Wednesday, September 30, 2009

Hawking Steps Down From Cambridge Post

Stephen Hawking is stepping down from his post as the Lucasian Professor of Mathematics at Cambridge. And no, not because they asked him to.

Hawking, famous for his research on black holes and theoretical physics, steps down Wednesday but will continue to work for the university as before.

Tradition dictates that professors retire from the post the year they turn 67 and Hawking celebrated his 67th birthday in January.

So now there's an empty, prestigious position at Cambridge! :)


Tuesday, September 29, 2009

Quantum Entanglement Visible to the Naked Eye?

Well, not quite, because all you see is nothing more than an electrical circuit. But the circuit itself is doing the quantum entanglement.

This Wired article reports on a paper published in Nature of the violation of Bell's inequality in a Josephson phase qubits[1].

In the new study, researchers used a microwave pulse to attempt to entangle the electrical currents of the two superconductors. If the currents were quantum-mechanically linked, one current would flow clockwise at the time of measurement (assigned a value of 0), while the other would flow counterclockwise when measured (assigned a value of 1), Martinis says. On the other hand, the currents’ directions would be completely independent of each other if everyday, classical physics were at work.

After attempting to entangle the superconducting circuits, Martinis and his team measured the directions of the currents 34.1 million times. When one current flowed clockwise (measured as a 0), the team found, the other flowed counterclockwise (measured as a 1) with very high probability. So the two were linked in a way that only quantum mechanics could explain.

To complete this, here's the 'abstract' of the paper in question.

Abstract: The measurement process plays an awkward role in quantum mechanics, because measurement forces a system to 'choose' between possible outcomes in a fundamentally unpredictable manner. Therefore, hidden classical processes have been considered as possibly predetermining measurement outcomes while preserving their statistical distributions. However, a quantitative measure that can distinguish classically determined correlations from stronger quantum correlations exists in the form of the Bell inequalities, measurements of which provide strong experimental evidence that quantum mechanics provides a complete description. Here we demonstrate the violation of a Bell inequality in a solid-state system. We use a pair of Josephson phase qubits acting as spin-1/2 particles, and show that the qubits can be entangled and measured so as to violate the Clauser–Horne–Shimony–Holt (CHSH) version of the Bell inequality10. We measure a Bell signal of 2.0732 plusminus 0.0003, exceeding the maximum amplitude of 2 for a classical system by 244 standard deviations. In the experiment, we deterministically generate the entangled state, and measure both qubits in a single-shot manner, closing the detection loophole11. Because the Bell inequality was designed to test for non-classical behaviour without assuming the applicability of quantum mechanics to the system in question, this experiment provides further strong evidence that a macroscopic electrical circuit is really a quantum system7.

This experiment definitely closed the detection loophole since they can make a detection of each qubit. But due to the distance of the separation, they cannot close the locality loophole. Still, they think that, in principle, due to the fast measurement that can be made, that loophole can be closed in future experiments.


[1] M. Ansmann et al., Nature v.461, p.504 (2009).

Happy Birthday, Enrico Fermi

Physicist Enrico Fermi was born on this day, Sept. 29, 1901. One can read a summary of his biography at the Nobel Prize website.

I still see hits to this blog of people looking at the apparent "mistake" that he made in the infamous picture of him by a blackboard, with the equation for the fine structure constant. Unless there are new revelations, we'll never know whether this was something he did deliberately, or that he made a simple mistake.


Monday, September 28, 2009

Unintelligent Design

I wrote a while back of a letter I read in Science about a different line of attack against the so-called intelligent design idea. It is to exposed the fact that if the human body was indeed the product of an intelligent design, the design itself isn't very intelligent. Based on simply, basic problem of the human anatomy, one could term ID as Incompetent Design, which makes any deity that is responsible for such a design to be highly dumb.

Well now, Art Hobson has also published something similar. In this case, he calls it Unintelligent Design. Here, he looks at one very common argument that ID proponents often use, the eye. Their typical argument is that the eye is way too complex for it to come out of evolution and random formation. Art Hobson used the same type of argument that I mentioned earlier to point the flaw in the human eye.

But the eye betrays its evolutionary origin with a tell-tale flaw: The retina is inside out. The nerve fibers that carry signals from the retina’s light-sensing cells lie on top of those cells and have to plunge through a large hole in the retina to get to the brain, creating the eye’s blind spot. Any intelligent designer would be offended by such a clumsy arrangement. The human eye was not designed; it was inherited as the result of long-term evolutionary development. The eyes of all vertebrate animals are linked with our invertebrate relatives that have only simple eyes that detect light but can’t form an image. In fact, molecular studies have recently found a direct link between the genetic structures that control primitive invertebrate light sensors and those that control sophisticated mammalian lens structures.

As with the tired argument about Thermo's second law and evolution, I'm guessing that this argument would not reach to those who should be educated. Not that they would care, or that this would change their minds anyway.


How Much of the Human Body is Made Up of Stardust?

This is another of those questions that is part of the series of posters produced by the APS's Physics Central. The last time I highlighted one of these, it was a question on how long does one have to yell to heat up a cup of coffee. This time, the question is on how much of our body is made up of startdust.

I'll cut right to the chase and give you the answer from that page:

Now that we have established that every element in the periodic table aside from hydrogen is essentially stardust, we have to determine how much of our body is made up of this stardust. If we know how many hydrogen atoms are in our body, then we can say that the rest is stardust. Our body is composed of roughly 7x1027 atoms. That is a lot of atoms! Try writing that number out on a piece of paper: 7 with 27 zeros behind it. We say roughly because if you pluck a hair or pick your nose there might be slightly less. Now it turns out that of those billion billion billion atoms, 4.2x1027 of them are hydrogen. Remember that hydrogen is bigbang dust and not stardust. This leaves 2.8x1027 atoms of stardust. Thus the amount of stardust atoms in our body is 40%.

Since stardust atoms are the heavier elements, the percentage of star mass in our body is much more impressive. Most of the hydrogen in our body floats around in the form of water. The human body is about 60% water and hydrogen only accounts for 11% of that water mass. Even though water consists of two hydrogen atoms for every oxygen, hydrogen has much less mass. We can conclude that 93% of the mass in our body is stardust. Just think, long ago someone may have wished upon a star that you are made of.

As Carl Sagan used to say, we are star stuff!


Sunday, September 27, 2009

UK's Science Figures Are "Science Fiction"

That seems to be the claim. The apparent "increase" in the number of students enrolling in science classes in the UK may not be as rosy as it has been made out to be.

But a new report claims the rise is accounted for, in part, by the growth in the number of 16-year-olds, while the proportion studying science A-levels has dropped since 1997.

At university level, big increases in the number of undergraduates studying science, technology, engineering and maths (STEM) subjects are also a "fiction", according to the study.

The Government now includes as "science", courses such as nutrition and complementary medicine, geography studies, sports science, nursing and psychology, even though in dozens of universities it is classed as an arts degree.

This is an issue of comparing apples with oranges, it seems. It is crucial that one gets a clear view of what is happening, and it is too bad that one is using rather dubious statistics to pain a more upbeat picture that it really is. It certainly looks like there's a lot more work to be done to improve the UK science picture.


Friday, September 25, 2009

2009 Nobel Prize Predictions

It is that time of the year again when Thomson Reuters plays this game of predicting this year's Nobel Prize winners. Last year, they got the one for physics completely wrong! :)

Still, it's a fun game to play, and along the way, we recognize and mention those who are utterly deserving of the award. This year, for physics, the prediction falls onto:

* Yakir Aharonov of Chapman University in Orange, California, Tel Aviv University, and the University of South Carolina, and Michael Berry of the University of Bristol in Britain for their discovery of the Aharonov-Bohm Effect and the related Berry Phase. "It describes certain aspects of electromagnetics that violate classical descriptions of physics," Pendlebury said. "They are all in every physics text book now. It seems odd to me that they have not been recognized by the Nobel committee."

* John Pendry of Imperial College of Science and Technology in London, Sheldon Schultz of the University of California San Diego and David Smith of Duke University, whose prediction and discovery of negative refraction makes possible meta-materials, used to make "invisibility cloaks" to deflect various wavelengths of electromagnetic radiation.

* Juan Ignacio Cirac of the Max Planck Institute for Quantum Optics in Garching, Germany and Peter Zoller of the University of Innsbruck in Austria, whose work on quantum switches has made possible quantum computers.

All of them are good and worthy choices.


Thursday, September 24, 2009

Is George Smoot Smarter Than A 5th-Grader?

Is Nobel Laureate George Smoot smarter than a Fifth Grader? Damn right he is! :)

George Smoot was a big scoop that the show "Are you smarter than a Fifth grader?" got.

The show entertains by painfully exposing just how little of their elementary school education adults retain, so having a Nobel laureate on stage called for even more ridiculous FOX theatrics than usual. In the opening sequence, the announcer booms, "Will he blow it, and be the laughing-stock of Nobel prize-winners everywhere?" I wonder if any of Smoot's Berkeley colleagues started to sweat at that point. Would the show expose the shortcomings of science? Would Smoot remember how to spell the word "Mississippi?"

Luckily for us, he crushed the challenged.

Still, I think it's interesting that most people associate "being able to memorize all of these disjointed facts" with being "smart". If that's the case, I have to be one of the dumbest people around, because I have a hard time remembering numbers, dates, names, etc. I understand concepts, and how to apply and manipulate them, but god help me if I have to recite the date of such-and-such. It took me long enough just to remember my own phone number.


Mildred Dresselhaus

Mildred Dresselhaus is one of the most influential physicist of our time, and her presence is certainly felt by many in this profession, especially in the US. So if you don't know much about her, this brief article would be a very good introduction to what she has accomplished, and had done not only within physics, but also within the physics/national community.


Wednesday, September 23, 2009

More on Spin-Charge Separation

It appears that a lot of new results are coming out on this lately. A while back I reported on the possibility of a clearer observation of spin-charge separation in a 1D system via the tunneling phenomenon.

This time, the observation of spin-charge separation comes from photoemission spectroscopy. The link in the article also gives you free access to the publication. What is interesting here is that they may have found something that isn't consistent with the Luttinger Liquid theory that describes such 1-D system and spin-charge separation.

These findings are surprising, given the generality of the previous argument and the robustness of Luttinger-liquid physics. If the relation between η and ν would hold, the positive value of η would imply a very fast decay of the single-particle correlation function (i.e., a much larger exponent ν) than anticipated, or indeed directly measured. There could be several ways out of this predicament. The simplest one would be some experimental artifact or surface problem, but that hardly seems compatible with the good quality of the data, the observation of the momentum dependence, the observed scaling, and the agreement between the ARPES and STM measurements. Salvation could come from the theory side: the fact that the material is not a system that can be directly mapped to a single-chain one-dimensional system, but rather to a double-chain one—a ladder system. Those systems are known to develop gaps in their excitation spectrum, in contrast to single-chain ones. Such gaps would be compatible with rapid decay of the single-particle correlations. Of course this would not explain the measured value of ν, or the more severe catch: such gaps should normally be seen in both STM and ARPES, and none have been observed at the relevant energy scales here. Other routes, such as disorder, can be explored but, as of today, the question remains.

I love surprises like this. It means that there's a lot more physics to be done and studied.


Tuesday, September 22, 2009

Cornell Synchrotron Center

This is a nice, brief history of Cornell's synchrotron research lab and efforts, which has been at the forefront in not only synchrotron physics, but also the early efforts of experimental particle physics.

Still, what's wrong with this picture?

A synchrotron is a device that uses a magnetic field to accelerate particles (e.g. electrons) at faster and faster speeds by boosting their energies as they travel around the ring.

I guess they meant electromagnetic fields, since I'm sure we all know that magnetic fields can't accelerate charged particles.


Monday, September 21, 2009

Science and Technology Policy in the Obama Era

Former Clinton Science Advisor Neal Lane will speak on this very topic at University of Texas at Dallas this Wednesday, Sept. 23. The event is to commemorate the 25th anniversary of "Issues in Science and Technology" journal.

“It is appropriate that the speaker who will mark the milestone of our 25th anniversary is a renowned physicist and university leader who took on the challenge of managing the nation’s premier physical science research agency and serving as the conduit between the scientific community and the White House,” said Kevin Finneran, editor in chief of Issues in Science and Technology. “He has devoted most of his career to the same mission as Issues: applying the insights of the science and engineering community to help solve the world’s pressing problems and achieve society’s goals.”

Sounds like a topic that would be of interest to many, especially those in the science field here in the US. If you get to attend this, I would love to hear a brief report.


Sunday, September 20, 2009

FY 2010 US Defense Science and Technology Appropriation Bill

The Obama administration has requested, in general, less money in FY2010 for the Defense Dept. for science and technology research. This is in contrast with a significant increase in the civilian science and technology funding request for the same fiscal year.

A summary of the various numbers passed by the different legislative branches can be found here.


Friday, September 18, 2009

Einstein's Nobel Prize

This "news" article purported to be the "Evolution and relativity - a dummies' guide". I think it is more appropriate that it was written by a dummy. I can't believe people can make this type of mistake still, especially during an internet age where one can EASILY check a few facts.

Here's the offending passage, which is rather obvious for any physics student:

It was the Jewish German theoretical physicist Albert Einstein (1879-1955) who was awarded the 1921 Nobel Prize in physics for his theories on relativity. He is regarded as the father of modern physics.

OK, for the last time, Einstein did NOT win the Nobel Prize for "his theories on relativity", even though it was implied in a rather oblique fashion. Here's the exact citation from the Nobel website:

for his services to Theoretical Physics, and especially for his discovery of the law of the photoelectric effect

One can find that within less than a minute of searching if one didn't know. How difficult can that be? I suppose it is a bit too much to ask that news editors actually would know to double check such "facts" before they are published.


Thursday, September 17, 2009

First Detailed Photos of Atoms

You'd be amazed that, to this day, there are "people" (I put that word in quotes because I often wonder if crackpots are really people) who still dispute the QM description of the atom. It's the same disease as those people who still think we didn't land on the moon or that the earth is flat, I suppose.

Well, chalk this up to another one of those "the more they test it, the more convincing it becomes". Using field-emission electron microscope, we can now really map the electronic orbitals. And SURPRISE! It clearly matches QM's description!

Quantum mechanics states that an electron doesn't exist as a single point, but spreads around the nucleus in a cloud known as an orbital. The soft blue spheres and split clouds seen in the images show two arrangements of the electrons in their orbitals in a carbon atom. The structures verify illustrations seen in thousands of chemistry books because they match established quantum mechanical predictions.

I'll edit this and put in the exact reference when the paper is out.


Wednesday, September 16, 2009

"It's Easy To Be Right.... "

I really, really, REALLY shouldn't be picking on sophomores, because I don't want to be THAT petty. But honestly, quote like this shouldn't make it into any kind of publication because it just conveys the wrong idea to the public on why many of us work in science.

The news article describes what should be a very enjoyable event where the public and other non-science students get to learn a bit about astronomy and talk to astronomers.

A lecture last night, “A Study in Scarlet: The Spitzer Space Telescope View of the Triangulum Galaxy,” was presented by Dr. Joannah Hinz, senior research assistant in the infrared astronomy wing. The lecture focused on the Triangulum Galaxy, one of three spiral galaxies in our local galaxy group.

The program, its directors say, aims to give everyone from old and seasoned astronomers to young and eager students with their first telescopes, a view of the universe’s expanse. Steward Observatory has been hosting public, evening lectures on astronomy since 1922.

A very commendable event, and something that should be done more often in many places. But then, they had to get soundbites, and this is where things go a bit sour.

Steward Observatory is paid for with taxpayer money and the lecture series is one way in which astronomers can give back to the public by sharing the exciting research they conduct, said Thomas Fleming, associate astronomer and senior lecturer at the observatory.

“You really have no idea how big the universe is,” he said. “If you don’t look to the stars, you’re ignoring 99.9999 percent of the universe. Every other department deals with what happens on this planet, we have the whole rest of the universe.”

Well, that's not quite true, is it? Considering that the search for dark matter actually might also be possible at the LHC is one example (unless, of course, what is meant by "department" here includes physics AND astronomy).

But then, things go REALLY sour here when they quoted a "... sophomore astronomy and physics major.. "

{think carefully, ZapperZ... there's still time to back out!}

“I like being right,” Pye pye Zaw, a sophomore astronomy and physics major said about why she choose to study the stars. “It’s easy to be right in a field where no one knows the right answer … Also, I really like shiny things.”

So I gasped a bit when I read that.

The history of physics is littered with WRONG ideas and conclusions during the development of the understanding of something. So while no one knows what is "right" when something is right at the cutting edge research front, EVENTUALLY, the right answers will come, and that's why we will see many fallen theories, descriptions, ideas, etc. Forget about the attitude of "I like being right", but having the delusion that one's idea is right simply because we still don't know what the right answer will be is astoundingly irrational.

The problem with this is that now it is out in the public, it gives a huge opening for opponents of science ("This is an example of egocentric people they're training to be scientists"). Sure, one could argue that they're using something that came out of the mouth of a sophomore in college, but I've seen many science critics use less to attack science and scientists.

Maybe this student will gain a bit more wisdom as she grows older. Still, I wouldn't use any of such phrase if she intends to apply for undergrad internships. I certainly wouldn't hire her if I see such statement in her application essay.


Tuesday, September 15, 2009

ATLAS Multimedia Contest Winners

The winners of the multimedia contest have been announced, and the winning videos are now available online.

They're not bad, and could be quite informative for the general public. The winning video by Phil Owen describes briefly the Standard Model, and the Higgs mechanism. So if you're not familiar with those, this might give you a good cartoon representation of what they are.


Monday, September 14, 2009

Best Morley-Michelson Experiment Yet!

The more they test it, the more convincing it becomes.

A new Morley-Michelson experiment produced a more accurate determination that the speed of light is the same in all directions.

Schiller and colleagues Christian Eisele and Alexander Nevsky gathered data as they rotated their experiment about 175,000 times over about 13 months, with each rotation taking 90 seconds. To investigate whether Lorentz symmetry had been violated, the team analysed their time series of beat frequency measurements in terms a simplified version of the Standard Model Extension (SME) – a mathematical framework that describes violations to Lorentz symmetry in terms of 19 measurable parameters.

Schiller's experiment is sensitive to eight of these parameters and the team was able to show that four are zero to about two parts in 10^17; one is zero to about one part in 10^16; and three are zero to about two parts in 10^13. According to Schiller, this represents a factor of more than 10 improvement over previous measurements of these parameters and a factor of about 100 million better than Michelson and Morley's original experiment.

Outstanding. That should put even more severe constraints on any theory that has any Lorentz violation.


Sunday, September 13, 2009

Steven Weinberg: Master Builder of the Standard Model

This is a terrific article on Steven Weinberg and his history with European particle physics, CERN, and the Standard Model. This was in conjunction with his visit and colloquium at CERN this past July.


Saturday, September 12, 2009

Is Physics iPods, or the LHC?

This is the question posted by Prof. Bill Wakeham in his piece on the Times Online.

There are two dramatically different perceptions of physics and thoughts on the way it should be presented to those who can ensure the subject’s future health - whether it’s to schoolchildren, their parents or politicians. One stems from the desire to spread the good news of physics; a cutting-edge discipline that underpins nearly all of our scientific advances in medicine, energy security, climate change and gadgetry. If you want to succeed in the world, whether it’s financially or as a world-changing scientist, physics is a sterling choice for A-level and degree-level studies.

On the other side, there is the purist’s view of physics. Physics is about the big questions – what is the origin of our universe, what are dark matter and dark energy, how many dimensions are there – and, to the purist, ‘leakage’ into what is, arguably, more socially useful sub-disciplines of physics is a cause for concern. Physics is the pursuit of pure and fundamental knowledge.

While the good news of physics is spreading and the number of young scientists staying on to do physics at A-level is moving up again, no one’s quite sure which of the two messages is having the biggest impact.

I really don't know if we have to choose between one or the other. Why does it have to be either or? Why can't we sell physics using BOTH? The very fact that this field can be both esoteric and practical at the same time is a big plus! How many other fields can boast such ability?

I would even go further and argue that for many young and incoming students, especially first year students at universities, the esoteric part of physics seems to be the one that gets the most publicity and devotion. This is reflected in a large part of the public that is ignorant about the application side of physics and why their modern electronics own their existence to the work of physicists. But even beyond that, there is a major missing piece of information that hasn't been effectively brought out - that the study of the physics that gives us the iPod can, in fact, be FUNDAMENTAL! The physics that was studied by Phil Anderson, Bob Laughlin, etc. has added to the fundamental body of knowledge in physics. No other system provides as clear of an evidence for the workings of quantum field theory than condensed matter systems. One only needs to look at the origin of the Higgs mechanism, or the origin of spontaneous broken symmetry, and that's that. The physics of iPods helps you understand the quarks!

So while physics has its "basic knowledge for the sake of knowledge" side and its "applied" side, there's plenty of examples in which both of these are the SAME thing. It is why one needs to present physics as being both, at the same time, in superposition with each other, even after an observation is made!


Friday, September 11, 2009

Quantum Hall Effects

If you've ever wanted to learn about the quantum hall effect, this is your chance. A lecture note on this very topic is now available online, all 102 pages of it!

Abstract: These lecture notes yield an introduction to quantum Hall effects both for non-relativistic electrons in conventional 2D electron gases (such as in semiconductor heterostructures) and relativistic electrons in graphene. After a brief historical overview in chapter 1, we discuss in detail the kinetic-energy quantisation of non-relativistic and the relativistic electrons in a strong magnetic field (chapter 2). Chapter 3 is devoted to the transport characteristics of the integer quantum Hall effect, and the basic aspects of the fractional quantum Hall effect are described in chapter 4. In chapter 5, we briefly discuss several multicomponent quantum Hall systems, namely the quantum Hall ferromagnetism, bilayer systems and graphene that may be viewed as a four-component system.

I've skimmed through the first few pages (yeah, like I have the time to read through carefully the whole thing...), and it looks quite good, especially if you're an advanced physics undergraduate or a graduate student. The first few pages alone will tell you why the study of quantum hall effect is so important and very fundamental that it transcends beyond condensed matter physics.


Argonne Open House 2009 Video

I mentioned earlier of the Voice of America report and video of the 2009 Argonne National Laboratory Open House. Well here's the Argonne's version of the Open House, which covers a lot more grounds and areas that were on display on that day.


The Last Days of the Tevatron

This Wired article examines not only the history of experimental high energy physics, but also the competition between the US and Europe in making the first discoveries in elementary particle physics.

High-energy particle physicists around the world are collectively holding their breath waiting for the Large Hadron Collider to come online and start unlocking the most elusive secrets of the universe. It’s as if time is standing still until their shiny new toy is ready to play with.

But not at Fermilab. Here, physicists are in the scientific equivalent of an all-out sprint, still clinging to the ever-thinning hope that before the LHC ramps up to full power, their own 28-year old particle collider, the Tevatron, will catch the coveted Higgs boson, a theoretical particle that is at the heart of the Standard Model of physics.

Along the way, the argicle described the heartbreak and cancellations of facilities such as ISABELLE (fondly named "WAS-A-BELLE" by many at Brookhaven nowadays) and the infamous SSC.

Time will only tell if the Tevatron will find something as the last big hurray as it sails into the sunset and physics history. Till then, full speed ahead....


Thursday, September 10, 2009

Approaches to Understanding Cosmic Acceleration

In "just" 28 pages, you get a rather extensive review of the current theory and understanding of our rapidly expanding universe via this cosmic acceleration[1]. The paper is an IoP publication, which is made available online for free only within the first month of online publication. So get it now while you can.

Abstract: Theoretical approaches to explaining the observed acceleration of the universe are reviewed. We briefly discuss the evidence for cosmic acceleration, and the implications for standard general relativity coupled to conventional sources of energy–momentum. We then address three broad methods of addressing an accelerating universe: the introduction of a cosmological constant, its problems and origins; the possibility of dark energy and the associated challenges for fundamental physics and the option that an infrared modification of general relativity may be responsible for the large-scale behavior of the universe.


[1] A. Silvestri and M. Trodden, Rep. Prog. Phys. v.72, p.096901 (2009).

Gunning for Free Electrons

This may be a press/publicity release, but it still has quite a bit of information for anyone wanting to catch up on the latest front in free electron laser (FEL). It describes the new DOE funding to look into the next generation of FELs.

I was quite interested in reading about the design of the photoinjector, especially the electron gun. Unfortunately, the article didn't describe exactly what they will be using as the photocathode or the candidate materials they're considering. All they described is that they want something with a high quantum efficiency and other criteria ("...the material must yield a high ratio of electrons to photons, with small emittance, and at the same time hold up under continuous use at hitherto unprecedented repetition rates – in high vacuum and a high accelerating field to boot. A variety of cathode materials will be tested for the new injector....")

The article also has useful link on FELs.


High-Energy Particle Physics Demystified

Wired has a rather informative interview with physicist Paul Halpern on the basic issue of high energy particle colliders and why all the excitement surrounding the LHC. He also went a bit into the devastating impact of the cancellation of the SSC.

The BIG take-home message out of this interview should be that the LHC is not just a machine to look at one thing. No one can justify building a $8 billion dollar facility just to study one thing - even Bernie Madoff can't pull that one off. There are a huge amount of other experiments and studies that are planned at the LHC, even beyond what were described in this Q&A.


Wednesday, September 09, 2009

Not All Interactive Engagement is the Same: Variations in Physics Professors’ Implementation of "Peer Instruction"

I mentioned earlier of Griffiths' assertion of trying to sell Physics as is, and his skepticism of trying to make physics more "fun" by trying all these new gadgets in classroom instruction.

This new paper[1] reports on an investigation that is consistent with that point of view. A study of physics professors using the same "Peer Instruction" technique reveals substantial differences in outcomes. It emphasized the connection between the instructors' outlook and philosophy themselves and how it can affect what the students can gain.

Although many professors talk about Peer Instruction and its implementation similarly in interviews, we have found that there are significant differences in professors’ classroom practices that combine over time to have significant pedagogical implications. We have identified observable and quantifiable aspects of practice which vary from classroom to classroom. Prior research has shown that faculty practices are constrained more by structural considerations such as expectations of content coverage, lack of instructor time, class size, or room layout than by their beliefs about productive educational practices.31 In this investigation, we find that instructors within similar structural or situational constraints are making different instructional decisions. These results suggest the need for a more detailed account of how instructors use their knowledge of educational innovations and situational constraints to arrive at practical decisions in the moment-to-moment demands of the classroom.

What it boils down to is that, no matter what new gadgets and techniques one adopts, it still depends on the skill of the instructor. A bad instructor will still give a bad lesson, no matter what technology one uses. I think in all of the discussion on trying to improve physics instructions, especially in colleges/universities, the ability to teach by these professors hasn't been sufficiently addressed. A motivated and excellent instructor can do more with a blackboard and a chalk than all those clickers and gadgets combined. I know, because I've had a few that can blow away all of these new instruction methods.


[1] C. Turpen and N.D. Finkelstein, Phys. Rev. ST Phys. Educ. Res. 5, 020101 (2009)

Tuesday, September 08, 2009

Secret Life of Scientists

NOVA has a web-only series on the private lives of several scientists. This series will introduce a new scientists every 2 weeks, and you can watch videos of their lives outside of their work.

This is the place where you can watch intimate, engaging, and funny videos with accomplished scientists who happen to have extremely compelling secret lives. You’ll hear these scientists talk about their work and about their “secrets” – the unique parts of themselves that make them who they are and often help to fuel their science. You’ll also see them answer penetrating and insightful questions like “When was the last time you ate blood?” and “Have you ever been called ‘Doogie Howser’?” Finally, you’ll get to interact via this blog with many of these scientists, with us – the SLoS team – and with the other folks who will make up “The Secret Life of Scientists” community (and that includes Inga… she was pretty young when she dated Einstein).

Not exactly "Big Brother", but it hopefully will be another thing that could dispel so many myths and stereotypes of scientists.


Chemical Vapour Deposition Synthetic Diamond: Materials, Technology and Applications

This is a humongous review article on CVD diamond.

Abstract: Substantial developments have been achieved in the synthesis of chemical vapour deposition (CVD) diamond in recent years, providing engineers and designers with access to a large range of new diamond materials. CVD diamond has a number of outstanding material properties that can enable exceptional performance in applications as diverse as medical diagnostics, water treatment, radiation detection, high power electronics, consumer audio, magnetometry and novel lasers. Often the material is synthesized in planar form, however non-planar geometries are also possible and enable a number of key applications. This article reviews the material properties and characteristics of single crystal and polycrystalline CVD diamond, and how these can be utilized, focusing particularly on optics, electronics and electrochemistry. It also summarizes how CVD diamond can be tailored for specific applications, based on the ability to synthesize a consistent and engineered high performance product.

Diamond, and in particular these CVD diamonds, are not only strong and hard, but also can have properties that can be tailored to meet various needs simply by different doping. It can be a good field emitter with the proper doping. Not only is it a strong insulator electrically, but it also has a relatively good thermal conductivity for an insulator, which makes it a good heat conductor.


Monday, September 07, 2009

VoA Video of 2009 Argonne Open House

This is a video of the Voice of America coverage of the recent Argonne Open House in 2009.

You can also read the news coverage of the event here.


A Mediocre Student?

I read this Op-Ed piece in the NY Times this morning, without reading who wrote it. Now, why don't you do the same before you take a peak. In particular, what would you think about the author after reading this paragraph? The author is describing his "education" or what he gained from his college years at Cornell.

It didn’t work out quite as I had anticipated. I didn’t know enough to participate in the exciting physics research that was going on at Cornell. I took German, in which the main thing I learned was that I have no head for foreign languages. My courses in philosophy left me puzzled about how ideas of Plato and Descartes that seemed to me absurd could have been so influential. I did not become wise.

So who wrote that? Spoiler below:


Would you have believed that that was written by Nobel Laureate Steven Weinberg?

Now, compare that very humble view with some of the crackpots around the 'net who think that they know everything there is to know after reading some pop-science books.


Sunday, September 06, 2009

Einstein on Mass and Energy

The concept (or misconception) of "relativistic mass" is a very common topic in many discussions, especially on the internet physics forums. I've seen countless questions on such thing. While there is an effort to no longer use the term "relativistic mass", I'm afraid that that name is totally ingrained into the current generation (and even the ones before) ever since the formulation of Special Relativity.

I've mentioned earlier a very concise paper by Lev Okun that made a very clear argument on why the concept of relativistic mass is really not accurate. In it, it was argued that it is the concept of energy and momentum that actually make more sense, and more meaningful as far as conceptualization is concerned. Now comes a new paper[1] that traces not only the physics of mass and energy, but also the historical development of the idea leading up to Einstein's realization that "relativistic mass" isn't accurate.

In the first paragraph of the introduction alone, one can see that this is highly consistent with Lev Okun's earlier assertion:

Einstein's first paper on relativity appeared when the concept of speed-dependent electromagnetic mass had already become a topic of considerable interest. He accept this idea but changed his mind after being confronted by a far more compelling insight. We will show that after reading Planck's 1906 article in which the concept of relativistic momentum was introduced, Einstein came to realize that it was the relativistic equations for energy and momentum that were primary. From that perspective, it became clear that the inertial mass m was invariant, and he never again spoke of mass as being speed dependent.

This is a very good paper, especially if one is interested in the historical development of the concept of "relativistic mass" and why it shouldn't be used.


[1] E. Hecht, Am. J. Phys. v.77, p.799 (2009).

Friday, September 04, 2009

'Overwhelming' Evidence for Monopoles?

A flurry of papers being published and appearing on Arxiv seem to claim the discovery of monopoles {link available for free only for a limited time}, but it is not where you think.

"People have been looking for monopoles in cosmic rays and particle accelerators — even Moon rocks," says Jonathan Morris, a researcher at the Helmholtz Centre for Materials and Energy in Berlin.

Now Morris and others have found the strongest evidence yet for magnetic monopoles, in small crystals about the size of an ear plug. When the crystals are chilled to near absolute zero, they seem to fill with tiny single points of north and south. The points are less than a nanometre apart, and cannot be measured directly. Nevertheless, Morris and other physicists believe they are there. They make their case in two papers published today in the journal Science, and other work published on the pre-print server

Here are the references:

1. Kadowaki, H. et al. preprint at (2009).
2. Fennell, T. et al. Science advance online publication doi:10.1126/science.1177582 (2009).
3. Kadowaki, H. et al. preprint at (2009).
4. Bramwell, S. T. et al. preprint at (2009).

It remains to be seen whether these monopoles from the "spin ice" system can actually be considered as the actual monopoles that we've been looking for (don't think this is what the Standard Model had in mind).

Not surprisingly, such a fundamental discovery came, not from cosmic rays or particle accelerators, but from condensed matter physics! There should be no more question on whether CMP studies "fundamental" ideas or not. It should be patently clear already by now.

Edit: adding the link from ScienceNOW on the same topic.

Edit 10/15/09: S.T. Bramwell paper has now appeared in Nature. The exact reference is: S.T. Bramwell et al., Nature v.461, p.956 (2009).


Thursday, September 03, 2009

Selling Physics As Is To Students

I've always recommended David Griffiths text books to students. Having encountered his E&M and QM texts, I thought that they were two of the best books covering those two subject matters. I often wondered if this is the result of him being a very good physics instructor.

Now, after having read his most recent article about teaching physics to students, I have my answer.

The article describes his views on efforts to make physics "more fun" in the class room, and all the new technology in trying to teach it.

In the US there is a movement inspired by physics education research (PER) to promote "active engagement" in the classroom. I applaud this – though it is hard for me to imagine any good teacher since Socrates who is not already practising it. But taken to extremes it can be destructive. When it is claimed, for example, that students learn nothing from lectures (because, apparently, they are not "actively engaged") I demur. It goes without saying that there are bad lectures, but there are also very good ones, in which students are totally engaged. Nobody's mind wandered during Coleman's lectures. In despair over the ineffectiveness and unpopularity of traditional methods, some PER people advocate "learning by discovery" in the lab. It is a nice idea, but stultifying slow and inefficient – how are we to rediscover 500 years of physics in a semester? I can explain the conservation of momentum in 15 minutes, but three hours in the lab would only convince an honest student that the law is false.

The Harvard University physicist Eric Mazur and others have introduced flash cards (now – inevitably – replaced by electronic "clickers") to enforce student engagement at lectures. They can be powerfully effective in the hands of an inspired expert like Mazur, but I have seen them reduced to distracting gimmicks by less-capable instructors. What concerns me, however, is the unspoken message reliance on such devices may convey: (1) this stuff is boring; and (2) I cannot rely on you to pay attention. Now, point (2) may be valid, but point (1) is so utterly and perniciously false that one should, in my view, avoid anything that is even remotely open to such an interpretation.

I quite agree with that view. I've mentioned many of these "teaching technologies" before on here, and I've always wondered to what extent these things are effective, and whether someone ELSE could conduct such a thing with the same result. My view has always been that, more often than not, it totally depends on the instructor and his/her enthusiasm, with or without such technology.

Still, that argument applies to Griffiths' article too.

I have been lucky. I spent most of my career at an institution where the students are reasonably bright and extraordinarily motivated, where effective teaching is genuinely encouraged and appreciated, and where I have enjoyed the freedom to pursue whatever strikes me as interesting and important. I have never suffered the interference of a brainless dean concerned only with grants and publications, and as a consequence I have been more productive than would have been possible in the usual academic straitjacket. I do not know what makes good teaching, beyond the obvious things: absolute command of the subject; organization; preparation (I write out every lecture verbatim the night before, though I never bring my notes to the lecture hall); clarity; enthusiasm; and a story-teller's instinct for structure, pacing and drama. I personally never use transparencies or PowerPoint – these things are fine for scientific talks, but not in the classroom. I want my students to know that something is happening in real time: I am thinking through each argument as I present it, not merely reciting something they might just as well have read in a book.

In an ideal world, we would have teachers like Griffiths and Coleman. But in reality, we don't. In fact, we'd be lucky if have half of the physics instructors we encounter in college are as interesting and enthusiastic about teaching as these two. As with the new technologies and new "tricks" that seem to be effective and could be due to the enthusiasm of the instructors themselves, so do the "old style" teaching methods of Griffiths that definitely needs someone with the same level of caliber and enthusiasm. Maybe the new technologies and new "tricks" of teaching physics to students are there to compensate for those instructors who don't have such skill and do not posses such enthusiasm. I don't know.

I do know, however, that we are never lucky enough to get outstanding teachers most of the time. What we do get, are average, even mediocre instructors, most of the time,with a few brilliant ones sprinkled along the way.


Top Quarks

If you haven't been reading Symmetry magazine, you've been missing a lot of fascinating stuff. Even if you're not into particle/high energy physics, you should read it since it often covers more than just that subject area.

An article covering the physics of top quarks caught my eye and, as expected, it is a wonderfully-written piece that most people (i.e. non physicists) can understand. It clearly shows that very important aspect of discovery in physics that I've mentioned several times on here in the context of my criticism against pseudoscience. You will notice that upon the first initial discovery of the top quark many years ago, we not only have verified its existence, but our knowledge of it continues to improve over the years as more and more tests are conducted and better technology evolves. We know more about the top quark now than we did before, and have gone WAAAAAY past the stage where we have to show that it exists. This is an important characteristics of a VALID PHENOMENON that many people do not seem to realize and appreciate.

If you do not know what is considered as a valid phenomenon and what isn't, try applying that rule and see what you get.


Wednesday, September 02, 2009

The Surprising Physics of Pipe Organs

I love reading stuff like this. For some odd reason, finding the answer to long-standing "common" puzzle has always been something I have always been keen on reading. So when I came around this article, I gobbled it up! :)

The problem deals with a puzzle that was observed by Lord Rayleigh, so it is OLD! It deals with a peculiar behavior exhibited by pipe organs.

In 1877, English physicist Lord Rayleigh observed that when two almost identical organ pipes are played side by side, something strange happens. Rather than each blaring their own tone, the two pipes will barely make a whisper. But put a barrier between them, and they sing loud and clear.

You have to read the whole article to figure out the explanation for this. Fascinating!


Science and Technology Policy: A View from Washington, D.C.

If you are in the Chicagoland area, this might be something worth attending.

As science and technology becomes more important in the health and well-being of our nation, Washington, D.C. is important in advocating for a more scientifically informed public. Join C²ST for a discussion with local representatives from Washington on how to maintain healthy and stable levels of funding for basic and applied scientific research and the impact of working to strengthen our countries’ basic scientific research facilities.

The panelists are Congresswoman Judy Biggert (13th-IL.) and Congressman Bill Foster (14th-IL.). It will be moderated by Nobel Laureate Leon Lederman. It will be held on Northwestern University campus on Friday, Sept.18.


Tuesday, September 01, 2009

More Tests On Local Lorentz Invariance

Any theory of violation of Lorentz invariance now has an even more stringent limit to overcome. A new report published in PRL has tested this to an even greater accuracy[1].

Abstract: We report on the results of a strongly improved test of local Lorentz invariance, consisting of a search for an anisotropy of the resonance frequencies of electromagnetic cavities. The apparatus comprises two orthogonal standing-wave optical cavities interrogated by a laser, which were rotated approximately 175 000 times over the duration of 13 months. The measurements are interpreted as a search for an anisotropy of the speed of light, within the Robertson-Mansouri-Sexl (RMS) and the standard model extension (SME) photon sector test theories. We find no evidence for an isotropy violation at a 1sigma uncertainty level of 0.6 parts in 10^17 (RMS) and 2 parts in 1017 for seven of eight coefficients of the SME.

We have yet to see such violations.


[1] Ch. Eisele et al., Phys. Rev. Lett. v.103, p.090401 (2009).