Wednesday, March 31, 2010

Meet Copernicium

A rather fun article in the LA Times today on the newest member of the periodic table - element 112, copernicium (Cn).

Copernicium, a heavier relative of zinc, cadmium and mercury, was first seen in 1996 by researchers at the Society for Heavy Ions Research in Darmstadt, Germany, after they bombarded a lead target with zinc ions.

It took the International Union of Pure and Applied Chemistry, which regulates nomenclature, nearly 14 years to resolve disputes between the Germans and American researchers over who was first to produce the new element, but the agency reported in the March issue of the journal Pure and Applied Chemistry that the Germans had priority and are thus entitled to propose a name.


But what made the article "fun" was all the background info on the last few named elements that made it into the periodic table, and also the still-unresolved claims of other discoveries.

Zz.

Tuesday, March 30, 2010

LHC Achives 7 TeV Collisions

Congratulations to everyone who has worked so hard for so long, especially those involved directly with the LHC accelerator/beam/detector hardware. They had a minor hiccup at the beginning, but it is there now.

Here's the latest CERN Press Release:

Geneva, 30 March 2010. Beams collided at 7 TeV in the LHC at 13:06 CEST, marking the start of the LHC research programme. Particle physicists around the world are looking forward to a potentially rich harvest of new physics as the LHC begins its first long run at an energy three and a half times higher than previously achieved at a particle accelerator.

“It’s a great day to be a particle physicist,” said CERN1 Director General Rolf Heuer. “A lot of people have waited a long time for this moment, but their patience and dedication is starting to pay dividends.”

“With these record-shattering collision energies, the LHC experiments are propelled into a vast region to explore, and the hunt begins for dark matter, new forces, new dimensions and the Higgs boson,” said ATLAS collaboration spokesperson, Fabiola Gianotti. “The fact that the experiments have published papers already on the basis of last year’s data bodes very well for this first physics run.”

“We’ve all been impressed with the way the LHC has performed so far,” said Guido Tonelli, spokesperson of the CMS experiment, “and it’s particularly gratifying to see how well our particle detectors are working while our physics teams worldwide are already analysing data. We’ll address soon some of the major puzzles of modern physics like the origin of mass, the grand unification of forces and the presence of abundant dark matter in the universe. I expect very exciting times in front of us.”

"This is the moment we have been waiting and preparing for", said ALICE spokesperson Jürgen Schukraft. "We're very much looking forward to the results from proton collisions, and later this year from lead-ion collisions, to give us new insights into the nature of the strong interaction and the evolution of matter in the early Universe."

“LHCb is ready for physics,” said the experiment’s spokesperson Andrei Golutvin, “we have a great research programme ahead of us exploring the nature of matter-antimatter asymmetry more profoundly than has ever been done before.”

CERN will run the LHC for 18-24 months with the objective of delivering enough data to the experiments to make significant advances across a wide range of physics channels. As soon as they have "re-discovered" the known Standard Model particles, a necessary precursor to looking for new physics, the LHC experiments will start the systematic search for the Higgs boson. With the amount of data expected, called one inverse femtobarn by physicists, the combined analysis of ATLAS and CMS will be able to explore a wide mass range, and there’s even a chance of discovery if the Higgs has a mass near 160 GeV. If it’s much lighter or very heavy, it will be harder to find in this first LHC run.

For supersymmetry, ATLAS and CMS will each have enough data to double today’s sensitivity to certain new discoveries. Experiments today are sensitive to some supersymmetric particles with masses up to 400 GeV. An inverse femtobarn at the LHC pushes the discovery range up to 800 GeV.

“The LHC has a real chance over the next two years of discovering supersymmetric particles,” explained Heuer, “and possibly giving insights into the composition of about a quarter of the Universe.”

Even at the more exotic end of the LHC’s potential discovery spectrum, this LHC run will extend the current reach by a factor of two. LHC experiments will be sensitive to new massive particles indicating the presence of extra dimensions up to masses of 2 TeV, where today’s reach is around 1 TeV.

“Over 2000 graduate students are eagerly awaiting data from the LHC experiments,” said Heuer. “They’re a privileged bunch, set to produce the first theses at the new high-energy frontier.”

Following this run, the LHC will shutdown for routine maintenance, and to complete the repairs and consolidation work needed to reach the LHC’s design energy of 14 TeV following the incident of 19 September 2008. Traditionally, CERN has operated its accelerators on an annual cycle, running for seven to eight months with a four to five month shutdown each year. Being a cryogenic machine operating at very low temperature, the LHC takes about a month to bring up to room temperature and another month to cool down. A four-month shutdown as part of an annual cycle no longer makes sense for such a machine, so CERN has decided to move to a longer cycle with longer periods of operation accompanied by longer shutdown periods when needed.

“Two years of continuous running is a tall order both for the LHC operators and the experiments, but it will be well worth the effort,” said Heuer. “By starting with a long run and concentrating preparations for 14 TeV collisions into a single shutdown, we’re increasing the overall running time over the next three years, making up for lost time and giving the experiments the chance to make their mark.”
Contact

CERN Press Office, press.office@cern.ch
+41 22 767 34 32
+41 22 767 21 41

1.CERN, the European Organization for Nuclear Research, is the world's leading laboratory for particle physics. It has its headquarters in Geneva. At present, its Member States are Austria, Belgium, Bulgaria, the Czech Republic, Denmark, Finland, France, Germany, Greece, Hungary, Italy, Netherlands, Norway, Poland, Portugal, Slovakia, Spain, Sweden, Switzerland and the United Kingdom. India, Israel, Japan, the Russian Federation, the United States of America, Turkey, the European Commission and UNESCO have Observer status.


Zz.

Monday, March 29, 2010

LHC Will Broadcast First 7 TeV Collisions Tomorrow

Don't forget, as I've mentioned earlier, you can get a live webcast of the start of the 7 TeV collision at the LHC tomorrow. Of course, there's no guarantee that they'll get that 7 TeV collision tomorrow itself, so you'll just have to take whatever comes.

Wired has other information on this event.

Zz.

Teaching Physics To Kids (And Dogs)

For the longest time, I resisted myself from making any comments on this. I respect other physicists who spend time and effort trying to educate the public on various aspects of physics. It isn't easy, not just because of the nature of the subject, but because we have to be very careful on what we say and how we say certain things. This is because we can mean one thing when we say it, but the public may understand things in a very different way because of the different "vocabulary" that we some time use. So trying to explain something, or writing a book, on physics is an endeavor that requires a lot of self-exploration and self-evaluation.

I've read a bit of Chad Orzel's book "How to Teach Physics to Your Dog", and I've read many reviews about it. It's a fun book, and I highly recommend it. However, I am a bit uncomfortable with the title of the book, and I will try to explain it here. I only hope the reasons don't become confusing and I end up sounding as if I'm criticizing the book, which is far from my intention.

What do we mean when we try to teach someone something? If I tell you that Newton's 2nd Law says "F=ma", have I taught you anything? If tell you that the largest planet in the solar system is Jupiter, have I taught you anything? To me, teaching means the imparting of knowledge, not simply the imparting of information. There's a difference there. Information can be a series of disconnected, disjointed items, whereas a knowledge is not just information, but how these items connect to each other. In other words, you know not only that "F=ma", but you know what it means, and how to use it. This isn't automatic. Many people know F=ma. In fact, we write it early in our class in intro physics. Yet, give these students a simply projectile problem to do right after you introduce that equation and see how many can use it to solve such a problem. This clearly shows that just because you have that information, it doesn't mean that you have the knowledge of what it is.

So that brings us back to whether you can teach your dog, or your kids, physics. At some level, you can. You can certainly show simple concepts until the kids see a pattern, and they now understand how something behaves. They might even be able to replicate such a thing with other examples. So yes, that would be teaching. But how do you teach kids (and dogs) quantum mechanics, for example? All the pop-science books meant for the public have done it simply by telling the readers the "weird" properties of QM, how a quantum system behaves, and what possible implication it could mean. But these are nothing more than telling someone a series of information. In fact, when done this way, these series of information, more often than not, appear disjointed and disconnected. People learn about the Schrodinger cat, for example, but do not realize that the same principle (superposition) is what makes quantum entanglement so weird. Without that principle, quantum entanglement is no more strange than the classical case of a simple conservation of (angular) momentum. Or would people realize that the Heisenberg Uncertainty Principle isn't really a "principle", or that it is not separate from the wavefunction itself and how we define what we call "observables"? The HUP is almost always automatically there when we deal with the Schrodinger equation wavefunction.

To me, this is not teaching physics. It is teaching ABOUT physics. There's a difference. There is value in teaching about physics, and many pop-science books do a tremendous service to the field by introducing people to it. But it should not be confused with teaching physics. The latter involves imparting knowledge in such a way that the recipient obtains the ability and skill to use and apply the information. I consider being able to use F=ma and solve kinematical problems as a sign that someone has a knowledge of F=ma. In Mary Boas's "Mathematical Methods in the Physical Science", she stated:

To use mathematics effectively in applications, you need not just knowledge, but skill. Skill can be obtained only through practice. You can obtain a certain superficial knowledge of mathematics by listening to lectures, but you cannot obtain skill this way.


And I would apply that to the difference between information and knowledge, physics and about physics, as used in this context. One needs to clearly differentiate the superficial understanding of something versus learning something. This should be done both by the instructor (or author) and the student (or the reader).

There's plenty of worthiness in a book that teaches physics, and a book that teaches ABOUT physics. One can only hope that a reader does not confuse the two.

Zz.

Sunday, March 28, 2010

LaserFest Video Contest

Hey, you could win $1000!

As part of the celebration commemorating 50 years of the laser, the APS is conducting a laser video contest. You can read the rules at the link.

If you are going to submit, or have submitted, a video, post a comment on here and a link if you wish. I'll try to highlight it so that you'll get extra audience! Remember, the deadline is May 16, 2010,

Zz.

Friday, March 26, 2010

LHC Live Webcast

If you have nothing to do on March 30, here's something you can look at for when the LHC is scheduled to have its first ever 7 TeV collision. The LHC will webcast the event, including live feed from the control rooms of all the major detectors.

If everything goes well, don't expect any "fireworks". Experimental physics typically is boring to look at, because nothing physics happens most of the time, unexpected explosion notwithstanding. :)

Zz.

Thursday, March 25, 2010

Chemistry Set For Word

Ooooh.. now this could be utterly useful. Microsoft has released a free add-on to Word that can chemical formulas and chemical images into Word documents.

The software maker said on Wednesday that it is releasing an add-on for the word processor that makes it easier to include labels, formulas, and chemical images into documents. Chem4Word, as the add-on is known, was introduced on Wednesday at the spring meeting of the American Chemical Society.


This isn't useful only in Chemistry. It should be useful for people in material science/condensed matter, as well as many others. I will have to check this out and see how easy it is to use. Now, it would be a lot more useful if it can also convert it to the appropriate HTML code...

Zz.

NAS Criticized For Hosting Templeton Prize Award

This is rather puzzling to me as well. The prestigious US National Academy of Sciences has agreed to host the award for the Templeton Prize. However, many scientists think this is a mistake.

"For the National Academy of Sciences to get involved with an organisation like this is dangerous," said Sir Harry Kroto, a British scientist who won the Nobel prize for chemistry in 1996 and later joined Florida State University.

"The National Academy should look very carefully at what the majority of its members feel about the apparent legitimising of the scientific credentials of the Templeton Foundation." he said.


This is certainly a strange decision. The NAS responded with this rather feeble response.

The NAS said it agreed to host the event because the winner was an NAS member. Sean Carroll, a physicist at California Institute of Technology, said: "Templeton has a fairly overt agenda that some scientists are comfortable with, but very many are not. In my opinion, for a prestigious scientific organisation to work with them sends the wrong message."


That makes very little sense. If a member of the NAS gets awarded with other strange awards, say the Discovery Institute want to award a member with the promotion of intelligent design, does that mean that the NAS would also host such a ceremony simply because the winner is an NAS member? I wouldn't think so.

I have a lot of respect for the NAS (even though many people think it is a little above a popularity club), but this decision by them is a head-scratcher.

Zz.

Wednesday, March 24, 2010

Culinary Physics Coming to Harvard

It was only a couple of days ago that I pointed to an article on the Physics of Cooking. Now comes a news report that avant-garde chef Ferran Adrià will be joining other chefs in teaching a course in gastronomy physics at Harvard.

Over 13 weeks, Andrés and Adrià will teach multiple times, while such renowned chefs as Blue Hill's Dan Barber and another Michelin-starred chef from Spain, Joan Roca, will appear once. Students will attend chef demonstrations, physics lectures and labs that explain the structure and characteristics of a classic emulsion (a liquid dispersed into another liquid) and more recent inventions such as Adrià's famous foams (air bubbles surrounded by thin sheets of fluid).

With a greater understanding of the physical parameters of food, students will learn how to manipulate them. Ditto for the chefs. Much of the culinary invention in recent decades has been a result of trial and error rather than scientific research. Adrià is reported to have invented the foam after a friend gave him a canister of nitrous oxide with which to experiment. Andrés developed a hot and cold foie gras soup at Minibar not because he knew that liquids at different temperatures have different densities (he learned that later) but because he had seen the technique used in Irish coffee.


I've seen Adria at his restaurant in one of the episodes of "Bizarre Foods" on the Travel Channel. While there certainly is a lot of creativity (and science) involved in his food preparation and presentation, I must say that I kinda like my food to be more "natural" rather than processed that much. I can understand the foam and the various nifty sauces to enhance the food, but when it has been transformed that much, it no longer becomes that appealing to me. Of course, I'm sure these things are wonderfully delicious, but I guess that my preference has always been the non-pretentious ethnic and simpler ma-and-pa type of cuisine.

It will be interesting if Harvard would put video of these courses online.

Zz.

Tuesday, March 23, 2010

CERN Sets Date For First Attempt At 7 TeV Collisions in the LHC

Press release from CERN:

CERN sets date for first attempt at 7 TeV collisions in the LHC

Geneva, 23 March 2010. With beams routinely circulating in the Large Hadron Collider at 3.5 TeV, the highest energy yet achieved in a particle accelerator, CERN has set the date for the start of the LHC research programme. The first attempt for collisions at 7 TeV (3.5 TeV per beam) is scheduled for 30 March.

“With two beams at 3.5 TeV, we’re on the verge of launching the LHC physics programme,” explained CERN’s Director for Accelerators and Technology, Steve Myers. “But we’ve still got a lot of work to do before collisions. Just lining the beams up is a challenge in itself: it’s a bit like firing needles across the Atlantic and getting them to collide half way.”

Between now and 30 March, the LHC team will be working with 3.5 TeV beams to commission the beam control systems and the systems that protect the particle detectors from stray particles. All these systems must be fully commissioned before collisions can begin.

“The LHC is not a turnkey machine,” said CERN Director General Rolf Heuer. “The machine is working well, but we’re still very much in a commissioning phase and we have to recognize that the first attempt to collide is precisely that. It may take hours or even days to get collisions.”

The last time CERN switched on a major new research machine, the Large Electron Positron collider, LEP, in 1989 it took three days from the first attempt to collide beams to the first recorded collisions.

The current LHC run began on 20 November 2009, with the first circulating beam at 0.45 TeV. Milestones were quick to follow, with twin circulating beams established by 23 November and a world record beam energy of 1.18 TeV being set on 30 November. By the time the LHC switched off for 2009 on 16 December, another record had been set with collisions recorded at 2.36 TeV and significant quantities of data recorded. Over the 2009 part of the run, each of the LHC’s four major experiments, ALICE, ATLAS, CMS and LHCb recorded over a million particle collisions, which were distributed smoothly for analysis around the world on the LHC computing grid. The first physics papers were soon to follow. After a short technical stop, beams were again circulating on 28 February 2010, and the first acceleration to 3.5 TeV was on 19 March.

Once 7 TeV collisions have been established, the plan is to run continuously for a period of 18-24 months, with a short technical stop at the end of 2010. This will bring enough data across all the potential discovery areas to firmly establish the LHC as the world’s foremost facility for high-energy particle physics.


Crossing fingers!

Zz.

Evolution and Earth's Entropy

A nice short paper on evolution and the earth's entropy. Here, the author estimated the difference in entropy of the earth between day and night.

Abstract: Entropy decreases on the Earth due to day/night temperature differences. This decrease exceeds the decrease in entropy on the Earth related to evolution by many orders of magnitude. Claims by creationists that science is somehow inconsistent with regard to evolution are thus show to be baseless.

It also strengthen the earlier arguments on this topic that I highlighted already. The moral of the story is that, if one understands physics (in this case, the 2nd Law of Thermodynamics) only SUPERFICIALLY, one can make many silly mistakes with it! This is why I dislike what Deepak Chopra is doing.

Zz.

Chopra Versus Shermer at CalTech and on Nightline - Follow-up

If you didn't read the earlier entry on the debate between Deepak Chopra and Michael Shermer at CalTech, you might want to catch up first.

One of my argument against Chopra is that he's using merely a superficial understanding of QM and applying it to where it doesn't belong or hasn't been shown to be valid. In fact, in that earlier article, he even agreed to get a lesson in QM by a theorist in the audience. Unfortunately, even with his admission that he doesn't know QM, it doesn't stop him from continuing with his ignorant "use" of it.

It appears that he has blog a rebuttal to that debate. And sadly, it continues to propagate the same faulty understanding of QM. His usage of the HUP is, to put it mildly, is very pedestrian.

It would be consistent with common sense if these particles, and the subatomic particles that they can be broken down into, were solid and stable in spacetime. But they aren't. Thanks to two breakthrough ideas -- the Uncertainty Principle and the Observer Effect -- nothing in Nature can be seen as solid and fixed in spacetime. The Uncertainty Principle says, in its simplest terms, that you cannot know the position of a particle and its momentum at the same time. The observer effect says that particles are only a superposition of possibility waves until a non-material observer causes them to collapse from one state, a wave, into another, a particle.

Already I can see readers glazing over, but these are important points for the existence of God and also for our existence. All solid objects exist, in essence, as invisible waves that extend infinitely in all directions. When an observer enters the picture, the wave collapses into a point, and that point is a spacetime event -- or a particle -- that you can measure. So it turns out that looking at a virtual electron (waves) causes it to appear as an actual electron (particle).


This, of course, isn't correct, because the HUP doesn't say anything about the accuracy of one single measurement of the position and one single measurement of the momentum. This is a common misconception of the HUP.

But the amusement doesn't stop there. He then tried to argue that quantum effects can be extended to "large" scale.

On the side of materialism, Shermer and many others say no. Quantum behavior, or as Shermer calls it "Quantum weirdness," is confined to the microscopic world. It doesn't leak into the macroscopic world of rocks, trees, clouds -- and the moon. But there are three weaknesses in this argument:

1. Recent discoveries have produced quantum weirdness on the macroscopic level. See this article about "supersizing" quantum mechanics

2. Quantum physics is behind all kinds of technologies used in the big everyday world: transistors, superconductors, experiments with superfluids. There are even cutting-edge experiments with time travel and teleportation, very Star Trek, although so far the results are on the level of light beams, not Scottie and Captain Kirk.

3. Most crucial of all, if you don't allow quantum phenomenon to interact with the big world, you run into a huge problem with physics itself. Quantum physics is the basis of our macroscopic physical world, so there has to be an interaction, even if that interaction is not fully understood.


Let's tackle this one at a time, shall we?

1. Look at the amazing set of conditions that a system HAS TO BE PUT UNDER for the quantum effects to show up. It has to be cooled down to ridiculously low temperatures, it is completely isolated from the environment, etc.. etc. In other words, it is NOT EASY to observe quantum effects in progressively larger and larger systems! Why? Because thermal noises and interactions with the environment can easily destroy the coherence of the quantum effects! He cited the news reports of such a thing, but he did not understand the physics, nor the experiment, on how we were able to observe such a thing. It is another clear example of my claim that he and his minions only know QM superficially, but still have no qualms and "using" it without any fundamental understanding.

2. This is right, QM is the physics behind devices, etc. However, these devices rely macroscopic behavior of the system. We measure not "electrons" directly, but current, let's say, which is a macroscopic measurement. In fact, one can safely say that the physical quantities that we measure, such as position, momentum, energy, etc, are ALL classical properties, because they require the system to interact not only with a macroscopic device, but also because we measure a LARGE NUMBER of them. Those devices do not make use of ONE particle, but rather a huge number of them. Any student who has done any amount of basic QM in school can see that when we average out a large number of system, the system approaches the familiar classical behavior (ref: harmonic oscillator). So while the microscopic description of the behavior of the system is quantum mechanical, the physical behavior of the devices above is purely classical (you don't see your semiconductor in your computer appearing in several locations simultaneously, do you?)

3. If the interaction of QM with the macroscopic world is not fully understood, then why in heck is a Deepak Chopra already using it? The problem here is that we KNOW that the classical world is different than the quantum world. You NEVER see a soccer ball appearing in different locations simultaneously. You NEVER see the macroscopic effect of quantum entanglement. So we KNOW these two are different. How different they are, and how QM can merge into such differences is the question that continues to be studied. It means that anyone making use of QM into a realm where we still don't fully understand is making an utterly speculative proposition.

It is ironic that he's using QM to support his crackpottery without even giving one second of consideration that QM has plenty of experimental evidence, while he has none. Again, it comes back to what I was saying earlier, than lacking direct experimental evidence to support his view, he simply piggy-back onto a well-established physics and say, hey, if it works there, it should work here as well, and left it at that without providing any evidence. This is what happens when one understands QM superficially without any clear view of the basic formalism of QM. As I've mentioned earlier, when they only see the philosophical implication of it and see all these "strangeness" appearing out of nowhere, they seem to think that anything goes and things can be invented freely.

I sometime wish that they leave our physics alone and invent their own silly theory of the world to back up their claims.

Zz.

Monday, March 22, 2010

Lasing With Electrons

This is a good brief article on the history and development of the free-electron laser. I think you also get free access to the relevant historical papers being highlighted here. You also get an overview of what they're doing at the LCLS.

The thing that should be pointed out here is that, while they share the same name, i.e. "laser", the regular laser and these free-electron lasers are not under the same domain of study. Regular lasers might fall under atomic/molecular physics, or even solid state physics, whereas free-electron laser falls under accelerator physics because it deals with high energy electron beam and various accelerator structures.

Zz.

The Physics of Cooking

Anyone following this blog for any considerable period of time would know that I like to cook - or, let's say, that it is a hobby. I mentioned a long time ago how I learn how to bake bread when I was preparing for my oral comprehensive exam in graduate school.

Now, while I do apply a bit of physics in my cooking, such as knowing that a denser concoction will take more time to heat through than something looser, I certainly don't pay as much attention to it as this author. He's describing the various physics that is involved in cooking, such at the various types of heat transfer.

A stove's burner supplies energy to a pan via conduction - i.e. two surfaces in contact. But here I'm more interested in what's happening inside the pan.

The bottom of the pan is made hot. So liquid at the bottom gets hot enough that it begins to evaporate, forming small bubbles.

When the bubbles get large enough, they peel off the bottom of the pan. Being less dense than the liquid around them, the bubbles float to the surface.

Finally, and less noticeably, some liquid at the surface is cooler than its surroundings, so it in turn sinks. This process is what we call convection.


Yeah, but Hamburger Helper???!! :)

Zz.

Saturday, March 20, 2010

National Lab Day

In case you haven't seen this yet, there's an ongoing effort to get students to learn about science by "doing" things. This includes everything from demonstrations, doing stuff in a lab, computer simulation, or visiting places. The project is called the National Lab Day here in the US.

While May 12, 2010 will be called the National Lab Day, the project has been going on for a while now this year. There are already teachers in schools seeking assistance for various aspects of their projects. If you are a teacher, this is the place to seek assistance with your various science education efforts. If you're a student and your science teacher hasn't seen this, show it to him/her. If you are a scientist/engineer, they need you to volunteer your time and/or expertise. Some of these may even be in your community.

It's a good way to get kids to not only be interested in science, but to have them learn from doing or observing something, rather than just reading books and listening in class.

Zz.

Friday, March 19, 2010

New Revolutions in Particle Physics - Part 10

The latest video on this series of lecture by Leonard Susskind is now online. I've updated the original blog entry that has all of these videos. You can find all 10 of them (so far) at one place.

Zz.

Thursday, March 18, 2010

Patterns, Correlates, and Reduction of Homework Copying

Holy Cow! I had WAAAAY too much fun read this paper!

This paper examines the behavior of students in a physics class at MIT, especially how much homework copying was down, and the impact on the exam results[1]. It is very fascinating.

Abstract:Submissions to an online homework tutor were analyzed to determine whether they were copied. The fraction of copied submissions increased rapidly over the semester, as each weekly deadline approached and for problems later in each assignment. The majority of students, who copied less than 10% of their problems, worked steadily over the three days prior to the deadline, whereas repetitive copiers (those who copied >30% of their submitted problems) exerted little effort early. Importantly, copying homework problems that require an analytic answer correlates with a 2(σ) decline over the semester in relative score for similar problems on exams but does not significantly correlate with the amount of conceptual learning as measured by pretesting and post-testing. An anonymous survey containing questions used in many previous studies of self-reported academic dishonesty showed ∼1/3 less copying than actually was detected. The observed patterns of copying, free response questions on the survey, and interview data suggest that time pressure on students who do not start their homework in a timely fashion is the proximate cause of copying. Several measures of initial ability in math or physics correlated with copying weakly or not at all. Changes in course format and instructional practices that previous self-reported academic dishonesty surveys and/or the observed copying patterns suggested would reduce copying have been accompanied by more than a factor of 4 reduction of copying from ∼11% of all electronic problems to less than 3%. As expected (since repetitive copiers have approximately three times the chance of failing), this was accompanied by a reduction in the overall course failure rate. Survey results indicate that students copy almost twice as much written homework as online homework and show that students nationally admit to more academic dishonesty than MIT students.

The impact on the exam results is very interesting. Students who copied more than 30% of their homework shows poorer performance in the exams. This is not surprising for many of us who have taught such subjects. I'm sure many of us have had suspicions on why a question that is similar to the one that the students have done correctly in a homework assignment, still can't be answered correctly.

But what made me laughed out loud was this passage in the paper:

Briefly, we found that students commit about 50% more copying than they self-reported on the self-reported survey. We showed that actual copying from both 2003 and 2005 data correlated with demographic factors: being male and being a business major as found in previous self-reported dishonesty surveys. Since our freshmen had not declared a major when they took the survey, we showed that copying is a leading indicator of becoming a business major.


This is hysterical, if somewhat sad. I wonder if this is a root cause of our economic debacle? :)

Zz.

[1] D.J. Palazzo et al., Phys. Rev. ST Phys. Educ. Res. v.6, p.010104 (2010).

Micron Size Quantum Object

An amazing feat of accomplishment here in this experiment. A group at UC-Santa Barbara has made a quantum oscillator the size of a 0.0002 millimeter-square wafer[1]. You can read a review of this work at Wired Science.

The mechanical object used in the experiment, published March 17 in Nature and led by Cleland and fellow UCSB physicists John Martinis and Aaron O’Connell, is a 0.0002 millimeter-square wafer of quartzlike material bracketed by metal plates. The wafer is a piezoelectric resonator, expanding and contracting in response to electrical voltages at a precise, extremely high frequency. Cleland likened its expansion and contraction to the inflation and deflation of a balloon.

The quantum device is a qubit, a term that generically refers to a kind of quantum transistor being used for quantum computation, in this case made from an ultrathin aluminum-based superconductor. At extremely cold temperatures, it goes quantum: It exists in an oscillating waveform spanning an excited state, an unexcited state, or both simultaneously, all controlled by electrical currents.


So we are beginning to see larger and larger sizes of objects exhibiting clear quantum mechanical behavior. However, note that, even though by quantum standards, these are "large" objects, they are still minuscule by our everyday scale. Yet, look at all the trouble they have to go through to be able to make such a size behave quantum mechanically. The cooling process to get it into its lowest quantum state is not trivial. We have to do that so that we CAN detect clearly the quantum behavior. It is not that easy to detect such behavior for large objects, and think of how difficult it is to detect quantum behavior from an object the size of a ping pong ball!

The points in all of this is that, to see quantum behavior in macroscopic objects at the macroscopic scale, one has to put the system into a very spacial situation. It makes it extremely difficult to see quantum effects at such a scale. This is one important point that pseudoscientists and crackpots have overlooked when they bastardize quantum mechanics. People like Deepak Chopra and The Secret used QM to justify their beliefs, but they somehow missed the fact that at the macro scale, the quantum effects predominantly unobservable. We continue to make baby steps at constructing larger and larger system that can exhibit quantum behavior, but these systems are very difficult to construct and requires a lot of "hoops" to jump through. So to declare that some human behavior or human consciousness can be described via a principle that can be explained using quantum mechanics is totally unjustified and unverified. It has no empirical basis at all.

Zz.

[1] A. D. O’Connell et al., Nature advance online publication 17 March 2010 (exact reference will be posted when it is published).

Wednesday, March 17, 2010

Economics and Econophysics

In an earlier blog entry, I pointed to an essay that argues why economics will never be like physics, no matter how much it tries to assimilate concepts and mathematical models of physics. Now comes an article in the latest issue of Am. J. Phys. that argues that even in two areas of study that deals with the economy, even they are not like each other. Christophe Schinckus of the University of Quebec argues in an opinion piece on why the fields of econophysics is a rather completely separate field of study that economics[1].

Are econophysics and economics complementary fields or totally separated disciplines? In this paper I argue that econophysics is not a subfield of economics, and these two fields are separate disciplines.

There are two kinds of gaps between economics and econophysics. The methodological gap refers to a way of doing science. Although economists base their work on a priori methodology, econophycisists use a data-driven methodology. The other gap concerns the way they think about reality. Econophycisists and economists do not see the world in the same way.

In contrast to econophysics, economics is not an empirical discipline. Even if there are debates about the empirical dimension of economics, the empirical dimension in economics is exaggerated. According to econophysicists, complexity studies need an empirical basis. “The real empirical data are certainly at the core of this whole enterprise econophysics and the models are built around it, rather than some non-existent, ideal market as in economics.” This empirical dimension is frequently mentioned in econophysical research and is often presented as the main difference with economics.


Well, there ya go. If economics is not even similar to a field of study in physics that also deals with the same subject matter, then it is even further away from other fields of physics. There are some who don't even think it is a science.

Zz.

[1] C. Schinckus, Am. J. Phys. v.78, p.325 (2010).

Abusing Albert Einstein

I'm glad that there are writers like Tom Chivers of the UK's Telegraph. There need to be someone who points out the stupidity in things like what he's highlighting in this article. In it, he's pointing to the recent book on the supposed "scientific case" for ESP where the authors used Einstein's quotes and possibly his physics to justify ESP.

But when a genuine hero of science has his consoling words to a bereaved woman twisted to make it sound like he believes what in a family newspaper I can only describe as “claptrap”, I think we should object. Make up your own nonsense, Ms Hennacy Powell, and stop dancing on the grave of a great man.


As with Deepak Chopra, it is amazing how people who do not understand physics can somehow bastardize parts of it to justify a pseudoscience. For some odd reason, they can't generate their own validity, because the lack proper empirical evidence. So instead, they latch onto established physics as "justification" that what they believe is valid because physics says it's possible. This of course, is completely bogus. The Standard Model says that the Higgs should be there. Now even when the Standard Model has been successful so many times, we still just simply don't take its word for it, and we still want to be able to detect these Higgs bosons. That's why we have the LHC. We simply don't accept it via "induction". There must be convincing empirical evidence that the Higgs is there.

Now why these people who piggy-back onto various aspects of physics cannot see this, I have no idea. I suppose if you only cherry-pick various superficial ideas in physics, you miss all the important details. And they hope that the rest of the public will miss them as well. More often than not, the public does!

Zz.

A Search for the Mpemba Effect: When Hot Water Freezes Faster Than Cold Water

I've mentioned before that when I got into physics, I didn't have some grandiose idea about solving the problems of the universe. I got into physics because I was curious about some of the apparently simplest observations around me. This is why I continue to be fascinated by this Mpemba effect.

I reported this a while back regarding both the theoretical and experimental observation of this effect. It appears that this effect is still being studied and remains a curiosity for others as well. A preprint appeared today on ArXiv detailing a "search" for this effect.

Abstract: An explanation for why hot water will sometime freeze more rapidly than cold water is offered. Two specimens of water from the same source will often have different spontaneous freezing temperatures; that is, the temperature at which freezing begins. When both specimens supercool and the spontaneous freezing temperature of the hot water is higher than that of the cold water, then the hot water will usually freeze first, if all other conditions are equal and remain so during cooling. The probability that the hot water will freeze first if it has the higher spontaneous freezing temperature will be larger for a larger difference in spontaneous freezing temperature. Heating the water may lower, raise or not change the spontaneous freezing temperature. The keys to observing hot water freezing before cold water are supercooling the water and having a significant difference in the spontaneous freezing temperature of the two water specimens. We observed hot water freezing before cold water 28 times in 28 attempts under the conditions described here.

There ya go! This effect certainly has a lot of legs!

Zz.

Edit 12/20/2010: This article has been published in AJP. The exact reference is:
J.D. Brownridge Am. J. Phys. v.79, p.78 (2011).

Tuesday, March 16, 2010

The Physics of Fundamental Constants

I've always found papers that collect many of the different resources, information, and references into one coherent publication to be extremely useful. This is one such paper.

P.J. Mohr and D.B. Newell, "The physics of fundamental constants", Am. J. Phys. v.78, p.338 (2010).

Abstract: This Resource Letter provides a guide to the literature on the physics of fundamental constants and their values as determined within the International System of Units (SI). Journal articles, books, and websites that provide relevant information are surveyed. Literature on redefining the SI in terms of exact values of fundamental constants is also included.

The authors included discussions on the various major fundamental constants, how each one was determined, and a list of references! The latter is the one I appreciate the most, because it tells you how these things came about in greater detail. If you don't have the patience to follow the CODATA report, this is the next best thing.

Zz.

Chopra Versus Shermer at CalTech and on Nightline

Oh, what I would give to be in the audience for this one...

Nightline filmed a two and half hour debate between True/Slant blogger (Skeptic publisher) Michael Shermer and Huffpo blogger (best selling author) Deepak Chopra titled "Does God Have a Future?" at Cal Tech yesterday. An edited version will air on March 23rd with the entire conversation to be available online on the same date.


It is interesting that when a theorist offered to teach Chopra about quantum mechanics, he accepted. This is rather strange because it clearly indicated that he is admitting that he doesn't know much about QM, but he's been "using it" in promoting his quackery all this time! What's wrong with this picture?

This is what many of the pseudoscientists do, i.e. bastardize QM without understanding what it is. All they "understood" are those they got out of pop-science books or articles. If that is all what QM is, then we should be able to make constructive devices out of such books and articles only. Well try it if you can. There are people who can't tell the difference between learning physics, and learning ABOUT physics. There IS a distinct difference between the two...

Now we'll just have to wait for not only the Nightline show, but also the whole thing to appear online....

Zz.

Monday, March 15, 2010

Physics in China

This is a rather informative overview of the rise of Physics in China, especially during the past decade. How much and how fast China has progressed in very advanced research during that time is extremely impressive. Such progress isn't just due to the increase in funding for physics, but also a reflection of its biggest resource - the Chinese population.

With a population of 1.3 billion and an economy close to overtaking Japan’s as the second biggest in the world, China seems set to become a front-rank nation in physics. Although its expenditure on science remains lower than that of the US and the EU, both in absolute terms and per capita, it’s catching up quickly. According to a recent report from the US National Science Board, China has already surpassed the US in the number of researchers (see the story on page 30 of this issue). 2

Indeed, the prospects for physics in China could depend on how it makes use of its greatest resource, its people. And in that respect, the challenges that lie ahead for China are not so much in funding but in creating an intellectual climate in which imagination and ingenuity, not just hard work and skill, can develop and flourish.


Zz.

Borexino Detects Geoneutrinos

More detection of geoneutrinos that was probably first observed at KamLAND a few years ago. This time, it appears to be a cleaner signal detected at Borexino experiment at the Italy's Gran Sasso National Laboratory {link may be available for free only for a limited time}. The preprint of the paper can be found on ArXiv.

The experiment ran for two years ending December 2009 and the Borexino collaboration (about 80 researchers from six countries) says that it detected 9.9 geoneutrino events, with uncertainties of +4.1 and –3.4. Spokesman Gianpaolo Bellini of the University of Milan says that the result also appears to rule out a controversial hypothesis that a large part of Earth's heat is produced by a naturally occurring nuclear reactor fuelled by uranium in the planet's core.


It's interesting how the difficult task here is not detecting neutrinos, but rather to be able to distinguish which ones come from where. One probably has to use both the energy distribution, time dependence, and path reconstruction to be able to discriminate the geoneutrinos from the others.

Zz.

Saturday, March 13, 2010

Brian Cox Deserts Labour Party

You have to be a really popular physicist when the possibility that you will vote for a different political party made the news. This is the case for Brian Cox, who has indicated that he will no longer support the current UK's Labour Party and will vote for Liberal Democrat instead.

He said that the Labour government’s investment in research and development was worse in real terms than it had been under Margaret Thatcher. In Cox’s view, the 2007 funding crisis that struck the Science and Technology Facilities Council, which supports research into physics and space technology, had been a “cock-up, the biggest screw-up in science policy in the past decade”.

Britain’s international reputation for science had been damaged, he said. Overall, Labour’s record on science funding was “not as good as it should have been”.


It's one of the more interesting scenario for the UK, where it seems to go the opposite way of the US, France, Germany, China, Japan, South Korea, etc. during this tight economic times. All of those countries significantly increased spending in the sciences during the past year with the hope that this is a future investment that will invigorate the economy in the long run.

Zz.

Friday, March 12, 2010

New Revolutions in Particle Physics - Part 9

Part 9 of this tour-de-force lecture series by Leonard Susskind is now available online. I've updated the original blog entry to include this video.

Zz.

Thursday, March 11, 2010

Between Encouragement and a Dose of Reality

What do you do when someone very young, say a high school student, come up to you and eagerly tells you that he/she wants to be a string theorist? Or a particle physicist? Or a nuclear physicist? Etc... etc.. i.e. pick any "sexy" physics profession that you can think of right now. What do you do?

Do you continue to encourage that person, or do you try to do that carefully while injecting a dose of reality?

Here's what I've written elsewhere on this matter, and I'll copy it here verbatim, with added commentary afterward:

I cringe every time I read in here of kids still in high school, or barely starting college, who already either are focused on a particular career, or already made up their minds that on a particular, exact career that they want to do. Now don't get me wrong, there's nothing wrong with having an ambition and aiming to want to be something. However, one needs to step back a bit and figure out if the "choice" being made here was made based on having all the necessary information (i.e. a well-informed decision), or made entirely based on superficial perception.

There are two important issues here that should be addressed and considered.

(i) It is highly unlikely that an 18-year old knows extremely well what is involved in being, say, a theoretical astrophysicist. So how did someone like that arrived at the conclusion that that is what he/she wants to be? More often than not, this person saw some TV shows, or went to some facility, or read some news coverage, and over a period of time, "fell in love" with the idea of being a theoretical astrophysicist.

(ii) It is also very likely that this person hasn't yet been exposed to ALL (or at least, a lot) of the exciting aspects of other field of studies. It is one thing to have seen all the "merchandise" and then make an informed selection, it is another to have only seen one or two and decided that those are sufficient to make a choice.

While there is nothing wrong with having a goal, there is a lot of things wrong when such a decision causes one to have blinders on and not even consider looking at other possibility. It is one of the reason why I conducted a non-scientific career poll on the PhysicsForums. I wanted to see how many here who actually ended up in the VERY exact field that he/she envisioned when he/she was that young. If you simply look at the results, you'll see that only 15% of the poll participants ended up in the very exact career that they envisioned[*]! Significantly more of the participants end up doing roughly the same type of field of study, but not exactly the area of specialization that they had in mind.

What is the lesson in all of this? The lesson here is that, if you're just starting out in your academic life, there's a VERY good chance that you WILL NOT end up in the very exact specialization that you had in mind. That is a very important take-home message, and could be one of your first smack of reality. What this means is that you should NOT close the door on other subject areas just because you already have an ambition to be something. Just because you want to be a theoretical astrophysicist doesn't mean that you shouldn't at least look into solid state physics or read new discoveries coming out of atomic/molecular physics. There's a good chance that you will not be a theoretical astrophysicist, and you need to prepare yourself for such a possibility. It is why I've always tried to emphasize an undergraduate education that is as WIDE-RANGING as possible. Want to be a theorist? Well, take that extra lab class anyway! You'll never now that your ability to make that thin-film deposition might be the very skill that get you that job, or that graduate school admission. Idealism can only go so far before financial reality steps in and smack you on your face.

[*] I am still skeptical of this number, and so far, only one participants have given an explanation on his selection. I think this number might be even significantly lower than what we end up with. I am guessing that many didn't actually read the full options posted in the first message of the poll. Of all the physicists that I've chatted with, I don't ever remember even one of them telling me that they are doing what they had in mind exactly when they were 17/18 years of age.


The fine line that I would walk here is to not discourage someone that young so that he/she continues to nurture that interest in physics. But the reality is that, there is a strong possibility that he/she would NOT go into such fields. Physics is such a wide subject area, and the less glamorous ones are often the ones that (i) have a larger chance of employment (ii) has more funding (iii) wider and larger number of opportunities. In many of my contacts with high school students, I think when the opportunity arise, I try to convey this view that physics is more than just the LHC or string theory. It is also the iPod and the silicon chips and the laser and the MRI. I can only hope that somehow, those blinders would start falling and they could see a wider horizon.

Zz.

Wednesday, March 10, 2010

Cryogenic Electron Emission

Hum... this is certainly something I didn't know about.

We know of various mechanisms of electron emission from a surface, especially metallic surfaces. Field emission and photoemission are two common examples. However, it appears that there's an emission that has no present-day explanation ... yet. This emission occurs as the temperature of a photomultiplier is cooled down below 220K, and the emission rate rises as one cools further.

This, of course, is counter-intuitive. In many experiments, we perform our measurements at very low temperature to reduce the "noise" level in our experiments. Thermal noises and also other agitation causes our data to also be "noisy". The Fermi function is also less spread out above the Fermi energy, so less number of energetic electrons are available as one approaches very low temperatures. So one would expect that a photomultiplier, which is nothing more than a cathode with an applied field, and a mechanism to multiply the electron emitted, would be less noisy as well as one cools it down. Instead, what we see here is that below a certain temperature, the number of dark counts seems to increase.

This certainly is an interesting phenomenon, and it is of interest to those in the detector physics field.

Zz.

Tuesday, March 09, 2010

Neil deGrasse Tyson's Long Lost Sibling?

Some time I think I post arcane nonsense in this blog! This is going to be one such example! :) :)

I watched the Graham Norton Show several months ago when Michael Buble appeared. It actually was quite a funny show, and Michael Buble performed his hit single at that time "Haven't Met You Yet". It was an amazing performance (it certainly made me buy his CD). But what struck me as strange was that as I was watching that performance, the trumpet soloists looked like someone familiar. I thought that was strange because why would I find someone familiar who happened to be one of the musicians on the Graham Norton show!

It was only much later when it came to me on why that soloist looked familiar - he looked like the famous astrophysicist and the director of New York's Hayden Planetarium, Dr. Neil deGrasse Tyson!

Well, of course, it isn't him, unless he moonlights as a backup musician! :) Still, it resemblance is uncanny. You can judge this for yourself. Here is a video of that performance by Michael Buble on the Graham Norton Show:



Look at the trumpet soloist at time 2:25 and 2:33. Next, look at a picture/video of Neil deGrasse Tyson at this link. Now you tell me they don't look alike!

:)

Sometime, I have no idea why these things stick in my head.....

Zz.

Monday, March 08, 2010

Popular Science Magazine Online

I don't read Popular Science magazine. I never have. But maybe there are people who do. So this may be news that some people might like. It appears that Popular Science as put its entire 137-year archive online and available for FREE!

We've partnered with Google to offer our entire 137-year archive for free browsing. Each issue appears just as it did at its original time of publication, complete with period advertisements. It's an amazing resource that beautifully encapsulates our ongoing fascination with the future, and science and technology's incredible potential to improve our lives. We hope you enjoy it as much as we do.


I didn't realize they've been around for that long. But then again, I've never read it, so how would I know?

Zz.

Sunday, March 07, 2010

The Particle Adventure

VoA is highlighting The Particle Adventure as the website of the week.

"Essentially, The Particle Adventure is an interactive tour of the world of quarks, neutrinos, antimatter, extra dimensions, dark matter, Higgs boson, as well as accelerators and particle detectors," explains Michael Barnett, a physicist at the Lawrence Berkeley Laboratory in California and one of the people behind The Particle Adventure.


This is a terrific site for people wanting to learn a bit more about elementary particles, and it is suitable for people at any level. I have included the link to the Particle Adventure webpage in this blog's links roster for as long as I've had this blog. So if you don't know about it till now, it's time to give it a try.

Zz.

Friday, March 05, 2010

New Revolutions In Particle Physics - Part 8

Part 8 of this Leonard Susskind lecture series is now available online. I've updated my original blog entry to include the video of this lecture.

Zz.

A Crackpot In Russia

Well, I'm sure there are more than just one crackpot in Russia. Still, Viktor Petrik is kinda special and seems to have been able to fool a lot of influential people in Russia and outside of it.

He has won some high-level support. United Russia, the ruling party, regularly gives him prominent roles in events on innovation, while officials including Boris Gryzlov, the speaker of Russia's parliament and No. 2 in the party, have publicly endorsed his products. The two men are listed as the authors of a patent granted in 2009 for a filter that Mr. Petrik says can turn radioactive waste into water that's safe to drink.


Not only that, but he's also "friendly" with a former US President:

Mr. Petrik says he has also met prominent people outside Russia and shows pictures to prove it. In December 2004, he visited former President George H.W. Bush in Texas and discussed his technology for cleaning groundwater. "When we met, Bush knew a lot about me already," he says, adding that he hopes to have another meeting with him in the next few months.

A spokeswoman for Mr. Bush said the meeting was "a very short courtesy call" and that they haven't been in touch since and have no plans for further meetings.


Does this surprise anyone?

His "resume" is also quite "stellar"!

Mr. Petrik says he learned hypnosis from his uncle. He got an undergraduate degree in psychology at Leningrad State University in 1976, according to university records.

He says he also studied physics but didn't get a degree. The university says it doesn't have detailed records of the courses he took.

He spent much of the 1980s in prison. Yevgeny Zubarev, a journalist who wrote frequently about Mr. Petrik in the 1990s, says he saw the criminal file and the central charge was smuggling antique furniture. Mr. Petrik acknowledges he was in prison but declined to comment on the charges.


I'm tempted to call him a modern-day Rasputin, but that's too easy. But again, the problem isn't with him. There will always be charlatans and con artists like this, no matter where and when. It is the people that someone are gullible enough to be fooled into buying such snake oil that are at fault. In many cases, the harm done is usually to the individuals who are silly enough to believe in such a thing. But when such jokers can influence people in power, then that's another matter and can affect the lives of many people. This then should be dealt with swiftly.

Zz.

Zz.

Thursday, March 04, 2010

Exotic Antinucleus Detected At RHIC

More exciting stuff coming out of RHIC lately. This one is way up there. They have announce the discovery of heaviest known antinucleus and the first antinucleus containing an anti-strange quark.

The new antinucleus, discovered at RHIC's STAR detector (http://www.bnl.gov/rhic/STAR.asp), is a negatively charged state of antimatter containing an antiproton, an antineutron, and an anti-Lambda particle. It is also the first antinucleus containing an anti-strange quark. The results will be published online by Science Express on March 4, 2010.


Zz.

Wednesday, March 03, 2010

Argonne's High School Summer Internship

This is a report from last summer's Argonne high school summer internship program for high school students around the Chicago area. There are some very bright students here. One can only wish that every students with some interest in science is given such opportunity to participate in programs like this. I like the fact that this is almost like a "mystery" game, and that these students not only have to fulfill the mission (i.e. to identify the sample), but also learn at least one particular characterization tool. Did they know that the skill of knowing such tools can, in fact, be a valuable trait when they go out into the work force and seek jobs? I hope someone impressed that upon them during the program.



Well done!

Zz.

Tuesday, March 02, 2010

Comedy Central Channel - Best Science On TV?

I must admit, I, for one, do not get my "science" from Comedy Central, even if I inadvertently did appear on it for a split second during an episode of The Daily Show. However, it seems that many prominent scientists think that The Colbert Report and The Daily Show are the two most consistent shows (both on Comedy Central) to hear scientists talk about their work to the public.

Carroll says the Science Channel has devoted itself to wacky pyrotechnics-based shows rather than real science. The satirical weekly The Onion mocked that the "Science Channel Refuses To Dumb Down Science Any Further" and noted shows such as Punkin Chunkin, which examines gourd-lobbing technology.

"It is a very bad thing for the country that Comedy Central is the go-to place for hearing scientists talk about their recent work, but it's great for Comedy Central," Carroll says.

Says Tyson: "Any access that real science gets to mass media is a good thing. Colbert and Stewart are very smart people. And they know the value and meaning of science."


Hum... not sure what to make of this. I don't think anyone has done any kind of study to see how effective science communication is from these shows.

Zz.

A Vision For UK Researech

The United Kingdom's Council for Science and Technology (CST) has released its report about the future of UK's scientific endeavor. In it, the council made several recommendations, among which to focus on the researcher, not just the research. This includes training Ph.D candidates on skills, such as management, that can be used in the private sectors.

There certainly is a lot to read in here.

Zz.

Monday, March 01, 2010

Neutrons - The Unsung Structure Probe

This article is a belated tribute to the often-ignored neutron. Not many people know that neutrons provide some of the best and most important probe to study a whole slew of things. This article hopefully will provide and enlighten many on its importance.

But neutrons have some unsung properties that make them useful for investigating matter. Because they are neutral, they can penetrate deeper into a sample than electrons can. Because they have mass and spin, they have a magnetic moment and can probe magnetism. Because they interact with nuclei rather than electron orbitals, they are sensitive to light elements and can even distinguish between hydrogen and deuterium. And they're nondestructive. These features are inspiring researchers to use neutrons to analyze a variety of materials, from coal and complex fluids to cell membranes and membrane proteins and including magnetic materials.


The inelastic neutron scattering probe has, since the early days of high-Tc superconductors, provided most of the evidence for the magnetic resonance peak for the Cu-oxide plane. So just in material science alone, this has been an extremely important technique. The Spallation Neutron Source at Oak Ridge, when it comes online, will be one powerful facility to study a whole zoo of things.

Zz.

Bridging Science And The Cinematic Arts

Seems to me that Hollywood is trying to get its act together in bringing in at least competent advice in its science content. The National Science Foundation and the CalArts school have announced a partnership ".... to forge collaborations between researchers and entertainment scholars to produce cutting-edge materials that inspire and inform mass-media audiences about science and engineering concepts..."

Not sure what the effect of this will be in future movies.

Zz.