeed, in studies spanning more than a century, not one of the many thousands of published papers alleging t o have observed telepathy, psychokinesis, or precognition, has achieved any level of acceptance among scientists outside the parapsychology community. This is truly remarkable. I can find no other example of a research area in which such a huge body of work has failed so completely to persuade scientists outside the band of true believers conducting the studies. Indeed, in the case of parapsychology it is difficult to see how even the true believers remain convinced.
In the first place, there is nothing resembling progress in parapsychology. Ordinarily, the maturing of an area of research involves three phases: the initial studies a redevoted to showing the effect is real, and to identifying the parameters that control the strength of the effect. As the effect is made stronger, research moves on to identifying plausible mechanisms. The final phase involves controlled laboratory tests of these mechanisms. Research into parapsychology is still stuck in the first phase, with each new study merely trying, without much success, to establish that there is something to study.
It seems there is little that can be done to strengthen paranormal effects. There is no indication, for example, that distance is a factor. There are claims that sensory deprivation increases the sensitivity of subjects to paranormal stimulation. In ganzfeld experiments, for example, the eyes of the subject are covered with diffusers. Any effect, however, is still too slight to convince most scientists.
Zz.
PAC Day 1
Everybody from our group arrived safely. But already there were grumbling of unhappiness.
Reporter 1:
During Sunday there was a special student poster session. It create a little bit of a controversy. There were lots of posters, so committee prescreened abstracts and did not visited most of the posters. Some students were not happy with that.
Unlike last PAC the welcome reception (I'm assuming this to be on Sunday evening - Zz) had alcohol for sale. Students were not happy with that either. I think the students were expecting free drinks.
Monday started with invited overview-type presentations. Vendors started setting up as well.
Reporter 2:
This morning (Monday) we were held prisoner listening to the plenary talks as the organizers decided to turn off wireless access to all the meeting rooms. Despite this, I still managed to miss most of what was said. Another notable was that this year they mixed the vendor booths and the poster sessions together. It was a bit chaotic at first but I was glad to see them treating the vendors well for once. Finally, the graduate students were happy today since they finally got the free alcohol they were waiting for, but we old timers on a budget were not as happy since there was no food.
That's nasty to turn off wireless access like that. I don't normally bring my laptop with me when I attend a talk at a conference. I figure if I don't care to listen to whatever is being presented, then I shouldn't be in the room in the first place. Just going online or doing some stuff while someone else is talking just doesn't sit right with me. Still, I certainly do not want to force this onto everyone and cut off the wireless access.
Zz.
Reporter 1:
During Sunday there was a special student poster session. It create a little bit of a controversy. There were lots of posters, so committee prescreened abstracts and did not visited most of the posters. Some students were not happy with that.
Unlike last PAC the welcome reception (I'm assuming this to be on Sunday evening - Zz) had alcohol for sale. Students were not happy with that either. I think the students were expecting free drinks.
Monday started with invited overview-type presentations. Vendors started setting up as well.
Reporter 2:
This morning (Monday) we were held prisoner listening to the plenary talks as the organizers decided to turn off wireless access to all the meeting rooms. Despite this, I still managed to miss most of what was said. Another notable was that this year they mixed the vendor booths and the poster sessions together. It was a bit chaotic at first but I was glad to see them treating the vendors well for once. Finally, the graduate students were happy today since they finally got the free alcohol they were waiting for, but we old timers on a budget were not as happy since there was no food.
That's nasty to turn off wireless access like that. I don't normally bring my laptop with me when I attend a talk at a conference. I figure if I don't care to listen to whatever is being presented, then I shouldn't be in the room in the first place. Just going online or doing some stuff while someone else is talking just doesn't sit right with me. Still, I certainly do not want to force this onto everyone and cut off the wireless access.
Zz.
Sunday, June 24, 2007
PAC07 Day 0
I mentioned earlier that while I won't be attending the 2007 Particle Accelerator Conference in Albuquerque this year, I will have "reporters" checking in now and then with reports from the conference. Today is when most of the attendees will be arriving, with the registration starting in the afternoon. I know that almost everyone from our group will be flying off today.
Hopefully, one of them at least will start to send reports (and pictures) either later today or early tomorrow.
Zz.
Hopefully, one of them at least will start to send reports (and pictures) either later today or early tomorrow.
Zz.
Saturday, June 23, 2007
Berkeley's Musical Serenade to Stephen Hawking
I guess when you become a world famous physicist and icon, you get serenaded by a full orchestra. That's what happened to Stephen Hawking when he visited Berkeley a few months ago. This link gives you a YouTube video of that event.
Zz.
Zz.
Physics of Bull-Riding
Yup! This is no bull. Since we have had the physics of [insert favorite activity or TV show], why not have the physics of bull-riding?
I can easily say that I don't see any significant probability that I'll be testing this in my lifetime.
:)
Zz.
"What some people don't know is that the force the bull exerts on the rider is the same as the force the rider exerts back on the bull. The difference is that the bull is about ten times the size of the rider, so that's ten times the acceleration," said UNR physics professor, Ron Phaenuf.
I can easily say that I don't see any significant probability that I'll be testing this in my lifetime.
:)
Zz.
Friday, June 22, 2007
Is There Glue in Cuprate Superconductors?
Phil Anderson has a very controversial and thought-provoking article in the latest issue of Science (Science, v.317, p.1705 (2007)). In it, he is questioning whether there really is a bosonic mode that is responsible for the pairing formation in high-Tc superconductors.
The two bosonic modes that are currently in the running as the coupling "glue" are phonons and spin-fluctuations/magnetic modes. These seems to be the more popular consensus that some form of bosonic modes help couple two electrons together to form the Cooper pair. Anderson argues that the evidence for the Hubbard repulsion U>2 eV and that a large antiferromagnetic exchange coupling J~0.12 eV cannot be explained by such bosonic modes. I'm guessing that he is still arguing for his resonance valence band (RVB) model for the cuprate superconductors.
This article should sufficiently annoys a good number of people working in this field. There is seldom a dull moment in the study of high-Tc superconductors, I tell ya!
:)
Zz.
The two bosonic modes that are currently in the running as the coupling "glue" are phonons and spin-fluctuations/magnetic modes. These seems to be the more popular consensus that some form of bosonic modes help couple two electrons together to form the Cooper pair. Anderson argues that the evidence for the Hubbard repulsion U>2 eV and that a large antiferromagnetic exchange coupling J~0.12 eV cannot be explained by such bosonic modes. I'm guessing that he is still arguing for his resonance valence band (RVB) model for the cuprate superconductors.
This article should sufficiently annoys a good number of people working in this field. There is seldom a dull moment in the study of high-Tc superconductors, I tell ya!
:)
Zz.
Dyson and the Nobel Prize
OK, OK, don't jump all over me for this. I KNOW that this is nitpicking, and everyone, including news media, can make "minor" mistakes like this. I am well aware of that. But still, you'd think some news editor would have said "are you sure?" when they read something like this.
This report isn't even about physics. Still, they managed to make a minor but embarassing mistake:
As far as I know, and a quick scan of the Nobel prize website, Dyson has not been awarded a Nobel prize of any kind. This is not to say that he isn't deserving of one.
Aspen Times needs to pay a closer attention to details like this.
Zz.
This report isn't even about physics. Still, they managed to make a minor but embarassing mistake:
Wednesday night, Challenge Aspen rented a small meeting room for volunteer training. On Thursday, a conference titled "Flight School" attracted 80 pilots to discuss all things aviation. Ester Dyson, daughter of Nobel Prize-winning physicist Freeman Dyson, led the conference.
As far as I know, and a quick scan of the Nobel prize website, Dyson has not been awarded a Nobel prize of any kind. This is not to say that he isn't deserving of one.
Aspen Times needs to pay a closer attention to details like this.
Zz.
The Compact Muon Solenoid
This is an MSNBC news article on the Compact Muon Solenoid (CMS), which is one of the massive detector at the LHC at CERN.
If you ever had the chance to see one of these beast yourself, don't miss that opportunity. It is quite impressive.
Zz.
"It is the heaviest scientific experiment ever," said Steven Nahn, a physicist from the Massachusetts Institute of Technology who is a member of the CMS research team.
To call this contraption "compact" seems like a gross misnomer: The CMS is compact only in relation to its rival sibling, the ATLAS detector, which is roughly twice as large but only half as massive. The contrasts in the weights and dimensions hint at the different designs for ATLAS and CMS - two detectors that are designed to probe the same types of subatomic mysteries.
If you ever had the chance to see one of these beast yourself, don't miss that opportunity. It is quite impressive.
Zz.
Thursday, June 21, 2007
No More Blackholes?
Whoa! This could be big in terms of physics news!
A new theoretical calculation proposes that blackholes cannot exist at all! As reported in Science daily news update (link open only for a limited time):
The preprint for this work can be found here.
Now, this is not coming from some fringe physicist either. Lawrence Krauss is one of the most respected physicist around. So this certainly carries quite a bit of weight. Still, there are still arguments against this:
In the end, as often is the case, we require more experimental observations.
Zz.
A new theoretical calculation proposes that blackholes cannot exist at all! As reported in Science daily news update (link open only for a limited time):
Physicist Lawrence Krauss and Case Western Reserve colleagues think they have found the answer to the paradox. In a paper accepted for publication in Physical Review D, they have constructed a lengthy mathematical formula that shows, in effect, black holes can't form at all. The key involves the relativistic effect of time, Krauss explains. As Einstein demonstrated in his Theory of General Relativity, a passenger inside a spaceship traveling toward a black hole would feel the ship accelerating, while an outside observer would see the ship slow down. When the ship reached the event horizon, it would appear to stop, staying there forever and never falling in toward oblivion. In effect, Krauss says, time effectively stops at that point, meaning time is infinite for black holes. If black holes radiate away their mass over time, as Hawking showed, then they should evaporate before they even form, Krauss says. It would be like pouring water into a glass that has no bottom. In essence, physicists have been arguing over a trick question for 40 years.
The preprint for this work can be found here.
Now, this is not coming from some fringe physicist either. Lawrence Krauss is one of the most respected physicist around. So this certainly carries quite a bit of weight. Still, there are still arguments against this:
Not so fast, says astronomer Kimberly Weaver of NASA's Goddard Space Flight Center in Greenbelt, Maryland. Although she appreciates the physics the Case Western Reserve team is describing, the problem is "we have never observed any events that would back this up." At the site of the supermassive black hole at the center of the Milky Way, for example, she says astronomers routinely observe what looks like interstellar material disappearing without a trace. Also, no one has yet detected Hawking radiation, which would be prerequisite evidence for black hole evaporation, Weaver says.
In the end, as often is the case, we require more experimental observations.
Zz.
Students Learn Physics by Building Mini-Golf Course
OK, now this is certainly something new, at least something that I've never come across before. I seen plenty of times student learn physics by building bridges, going to amusement parks, tossing water balloons, etc.. but never by building a mini-golf course! How creative!
These students learned a lot about Newton's laws from this project. So whoever thought of this deserves a lot of credit. Now I hope that no one gets any ideas about teaching the kids about statistics and probabilities by making them build a casino!
:)
Zz.
These students learned a lot about Newton's laws from this project. So whoever thought of this deserves a lot of credit. Now I hope that no one gets any ideas about teaching the kids about statistics and probabilities by making them build a casino!
:)
Zz.
Wednesday, June 20, 2007
Brookhaven 2007 Summer Sunday Tours
If you are going to be on Long Island, NY during one of the dates for the tour, I would suggest you not miss visiting Broohaven Nat'l Lab during their Summer Sunday tours. This is an excellent opportunity to visit a world class laboratory with world renowned facilities.
Note that if you intend to visit them during either the NSLS tour or the RHIC tour, those two can be VERY popular and very busy. So you are strongly urged to arrive early.
Zz.
Note that if you intend to visit them during either the NSLS tour or the RHIC tour, those two can be VERY popular and very busy. So you are strongly urged to arrive early.
Zz.
The Quest for the Advanced Exotic Beam Laboratory
A Chicago Suntimes news report describes the purpose for the proposed Advanced Exotic Beam Laboratory that the Dept. of Energy is seeking to build. Both Argonne and Michigan State University are in the running to host this facility that would cost roughly $550 million.
This project was initially called RIA - Rare Isotope Accelerator, that was supposed to cost about $1.1 billion. Even though that had high importance and recommendation, budget constraints have cut it down, and the name also went away. So rather than calling it RIA Light, they found a convoluted name to give to this facility. Actually, I think the folks at Michigan State might be calling it by another name.
Zz.
This project was initially called RIA - Rare Isotope Accelerator, that was supposed to cost about $1.1 billion. Even though that had high importance and recommendation, budget constraints have cut it down, and the name also went away. So rather than calling it RIA Light, they found a convoluted name to give to this facility. Actually, I think the folks at Michigan State might be calling it by another name.
Zz.
Teachers Need to Know Science is Fascinating
This is a news report of a speech given by Lawrence Krauss to the Canadian Association of Physicists' Congress. Many of the things he said are plainly obvious.
It is from my personal observation that many students that I've encountered in college who hate physics, tend to have bad physics teachers while in high school. So high school science teachers certainly play a very significant role in the student's outlook and perception of science, and certainly true for physics. Yet, many of these teachers either have no sufficient background, insufficient resources, or are not given any incentive to promote the subject they are teaching.
It is why I continue to highlight and applaud a few of these high school teachers that go out of their way to make physics fascinating to the students. The system they work in really give them no incentive to do that, yet, they still do. I can only guess that they themselves sees physics as fascinating, and want to convey that to the students.
So yes, teachers NEED to know that science is fascinating. It is the only way to give the students the sense of enthusiasm for what is being taught.
Zz.
According to a presentation Krauss delivered to the Canadian Association of Physicists' Congress Tuesday, 90 per cent of U.S. middle school science teachers have no post-secondary education in science themselves.
The result is an army of teachers terrified of and uncomfortable with the material they're teaching, and consequently, a class of equally squeamish students, Krauss said.
It is from my personal observation that many students that I've encountered in college who hate physics, tend to have bad physics teachers while in high school. So high school science teachers certainly play a very significant role in the student's outlook and perception of science, and certainly true for physics. Yet, many of these teachers either have no sufficient background, insufficient resources, or are not given any incentive to promote the subject they are teaching.
It is why I continue to highlight and applaud a few of these high school teachers that go out of their way to make physics fascinating to the students. The system they work in really give them no incentive to do that, yet, they still do. I can only guess that they themselves sees physics as fascinating, and want to convey that to the students.
So yes, teachers NEED to know that science is fascinating. It is the only way to give the students the sense of enthusiasm for what is being taught.
Zz.
Tuesday, June 19, 2007
Researchers propose electric jet engines powered by superconducting magnets
Y'know, you sometime wonder if people have thought of something through before they propose it.
These researchers are proposing that aircraft can function more efficiently using superconducting turbines, which are powered by superconducting magnets. I'm not kidding you.
Just because YBCO becomes a superconductor at liquid helium temperature does not mean all the problems are solved. It is a Type II superconductors, which means that there will be magnetic vortices migrating all over the place when it is within a magnetic field of sufficient strength. This diminishes it's "zero conductance" property. Furthermore, the reason why these high-Tc superconductors are not used in all those superconducting magnets that are being installed at the LHC is because they can't tolerate high magnetic fields because the low supercurrent density tends to quench superconductivity at sufficiently high fields.
But more importantly, they seem to ignore the fact that (i) you have to carry the cryogenics and (ii) you have to maintain the cryogenics. This adds weight AND require extra power consumption. Did they take this into account when they estimated all of these "efficiency"?
To be fair, I should read the paper they published rather than rely on some silly news report, especially from Sci-Am that lacks any exact citation to it. So I'll try to get a hold of it when see if I will change my mind afterwards.
Zz.
These researchers are proposing that aircraft can function more efficiently using superconducting turbines, which are powered by superconducting magnets. I'm not kidding you.
A superconducting magnet, however, would be much more efficient and powerful for its size. When chilled to 77 kelvins (–321 degrees Fahrenheit) or colder, so-called high-temperature superconductors such as the ceramic YBCO (yttrium barium copper oxide) begin to carry electricity without resistance, which produces a strong magnetic field without wasting energy.
Just because YBCO becomes a superconductor at liquid helium temperature does not mean all the problems are solved. It is a Type II superconductors, which means that there will be magnetic vortices migrating all over the place when it is within a magnetic field of sufficient strength. This diminishes it's "zero conductance" property. Furthermore, the reason why these high-Tc superconductors are not used in all those superconducting magnets that are being installed at the LHC is because they can't tolerate high magnetic fields because the low supercurrent density tends to quench superconductivity at sufficiently high fields.
But more importantly, they seem to ignore the fact that (i) you have to carry the cryogenics and (ii) you have to maintain the cryogenics. This adds weight AND require extra power consumption. Did they take this into account when they estimated all of these "efficiency"?
To be fair, I should read the paper they published rather than rely on some silly news report, especially from Sci-Am that lacks any exact citation to it. So I'll try to get a hold of it when see if I will change my mind afterwards.
Zz.
Could There Be More Than One Dimension of Time?
There might be two if these USC theorists are correct. If you missed the latest Physics News Update, you might find this interesting:
This makes time appear even MORE closer to the properties of space. So people who somehow think time is an "illusion" but not space will have another sharp, pointy object to burst their balloons.
Zz.
The physics world accepts the idea of spacetime, a combined metrical entity which puts time on the same footing as the visible three spatial dimensions. Further spatial dimensions are added in some theories to help assimilate all physical forces into a unified model of reality. But what about adding an extra dimension of time too? Itzak Bars and Yueh-Cheng Kuo of the University of Southern California do exactly that, and add an extra spatial dimension too. Bars explains this proposal with a comparison. Just as a projection of a 3D object onto a 2D wall can have many different shapes, and each such shape is incapable of fully conveying all the properties of the 3D object, so the single-time description of dynamics in the standard formulation of physics is insufficient to capture many properties of dynamical systems which have remained mysterious or unnoticed. The addition of an extra time and an extra space dimension, together with a requirement that all motion in the enlarged space be symmetric under an interchange of position and momentum at any instant, reproduces all possible dynamics in ordinary spacetime, and brings to light many relationships and hidden symmetries that are actually present in our own universe. The hidden relationships among dynamical systems are akin to relationships that exist between the multiple shadows of a 3D object projected on a 2D wall. In this case the object is in a spacetime of 4 space and 2 time dimensions while the shadows are in 3 space and 1 time dimensions. The motion in 4+2 dimensions is actually much more symmetric and simpler than the complex motions of the shadows in 3+1 dimensions. Besides the general unification of dynamics described above, what does this addition to one extra time and one extra space dimension (in addition to all those extra space dimensions called for in string theory) accomplish that could not be achieved without it? Bars (bars@usc.edu) says that his theory explains CP conservation in the strong interactions described by QCD without the need for a new particle, the axion, which has not been found in experiments. It also explains the fact that the elliptical orbit of planets remains fixed (not counting well-known tiny precessions). This *Runge-Lenz* symmetry effect has remained somewhat mysterious in the study of celestial mechanics, but now could be understood as being due to the symmetry of rotations into the fourth space dimension. A similar symmetry observed in the spectrum of hydrogen would also be accounted for in 2-time physics, and again explained as a symmetry of rotations into the extra space and time dimensions. There are many such examples of hidden symmetries in the macroscopic classical world as well as in the microscopic quantum world, Bars argues, which can be addressed for the first time with the new 2T formulation of physics. There have been previous attempts to formulate theories with a second time axis, but Bars says that most of these efforts have been compromised by problems with unitarity (the need for the sum of all probabilities of occurrences to be no greater than 1) and causality (maintaining the thermodynamic arrow of time). The USC theorists have reformulated their model to fit into the ongoing supersymmetry version of the standard model and expect their ideas to be tested in computer simulations and in experiments yet to come. (Physical Review Letters, upcoming article; http://physics1.usc.edu/~bars/)
This makes time appear even MORE closer to the properties of space. So people who somehow think time is an "illusion" but not space will have another sharp, pointy object to burst their balloons.
Zz.
Why Can an Opera Singer be Heard Over the Much Louder Orchestra?
OK, so this may not be one of those nagging questions that you are seeking an answer to, but still, the response to this question is quite fascinating.
Zz.
Zz.
Sunday, June 17, 2007
PAC07
This is one week before the start of the 2007 Particle Accelerator Conference in Albuquerque, New Mexico. I have attended the last 2 PACs, PAC 2003 in Portland, OR, and PAC 2005 in Knoxville, TN. Unfortunately, I will not be attending to the one this year. But, it doesn't mean that you won't be hearing anything about. I have recruited several volunteers to send me daily reports on the going-ons at this year's PAC, ranging from the scientific content to what they serve at the banquets and coffee breaks. So we will have a good coverage of what goes on during the event.
If you happen to be in Albuquerque the weekend before the start of the conference (June 23rd), you may want to drop by the Science Weekend organized by the PAC organizers and organizers of Pulsed Power and Plasma Conference. See the PAC webpage for more detail.
Zz.
If you happen to be in Albuquerque the weekend before the start of the conference (June 23rd), you may want to drop by the Science Weekend organized by the PAC organizers and organizers of Pulsed Power and Plasma Conference. See the PAC webpage for more detail.
Zz.
Friday, June 15, 2007
More Security Breach at Los Alamos?
OK, altogether now .... "NOT AGAIN??!!!!!!"
Yes, again. It seems that either bad luck, or poor judgement, or both, seems to be following Los Alamos, no matter who is in charge or who is running the lab. In this case, there is another security breach when people were using unsecured e-mail to pass or discuss classified info.
Zz.
Yes, again. It seems that either bad luck, or poor judgement, or both, seems to be following Los Alamos, no matter who is in charge or who is running the lab. In this case, there is another security breach when people were using unsecured e-mail to pass or discuss classified info.
Zz.
Review of US Program for Detector R&D for the ILC
Argonne is hosting a review of the effort from the US collaborators for the detector R&D for the International Linear Collider (ILC). The program and presentation viewgraphs for this review can be found at the here.
Zz.
Zz.
Thursday, June 14, 2007
Hawking Writing Children's Book
I kid you not!
It appears that Stephen Hawking is now dabbling in writing a children's book.
Maybe I can actually understand this one, because like Steven Weinberg, I thought "A Brief History of Time" was excruciatingly difficult to understand and follow.
Zz.
It appears that Stephen Hawking is now dabbling in writing a children's book.
"George's Secret Key to the Universe," the story of a young man's computer-driven adventures, will be published this fall by Simon & Schuster.
"Just like 'A Brief History of Time' inspired millions of adult minds around the globe, 'George's Secret Key to the Universe' will make this complex material readily accessible to a younger audience.
Maybe I can actually understand this one, because like Steven Weinberg, I thought "A Brief History of Time" was excruciatingly difficult to understand and follow.
Zz.
Baby monitor picks up video from NASA
Quick! Turn on your baby monitor and see what you get!! :)
How come none of my appliances malfunction in such a manner? All they do is just sputter and die!
:)
Zz.
How come none of my appliances malfunction in such a manner? All they do is just sputter and die!
:)
Zz.
Boosting Condensed Matter and Materials Physics Research
This is a new report (released today) by the National Research Council, an arm of the US National Academies of Sciences. The report highlights the importance of condensed matter physics and material sciences, and why the US leadership position in this field is in jeopardy (i.e. it is heading in the same direction as high energy physics).
Considering that there are a lot of OBVIOUS and direct impact out of this field of study on our everyday lives, one would think that it would be a no-brainer to illustrate its importance. But one would be surprised to realize that for many people who are not familiar with physics, the field is still considered to be rather "esoteric". Most people think physics only as particle physics, nuclear physics, or String theory, and do not even consider or know of anything practical that comes out of it. Such a misconception pervades through a large portion of society and certainly through politicians that make funding decisions.
Zz.
Considering that there are a lot of OBVIOUS and direct impact out of this field of study on our everyday lives, one would think that it would be a no-brainer to illustrate its importance. But one would be surprised to realize that for many people who are not familiar with physics, the field is still considered to be rather "esoteric". Most people think physics only as particle physics, nuclear physics, or String theory, and do not even consider or know of anything practical that comes out of it. Such a misconception pervades through a large portion of society and certainly through politicians that make funding decisions.
Zz.
Wednesday, June 13, 2007
We Want To Study Physics Followup
If you missed this report when I posted it earlier, you may want to read it. It seems that the protest by the Nepalese students demanding greater access to physics classes may have worked. In the Letters section of the APS News May 2007 issue, a Nepalese student in Ohio wrote this:
I'd say good for them!
Zz.
Regarding the picture with the headline "Getting high on physics", published in the March 2007 APS News, I would like to inform you that the number of students in the physics class at Tribhuvan University in Nepal has increased. This happened because of the demonstration by students on December 12, 2006 in front of the Nepal's Ministry of Education and Sport, as shown in the picture, in which they demanded greater access to physics classes.
I'd say good for them!
Zz.
Cracking the Supersolid
Did you read the terrific overview on the issues surrounding the "supersolid" written by Phil Phillips and Alex Balatsky (Science, vol. 316, 1435 (2007)). If you did, they have uploaded what they say is an extended version of that article. So you may want to read this even if you already read the Science version.
Zz.
Zz.
Tuesday, June 12, 2007
John Cramer May Not Be Running Out Of Time
I wrote earlier about a news piece regarding University of Washington's John Cramer and his failure to find funding support to continue his research on a highly speculative "time travel" work. The work was even "too weird" for DARPA.
Well now, after that story broke in the media, the sympathetic public has donated more than $35,000 for him to continue with this line of work.
So it looks like he might be able to continue with this. But what exactly can be done with $35,000? If he's thinking of doing any experimental work, that would require significantly more than that, I would think. It would not even pay half of his salary. And all this is before the University takes in its "overhead" costs, as they normally do. Doing physics is EXPENSIVE.
This is not the first time some parts of physics had to be rescued via donation. A couple of years ago, the Relativistic Heavy Ion Collider (RHIC) at Brookhaven would have been shut down for a year's worth of run due to budget cutbacks until they were bailed out by a substantial donation from a company to keep running. That was when I think everyone kinda sat up and realized the pathetic level of basic research funding that the country in at that time. We had to seek donations to keep a nuclear physics facility that was at its prime.
Who knows. Maybe soon enough, when we hire graduate students or postdoc, part of their job requirement might be to stand on street corners passing out donation cans and begging for money.
Zz.
Well now, after that story broke in the media, the sympathetic public has donated more than $35,000 for him to continue with this line of work.
"This country puts a lot more money into things that seem to me much crazier than this," said Mitch Rudman, a music industry executive in Las Vegas whose family foundation donated $20,000 to the experiment. "It's outrageous to me that talented scientists have to go looking for a few bucks to do anything slightly outside the box."
So it looks like he might be able to continue with this. But what exactly can be done with $35,000? If he's thinking of doing any experimental work, that would require significantly more than that, I would think. It would not even pay half of his salary. And all this is before the University takes in its "overhead" costs, as they normally do. Doing physics is EXPENSIVE.
This is not the first time some parts of physics had to be rescued via donation. A couple of years ago, the Relativistic Heavy Ion Collider (RHIC) at Brookhaven would have been shut down for a year's worth of run due to budget cutbacks until they were bailed out by a substantial donation from a company to keep running. That was when I think everyone kinda sat up and realized the pathetic level of basic research funding that the country in at that time. We had to seek donations to keep a nuclear physics facility that was at its prime.
Who knows. Maybe soon enough, when we hire graduate students or postdoc, part of their job requirement might be to stand on street corners passing out donation cans and begging for money.
Zz.
Monday, June 11, 2007
Unparticle Physics
Hum... looks like this is another theory that could possibly be tested with the LHC (I think they need to start putting out the "Now Serving...." number machine there at CERN).
Zz.
In scale-invariant theory—where objects don’t change when their dimensional qualities are multiplied by a rescaling parameter—the concept of particles doesn’t work because most particles have a definite nonzero mass. In quantum mechanics, this isn’t a problem because the standard model does not have scale-invariance. But Georgi suggests that there could be an undiscovered sector of the standard model that is exactly scale-invariant.
Zz.
Sunday, June 10, 2007
More Science Bloopers
I mentioned earlier that Robert Crease is collecting from the readers of Physics World/PhysicsWeb their favorite science bloopers in the media. This month's issue of Physics World has Part II of Crease's article.
The mistakes here aren't as "annoying" as the bastardization of various aspects of physics that we have found recently. Still, they are certainly amusing, at least.
Zz.
The mistakes here aren't as "annoying" as the bastardization of various aspects of physics that we have found recently. Still, they are certainly amusing, at least.
Zz.
Saturday, June 09, 2007
Bad Physics
It is often amusing when people who are writing an article that has nothing to do with physics, tries to either justify, or make some similar comparison, to something in physics. The article titled "Obama Physics" was one such example. This is another one.
This article talks about "parthenogenesis", that deals with how species reproduce. I certainly am not an expert in it, but I find this paragraph to be rather amusing and a chance to illustrate this concept in physics clearly to people who do not understand it:
I think of all the consequences of Special Relativity (SR), this part is one of the most misunderstood by the general public.
1. Conventional physics does not "break down" as one approaches the speed of light. this is because SR IS a part of "conventional physics". Maybe this author meant "classical physics". It is misleading and wrong to not include SR within conventional physics. Stating it as it is gives the impression that physics simply doesn't work close to c. This is absolutely wrong.
2. Time doesn't slow down when one approaches c. This is a very popular misconception. The principle of time dilation requires TWO OBSERVES IN DIFFERENT INERTIAL FRAMES. Let's say B is moving with respect to A. If A looks at B's clock, A will see that B's clock is moving slower. However, B can also say the same thing, since we have no preferred frame. B will see A's clock also moving slower. HOWEVER, neither A nor B will see THEIR OWN CLOCK as being slow. The time interval in their own frame doesn't change! So even if B is moving close to c with respect to A, B will NOT see its time slowing down. It will see A's time slowing down! So what is stated in the article is utterly wrong.
Again, I'm sure this is just nitpicking, but it is surprising how many people who don't normally read actual physics texts would get a lot of their understanding of physics via articles like this. At the very least, someone using something in physics to illustrate their point should pay a bit more attention on the ACCURACY of what they are writing.
Zz.
This article talks about "parthenogenesis", that deals with how species reproduce. I certainly am not an expert in it, but I find this paragraph to be rather amusing and a chance to illustrate this concept in physics clearly to people who do not understand it:
For explaining everyday life—babies, puppies, puberty—the mommy-daddy story of procreation works fine. But at life's edges, conventional biology, like conventional physics, breaks down. As you approach the speed of light, time slows and distances shrink. And as you approach extinction, genes find new ways to pass themselves on. Scientists call it "reproductive plasticity." A Komodo dragon manufactures a mate. A shark's got to do what a shark's got to do.
I think of all the consequences of Special Relativity (SR), this part is one of the most misunderstood by the general public.
1. Conventional physics does not "break down" as one approaches the speed of light. this is because SR IS a part of "conventional physics". Maybe this author meant "classical physics". It is misleading and wrong to not include SR within conventional physics. Stating it as it is gives the impression that physics simply doesn't work close to c. This is absolutely wrong.
2. Time doesn't slow down when one approaches c. This is a very popular misconception. The principle of time dilation requires TWO OBSERVES IN DIFFERENT INERTIAL FRAMES. Let's say B is moving with respect to A. If A looks at B's clock, A will see that B's clock is moving slower. However, B can also say the same thing, since we have no preferred frame. B will see A's clock also moving slower. HOWEVER, neither A nor B will see THEIR OWN CLOCK as being slow. The time interval in their own frame doesn't change! So even if B is moving close to c with respect to A, B will NOT see its time slowing down. It will see A's time slowing down! So what is stated in the article is utterly wrong.
Again, I'm sure this is just nitpicking, but it is surprising how many people who don't normally read actual physics texts would get a lot of their understanding of physics via articles like this. At the very least, someone using something in physics to illustrate their point should pay a bit more attention on the ACCURACY of what they are writing.
Zz.
Friday, June 08, 2007
Single Electron Motion Caught on Video
Now, whenever someone says that no one has ever seen a single electron, show him/her this. Of course, there could be an argument that you're not seeing the electron directly, but rather the bubble that it creates. Then you can argue that no one sees anything directly, but rather the light that got reflected off all the objects. So there! It's all the same! :)
These researchers actually managed to not only see the motion of a single electron, but they also videotaped it using ordinary camcorder! How cool is that?
People's creativity never fail to amaze me.
Zz.
These researchers actually managed to not only see the motion of a single electron, but they also videotaped it using ordinary camcorder! How cool is that?
People's creativity never fail to amaze me.
Zz.
Farewell to CLEO
Another particle physics detector is on the block to be dismantled. CLEO at Cornell's Wilson Synchrotron Laboratory is scheduled to be demolished next year. The public will have an opportunity to get a final look at it during an open house this Saturday. So if you're in the neighborhood, this might be a great opportunity to get a closer look at a particle accelerator and collider complex.
Zz.
Zz.
Thursday, June 07, 2007
Wireless Power A Reality
This is utterly cool. I didn't know they could make progress this quickly. It was only last year was there a paper out of MIT that proposed for the "transmission of electricity" wirelessly. Now, the same group has demonstrated the concept by lighting a 60W lightbulb without any wires!
Way to go, people!
Zz.
Way to go, people!
Zz.
Even More and More Bastardization of Quantum Mechanics
This sounds familiar:
First of all, it is hilarious that this person would think that equating this video to that stupid movie is an advantage. Secondly, I'd like to see what "scientists" they cooked up that are "versed" in QM, and what kind of acrobatic connection they could make with cognitive behavior.
Again, no one has ever shown that the rules of QM can be applied to a large classical system that has suffered coupling to all those degree of freedoms and become incoherent. I have mentioned this before in another article that tried to make use of QM's phenomena and applied it to "marketing". It is sad that, without proper knowledge of QM, these people think they can simply justify their claim simply by hijacking QM phenomena into ways it hasn't been shown to clearly apply. I mean, go ahead and claim that you have evidence that there is a "correlation" between intention and results, but don't hijack QM to justify such a thing! There is a HUGE gap between the two that hasn't been filled yet!
Do I expect these people to listen to what I say? Nope!
Zz.
Maybe he was one unlucky guy, but I tend to think he just believed he was unlucky.
I recently watched an inspirational video called The Secret, which conveyed this idea well.
Delivered in a new-agey Da Vinci Code-esque style, The Secret is unveiled by a series of scientists, authors and philosophers versed in the language of quantum physics and cognitive behavioural science. If you've seen the docudrama What The Bleep Do We Know?, it's in the same vein.
The video's message: the Law of Attraction governs our joy, health, money, relationships, love and happiness.
First of all, it is hilarious that this person would think that equating this video to that stupid movie is an advantage. Secondly, I'd like to see what "scientists" they cooked up that are "versed" in QM, and what kind of acrobatic connection they could make with cognitive behavior.
Again, no one has ever shown that the rules of QM can be applied to a large classical system that has suffered coupling to all those degree of freedoms and become incoherent. I have mentioned this before in another article that tried to make use of QM's phenomena and applied it to "marketing". It is sad that, without proper knowledge of QM, these people think they can simply justify their claim simply by hijacking QM phenomena into ways it hasn't been shown to clearly apply. I mean, go ahead and claim that you have evidence that there is a "correlation" between intention and results, but don't hijack QM to justify such a thing! There is a HUGE gap between the two that hasn't been filled yet!
Do I expect these people to listen to what I say? Nope!
Zz.
The Physics of Bowling
Don't you think that there seems to be a recent flood of "The Physics of ...." something? Not that there's anything bad about it. It is just rather amusing.
We already have the Physics of Star Trek, Golf, Basketball, etc.. etc. Add this to the list - the Physics of Bowling.
I only wish that this Wired article stop making references to "geek" when articles like this appears. That is rather annoying.
Zz.
We already have the Physics of Star Trek, Golf, Basketball, etc.. etc. Add this to the list - the Physics of Bowling.
I only wish that this Wired article stop making references to "geek" when articles like this appears. That is rather annoying.
Zz.
Wednesday, June 06, 2007
Relativistic Tennis with Photons
Whoa! If this thing really works, all those multi-million dollar x-ray FEL facility such as the LCLS being constructed at SLAC might be obsolete!
Reported in today's Science daily news (link open only for a limited time), a team from Advanced Photon Research Center at the Japan Atomic Energy Agency has shown the ability to generate an ultrashort and ultraintense x-ray pulse using just ordinary laser.
They have recently uploaded two preprints on ArXiv that you may want to check out:
1. Relativistic Tennis with Photons: Demonstration of Frequency Upshifting by a Relativistic Flying Mirror through Two Colliding Laser Pulses
2. Generation and Observation of Coherent, Long--Lived Structures in a Laser--Plasma Channel
Zz.
Reported in today's Science daily news (link open only for a limited time), a team from Advanced Photon Research Center at the Japan Atomic Energy Agency has shown the ability to generate an ultrashort and ultraintense x-ray pulse using just ordinary laser.
However, Sergei Bulanov of the Advanced Photon Research Center at the Japan Atomic Energy Agency in Kyoto and colleagues say they have a prototype that can generate pulses of x-ray laser light on the cheap. The researchers call their technique "relativistic tennis with photons," but a more violent analogy may better convey how it works. Suppose you throw a golf ball at a locomotive that is speeding toward you. The golf ball will bounce off it and come flying back at you with tremendous energy--just before you get run over.
The golf ball is a pulse of ordinary low-energy photons. With a tabletop setup, Bulanov and colleagues create the equivalent of a locomotive by firing a different laser into a cloud of plasma, where it creates a wake that travels at near-light speed. When the photons hit the wake, their energy increases 56-fold. They are also focused into an ultrashort, ultraintense blast by the wake, which is shaped like a miniature radar dish.
They have recently uploaded two preprints on ArXiv that you may want to check out:
1. Relativistic Tennis with Photons: Demonstration of Frequency Upshifting by a Relativistic Flying Mirror through Two Colliding Laser Pulses
2. Generation and Observation of Coherent, Long--Lived Structures in a Laser--Plasma Channel
Zz.
The Physics of Hot Air
No, this isn't a treatise on Chicago politics. :)
A bunch of kids got first-hand look at the physics of hot air by going on a hot-air balloon. It appears that these kids got to learn about this concept while having fun.
Zz.
A bunch of kids got first-hand look at the physics of hot air by going on a hot-air balloon. It appears that these kids got to learn about this concept while having fun.
Zz.
Tuesday, June 05, 2007
UK Science Teacher Shortage Warning
It appears that the situation in the UK is not getting any better, especially after a group made a dire warning of an acute shortage of qualified school teachers, especially in physics.
I have mentioned this before that in my experience, many people who grew to dislike physics, usually had a very bad introduction to it, which is highly understandable. It isn't confined to just physics. So having a high school teacher who is teaching a subject he/she didn't specialize in not only might compromise the accuracy of the subject being taught, but also lacking the "enthusiasm" of the person who genuinely is interested in the subject matter. This last part, I think, is what robs of the students the interest in physics.
It is also why I try to highly some of the teachers and instructors who, in their love and enthusiasm for the subject, went out of their way to make physics more interesting, more exciting, and more accessible to their students. These are the most valuable people in the efforts to get more students to take physics classes, and not necessarily major in physics.
Zz.
I have mentioned this before that in my experience, many people who grew to dislike physics, usually had a very bad introduction to it, which is highly understandable. It isn't confined to just physics. So having a high school teacher who is teaching a subject he/she didn't specialize in not only might compromise the accuracy of the subject being taught, but also lacking the "enthusiasm" of the person who genuinely is interested in the subject matter. This last part, I think, is what robs of the students the interest in physics.
It is also why I try to highly some of the teachers and instructors who, in their love and enthusiasm for the subject, went out of their way to make physics more interesting, more exciting, and more accessible to their students. These are the most valuable people in the efforts to get more students to take physics classes, and not necessarily major in physics.
Zz.
Monday, June 04, 2007
Harnessing the Power of Plasma Wakefields
I reported earlier on the recent publications on high gradient achieved in plasma wakefields. There is a very good overview of the current state of knowledge in this area of study by Chan Joshi, one of the leading authority in this area. This provides a good historical progression and also the present set of problems that are still being studied for this particular technique of particle acceleration.
Zz.
Zz.
Back from Vacation!
I'm back from my vacation and now I need a vacation to recover! Mickey said hi and wishes that everyone can study physics, professionally or on their own. :)
I'll spend a few days trying to catch up on what I've missed, and then hopefully, we'll be back up to speed with everything.
Zz.
I'll spend a few days trying to catch up on what I've missed, and then hopefully, we'll be back up to speed with everything.
Zz.
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