Tuesday, July 31, 2007

Getting People to Understand, Support Fermilab's Effort

It looks like Fermilab has learned some lessons from its disastrous SSC campaign.

There is now a considerable effort from the lab to involve the surrounding community in the design of the proposed International Linear Collider (ILC). This involvement is crucial if Fermilab wants the approval of its neighbors and become a viable candidate to host this gigantic facility (and to sustain its life as a high energy physics collider facility).


How a Fake Word From The Simpsons Ended Up in a Perfectly Cromulent String Theory Paper

It is no secret that I'm not a fan of how String Theory is done. To me, it is more hype than substance. Still, even I didn't realize this. It seems that a made-up word from one of the episodes of the Simpsons made it into a String Theory paper. The word in question is "embiggen". If your spell checker didn't like it, it is with good reason since the word doesn't exist.

Still, it didn't prevent some string theorists from using it in their paper. What were the referees doing? Snoring through the paper? But then again, considering that a "paper" in String Theory probably means uploading it onto the e-print ArXiv, there were no referees and no journal editor to actually monitor such quality control issues. And considering that none of these things can be verified to be correct or valid in the first place, what difference does it make if the paper is full of made-up words?

I don't know about you, but this whole thing can't be a positive image for String Theory.


Monday, July 30, 2007

Stronger Evidence for Human Origin of Global Warming?

This report is based on an upcoming PRL paper by physicist Pablo F. Verdes of the Heidelberg Academy of Sciences.

Verdes calculated the amount of non-natural influence required to match the increases in temperature observed in the last 150 years. He plotted the influence over time. Then, he compared it to the evolution of greenhouse gasses, taking into account the cooling due to aerosols. With allowances for error, he found that influences attributable to greenhouse gasses mirror the graph of non-natural influence needed to explain the observed temperature increase of recent decades.

As the "debate" about the existence of global warming, and the causes of it, there are mounting evidence for human activities being a significant cause of it.

I'll edit this entry to include the exact reference once this paper has been published.


Edit: This is the exact citation to this paper:

Pablo F. Verdes, Phys. Rev. Lett., v.99, p.048501 (2007).

There is also a review of this work on PhysicsWeb.

The Wrong Team Won Baseball's 2003 World Series?

That's the case, according to statistics and physics.

"The world of sports provides an ideal laboratory for modeling competition because game data are accurate, abundant, and accessible," answers the study in the journal Physical Review E. "Even after a long series of competitions, the best team does not always finish first."

Whoa Nellie. I didn't realize that Phys. Rev. E publishes these things.

The problem, say study authors Eli Ben-Naim and Nick Hengartner of the Los Alamos (N.M.) National Laboratory, is that the baseball season, at a mere 162 games, is too short. Instead, the number of games that would keep a lucky-but-lousy team from dethroning a statistically superior team is 265.

Oh no. No, no, no, no, no! As someone who lives barely 2 blocks from Wrigley Field (the Chicago Cubs baseball home field for those who don't know baseball), the last thing I want is for a longer baseball season - even if it means the possibility of the Cubs finally winning the damn thing in a gazillion years. :)

In any case, I really don't see the point of all this. An underdog, or a team/person that isn't the most talented or the best, have won it all in many sports. It simply is a matter of who performed the best on that particular day. So I'm not sure why baseball should be any different.


Sunday, July 29, 2007

Fun With Physics

If people can't come to a physics demonstration, the physics demonstration will come to the people. That is what this group of students and instructors did. In an effort to make physics fun and accessible, they visited parks in the city and brought several fun physics demonstration.

Inner-city students were getting a sampling of science with their lunch, thanks to an outreach program from the Ott Planetarium and several science departments at Weber State University. A group of WSU students, accompanied by physics associate professor Adam Johnstun, has visited parks that serve free lunch in the Ogden School District for the last two weeks to give youngsters hands-on experience with science.

Great job to those involved. There can never be too many of this type of effort.


Saturday, July 28, 2007


Just in case people don't know it already, the Physical Review journals have two journals that are titled with "Physical Review Special Topic" (PR ST). The first is PR ST Accelerators and Beams (PR ST AB). This journal deals with accelerator and beam physics issues. The second is PR ST Physics Education Research (PR ST PER), which is self explanatory.

What is special about these two journals is that they are available for free to everyone. So you could access articles from these two journals with no fee.


Friday, July 27, 2007

Hacking the Wii Remote for Physics Class

As if the demand for Nintendo Wii isn't high enough already, now comes a way to hack the remote and use it for physics demonstrations. This isn't highly surprising since the remote contains an accelerometer, or in this case, 3 of them. The high demand for Wii has also driven down the cost of one of these things, so that's a great accidental "by product" of this device.


Follow-up to Women and the Physics Nobel Prize

I was asked at least a couple of times if I want to predict the next woman who might win the Nobel Prize in physics. Of course, this is impossible to do since one has to actually figure our which of the authors that one has read, but never met, are actually women.

Still, I do have two names that automatically popped into my head as the leading candidates to be nominated and could possibly get the Nobel Prize in physics, based on what they have done so far.

The first candidate is someone I've mentioned already on here, Lene Hau of Harvard. She and her group has been prolific in "stopping light", and refining this ability to store light in ultra-cold gasses. Not only is this a fundamental curiosity, but it can also be of importance in quantum computing and how light couples with matter.

The other candidate is Deborah Jin of JILA. Her group's work on fermionic condensate bridges between the BEC and BCS states, which is an important fundamental knowledge that connects the two.

So let's see if I get any of this correct. :)


More Celebration on BCS Theory 50th Anniversary

I wrote earlier on the celebrations being held at several places to commemorate the 50th Anniversary of the publication of the landmark BCS Theory of Superconductivity by Bardeen, Cooper, and Schriefer. The celebration hasn't stopped. An announcement by the Condensed Matter division of the APS indicates an even grander upcoming celebration:

The Department of Physics at the University of Illinois at Urbana- Champaign is commemorating the 50th anniversary of the publication of the BCS theory of superconductivity with a four-day conference Oct. 10-13, 2007. This conference, BCS@50, will cover the history of the discovery, the current status of research
in superconductivity and its applications, as well as areas of science shaped by the ideas of BCS. The current list of speakers and panelists can be found at http://www.conferences.uiuc.edu/bcs50.

Attendance will be limited to 250 participants; therefore, we urge you to register early to secure your place in this exciting event. The registration fee is $250, which includes attendance at all conference sessions, continental breakfasts, breaks, lunches, Wednesday evening BBQ, Thursday evening keynote reception, Friday evening banquet, and all conference materials. Secure online registration is now open and available at the website above. The website also includes information regarding housing.

Why at UIUC, you ask? B, C, and S were at UIUC when this paper was published. So that's the connection. UIUC continues to have an extremely strong and respected program in superconductivity.


Women and the Physics Nobel Prize

I continue to be amazed at some of the errors being reported in the media, even if it is simply a report of somebody else's mistake. The fact that the reporter and the editor didn't catch it is quite a glaring reflection on how much (or little) they pay attention to science.

I mentioned earlier about the mistake done with regards to Dyson and the Nobel Prize. A news report made a mistake of assuming that Dyson has won a Nobel Prize. He hasn't. So now comes another blunder. This reporter attended an "economic conference" where a speaker said this:

Finally, as Steven Pressman, an economist at Monmouth University, noted, "Female economists rarely receive the highest accolades or the tangible symbols signifying approval or distinction." He’s right! Since 1969 (when the Nobel was first awarded in economics), women have won Nobel prizes in all categories except economics and physics. Even Joan Robinson and Barbara Bergmann, two of the most distinguished female economists in history, have been snubbed.

Er... Hello? What did Marie Curie won the Nobel Prizes in? She did it once in Physics, and another one in Chemistry. I mean, this is not even considered an "obscure" fact because this is such a major accomplishment. Not only that, we have a second woman that won the Nobel Prize - Maria Goeppert-Mayer did it in 1963.

So really, there's no excuse.....



OOOPS! It is my mistake this time.

The writer clearly wrote "Since 1969.... ", which I obviously didn't pay attention to. Rather than delete my boo-boo, I'm going to leave it here just to remind me to be MORE CAREFUL in reading these things in the future and not to be too fast to jump all over it.


Thursday, July 26, 2007

Science and the Simpsons

I mentioned earlier about the article on Hollywood Blockbusters and their science "literacy" content. Here's possibly another one - The Simpsons Movie! Actually, this is more about the Simpsons TV series and its science/math content.

This is a fun reading.


Award-Winning Documentary Outlines the Contributions of Black Scientists

This is a news article on a award-winning documentary that highlights the contribution of African-American scientists, especially during the period of World War II. Many of these scientists either never got the credit they deserve, or it came later. It is also rather painful to read the kinds of treatment they had to endure, even when what they did was vital to the war effort and the security of the nation.

I suppose even today, while it is no longer as blatant and as bad as it was during the period covered in the documentary, there are still issues surrounding the fair treatment of minorities and women in the sciences. My personal take on this is that in terms of one becoming a physicist, the issue of race is no longer there. The small group that I work in has such a diverse ethnic, racial, and national composition. We have scientists/engineers/students from the US (of course), China, Brazil, Russia, Malaysia, and Lebanon. And for most students and faculty members in physics, it is highly common to have students from all over the world in the classes and in research projects. So in physics and other sciences, I would hazard a guess that one tends to have more contacts with people from various parts of the world than in most other areas (unless of course one works in some international relations vocation). So scientists, in general, I would think would be more familiar with other nationalities, and the issues of someone being different is usually not a big issue.

What could be a big issue is in the promotion of people into upper management and decision-making position. The question on whether there are enough minorities and women in tenured positions at well-known schools have always been an issue being discussed continually. A former Harvard president even "lost" his job recently for a rather flippant remark made about why there are fewer women in the sciences. So this issue certainly hasn't gone away.


Follow-Up to "The Race For the God Particles"

Is if it was bad enough that the recent spewing of rumors surrounding the "bump" in the D0 data was covered by the NY Times, now even the Columbia Journalism Review is also giving their opinion on the whole debacle.

Is this the kind of publicity that the people involved in it were seeking for? I hope they are happy now.


Atoms Swap Spins

This is another rather cool experiment (pun intended) published in this week's Nature[1]. They have managed to "swap" spin states between cold Rb atoms.

Anderlini et al. find a way to make use of a similar symmetry-based constraint. They work with bosonic rubidium atoms, 87Rb, that have a symmetric total wavefunction. This wavefunction has two components: a spin component describing the internal state of the atoms, and a spatial component describing their locations. Because of the fixed exchange symmetry of the total wavefunction, the symmetries of the spin and spatial wavefunctions are precisely related: if the spin wavefunction for 87Rb atoms is symmetric, then the spatial wavefunction is also symmetric, and vice versa. Crucially, antisymmetric spatial wavefunctions hinder particles from getting close to each other, whereas symmetric spatial wavefunctions favour it. Because the atoms interact effectively only when they come into contact, particles in symmetric spatial states interact with each other, whereas particles in antisymmetric spatial states do not.

Anderlini et al. stored quantum information in the atoms' spin wavefunction, such that the stored bits determined its symmetry character — symmetric, antisymmetric or a superposition of both. The spin wavefunction also controlled the spatial wavefunction through the direct link between their symmetries, and so determined the collisional properties. Thus, the state of the quantum bits controlled the atoms' interactions.

Also read the News and Views review in the same issue of Nature, and also a report on this work on PhysicsWeb.


[1] M. Anderlini et al. Nature v.448, p.452 (2007).

Wednesday, July 25, 2007

Mobile Telephone Masts 'Do Not Cause Illness'

See, this is why any claim requires a meticulous, scientific study, and why anecdotal evidence isn't sufficient to claim validity. A study of 44 "sensitive" individual who claim to be affected by cell phone signals and 114 others who are not shows that the signal does not cause the illnesses that were claimed (link open for free only for a limited time).

Fox and her colleagues tested 44 people who claimed to suffer various illnesses as a result of exposure to mobile telephone signals, and 114 people who did not. They used a laboratory set-up containing a replica transmitter broadcasting both conventional and '3G' telephone signals.

When told that the transmitter was switched on for 50 minutes, 'sensitive' individuals reported higher anxiety, discomfort and tension. But when asked to tell whether the transmitter was on or off, only two of the 44 'sensitive' volunteers were correct six times out of six. Five of the controls were equally successful.

This is an extremely important point that many in the general public do not realize. The effects need to be large enough such that one can eliminate RANDOM CHANCE of a positive result. The fact that 2 of the 44 got it correct 6 out of 6 times does not mean anything beyond pure chance, because the 5 control subjects who are not sensitive to it also got it right! For something to be valid in science, it must be large enough to be above "background", in this case, random chance of getting it right 6 out of 6 times. This is the only way to get a convincing, scientific result.


The Race For The God Particle

This is a rather lively article from the NY Times about the search for the Higgs at Fermilab, and how "rumors" about any hint of discovery is being spread. In the age of the internet, what used to be simply a piece of information that only a few people would have known, is now being reported by some worldwide, either via unconfirmed news reports, or people's blogs.

I don't know about you, but I consider scientists who report on unconfirmed discovery as being irresponsible. We run the risk of looking like the heath industry, where it seems that every few months, something else is right and something else is wrong. The general public can't tell which is a rumor, which are still not confirmed, and which are truly verified and accepted. As someone who has to battle crackpots often, I see it all the time. People scoop what they read, especially when it was written by a "legitimate" scientist, and use it to further their ignorance.

This issue was covered recently in the May 2007 issue of PhysicsWorld. News media were picking up reports from blogs, of all places, about this "bump" in the D0 data. This is not how science should be done, and certainly not how physics is done. Scientists have the responsibility not to cry wolf, especially when such a thing can be avoided. We're not talking about legitimate reports or results that eventually proved to be mistaken. We're talking about knowingly reporting something that is still in the early stages of being verified. It is of my opinion that such acts is motivated by the need for publicity, which is one of a scientist worst enemies. Just ask Fleishman and Pons.

I just wish these physicists involved with this debacle would grow up and learn from what has transpired.


Dan Koshland, 1920-2007

In an earlier post, I highlighted a wonderful essay titled "Crazy But Correct" by Dan Koshland. In it, Koshland tried to convey the idea that there are many crazy ideas in science that should not be dismissed off-hand. However, such ideas must also pass through the rigorous process of review and quality control.

It is with sadness that Science has reported the passing of this great person (link open for a limited time only). If you have the chance to read that full essay by Koshland, read it! His influence has gone way beyond just his field of study.


Tuesday, July 24, 2007

Podcast Interview With Walter Isaacson

I mentioned about Walter Isaacson's book on Einstein a while ago. Thanks to a Bloomberg representative who alerted me on a podcast of an interview with Isaacson on Bloomberg Radio last night (July 23, 2007).


The Physics of Maxwell Demons and Information

This is a rather good review of the issues surrounding Maxwell Demons, and the connection with Information. So check it out if you've been curious about such things.


Monday, July 23, 2007

VERITAS Telescopes Celebrate First Light

This article contains a very good overview of the VERITAS project and includes the recent "first light" observation. Roughly similar to the AUGER Observatory, VERITAS looks at high energy gamma rays that hits the earth's atmosphere.

It is interesting to note that the article actually mention this:

VERITAS is the latest stage in the evolution of very-high-energy (VHE) gamma-ray astronomy, a field where many aspects are closer to particle physics than to traditional astronomy.

Someone better not let Simon White read that, because this is exactly what he was complaining about - the invasion of physics into astronomy! :) Whether he likes it or not, particle physics is intimately tied to astronomy/astrophysics.


Tall Tales of the Tape

Here's a rather fascinating article about the distance traveled by a home run ball in baseball. The article claims that, based on physics, most of the long distances reported were mainly hype.

Still, I didn't know that when they say a home run ball has traveled such-and-such distance, they actually meant the actual distance of traveled by the ball. I've always thought that this is the distance between homeplate and where the ball LANDED. I think this is a more logical measure of distance. I mean, someone could hit a really high flyball and it could have landed only 10 feet away. Yet, if you measure the distance traveled by the ball, it could be a large number. But this number is meaningless and irrelevant to baseball, isn't it? All we care about is where did the ball land, because if it lands in the stands, then it is either a homerun or a foul ball. How far it traveled in the air makes no difference. So why should this distance be the one that is quoted? It makes no sense other than hype.


Sunday, July 22, 2007

Bouncing Liquid

Hey, this is a rather cool experiment on "bouncing oil" (link open for a limited time only). I'm not sure what kind of information they got out of this, or if there's any application to it. However, here's the interesting part:

The bounce here is due to a thin layer of air that separates the two liquid surfaces, the researchers say in an article submitted to Physical Review E.

They point out that the effect can easily be recreated in a kitchen experiment with cooking oil. Just fill a glass pie dish with about 4 centimetres of oil and pour onto it a thin stream from a cup about 3 to 6 centimetres above the surface. While pouring, move the stream in a circle about once every 2 seconds (or perhaps less messily rotate the dish on a Lazy Susan). The bounce can be encouraged by passing a chopstick or some other small rod through the stream every now and then.

Now when was the last time a paper bound for any of the Phys. Rev. journals contains an experiment that you can actually do in your kitchen?! :)


The Cult of the Amateur

I resisted in having a blog of my own till some time last year, even though several people have suggested that I should have one. Frankly, I didn't see the point of having one (or more). I also didn't think that people would want to read about my opinions and what I find to be interesting. Most of my effort in writing about physics was directed to one of the online forums that I've been very active in.

That all changed when I realize that if I were to leave that forum, none of what I have written or some of the resources that I had highlighted would still be "mine". This is especially true for the "So You Want To Be A Physicist" essay that I've put a lot of effort in. Besides, I've been told that my "opinionated" writings on physics are actually "fun" to read (whatever that means). I also figured that since other people less capable than me can have their say about physics (i.e. all those crackpot blogs), why can't I? :)

That was the genesis of this blog. It isn't just a way for me to highlight some of the important work in physics, but also my opinion on a number of things related to physics, ESPECIALLY on how the general public, through the popular media, learn about physics and about physicists.

While this is fun, the whole issue of anyone capable of writing about anything and everything on the 'net is always something I face almost everyday, especially in the public forums. It is awfully exasperating when you try to discuss or explain something on physics to someone, he/she tries to counter what you just explained with something from Wikipedia or, worse still, a crackpot webpage. I'm not a fan of Wikipedia. The whole concept that anyone can write something on any topic, and edit any topic, just doesn't sit well with me. People seem to no longer care about the integrity and validity of their sources. All they care about is that it is written somewhere, and that's good enough. Wikipedia certainly gives the illusion to many that the information is valid, despite the disclaimer, and despite the fact that anyone can edit those information.

It appears that my sentiment isn't unique. Andrew Keen was interviewed recently and he seems to feel the same way:

In an online society where anyone can start a blog on physics, contribute to the encyclopedia entry on Russia in Wikipedia or mash up a song by Bruce Springsteen, Keen worries that the experts - trained physicists, professional students of Russia and maybe even Bruce Springsteen himself - will lose their voices, their power and their careers. But most of all, Keen worries that the Internet might rob American society of cultural meaning and a respect for truth.

"The cult of the amateur has made it increasingly difficult to determine the difference between reader and writer, between artist and spin doctor, between art and advertisement, between amateur and expert," Keen writes. "The result? The decline of the quality and reliability of the information we receive, thereby distorting, if not outright corrupting, our national civic conversation."

People need to wake up and pay attention to not only what they're reading, but WHERE they're reading these things. Pay attention to the nature of the source, especially when you don't have the expertise to evaluate the validity of the subject matter.


Newspaper Editor Knows A Crackpot When He Sees One

This newspaper editor restores a bit of my faith in popular media. There is a shred of hope of someone sensible in the publishing/media empire after all!

Several months back, I got a call from two gentlemen who claimed to have invented a new type of automotive engine. They stopped by the newspaper and I sat down to interview them. I quickly realized that what they were describing was a "perpetual motion machine," a machine that supposedly keeps running on its own power without the need for additional energy. Perpetual motion machines don't exist. They are a violation of the laws of physics.

And right he is! But what is more important here is that when strangers come calling out of nowhere and want to advertise something that contradicts an engineering or scientific principle BUT without first having experts looking into it, then all warning bells and whistles should go off immediately. It is unfortunate that many news media do not consider that. Fortunately, this editor did.

I didn't know whether the "inventors" are fooling themselves or trying to fool someone else, but I know that the machine could not possibly work the way they described it to me. I'm not an engineer, and I'm not qualified to look at the machine and tell you exactly what it's doing, or not doing, but I know the underlying scientific principle. I told them I wouldn't do the story.

That is exactly what should have been done. Ask them to get their invention verified by the experts FIRST. Science cannot and should not be done in the popular media. If it is, the public will be inundated with all these information and they can't tell which one is valid and which isn't. It is bad enough that many of them already believe in astrology.


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.

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.


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.

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.


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.


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.


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.


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.


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.

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?


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.

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.


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.


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.


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... :)


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.

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.


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.


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.


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.


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.


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.


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.

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:

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.


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.

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.


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.


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.


Fictitious Forces

Here's an explanation of "fictitious forces", given by no less than 2004 Nobel laureate David Politzer.


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.

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!


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.

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.


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:

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.


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.


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.

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.


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.


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.

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.


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.


Kobayashi and Maskawa Win the EPS High Energy and Particle Physics Prize

Press release from the KEK:

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.


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.


Thursday, July 05, 2007


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.


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.


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).

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.


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.


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).

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.


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.