Friday, November 30, 2007

The Science of The Pirates of the Caribbean

I love it when two of the things that I'm passionate about merges. It has happened a few times before, such as when it was discovered that Enrico Fermi actually used words and characters from the Winnie the Pooh (OK, so that isn't exactly Disney) to label some of his work, or the physics in Pixar's animation.

So here's another example. It appears that Western Illinois University has been organizing a science night for the public. It is usually themed, and this time, it is a presentation of the science coming out of Disney's Pirates of the Caribbean movie.

Thursday's event featured movie clips from the "Pirates of the Caribbean" movies with related experiments, such as the physics of the movie's fight scenes, mystery ships, weight distribution and even a few small explosions using simple ingredients such as Diet Coke and Mentos candy.

One student made a rocket sled propelled by a fire extinguisher, while another used an inhaled gas to deepen two students voices more to a "pirate" tone. The final event was the favorite as liquid nitrogen was mixed with heavy cream and other ingredients to make ice cream for the crowd.


I suppose you gotta try everything you can to make science entertaining to the public.

Zz.

Thursday, November 29, 2007

Debye Was Not An Anti-Semite Or A Nazi

This is rather interesting, mainly because I missed the whole controversy in the first place. A news report in Science's daily news update based on a thorough investigation historian Martijn Eickhoff of the Netherlands Institute for War Documentation appears to have exonerated Peter Debye of being a Nazi and an anti-Semite. The allegations were made by physicist and journalist Sybe Rispens in a book and in a magazine article titled "Nobel Laureate With Dirty Hands".

The 200-page study by historian Martijn Eickhoff of the Netherlands Institute for War Documentation, commissioned by the Dutch science ministry and published yesterday, concludes that Rispens's picture of Debye was a "caricature" that contains multiple errors. Eickhoff points out that Debye seemed to think that he had to do what he could to keep German physics afloat. Although he didn't actively resist the Nazi regime, there were "moments of opposition," the study notes, such as his helping two Jewish colleagues escape from Germany. To retain his position, he developed a "survival mechanism of ambiguity."


The full report in English can be found here.

Zz.

Krauss Explains His Remarks

There are two lessons here:

1. Don't read New Scientist (I don't)
2. Physicists should pay attention to what they say before saying it.

I highlighted the terrific article by Helen Quinn in Physics Today several months ago. In it, she plea for us to pay attention to the words and phrases we use, because such things can be easily misconstrued by the media and the general public. I think Lawrence Krauss should have paid attention to this relevant essay before he sat down for the interview with any New Scientist reporter.

This, of course, came about because Krauss gave an interview that caused even experts in cosmology to scratch their heads. He made headlines when the said to the effect that we somehow are hastening the demise of the universe simply by observing dark energy, and equating it to an aspect of quantum mechanics in how an observer affects a system simply by observing it. When this came out, of course all the news media picked it up.

You'll notice that I did not report it here at all, till now. Oh, I definitely read it the day it came out, but way in the beginning, I noticed that it came out of New Scientist (that has the propensity to reach for sensationalism more than accuracy), and that the statement itself is nonsense. I half-heartedly was hoping that Krauss was pulling an Alan Sokal with New Scientist. Alas, I won't be getting such pleasures.

Krauss has now clarified what he wanted to say, and what he meant. It certainly isn't what was written in New Scientist, I can tell you that.

"I was too glib," the scientist said in a phone interview. "I had just completed this paper about a subject that I found so fascinating, and I was excited to talk to another scientist about it. But I was running off to Nashville from California. And I didn't spend enough time explaining myself."
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But Krauss admitted that he had gotten caught up in his excitement about quantum mechanics and should have chosen his words more carefully. What he meant, he said, is that by observing dark energy, scientists might have pinpointed more accurately where the universe is in its evolution - and that it might be less stable than we thought.


Let this be a lesson to every scientist. I myself have learned such a lesson a while back, although on a significantly lesser scale than what Krauss is going through. The public that you're talking to does not understand science, and certainly cannot put into context the words that you are using. They will take it at face value, and you'd better have an extra pair of ears listening to what you are saying before you let it through.

Zz.

Wednesday, November 28, 2007

Sheep Collisions: the Good, the Bad, and the TBI

I seldom try to "advertise" a paper on arXiv that is yet to be published, but I just found this a fascinating read and an amusing one as well.

The authors of this preprint are trying to show how an analysis in Halliday and Resnick on why 2 sheep can survive a violent head-butting without suffering any brain injury is not actually correct. The subject matter is rather amusing (at least to me), but there's some rather good basic mechanics issue here being presented, especially for motion without the assumption of a constant acceleration. So I think any physics undergraduate that have had sufficient calculus can follow this.

Now, anyone willing to read it carefully enough to see if they've done the physics correctly? :)

Zz.

Schrodinger's Kittens Enter The Classical World

This is a rather fascinating angle on the quantum to classical transition. The traditional explanation on the cause of the difference between quantum world and the classical world is the onset of decoherence, where the system interacts with its environment. That interaction with the large degree of freedom causes the emergence of our familiar classical world. We have seen several experiments that showed that the onset of such decoherence gave us back the familiar classical description. In fact, it has been shown that even with just ONE interaction, a single-particle system can quickly lose its quantum coherence.

However, a new theoretical research has taken a different angle. Two physicists in Austria has published a paper[1] showing that the emergence of classical observation can be also be obtained without having any decoherence effect, but rather due to the "coarse-grained" measurement that we make. A review of this work was reported in Nature Daily News (the link may be available for a limited time and may require registration and/or subscription).

Johannes Kofler and Časlav Brukner of the University of Vienna and the Institute of Quantum Optics and Quantum Information, also in Vienna, say that the emergence of the 'classical' laws of physics, deduced by the likes of Galileo and Newton, from quantum rules happens not as objects get bigger, but because of the ways we measure these objects. If we could make every measurement with as much precision as we liked, there would be no classical world at all, they say.


We know that "size" isn't the issue here, especially with the recent SQUID experiments of Delft and Stony Brook. However, the conventional thinking is that the larger the size, the more difficult it is to maintain coherence of all the parts of the system. What the new approach here has tried to explain is that with the larger size, the precision of our measurement also tends to get worse. Unfortunately, their proposal to measure and detect the quantum effects on large system appears to be rather daunting, if not almost-impossible.

Kofler says that we should be able to see this transition between classical and quantum behaviour. The transition would be curious: classical behaviour would be punctuated by occasional quantum jumps, so that, say, the compass needle would mostly rotate smoothly, but sometimes jump instantaneously.

But watching such quantum jumps between life and death for Schrödinger’s cat would require that we be able to measure precisely an impractically large number of quantum states. For a 'cat' containing 1020 quantum particles, say, we would need to be able to tell the difference between 1010 states – too many to be feasible.


Still, I wouldn't put it past some experimentalists coming up with an ingenious way to test this.

Zz.

[1] J. Kofler and C. Brukner, Phys. Rev. Lett. v.99, p.180403 (2007).

Tuesday, November 27, 2007

More Tests of Leggett Inequality

Earlier, I highlighted the paper by the Zeilinger's group that rules out a class of realism model via the violation of the Leggett inequality. Now comes two more papers in last week's Phys. Rev. Lett. that made further tests of such violation.

The first one is more of a refinement of their earlier work from the Zeilinger's group. This one supposedly rules out a larger class of local realism model without the assumed rotational symmetry of the earlier tests.

T. Paterek et al. "Experimental Test of Non-Local Realistic Theories Without The Rotational Symmetry Assumption", Phys. Rev. Lett. 99, 210406 (2007).

The second paper in the same issue also tests the Leggett inequality and finds a clear violation of it.

Cyril Branciard et al. " Experimental Falsification of Leggett's Nonlocal Variable Model", Phys. Rev. Lett. 99, 210407 (2007).

It is amazing that tests after tests all produce a consistent result that are in full agreement with quantum mechanics. At some point, this will become a very convincing body of evidence.

Zz.

Monday, November 26, 2007

A Teacher In Perpetual Motion

So why can't we all get teachers like Micheal Lampert when we were in high school?

The demonstrations highlight Lampert's skill at bringing science to life and his ability to tailor lessons to different learning levels.

"He's just a master to watch in the classroom as he instills in students a real interest in science," principal Ed John says.


The most profound part of this whole article is what he himself believe to be the most effective means of teaching:

"The only thing that's successful with these kids is to be one-on-one with them and talk to them. That's the secret to bringing out learning," he says.


It is unfortunate that many schools cannot only afford such luxury, but also the luxury of having a physics teacher with a great physics training and background.

Still, I think I've discovered the most effective means of making students interested in physics!

Lampert has made a big impression on microelectronics student Ian Love, 15. "Once, he used a high-voltage transformer that took wall current, stuck both electrodes into a hot dog and fried the hot dog," Ian says. "It was like an electrocution of the hot dog. I can't wait to take his physics class next year."


Electrocute a hot dog! That's all you need! They'll be eating out of your hands after that, figuratively and literally! :)

Zz.

Fake Photos Alter Real Memories

Our minds can play tricks on us. That is why anecdotal evidence is not the same as scientific evidence. The process of science tries to ensure that the evidence is valid and not simply something fleeting that fools our mind.

Over the years, there have been many evidence on how our mind can play tricks on us, to the extent that we truly believe something actually happened, when in effect, it did not. At the very least, our view of "facts" can actually be altered simply by external stimuli. This is what has been shown to occur in this latest research. A number of subjects have been shown faked photos of famous public events, and these photos can actually alter the perception of the subjects who viewed them.

The original Tiananmen Square image was altered to show a crowd watching at the sidelines as a lone man stands in front of a row of tanks. The Rome anti-war protest photograph was altered to show riot police and a menacing, masked protester among the crowd of demonstrators.

When answering questions about the events, the participants had differing recollections of what happened. Those who viewed the altered images of the Rome protest recalled the demonstration as violent and negative and recollected more physical confrontation and property damage than actually occurred.

Participants who viewed the doctored photos also said they were less inclined to take part in future protests....


Scientific methodology is designed to ensure that we're not seeing something that is influenced by how our mind can play tricks on us, or how things can influence on the evidence itself. That is why a scientific evidence is more RIGOROUS than an anecdotal one.

The full reference for this work is listed below:

Dario L. M. Sacchi et al., Applied Cognitive Psychology v.21, p.1005 (2007).

Zz.

Sunday, November 25, 2007

Researchers End Debate Over Fractal Analysis Of Authentication Of Pollock's Art

I mentioned the controversy surrounding this fractal authentication of Jackson Pollock's paintings about a year ago. And now, a year later, it appears that this issue has been resolved. The fractal method isn't reliable and has failed.

The university's physicists recently "put the nail in the coffin" in the debate about using fractal analysis in authenticating art as they completed a second study related to fractal analysis and Jackson Pollock's drip paintings.
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"No information about artistic authenticity can be gleaned from fractal analysis," said Katherine Jones-Smith, lead author of the study.


This should put an end to this saga. Too bad that there are still paintings that are still under dispute.

The preprint for this work can be found here.

Zz.

Saturday, November 24, 2007

The Physics of Shamu

Hey, if you have gone to Seaworld parks, and have seen the Shamu show, this article on the physics of Shamu might interest you.

I need to time my jumps perfectly in order to get the greatest amount of lift. Right before Shamu’s forward and upward momentum peaks, I flex my knees a bit and spring forward. Flying through the air feels free and effortless. Heading toward the water’s surface, my inertia is about to be halted rather abruptly. An object in motion tends to stay in motion, with the same speed and direction, unless acted upon by an unbalanced force. I aspire to a perfect arch before plunging into the water. That isn’t always the case, however. Belly flops, windmills (picture arms flailing) and back slaps are part of any Shamu trainer’s experience. The law of inertia is all too evident as I hit the water. Shamu, it seems, does not experience the same phenomenon.

The laws of physics are very evident in killer whales, to be sure.
Energy. Force. Magnitude.


I just wish that the author didn't write about Newton being "the father of modern physics". That's a bit misleading since "modern physics" is normally associated with quantum physics and special/general relativity.

Zz.

Thursday, November 22, 2007

'Cooper Pairs' Can Be Found In Insulators As Well Superconductors

This is a rather fascinating report. A team from Brown University has found evidence that Cooper Pairs can exist not just in a superconductor, but also in an insulator.

“Our finding is quite counterintuitive,” said James Valles, a Brown professor of physics who led the research. “Cooper pairing is not only responsible for conducting electricity with zero resis-tance, but it can also be responsible for blocking the flow of electricity altogether.”


However, unlike a superconductor, these Cooper pairs do not condense into a coherent state and, therefore, do not conductor electricity. It is interesting to note that this is similar to the behavior of the high-Tc cuprates in the pseudogap state. This is where one obtains a paring of the charge carriers ABOVE Tc. Here, no long-range coherence occurs even though pairing has occurred. Whether these paired carriers are precursor to superconductivity as the material goes below Tc, or are competing with superconductivity, is still a question yet to be answered.

Also interesting to note that this isn't the only situation where paring, and even superconductivity, can occur in an insulator. When an insulator shares a common surface with a superconductor, there is something call the proximity effect, whereby the superconducting wavefunction "leaks" into the insulator over some length (of the order of the the coherence length). What is different in this new work is that this pairing occurs on stand-alone insulator.

The exact citation to this work is:

M. D. Stewart, Jr. et al., Science v.318, p.1273 (2007).

Zz.

Wednesday, November 21, 2007

Educators Tout Benefits of 'Physics First' Program

I've always of the opinion that physics should be the first science subject that is taught to students. Nobel laureate Leon Lederman is a major advocate for this effort with his Project Arise. There are a lot more things around us that are clear example of physics in action.

It seems that this policy has been implemented in several schools, where physics is being taught at the high school freshman level. From all indication, this seems to have a rather positive effect in the students as they progressed through their education.

Zz.

Tuesday, November 20, 2007

Hollywood Comes to CERN

.. which isn't unexpected if you're filming the movie version of Dan Brown's "Angels and Demons". After all, the book's setting in the beginning is at CERN.

They have the same cast as "The Da Vinci Code", i.e. Tom Hanks will return as the same character. But interestingly enough, the "Angels and Demons" book came out first before "The Da Vinci Code". I suppose there isn't anything from one that significantly influence the other in terms of character and story line.

Zz.

Infrared Laser Can Be Fine-Tuned To Selectively Target And destroy Lethal Microorganisms

Here's another physics research work that one can use whenever someone claims that the study of physics has no practical application.

Physicists at Arizona State University, Johns Hopkins, and the Armed Forces Radiobiology Research Institute can now selectively zap microorganisms without harming the surrounding cells.

In their paper titled 'Selective inactivation of microorganisms by near-IR femtosecond laser pulses', physicists from Arizona State University detail how their new laser technique can destroy viruses and bacteria such as AIDS without damaging human cells. Also interesting to note is its potential to help reduce the spread of hospital infections such as MRSA — more commonly referred to in the media as the "superbug" or staph infection. MRSA is called the superbug because of its resilience and its ability to survive most treatment regimens including penicillin and methicillin.


The exact reference to this work is:

K T Tsen et al., J. Phys.: Condens. Matter v.19, p.472201 (2007).

Zz.

Monday, November 19, 2007

Don't Throw Your Physics Experiment Out In The Trash!

Here's a hint: don't simply throw out your physics experiment out in the trash can! You could cause a lot of problems, such as the one that happened at the University of San Diego.


The “device” – six glass root beer bottles with rubber stoppers linked by wires – alarmed a security guard, who called authorities just before noon, fire department spokesman Maurice Luque said.

Luque said bomb investigators with the Metro Arson Strike Team took photographs of the contraption and showed them to a physics professor on campus, who confirmed it was a student experiment.


Never a dull moment... :)

Zz.

Erykah Badu Dabbling In Quantum Physics?

I'm not making this up!

Erykah Badu, for those of you who are not up-to-speed with contemporary music, is a well-respected, grammy-winning, hip-hop artist. So she isn't Britney Spears, thankyouverymuch! Still, I'm taken aback a little bit when I read in this interview that she has been dabbling in "studying" quantum physics, and that has somehow influenced her in her upcoming album.

This album is special to me because I went deep into my Hip-Hop purse to pull out some of the most creative, scientific, mathematical producers that I could find, because that’s what I was feelin’ at the time. I had been starting to dabble in the studying of quantum physics and wanting to really, I don’t know, participate in the changing of frequencies in different areas of music. And I said, “Okay, the most likely candidate would be Dilla.” So I’m searching through my Jay Dilla mixtapes and pulling things out. [Other producers include] Madlib, Kareem Riggins, 9th Wonder, Sa-Ra, my comrade Jah Born, who did “On and On,” Frequency, my production crew - that’s Rashad Smith, James Poyser, ?uestlove. Am I leaving anybody out?


I'm guessing by what she meant as studying is that she's reading pop-science books on quantum physics. That wouldn't be so bad. I just hope that she's NOT learning about it by reading books such as "The Secret" or something worse than that.

Next, I fully expect to hear that Mariah Carey is studying Special Relativity.

:)

Zz.

Physics Phun Night

I highlighted Purdue's yearly Physics Open House event earlier. Not to be left out is the yearly University of Arizona Physics Phun Night.

Held in the Physics and Atmospheric Sciences building, the event was sponsored by the physics department and was geared toward children and families, said physics lab coordinator Larry Hoffman.


Sounds like the visitors had a lot of fun at some of the demos they were showing.

Zz.

The Physics of Turkey

Hey, why not? :)

This Thursday is a major holiday here in the US - Thanksgiving. The traditional meal involves a turkey, usually a whole turkey roasted in the oven (although deep-fried turkey is catching up there). So just in time for the holidays, we have the physics of turkey-cooking. It's your opportunity to learn or brush up on your thermodynamics.

:)

Zz.

Sunday, November 18, 2007

Purdue's Physics Open House

Purdue University Physics Dept. threw another of these Physics fest this year (I reported the one from last year).

I'll say it again here. This is such a good idea. Major universities should do this often. Not only are you introducing the general public to science, you are also opening your school up to the neighborhood so that they learn what exactly it is that you do. Often, universities and the surrounding communities don't talk often, and that can create tension between the school and people who live there. Having events like this opens up the school for local visitors, especially if it is a state school that is funded by taxpayers.

Zz.

Saturday, November 17, 2007

The Emergence of Science Cafe

I didn't know that this is getting to be as popular as being reported here. It seems that throughout the country, small cafes and bars are having "meetings" on science that are getting to be quite an event.

Science groups for young professionals who don’t wear white coats, like the year-old Secret Science Club at Union Hall, are cropping up in bars and bookstores all over the country, from Massachusetts to Montana.

“If you have a certain type of job, after a while that part of your brain starts to deteriorate,” said Amy Lee, 25, who works at an Internet startup and was attending her second Secret Science Club meeting. “You want to use it again. Plus, there’s alcohol.”


Ah!!! So that's the secret! :)

It does make sense, and it's different.

Zz.

Friday, November 16, 2007

The Adventures of the Flying Spaghetti Monster

Sometime, I'm thoroughly amazed (not to mention, highly amused) at the things that a physics student can get into. I will admit that I wasn't aware of the existence of the Flying Spaghetti Monster till I read this news report. However, it appears that the creation of one physics student at the Oregon State University by the name of Bobby Henderson will now be the subject of a discussion at the upcoming American Academy of Religion annual meeting.

You have got to read the news article to get up to speed here. It's too hilarious and, I would say, an effective means to illustrate the absurdity of forcing Intelligent Design into a science class.

So, whether you intentionally planned this or not, well done Bobby!

Zz.

Thursday, November 15, 2007

"Violating" Einstein's Photoelectric Effect

One of the most spectacular theoretical description that Einstein had ever produced is the corpuscular nature of light that he used in his 1905 photoelectric effect paper. In fact, there have been arguments put forth that of all of his 1905 papers, the one proposing this model for light is what is truly most revolutionary, even more than his special relativity theory.

In case you need a refresher, the photoelectric effect experiment is where you shine light onto a surface of a material (typically a metal). If the light has a sufficient "energy", then photoelectrons are emitted. What was puzzling before the 1900s was that light, as understood as a wave via the Maxwell Equations, seemed to not be behaving the way it should within this photoelectric effect experiment. The energy of the light wave was tied to its intensity - the larger the intensity, the larger the energy. Yet, in the photoelectric effect experiment, there were two puzzling observations:

1. As one increases the intensity, the energy distribution of the emitted photoelectrons does not change. Electrons are not emitted with more energy. Rather, increasing the intensity simply increases the number of electrons being emitted. The energy distribution remains the same as before.

2. If the frequency of the light is below some value, then no matter how intense the light is, no electrons is emitted.

Einstein took those two puzzling observations and reformulated the light description, tying the frequency, not the intensity, to the energy of light. Not only that, he proposed that light's energy comes in discrete quantum (photon). He then proposed a simple description of the photoelectric effect experiment:

KE = hf - F

where KE is the kinetic energy of the emitted photoelectrons, hf is the energy of each photon (f is the frequency of light and h is the Planck constant), while F is what is known as the work function of the material. When the photoelectric effect is defined this way, then a natural explanation for both #1 and #2 is obtained. Since light's energy only depends on the frequency, increasing the intensity does nothing to the energy of each photon. The intensity only affects the rate of photons being emitted, thus that explains why we obtain more photoelectrons, but with the same energy distribution. And if the frequency of light is less than the work function F, then no matter how high the intensity is, it is still less than F and therefore unable to produce any photoelectrons.

This photoelectric effect description was soon experimentally verified by Millikan (who initially was very skeptical of Einstein's description, but later on admitted that all of the experiments seemed to point to its validity). Since then, Einstein's formulation of what light is has certainly been verified and accepted many times over, and is the only description of light being used in many advanced application such as photoemission spectroscopy.

Still, does this mean that we do not have any evidence that this description can be "violated"? I'm putting "violated" in quotes because, as I'll explain later on, it turns out that, as is the case in many areas of physics, the photoelectric effect description of Einstein is only the simplest, most naive description of a "single-photon" emission. What this implies is that we have several situation where the Einstein's photoelectric effect equation can be "violated".

There are two different types of experiments where this can be done.

A. The Schottky effect type experiment.

This type of experiment was done[1] even way back in the 20th century, even by giants in physics such Ernest Lawrence[2]. This is where the same photoelectric effect experiment was done, but in a rather high external accelerating electric field. This field is applied usually perpendicular to the metal's surface in the direction that will accelerate the emitted electrons away from the metal's surface. What is observed here is that one can in fact observe emission of electrons even when the energy of the photons is LESS than the work function (violation of #2 above). What is going on here is that the applied electric field acts in such a way that it lowers the effective work function of the metal. The photons with a lower energy can start to emit electrons even below the metal's bulk work function.

B. Multiphoton photoemission.

This discovery occurs especially after lasers were invented, and high intensity monochromatic light sources become easily available. What is observed in these experiments is that, even without applying any high fields to the metal (i.e. no lowering of the effective work function), one can still get photoelectrons even using photons with energy lower than the work function, especially when one increases the intensity of the light source by a lot. This again violates #2. A very simple explanation for this is that, with highly intense light source such as those coming from a laser, one can induce a multiphoton photoemission process.[3,4] This is where the first photon excites an electron in the metal's conduction band to an intermediate state. Normally, its lifetime in the femtosecond range would cause it to decay back down. But with a highly intense light source, the probability of another photon being absorbed by that excited electron before it decays becomes significant. Thus, if you have a light source with photon energy just slightly more than half of the work function, there is a non-negligible probability that you can now have an emission of electron due to the absorption of 2 photons. One can easily imagine this being done for 3, 4, etc.. photons. Of course, the probability of emission with higher number of photons is significantly lower.

So here, I've just described two different ways of violating Einstein's photoelectric effect description[5]. So does this mean that we should try to get the Nobel committee to revoke Einstein's prize? Does this mean that the photoelectric effect description is no longer valid?

NO!

The most significant consequence of Einstein's photoelectric effect description - the photon - is STILL valid and very much alive. In fact, the multiphoton experiments could not be easily explained without using the concept of photons. What we know now is that the Einstein's description is valid only for the simplest case - an emission of electron using single photons only, i.e. single-photon photoemission and under a revised definition of the work function being the EFFECTIVE work function, rather than the original bulk work function. As with other aspects of physics, we make progress in the study of an area, and now we know more of what we didn't know then. Einstein's work opened the pathways to viewing light in a different way. Without such insight, most of what we know now in this area would not have been possible. Just as Newtonian mechanics became more of an approximation (albeit a valid one at our normal scales), the Einstein's equation also became more of a special case valid for the simplest situation.

Zz.

[1] E. Guth and C.J. Mullin, Phys. Rev. v.59, p.867 (1941).
[2] E.O. Lawrence and L.b. Linford, Phys. Rev. v.36, p.482 (1930).
[3] K. Giesen et al., Phys. Rev. Lett. v.55, p.300 (1985).
[4] W.S. Fann et al., Phys. Rev. B v.44, p.10980 (1991).
[5] There is actually another way, via heating the metal. See, for example, R.H. Fowler, Phys. Rev. v.38, p.45 (1931).

Wednesday, November 14, 2007

The Most Accurate Measurement Ever Made

Would you ever think that using single photons and an interferometer, one could get the most accurate measurement ever made up to now? One certainly can, as shown by this very elegant experiment (link may be available for free for a limited time). In fact, they got close to the Heisenberg Uncertainty limit!

But Pryde and his coworkers in Australia have demonstrated a way of reaching the Heisenberg limit of measurement precision without needing these elusive states: by looking at photons traversing an interferometer's arms one at a time. The key is to avoid making measurements that determine which arm the photon is in, until the beams are recombined at the end. This allows the shot noise to be more or less smoothed away.


Another very clever experiment. Way to go, people!

Zz.

Tuesday, November 13, 2007

Sand Could Shed Light On Quark-Gluon Plasma?

Like I've said many times before, you just never know when the most fundamental understanding in physics could come from. Who would have thought that shooting sand at a target would give you insight into the quark-gluon plasma that was thought to be present close to the Big Bang? But there it is!

Furthermore, Nagel and colleagues believe that this liquid-like behaviour of colliding particles has been seen before -- at the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory in the US. Two years ago, researchers at the RHIC smashed together pairs of gold nuclei to create multi-particle “quark-gluon plasma”. Such a plasma is believed to be present in the early Universe – just before it has cooled enough for quarks and gluons to combine and form protons and neutrons.


Just as Peter Higgs found the inspiration for the Higgs mechanism from condensed matter, you just never know when the next source of inspiration in physics would come from.

Zz.

Monday, November 12, 2007

Surprise!! More Bastardization of Quantum Mechanics

Remember that I had already mentioned that, when people do not understand the mathematical description of quantum mechanics, they only get to see all of these things appearing out of nowhere, and conclude that anything is possible. What's worse, they can't tell the difference between QM phenomena, and things that come out of mysticism and other psychic pseudoscience. They seem to think that one can easily extrapolate all the "weirdness" of QM into other realm, without any justification that such extrapolation is valid. In other words, they learn about physics in bits and pieces, and ignore the rest, such as the concept of decoherence that I've covered in the last few blog entries here.

If you don't believe me, here's one example. This appears to be a news article out of the Philippines, where they are claiming that there's no difference between what QM is saying, and what mystics are saying.

This negative attitude may soon change. Psychics and mystics have found an unexpected ally within the ranks of a relatively new scientific field called by various names like quantum mechanics, modern physics, particle physics and, lately, quantum physics.

In fact, the way pioneers of quantum physics describe the ultimate nature of physical reality is often indistinguishable from the way mystics talk about it.
This uncanny and incredible parallelism in the thinking of both mystics and modern physicists was not lost on several keen observers of recent developments in science.


These people obviously forgot one VERY IMPORTANT DIFFERENCE - EMPIRICAL EVIDENCE.

I suppose when one is scientifically illiterate, that issue never crossed one's mind.

The "weirdness" of QM are well-tested, not only qualitatively, but also QUANTITATIVELY! And they can be produced almost on demand - just look at your modern electronics. We know QM well enough that we USE it for practical purposes.

Now when was the last time your local neighborhood psychic can produce a transistor?

So yes, there is a HUGE difference. But if you are blind, how can you tell? So the bastardization continues.

Zz.

Do Classical Laws Arise From Quantum Laws?

This is a timely subject, since the issue of "decoherence", and how far quantum laws can be extrapolated into our classical world seems to be the topic of discussion on here (see comments from the last few blog entries).

Physicists from Austria have formulated a theoretical scenario in which QM laws are the underlying physical description of the classical world that we see today.

“Our motivation is to understand how the classical world comes out of quantum physics,” Kofler says. “The established approach in research is decoherence where one has to take into account the complexity of systems and interactions with environment.” It is interaction with the environment that brings decoherence into play, destroying quantum coherences and making it impossible to observe quantum phenomena. “We believe we found a process complementary to decoherence which can explain the quantum-to-classical transition.”


The exact reference to the paper is as follows:

Johannes Kofler and Časlav Brukner, "Classical World Arising out of Quantum Physics under the Restriction of Coarse-Grained Measurements", Phys. Rev. Lett. 99, 180403 (2007).

Again, many people who don't understand this think that QM phenomena can be easily extrapolated, and used in mystical ways to explain human behavior, our world, etc. They can't! QM phenomena are not easy to find. If it is, we would have seen it already and won't have to wait till about 100 years ago in human civilization to formulate it! And not only that, QM effects are difficult to maintain because a system can interact so easily with its environment, destroying the coherence that is necessary to preserve such quantum phenomena.

So stop it already!

:)

Zz.

Nestle Uses Physics to Explain Complex Food Interactions

Physics is everywhere!

Of course we know that. Here's another example of where physics is useful - in the transport of flavors and nutrients in food!

A detailed mathematical model is presented in the journal using self-consistent field theory (SCFT), a quantum mechanical theory that enables the calculation of phase diagrams for the system.

Prior to this, no quantitative theoretical framework had been established to fully interpret the structural changes that occur in lipid-water interfaces under varying conditions, said the researchers.


I guess we can classify this as the physics of food structure.

Zz.

Could the Space Shuttle Return to Earth Slowly and Skip Heat Shields?

Good question! This article attempts to answer that.


You can actively slow your descent, but that needs a rocket to slow you down.

What sort of a rocket do you need to make your speed constant? Well, it would have to do pretty much what the rocket did to get you up into orbit in the first place.


To me, the best way of educating the public of science is to illustrate how it is used in things they see everyday. So questions and answers like this are some of the most effective means of science education.

Zz.

Sunday, November 11, 2007

Einstein Is Still Right On Time

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

New tests of Relativity's time dilation effects have been verified to even greater accuracy.

An international team of researchers used a particle accelerator to whizz two beams of atoms around a doughnut-shaped course to represent Einstein's faster-moving clocks.

They then timed the beams using high-precision laser spectroscopy and found that, compared with the outside world, time for these atomic travellers did indeed slow down.

"We were able to determine the effect more precisely than ever before," said lead researcher Gerald Gwinner of the University of Manitoba in Winnipeg, Canada.

"We found the observed effect to be in complete agreement."


Told ya!

:)

Zz.

Between Science and Fiction

For some odd reason, I am rather annoyed by this, or rather, highly irritated.

This is a news article on Alan Lightman. It was an interview with the physics-trained author on the occasion of the release of his latest book "Ghost". The book focuses on the "controversy" between science and religion. Nothing new there. This isn't what annoys me. What did annoy me was this:

Q: "Ghost" may be critical, but it doesn't assert one viewpoint, science or religion, above the other.

A: No, I intended not to come down on either side. I think religion and science have been two of the major sources that shaped civilization. They both represent very deeply held beliefs that are matters of faith. One doesn't often hear of scientists spoken of as people of faith, but they believe in the laws of the universe and that takes a powerful amount of faith. Both of these world views are deeply held and visceral and not subject to evidence.

Q: "Not subject to evidence?" Wouldn't scientists say that everything they do and believe is based on evidence?

A: Yes, they would say that, and of course that is true for all the experiments they have done, but what they have faith in is that all the experiments they will do will also be true. They have faith, for example, that the equations for relativity hold true everywhere in the universe. They have faith that the universe is reducible to cause-and-effect relationships and reducible to rational causes. Those are matters of faith.


With all due respect to Dr. Lightman, this is CRAP!

To say that something is simply taken as a matter of faith usually means that there's no empirical justification for accepting it. One accepts a particular religion not based on empirical evidence, but rather for other reasons.

One can't say that with science. Why do we accept the validity of Special Relativity? Because we have seen it verified experimentally! We simply didn't accept it as a matter of "faith" when Einstein introduced it in 1905. In fact, historical records have shown that there were a lot of challenges and opposition to it, so much so that even the Nobel committee was hesitant to award him a Nobel prize for it. The same can be said with other aspects of science that have been deemed to be valid. They were never taken as a matter of faith. They were verified empirically.

This is where Lightman argument that it is a matter of faith of our acceptance of how our FUTURE experiment will turn out rings hollow. The FACT that science CAN accurately predict the behavior of a system that are yet to occur is the whole reason why it exists. When you can quantify a system based on a set of knowledge gained previously, and predict what will occur in the future accurately, you have understood that system extremely well, and that is all there is to it. Is the fact that we expect our modern electronics to work when we turn it on next simply based on "faith", or is it more based on the knowledge that we have sufficiently understood how it will behave? Such acceptance is not based on "faith". It certainly is quite different than the acceptance of a belief or religion.

Furthermore, our acceptance of any scientific principle is contingent upon the criteria that we continue to test it until we find where it breaks down. When that occurs, we refine our understanding, formulate a new, more general and encompassing knowledge, and modify our acceptance of it. Is this the typical symptom of accepting something on faith? People who believe something based on faith typically really do not care if there are "contradicting" evidence facing them. Earth is not 6000 years old? We don't care! Considering how science has and continues to evolve as we understand our world a lot more, this is not even close to be considered as acceptance based on faith.

I think it is highly irresponsible of any writer to equate the acceptance of science as being nothing more than equivalent to the acceptance of religion. Certainly in this day and age where science is under attack by religious fanatics and being dismissed by some people in political power, such claims only provides more fuel against science. That it was made by someone who was trained as a physicist makes it even worse. Do some theorists sometime forget about experiments, and the lack thereof in religion? The use of the SAME word - "faith" - to describe the acceptance of both science and religion is insulting, and undermines the clear and distinct difference between those two.

Zz.

Saturday, November 10, 2007

Another Bastardization of Quantum Mechanics

Again, as with previous cases, someone who barely understands QM is using it to justify some human "intuition" or feelings. This time, it is the bastardization of the principle of quantum entanglement.


Since the universe came into existence, these subatomic particles have been entangled and remain in contact in "no time." The implications are that, instead of being separate and apart from the universe, we are all linked in a cosmic dance with everything, everywhere, near and far. There is no separateness.

I know that from the moment of my birth, I have been entangled in the lives of others, everyone from the nurse in the hospital that fed me, to the old man who gave me directions to the Howard Johnson's in Savannah, to a small brown Moroccan man who brought me some mint tea, to the woman that gave me a son, to the friend who once punched me for being a jerk, to the manager at McDonald's who gave me a job, to the innocent boy who once drew me a picture with broken crayons, to the father and mother who gave me life itself, to the co-worker who bought me a Diet Pepsi when I was a nickel short, to the man who changed my oil, to the nun who scolded me for spitting on a classmate, to the woman who held my hand as I viewed the Mona Lisa, to the Chinese worker who put together the alarm clock in my bedroom, to the policeman who gave me a ticket for not wearing a seat belt, to the dying man who inspired me to run a marathon, to the stranger who smiled while passing me in the grocery store, to the lady who wanted a heater installed, to a Michigan Avenue stranger who needed a few dollars.

We are all irretrievably entangled in each other's lives. There is no separateness.


This ignores the fact that:

1. Entanglement isn't observable at the human scale of classical mechanics

2. Entanglement requires the preservation of COHERENCE between all the entangled entities. Once a measurement or interaction has been made, you lose that coherence and any resemblance of entanglement is long gone!

This person somehow didn't think through on what happened AFTER the measurement is made. Are those 2 photons still in existence? Are they still entangled? The answer is NO. The paper that I just highlighted before this blog entry shows that even an interaction with just ONE other particle is sufficient to destroy the single-particle coherence! It also means that since what we visually see at the classical scale have undergone many interactions with many degrees of freedom. They all have lost coherence and are no longer entangled with anything, and certainly NOT from the very beginning of the universe, thankyouverymuch!

When people bastardize physics like this, they're not doing physics any favor. This is because they have extended physics into the realm of mumbo jumbo that not only trivializes physics, but also its applicability. They have cheapened it with unverified claims and watered down its importance and relevance. When false claims like this continues to be made, eventually no one would believe such a thing anymore. Do the public then remembers who made such stupid claims in the first place, or do they remember and blame the science?

Zz.

Friday, November 09, 2007

The "Simplest" 2-Slit and Decoherence Experiment

While the big news this week is the major report out of the Auger Collaboration, the other significantly as important paper in the same issue as Science is a very elegant and astounding report.

The Simplest Double slit: Interference and Entanglement in Double Photoionization of H2, D. Akoury et al., Science v.318, p.949 (2007).

Abstract: The wave nature of particles is rarely observed, in part because of their very short de Broglie wavelengths in most situations. However, even with wavelengths close to the size of their surroundings, the particles couple to their environment (for example, by gravity, Coulomb interaction, or thermal radiation). These couplings shift the wave phases, often in an uncontrolled way, and the resulting decoherence, or loss of phase integrity, is thought to be a main cause of the transition from quantum to classical behavior. How much interaction is needed to induce this transition? Here we show that a photoelectron and two protons form a minimum particle/slit system and that a single additional electron constitutes a minimum environment. Interference fringes observed in the angular distribution of a single electron are lost through its Coulomb interaction with a second electron, though the correlated momenta of the entangled electron pair continue to exhibit quantum interference.

A review of this work can also be found at PhysicsWorld (free registration is required) and at PhysOrg.

What they essentially did is this. They use the H2 molecule as a "double slit". The different between the regular double-slit experiment is that the regular experiment typically uses plane waves, whereas here, you essentially get spherical waves originating from each of the H atom in the molecule. Still, the physics is the same and you get angular interference pattern. They used photons of energies 240 eV and 160 eV to cause a double-photoionization of the H2 molecules, resulting in 2 electrons, but with varying energy.

When they use photons of 240 eV, the electron tagged as "1" comes out at between 185 and 190 eV, while the second electrons comes out with less than 5 eV. Due to the widely different kinetic energy, electron 1 doesn't really "see" electron 2, so electron 1 essentially can be described via single-particle physics. This is where you get the expected interference pattern as the experiment is repeated many times.

But when they use photons of 160 eV, they get two different cases. The first case is electron 1 emitted with energy 110 eV and electron 2 emitted with energy < 1 eV. They get roughly the same result as before. However, for the 2nd case where electron 1 has energy of 95 eV and electron 2 has energy of between 5 and 25 eV, the interference pattern almost completely disappear! In this second case electron 1 has now "seen" electron 2, and has sufficiently coupled to electron 2 to demolish the single-particle description of it. In essence, electron 2 has caused a decoherence of the single-particle description of electron 1, cause electron 1 to behave classically.

What this report is saying is that it only requires ONE particle and one interaction to induce a decoherence of a single-particle picture. Electron 2 is sufficient to be the "environment" that electron 1 couples to to induce such decoherence. Interestingly enough, while the single-particle picture is no longer valid for electron 1, both electron 1 and 2 are now "entangled" and their correlated momenta actually can still exhibit quantum interference. The system has evolved into a 2-particle state.

I love, LOVE clever experiments like this!

Zz.

A Celebration of Science

This is a wonderful report on the Festival of Science in Genoa, Italy. This writer is from the UK, and so made the comparison of science interest in Italy and the UK.

Even so, 250,000 attendances from a city of 600,000 people seems like good going. The implication is that the society that gave birth to Galileo, Galvani and Dante Alighieri, is doing well, and keeps an ever-open mind. Since attendances at British science festivals range from the haphazard to the downright disappointing (at one event, my fellow panelists and I left the podium and sat with the audience while we talked, because it seemed only polite to keep him company), it suggests that the island that produced Newton, Darwin and Charles Dickens has become more insular, and is now more interested in Big Brother than in the Big Bang.


I wish we have some Science Festival here in the US. If we can have music festival, art festival, etc.. etc.. why not a science festival where, for a few days, the general public can hear prominent physicists/scientists talk about science, and not only that, talk about it intellectually and not dumb it down? We have seen how encouraging the reception was when Hawking showed up to give a "speech".

So far, the only thing close to such a festival as far as physics is concerned is when the APS have their March and April meetings and have some events that are opened to the public. To me, this is more of a "side event". A festival of science should have as its main focus, the presentation of science to the public. It should include both speeches and hand-on demonstrations, including that Wonders of Physics traveling show! :)

Zz.

Thursday, November 08, 2007

Highest-energy Cosmic Rays Linked With Violent Black Holes

The first major result coming out of Pierre Auger observatory has now been reported.


Using the Pierre Auger Observatory in Argentina, the largest cosmic-ray observatory in the world, a team of scientists from 17 countries found that the sources of the highest-energy particles are not distributed uniformly across the sky. Instead, the Auger results link the origins of these mysterious particles to the locations of nearby galaxies that have active nuclei in their centers. The results will appear in the Nov. 9 issue of the journal Science.

Active Galactic Nuclei (AGN) are thought to be powered by supermassive black holes that are devouring large amounts of matter. They have long been considered sites where high-energy particle production might take place.


As I've said earlier, I have an indirect involvement in this via the AirFly collaboration. One of the technique they use at the Auger observatory is to detect the fluorescent signal made by electrons streaming through the atmosphere. These electrons came from showers in the upper atmosphere made by these high energy cosmic rays and gamma rays. What we provide is a way for them to calibrate their signal with the energy of the electrons as they pass through different nitrogen gas pressure.

In any case, it is fun to see how things have progressed, and now we're starting to see results. Let's hope Auger North gets built soon.

Zz.

Edit: This is the PhysicsWorld review of the report.

SETI: Is It Worth It?

{EDIT ON 11/28/2007 - It appears that some poor, pathetic soul who cannot read very well has decided to use this blog entry in agreement to somehow propagate the notion that aliens have already landed on earth. Ignoring the fact that this person had somehow misread the intention of the blog, he has also ignored all of my criticism on adopting quackeries such as this based on the flimsiest of "evidence". So it is strange that this person would "agree" with me on this, yet almost every single tone and entry in my whole blog have been devoted to debunking silly claims such as the one he's making.

If you read this from some entry by this person in a public forum, complain to the moderator or forum owner. You have a CRACKPOT on your website who has been spamming the open forums with the identical post.}



This is an article defending the existence of the Search for Extraterrestrial Intelligence (SETI).

Frankly, I don't understand why, even when it is not funded by any taxpayers money, there are still critics of it. So it is a very long-shot haunch. If people can put their hard-earned money on crackpotteries such as the hydrino and perpetual motion machine, this is certainly a less dumb means of using their money. Using an argument that the money should be spent towards eliminating hunger and poverty and other social aliments is actually quite insulting - to the people who are experiencing hunger and poverty, etc. This is because it trivializes the nature of the problem, that by simply pouring in money, we could solve something that could easily be a complicated political, social, cultural, religious, and economic problem. I could easily use the same logic at criticizing these people for spending money buying CD and DVD's and going to all those fancy restaurants. Why not use those money to fund medical research instead?

When I was "younger", I was quite "gung-ho" about the SETI project and did send them some money. But as I got older, my "gaa-gaa'ness" for the mission died off and I stopped sending them money. Maybe as one gets older (and hopefully wiser), one tends to see things differently. What was "interesting" may not be that "important" in one's priorities. So I certainly don't send any monetary support for SETI anymore. But I don't believe that those who do should be criticized, and certainly not criticized this way.

Zz.

Accelerating Science at the North Physics Laboratory

I love reading about stories of various physics facilities around the world, especially those that have some historical significance. I think it is because, in many cases, people simply do not appreciate or give enough recognition to the historical importance of scientific facilities the way they do towards military, cultural, and political history.

This article describes the cyclotron facility located at the University of Washington in Seattle. This facility may not have that much historical significance (yet), but it is still fascinating to read what something as small as that can actually do and contribute to the body of knowledge. Most of the new physics that we get today are not done out of large-scale facilities, even those those facilities and their discoveries tend to get a disproportionate amount of publicity.

Zz.

Wednesday, November 07, 2007

New Particle Accelerator To Be Built In Germany

Without much fanfare, and without much fuss, a new particle accelerator will be built in Germany. Named the Facility for Antiproton and Ion Research (FAIR), it will cost a total of $1.7 billion.

One of its goals is to try and recreate the conditions during the Big Bang.

"This laboratory will be recreating a mini version of the Big Bang," Horst Stöcker, scientific director of the German Society for Heavy Ion Research (GSI), which will oversee the facility, told the news agency DPA. "The substance we will be making resembles that in the first microseconds of the Big Bang, when it was a million times hotter than the center of the sun. We're talking a million times 10 million degrees Celsius."


How will this new accelerator differ than the LHC being constructed at CERN?

The project differs from the massive new particle accelerator currently nearing completion at CERN near Geneva in Switzerland in that it will focus more on the intensity of its particle beam rather than on the speed achieved. The CERN project, which hopes to begin experiments in 2008, hopes to find subatomic particles and antiparticles to help provide evidence backing up string theory.


I wish the process in building the International Linear Collider (ILC) is as unfussy as this. Unfortunately, with a $10 billion price tag, the ILC is naturally more complicated and more involved.

Zz.

Tacoma Narrows Bridge Is Falling Down

So I'm sure everyone has seen the video footage of the infamous Tacoma Narrows Bridge collapse. It became a case study of engineering design, and also a lesson in my physics classes.

This news article describes the detailed event leading up to that collapse, involving a few people who were present right before the historical event. While there were no human fatalities, the incident did kill Tubby, a pet dog who was stuck in one of the vehicles left on the bridge that day.

Zz.

Tuesday, November 06, 2007

Another Physics of Golf Swing

Wow! This seems to be a popular topic.

I highlighted a website a while back that describes in painful detail the physics of a golf swing. Turns out there's another person, a professor at Yale, who also has a description on the physics of a golf swing.

Would be interesting to compare the two approaches.

Zz.

Pencil + Sticky Tape = Desktop Supercollider + Post-Silicon Processors

OK, so the title is a bit of an exaggeration, but still, the article is rather entertaining to read. It is an article on how some of the most common objects and material that we see can, in fact, be some of the most exotic and could reveal something more fundamental about our world. It is more about the hottest compound in condensed matter/material science right now - graphene.

You can read for yourself why this material is such a hot area of research currently, but pay attention to the end of the article.

Geim and his co-workers suggest one such. Normal electrons can tunnel through potential barriers: as the barriers get higher the tunnelling becomes exponentially less likely to happen. Yet theory suggests that at very high speeds and with very high barriers, electrons will start to find it easier to get across as the barriers get taller. This is called the Klein Paradox, and demonstrating it in the universe outside graphene would need the sort of conditions you find close to an exotically heavy nucleus or, if you're particularly keen, a black hole. In graphene, you may be able to recreate an appropriate barrier with an ordinary semiconductor junction: there's talk of desktop super-colliders.

Other areas that graphene may illuminate include direct observation for the first time of relativistic electrons generating their own anti-particles – and there are even suggestions that some aspects of string theory, long thought to lie well beyond practical observation, may become testable.


And this shouldn't surprise anyone, especially if you're read my take on the physics that we learned from condensed matter. Many condensed matter systems can become the "testbed" of some of the most complex and exotic theories of nature.

Zz.

Monday, November 05, 2007

Sci-fi Meets Sci-fact

If you are in Tempe, Arizona on Nov. 8th, you might want to attend this at the campus of Arizona State University. Renowned physics Lawrence Krauss will talk about the physics of Star Trek and other sci-fi fantansies. Krauss, as I'm sure you know, wrote the book on the physics of Star Trek. So this should be fun.

Zz.

Wonders of Physics at Asheville, NC

I mentioned earlier about the Wonders of Physics show that first started at the University of Wisconsin-Madison. The "road show" version is coming to Asheville, NC on Nov. 12. While the show is free, you need to make a reservation.

So if you're in the area, you might seriously want to consider attending this. It'll be a memorable show.

Zz.

The Kondo Effect

I was 'trolling' around the 'net looking for a few articles when I came across this article on the Kondo effect. This is where the resistivity of a certain type metal, as you lower the temperature, suddenly shoots up, which is not what is expected. This phenomenon was discovered in the 1930's, and was explained by Jun Kondo in the 1960's.

What is fascinating here is that this is, as far as I know, the first example of an "asymptotic freedom" in nature that was discovered. This, of course, was waaaaay before the same type of description was applied to the strong interaction in elementary particles. It reinforces my view earlier that there are many aspects of condensed matter physics that actually are extremely important and "fundamental". Peter Higgs, in fact, clearly confesses to getting his idea about the Higgs mechanism out of condensed matter. So these are just a few of the examples where this field actually has a huge and significant contribution to fundamental knowledge. It isn't just an "applied physics" field, even though it is responsible for the understanding of properties of materials that we use.

I just wish many students that are going "ga-ga" over String theory and particle physics would realize this.

Zz.

Sunday, November 04, 2007

Forum on Physics and Society Newsletter

The Oct. 2007 issue of Forum on Physics and Society newsletter is now available online.

Table of Contest:

News of the Forum

* Upcoming Forum Election
* Forum Short Course on Physics of Sustainable Energy
* Deadline Approaching for AIP State Dept. Fellowship

Articles

* What Are Nuclear Weapons For? Michael May
* What are Nuclear Weapons For? John S. Foster, Jr. and Keith B. Payne
* Nuclear Fuel Banks: A View From the South Fernando de Souza-Barros
* The Origins of CAFE Allan R. Hoffman
* The CAFE Formula, David Hafemeister
* Sputnik – 50 Years Later Alan J. Scott

Commentary

* Three Inconvenient Truths, Robert Ehrlich

Reviews

* Out of the Shadows: Contributions of Twentieth-Century Women to Physics, Edited by Nina Byers and Gary Williams, reviewed by Marty Epstein
* God: The Failed Hypothesis—How Science Shows That God Does Not Exist, By Victor J. Stenger, reviewed by Lawrence S. Lerner
* The God Delusion by Richard Dawkins, reviewed by Richard Wiener


Zz.

Saturday, November 03, 2007

Scientists Taking Next DUSEL Step

The plan to build the underground lab at the Homestake mine is progressing.

In July, the National Science Foundation chose Homestake as the site for a proposed Deep Underground Science and Engineering Laboratory. Now, scientists and engineers are designing the proposed lab. "This meeting this weekend is crucial in putting together the initial suite of experiments," physicist Kevin Lesko of the University of California at Berkeley said.


Still, that thing about the water still rising is a bit disconcerting.

The South Dakota science authority re-entered the mine in July, and crews are slowly working their way down the 5,000-foot Ross Shaft to install pumps to remove the water that has been filling the mine since it was sealed shut in 2003.

Dave Snyder, executive director of the science authority, told scientists Friday that water had risen from the bottom of the mine, 8,000 feet underground, to 4,996 feet underground "as of an hour ago."

If water reaches the 4,850-foot level, South Dakota's plan for a Sanford Laboratory will be more expensive, but Snyder said the water had risen only 4 feet since July 27. He estimated the water would not reach "the 4850" until February, and crews are working double shifts to start pumping before then.


I can already see it. One of the safety courses[1] all workers have to take before working there will be on how to swim! :)

Zz.

[1] If you have worked in a US Nat'l Lab, then you'll know that you have to go through all of these safety classes first, depending on the nature of your job, before you can start work.

Leonard Susskind Joins Perimeter Institute

Another big coup for the Perimeter Institute. Renowned theorist Leonard Susskind has joined its faculty.

They continue to attract well-known physicists over there. Nice job!

Zz.

Friday, November 02, 2007

Snake Oil Science: The Truth About Complementary and Alternative Medicine

Want something to read over the holidays while you try to get away from annoying relatives? Try this one: "Snake Oil Science: The Truth About Complementary and Alternative Medicine", by R. Barker Bausell (Oxford Univ. Nov. 2007)

Bausell’s casual writing style and dry wit produce a lively but scientifically sound, well-documented work that objective readers should find informative. A good companion to Robert Park’s Voodoo Science: The Road from Foolishness to Fraud, it is highly recommended for public and medical libraries.


So along with Bob Park and Richard Dawkins, scientists are certainly on the offensive at all of these pseudosciences that till now seem to be having their honeymoon seducing the public. It's about time too!

Zz.

Experimental Evidence for Quantum Spin Hall Effect

A new report published in Science this week presents compelling evidence that verify the existence of the quantum spin Hall effect[1]. It appears that they have achieved something similar to a "dissipationless flow" of the spin current.

This is touted as being a crucial step in spintronics.

Zz.

[1] M. König et al, Science v.318, p.766 (2007).

Citizen Science

This is a very timely article by Robert Crease of Stony Brook. He highlights two different college courses (they're more like projects), one at Stony Brook itself while the other at Columbia University, on efforts to introduce and educate students on science, regardless of their majors and specialties.

He clearly stated the exactly difficulty in trying to accomplish such a mission:

On the one hand, they must incorporate a significant amount of mathematics and scientific knowledge if they are to be effective in teaching the science relevant to the modern world. On the other hand, they must appeal to students with little or no background in maths and science.

This clash usually dooms such courses. If they weaken the science and maths component, they become more about science than genuine science courses — versions of what is often pejoratively called "physics for poets". If they do not weaken it, they risk being too intimidating and difficult for the target audience.


As I've said in another blog post, there is a distinct different between studying physics, and studying ABOUT physics. One doesn't actually get the feel for what physics is if one doesn't actually study physics itself.

The first of these efforts in teaching science to the masses is from Columbia University:

Columbia University's "frontiers of science" course is compulsory for all first-year undergraduates. It is part of the core curriculum, which aims to give each student "a rigorous preparation for life as an intelligent citizen in today's complex and changing world".

"Frontiers of science" is Columbia's largest single course. Once a week, students attend a one-and-a-half-hour lecture and a two-hour seminar. The lecture is given in the university's theatre, where the 560 or so students fill the orchestra pit and spill onto the balcony. The seminars are smaller, consisting of groups of 20 students each, and taught by professors and postdocs selected following an international search.


The other is from Stony Brook University:

Meanwhile, Stony Brook University runs an "introduction to experimental research" course that takes a different tack. It takes place in the Nuclear Structure Laboratory in the basement of Stony Brook's Van de Graaff building among dozens of scintillation counters and the infrastructure for monitoring them that is associated with a project called Mariachi (Mixed Apparatus for Radar Investigation of Atmospheric Cosmic-Rays of High Ionization). The course has no formal lectures or seminars, but instead thrusts its dozen students almost immediately into selfdesigned research projects to detect and study cosmic rays.
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The beauty of the course is that, while cosmic rays are scientifically interesting because they provide clues to the origin and structure of the universe, they allow important research can be carried out without using much maths. This allows Marx to get students and teachers with a range of backgrounds involved in a scientifically viable project with significant connections to wider scientific issues in cosmology. Even physics students like it because it is a lab course much less micromanaged than most; students develop their own projects rather than being told exactly what to do.


I think I would gravitate more towards the Stony Brook project (but then again, I'm bias since I'm an experimentalist). I think there's nothing better than having students to actually have to do things and measure things. It is a more direct and transparent study of how nature behaves, rather than simply listening to what someone has to say.

Still, these are commendable efforts in educating the public (in this case, students who need not necessarily go into science) in science. It adds to the previous two efforts that are being done at other universities in this regard (Physics for Future Presidents and the course New Mexico State University).

Zz.

Thursday, November 01, 2007

Dr. Atomic at Lyric Opera of Chicago

Doctor Atomic will be performed at the Lyric Opera of Chicago from Dec. 14, 2007 through Jan. 19, 2008. This is a critically-acclaimed opera based on the events surrounding the first detonation of the atomic bomb at Los Alamos in New Mexico.

Not into opera, you say? Well, look at it this way, at least it is in English! :)

Zz.

MOG Trumps Dark Matter?

First we had MOND. Then came the observation from the Bullet cluster that puts MOND into trouble and give further support to Dark Matter. Now along comes MOG (link may be open for free only for a limited time), as reported in today's Science daily news update.

In a paper published online 25 October in the Monthly Notices of the Royal Astronomical Society, Moffat and co-author and Perimeter Institute colleague Joel Brownstein argue that their modified theory of gravity, which they call MOG, can also explain the Bullet cluster discrepancy. Einstein argued that gravity arises because mass warps space and time--he even came up with an equation for how the warping works. Moffat says he added "minimal" additional terms to Einstein's equation that subtly change how gravity behaves on galactic scales. The upshot is that gravity is stronger at these scales than Einstein predicted and that MOG can explain the gravity of the Bullet cluster without dark matter. Brownstein says he and Moffat have applied MOG to the behavior of more than 100 galaxies and more than 100 clusters, and in all cases, it has successfully predicted their motions "without the necessity of adding dark matter."


Of course, many astrophysicists are not convinced, so we will just have to wait and see how this turns out, especially with more and more observations being planned. Even the LHC will come into play at the search for the possible dark matter candidates.

Zz.