Wednesday, April 30, 2008

A Memristor?

Quick, before you read this, what do you think is a "memristor"?


Give up? It's a resistor with a "memory"!! I didn't know that either!

The existence of the memristor, short for 'memory resistor', was first suggested in 1971, but only now have researchers succeeded in creating a real, working example. They hope that the new components could revolutionize computing, promising an end to frustrating waits for your computer to boot up.

"A memristor is essentially a resistor with memory," explains Stan Williams of HP Labs in Palo Alto, California, who reports the memristor's creation in this week's Nature. "The actual resistance of the memristor changes depending on the amount of voltage and the time for which that voltage has been applied to the device."

The reference to the paper is:

D.B. Strukov et al., Nature 453, 80–83 (2008).



Shaken But Not Stirred

Although it isn't designed to detect earthquakes, many synchrotron facilities around the world, especially the latest generation facilities, can actually detect when an earthquake is occuring, some time halfway around the world. The recent earthquake in Southern Illinois that occured a couple of weeks ago was certainly felt in various parts of Chicago, and it was certainly detected by the Advanced Photon Source at Argonne.

The magnitude 5.2 earthquake that shook southern Illinois was “detected” by the beam position monitors that keep the electron beam on course in the APS particle accelerator (see the accompanying figure), but the machine continued to orbit electrons at nearly the speed of light with no noticeable adverse effects. Other monitors (x-ray beam position monitors) assured that x-ray beams illuminated experiment samples as small as molecules.

There are of course many steps in place to either make sure the beam continues to be stable, or in the worst scenario, that it gets dumped safely if it goes too far off course. The same thing is in place in many other facilities around the world, especially the LCLS being constructed at SLAC in the earthquake-prone California, which has an even more stringent beam operating parameters to produce its FEL.

I was told by someone working at the APS that they even detected the huge earthquake in the Indian Ocean from a few years ago that caused the massive and deadly tsunami. So this is one very sensitive machine with very precise diagnostics ability.


Tuesday, April 29, 2008

Revamping Intro Physics Laboratory - Part 6

{{Note: If you wish to follow what has transpired so far in this series, here are Part 1, Part 2, Part 3, Part 3-Follow-up, Part 4, and Part 5}

This may be a bit misleading because it is not strictly a "laboratory exercise". In fact, I think it might be more suitable to be presented during class. Still, it involves the students doing something, so that fits in with the spirit of a laboratory.

This exercise has 2 parts to it. The first is in class where the students are asked to think about a situation, and write down what they think should occur. Then, they get to go out and test it themselves and observe the situation. They then come back and write down what they observe, and compare it to what they wrote earlier of what they THINK should occur. Finally, they get to explain their observations, especially if what they wrote earlier is different than what actually occurred.

So what is the exercise? Here goes...

You are in a stationary vehicle (a train, bus, or a large vehicle). You have a helium balloon attached at the end of a length of string, so the balloon floats freely (without being confined or rubbing against other objects), while you hold the other end of the string. The vehicle then accelerates forward. What happens to the balloon?

The whole point here is to see the effect of the acceleration in a vehicle (on earth) on an object that is less dense than air. You first give this in a class (or a lab) towards the end of the session, and then ask the students to write down what they think they will observe. They don't have to give you any reason, just what they expect to happen.

Then, give them some way to get a helium balloon. This shouldn't be too expensive, should it? Maybe they can get on a train to go downtown, let's say, with a group of their friends. That would be a great way to observe the balloon. Advice them that maybe it would be a good idea to write down there and then some notes on what they observe, and any relevant circumstances surrounding the observation (i.e. was the train packed? Did the balloon float freely? Were the windows open? Was the air conditioning blasting right at them? etc.) Then when they come back, they need to write down exactly what they observed, and compare that to what they wrote earlier before they did the "experiment".

I would then suggest that everyone discussion what they have done. Who predicted an observation that is consistent with what they actually observed? Who didn't see what they thought would happen? Why?

Now, it would be OK to tell the students before they did this that they need to make sure that there are no significant moving air, because that would ruin any effects of the acceleration. But I'm even tempted not to say that. This is because if there are students who did not consider this effect, then there could easily be a discussion on the nature of the 'experiment', and why the result that these students get doesn't quite tell you the effects of the acceleration. The "observation" isn't valid as far as finding the effect of the acceleration in a vehicle on the balloon, because other external factors have intruded into the observation. If these students acknowledged this extra factor, then they have been observant, and understands the non-validity of their observation. If the students did not realize this, then hopefully, other students will point it out during the discussion.

I'm hoping that during the discussion session is where the students start "argue" about the validity of each other's observation, such as the possibility that the wind or other factors might affect some other's observations. I'm also hoping that they might try to come up with some physics on what exactly is the most valid observation for a balloon in an accelerating vehicle that isn't affected by any other external factors. As the instructors, I would suggest you simply stay out of the way, and see how the students are thinking and reasoning their way through this. You can certainly offer some guidance, but the "thinking process" may take awhile, especially if there are many students who observe things differently from each other. They need to weed out which observation is "faulty" as far as answering the question at hand. Once they figured out the valid observation, then they need to figure out why it happened that way. It is the students that need to make their own self-discovery.

BTW, the valid observation in this case is that the balloon will tilt FORWARD, in the direction of the motion of the vehicle. This is, at first, counter-intuitive, because when a vehicle accelerates, objects tend to get pushed back in the opposite direction of motion. So the first inclination is to expect the balloon to tilt backwards. However, a floating balloon is less dense than the air surrounding it. So when the vehicle accelerates, the air surrounding the balloon gets pushed to the back of the vehicle more than the balloon, and thus displacing the balloon forward.

Strangely enough, it observation shouldn't be THAT unusual, because there's an identical situation to this that we are quite familiar with. If we apply Einstein's equivalence of gravity to acceleration, then technically, we are accelerating "upwards" at 9.8 m/s^2. Now try letting go of a helium balloon. It floats UP, in the direction of our "motion". It's the same effect we see in the accelerating vehicle. Yet, I'm sure, for many people, the observation of the balloon tilting forward is non-intuitive. If you are lucky enough to have students who actually argue using this point, then you have one heck of a student! I consider the ability to see the similarities of something "new" with something that they are familiar with as a major accomplishment. It is how we can describe many things that appear to be "different", yet share almost the same type of description or phenomena. I would suggest that if no students realize this, that you bring it up at the end of the discussion.


Monday, April 28, 2008

Physicists Quantify the 'Coefficient of Inefficiency'

One of the skill one learns as a physicist is to tackle a problem systematically, and to quantify it, if possible, by making an effective, accurate model of the system. This problem doesn't have to be in physics. It can be anything. I mentioned earlier of someone who tried to find the most optimum way to load an airplane, simply because he became curious after observing how an airplane is typically boarded. Well, this is a similar problem.

Three physicists from the University of Vienna examines the efficiency of committees in making a decision in terms of the number of people that makes up the committee.

To understand why, Thurner and fellow physicists Peter Klimek and Rudolf Hanel turned to the British historian C Northcote Parkinson, who studied how the British Navy was once administered. Parkinson, who died in 1993, discovered a strong correlation between a committee’s ability to make a good decision, and its size. In particular, Parkinson found that committees with more than about 20 members are much more ineffectual at making decisions than smaller groups — something he dubbed the “coefficient of inefficiency”.

You can read the preprint of the paper from a link given in that article. It is a clever way to quantify and model this problem. Now if only people who form such committees would pay attention to it.


Symposium Focuses on Energy Challenges

If you're in Chicago or near the Northwestern University campus, this might be something interesting to attend.

Steve Chu, who won the 1997 Nobel Prize in physics and is director of the Lawrence Berkeley National Laboratory of the U.S. Department of Energy, will deliver the keynote address at the Northwestern-Argonne Energy Symposium on Friday at Northwestern University.

The symposium, themed "Energy: The Challenge for the 21st Century," is free and open to the public. The program is from 8:30 a.m. to 5 p.m. in the Ryan Family Auditorium in the Technological Institute, 2145 Sheridan Rd., Evanston.

With the cost of gasoline here in the US rapidly approaching an average of $4 per gallon, this has become certainly a very hot topic.


Sunday, April 27, 2008

Just Because You Say It Is Based On Quantum Physics, Doesn't Make It So

So many pseudoscience are so damn quick to attach themselves to "quantum physics", as if they know what quantum physics is. I've already mentioned several instances of the bastardization of quantum mechanics by a few people who are using it to validate whatever it is that they are claiming. Well, count this one as one of them. It is the "ancient medical treatment" called Shirodhara.

I honestly don't care at all what people wish to do with their bodies. However, when they tried to justified it by saying some nonsense to the effect that it is verified by some aspects from physics, then that gets my goat.

Ayurveda, the primary health system in India, and western biomedicine, the primary system in North America, differ in their view of the body. "It needs to be emphasized that ayurveda is very much a science," Dr. Gupta stresses. "The foundation of ayurveda is based on quantum physics instead of molecules, cells and gross structure.

What the hell does that mean? And why is "molecules" different from quantum physics?

First of all, there's some inconsistencies here. This practice has been going on for "5,000 years". If it is true, how can it be "based on quantum physics", when quantum physics was only formulated in the early 20th century? Did someone from 5,000 years ago time-traveled to the time or Bohr, Einstein, Schrodinger, Heisenberg, etc. and got the knowledge about quantum physics and then got back to 5,000 years ago to form the Ayurveda medical treatment? Sure, I'll buy that!

OK, so maybe it isn't that. Does that mean that they realize that, like Chemistry, which came way before quantum physics, that what they are using can actually be "explained" by quantum physics? Really? Such as what? In Chemistry, many aspects of what is measured (as in QUANTITIVE MEASUREMENT), can be explained in terms of the formulation of quantum physics. The energy state of the hydrogen atom, the nature and strength of chemical bonds, the behavior of molecules, etc. In other words, a lot of things that were measured can be quantitatively derived from quantum mechanics.

Now I would bet you no such comparison has ever been made with this Ayurveda. Oh sure, they might bastardize various aspects of the superficial idea of "entanglement" (this seems to be a popular effect to be bastardized - refer to "The Secret"), but this is FAR from claiming that you have a foundation based on quantum physics.

What these crackpots do not realize is that to be able to say that something is based on quantum physics, one must DERIVE the effect for THAT PARTICULAR SYSTEM, using quantum physics. Start with the Hamiltonian, and use whatever means one has to drive both the QUALITATIVE AND QUANTITATIVE result that agrees with whatever it is one is trying to show an agreement of. One simply cannot use "superficial induction". Just because the phenomenon of entanglement has been shown to work in 2 photons does NOT mean that such phenomenon is valid for 2 apples! It isn't! But that is why these crackpots are doing.

I really don't know how the Edmonton Journal could have seriously published this with a straight face.


Saturday, April 26, 2008

The US Army Issues Polygraph To Soldiers In Afganistan and Iraq

Holy cow!

I didn't know about this until it was brought up by Bob Park in this week's column of What's New. So the US army thinks that they could improve security by using portable polygraphs.

The Defense Department says the portable device isn't perfect, but is accurate enough to save American lives by screening local police officers, interpreters and allied forces for access to U.S. military bases, and by helping narrow the list of suspects after a roadside bombing. The device has already been tried in Iraq and is expected to be deployed there as well. “We're not promising perfection — we've been very careful in that,” said Donald Krapohl, special assistant to the director at the Defense Academy for Credibility Assessment, the midwife for the new device. “What we are promising is that, if it's properly used, it will improve over what they are currently doing.”

This is astounding, considering that the NAS study has concluded that such devices are useless. They must be desperate enough to make use of voodoo science (a nod to Bob Park) to ensure safety over there. I think it would have been cheaper to simply hire a psychic, or train an army personnel in the art of reading tarot card.

As Bob Park said, these portable devices should work as well as the non-portable versions.


Leaps of Faith

Here's someone who understands the importance of basic, theoretical physics research - Mike Lazaridis, founder and co-CEO of Research in Motion (i.e. make of the Blackberry).

That's one reason why, in 1999, Lazaridis donated $100 million of his nascent fortune to seed the institute. Another, he says, is "because people take theoretical physics for granted." No kidding. This world of equations and chalk dust is about as far away as you can get from the world of commerce. Why anyone would hand over such a massive amount of money—at the time, close to one-fifth of Lazaridis's net worth—to a collection of wild-haired math freaks is lost on most of the folks on Bay Street. Sure, Lazaridis knows that quarterly earnings are important. (In its most recent quarter, RIM posted a higher-than-expected profit of $412.5 million and shipped 2.2 million new BlackBerrys, the first time in the company's history that it broke through the two-million-mark in a quarter.) But he also knows that without the kind of work being done at Perimeter, chances are slim that someone will develop another world-beating technology like RIM's 60 or 80 years down the line.

Many of the CEO's of major technological and electronics companies are aware of this. The question is, do the general public and the politicians know this?


Physics In Action at Theme Parks

Summer is almost here (at least here as in the northern hemisphere). With that, many theme parks are gearing for their busiest time of the year. Taking advantage of this are several schools and programs that try to marry the fun of theme park rides with physics lessons.

There are two recent examples to this. The first one is the Physics Day for area students at the Six Flags theme park in Largo.

Barnabas Adekanye, Irving Delco, Frailen Ramirez, Ludwin Romero and Johnny Wilks, all sophomores at Northwestern High School in Hyattsville who study engineering, were somewhere in the middle. They had brought a 28-page workbook of problems to solve. It was complicated stuff with a lot of formulas.

"Compare the change in potential energy to the gain in kinetic energy," went one question about the Mind Eraser. "Within experimental error, was energy conserved? Explain your answer."

Johnny, 15, had an easier explanation for what they were learning: "Like how the gravity and force relates with the loops and stuff."

The second example is a trip to Ceder Point by students from Windsor, Canada. I think it is a valid concern to look at it closely and see if the students are learning something, rather than simply using it as an excuse for a trip to a theme park. There has to be a conscious program to clearly demonstrate the physics principle to the students, and that the students actually got something. I think most of these programs try do that.


Thursday, April 24, 2008

Death For Phonons In High-Tc Superconductors?

This is a highly interesting and certainly provocative result.

Remember I posted a while back on the "kink" observed in the angle-resolved photoemission spectra (ARPES) on high-Tc superconductors? There have been a continuing debate since the kink was observed on the origin of this observation. Two leading candidates are the coupling of the charge carrier to a spin fluctuation mode, and a coupling to the phonons.

Now two separate theoretical papers have calculated the coupling to the phonon modes and have arrived at the conclusion that such coupling cannot account for the strength of the kink observed in ARPES spectra.

In recent years, despite mounting experimental evidence against it, some physicists have clung on to this interpretation. But now teams from Germany and the US have performed calculations to suggest that lattice vibrations in cuprates can at best account for just a small fraction of the materials’ superconducting behaviour.
Manske’s team found that the theoretical energy–momentum relationship produced by these calculations did contain a kink — but about a three to five times smaller than the 2001 observations (Phys. Rev. Lett. 100 137001). This is bad news for physicists who have been hoping phonons can account for all of the behaviour of high-temperature superconductors. “It is embarrassing for people to admit they have worked on something for 20 years if it is not true,” jokes Manske.

Meanwhile, Steven Louie and colleagues at the Univerisity of California in Berkeley have come to a similar conclusion with the cuprate LaSrCuO4. From their calculations, the phonon contribution is almost an order of magnitude too small for the observed kink (Nature 452 975).

This could be rather devastating to the phonon picture. If this is true, the two new results still cannot account for the origin of superconductivity, but at least they have eliminated a red herring. Still, all this could be moot if an earlier report is true about the absence of any kind of "glue" in the mechanism for high-Tc superconductors.

So stay tune. The story is by no means over, and the fat lady hasn't even warmed her vocal cords yet.

Non Sequitur

Thanks to Jim McNamara at PF for pointing this out. I thought it was a hilarious cartoon.

I don't know if that is a permanent link, unfortunately, for this cartoon.

Update: Thanks to Tom for the permanent url to the cartoon.


Wednesday, April 23, 2008

Bubble Fusion Fiasco Just Won't Go Away

Reported in the new edition of Nature (23 April 2008), it appears that Purdue University has sent its final report to the Office of Naval Research that funded Taleyarkhan's work on the so-called bubble fusion that is being questioined. But that's not it. He himself plans to contact the ONR directly to dispute the report (which implies that the report isn't favorable towards him). And, get this, he also plans on suing certain people!

The engineer is also pursuing a defamation lawsuit, filed last month in Tippecanoe County in Indiana against scientists who questioned his claims of bubble fusion. The defendants include Purdue faculty members named in Nature articles, which helped trigger an institutional review. “The complaint filed is to clear up my reputation,” Taleyarkhan says.



Tuesday, April 22, 2008

Can Buckyballs Make Flash Memory More Efficient?

The flash memory that is now very common in many devices may get a big boost if this report is correct. It seems that using buckyballs (C60 fullerenes) could operate at a lower voltage (link may be accessible only for a limited time for non subscribers) and thus, make the flash memory devices more efficient.

“We’re the first ones trying to borrow molecular electronics concepts and put them into non-volatile memory,” says electrical engineer Tuo-Hung Hou of Cornell University in Ithaca, New York, who led the research (T.-H. Hou et al. Appl. Phys. Lett. 92, 153109; 2008).

This is also another example of a possible wide-ranging application of physics.


Monday, April 21, 2008

Towards A No-Loophole Bell-Type Experiment?

Looks like we are well on our way to achieving that and nailing the coffin shut on Local Realism..... or are we?

The paper published last week in PRL[1] seems to point to the possibility of a loophole-free Bell experiment. While entanglement experiments with photons have closed down the locality loophole, and experiments with "particles" such as protons, neutrons, etc... have closed down the detection loophole, no experiments have managed to close both of them simultaneously.

This experiment with Yb+ atoms is well on its way to getting there. While they have certainly closed the detection loophole, they have reduced the possibility of the locality loophole by separating the atoms by 1 m (previously, the spatial separation was of the order of microns). So this is a tremendous improvement.

Eventually, it will be convincing enough, if it isn't already.


[1] D.N. Matsukevich et al., PRL v.100, p.150404 (2008).

Phenomenology of the Normal State In-Plane Transport Properties of High-Tc Cuprates

I always like it when authors upload their published papers. It gives those who do not have access to the various journals a chance to get a copy of a peer-reviewed, published papers, especially if they're in respectable journals.

This paper is more of a review of the current understanding of the anisotropic nature of the in-plane transport of the cuprate superconductors. The cuprate superconductors are well-known to have highly 2D nature in its charge transport, most probably due to the layered nature of the compound. It is believed that the transport occurs in the copper oxide planes, especially since the resistivity perpendicular to the planes is roughly 3 to 4 orders of magnitude higher. However, even within the copper oxide plane itself, there is a considerable anisotropy in the transport direction, as seen in various measurements.

The paper has a very good review of our state of knowledge on this issue so far, and also a good background info regarding the cuprates superconductor for those who need to get up to speed.


Teaching Superfluidity at the Introductory Level

I've only glanced through briefly this preprint, but from what I can see, it might provide a useful intro to superfluidity to undergraduate students, and even to those with some physics background. This isn't a topic that is dealt with in extensive details at the modern physics intro level, so it might fill a gap (no pun intended).

If you have read this and have comments about it, I'd like to hear them, especially if my impression of it isn't accurate.


Who or What is RVB?

In an earlier entry related to the "No glue for cuprate superconductors", I mentioned that Phil Anderson might be right after all since this could be consistent with what he has been pushing all along. Of course, what I had in mind was his Resonating Valence Bonds (RVB) theory as applied to the cuprate superconductors. I believe he has argued for the non-conventional (as in no boson coupling) origin of the superconductivity in the cuprates. So this result is certainly in favor of that picture.

In any case, not sure if it was deliberate or terrific timing, there is a start of at least a couple of columns on RVB in Physics Today. The first article appeared in the April 2008 issue, which you can read for free even if you're not an APS member. In this article, he describes basically the history of RVB theory. But I think I am more interested in the teaser that he gave at the very end, which is supposed to describe "... the rise and fall and rise again of RVB's relevance to high Tc and other superconductors..."

Now THAT, is a physics cliff-hanger!



Sunday, April 20, 2008

A Case Study of Gender Bias

OK, this thing has the potential of becoming a rather big news especially when the popular media picks it up or the a coverage in Nature (whichever comes first). This arXiv preprint titled "A Case Study of Gender Bias at the Postdoctoral Level in Physics, and its Resulting Impact on the Academic Career Advancement of Females" is getting quite a bit of legs. You might want to also look at the trackback links to read more about it.

I'm not endorsing or disputing the report, simply pointing it out since the cat, obviously, is out of the bag. I'm guessing there's more to come on this.


Looking Into Nuclear Power

Two different articles appeared almost at the same time discussing the use of nuclear power to generate electricity. So you might want to read them here and here.

I will fully admit that I am very much in favor of nuclear power. As with many aspects of physics/science policy in which ignorance and lack of knowledge have interfered with the decision-making process, nuclear power has suffered from the same fate. Both article addressed many of the issues involved currently when one talks about nuclear power.


Saturday, April 19, 2008

Saving Energy While Driving

So I don't remember which TV public service announcement that I heard this from. I think it was on one of the cable channels that was advising how you can make NY City more "green". In any case, that isn't relevant. What it did say was that you can save gas if you drive with your windows up, especially at high speed.

Of course, with everything being the equal, this is true. If you drive with your windows down, you create more drag, or air resistance, for your vehicle. Thus, you burn more fuel as you drive, especially when you're driving very fast.

HOWEVER (somehow, I think you were expecting that, weren't you? :)), let's consider the situation here of when you usually drive with your windows down. It is typically in the summer, or when the weather is warm. So, if you roll up your windows, you inevitably crank up the air-conditioning! So now, you've reduced air drag on your vehicles, but you're using up additional fuel due to the air conditioning.

So which one uses up more fuel - driving with the windows down but no air conditioning, or driving with the windows up but with air conditioning? I haven't looked into the calculations of how much power is used is a typical car air-conditioner, and I haven't looked into it yet on the amount of drag created when a car drives around at, say, 60 mph (yes, we still use mph here in the US). Does anyone have some rough estimates on what these might be? Off the top of my head, I would think that driving with the windows down instead of using air conditioning might be more energy efficient than the other alternative.

Of course, driving with the windows up and not using air conditioning is a no-brainer better option. But the PSA didn't say that. All they said was to drive with the windows up to save fuel. That is not the complete story.


Friday, April 18, 2008

Physics for Sports Nuts

Highly unusual for the Wall Street Journal to review a book about the physics of sports, but here it is. The reviewed "Why a Curveball Curves: The Incredible Science of Sports", which was compiled by the editors of Popular Mechanics. To quote the reviewer's own words:

This book is quite possibly every sports nerd's dream.

So don't feel self-conscious if you go out and buy it at a bookstore near you. :)


Wednesday, April 16, 2008

Quasar Tests General Relativity to the Limit

Wow. This is a rather impressive piece of work in terms of prediction and subsequent measurement. A group of astronomers have made what appears to be the most compelling evidence of the validity of General Relativity (GR) in strong gravitational field, and in the process, produced a more direct evidence of the existence of black holes, and an indirect evidence for gravitational waves.

The quasar pulse occurred right on schedule, strongly suggesting that OJ287 is a binary black hole system (Nature 452 851). In addition to verifying the enormous mass of the primary black hole, the result shows that the orbit of the secondary black hole precesses at a rate of 39 degrees per period. For comparison, the distorting effect of the Sun on the local space–time causes Mercury's orbit to precess by little more than 0.1 degrees per century.

Furthermore, the work suggests that the binary system is losing energy by emitting gravitational waves — a key prediction of Einstein's theory that is yet to be verified directly. When this emission is not included in the model, the quasar outburst is predicted to occur 20 days later, providing indirect support for gravitational waves.



Analysing the Afterlife

I normally do not go after something like this, because, frankly, it's a no-win situation. You can't make any rational argument against something that is irrational. However, when someone invokes something out of physics or scientific process to justify their irrational belief, then it is then fair game to evaluate the fallacy of his/her argument.

This author is trying to argue that one simply cannot dismiss the idea of an 'afterlife', whatever that may be. His main arguments?

Scientific and psychological reasoning and scepticism have yet to firmly counter the notion that there is an afterlife.


experiential evidence from around this world points to some form of existence in ‘the next’.

The first one is silly and just plain lazy. He's arguing that you can't prove that it doesn't exist. This is nonsense because it is the burden of a person arguing for the existence of something to show that it exists, not the other way around. So while his argument is to counter a previous article that appears to argue why it this afterlife doesn't exist, to turn around and argue that it does based on the point that "you can't prove it doesn't" really is extremely weak.

But the second part is what is more fascinating in terms of proving my continuing point that the general public, or at least those not in science, do not have any clue on the difference between anecdotal and scientific evidence. He is actually touting this "experiential evidence" as if this is something that is reliable and valid. It is a FACT that our minds can play tricks on us. It is a FACT that has been shown many times how people can believe that they saw something that never occurred (see here, here, and here). Therefore, experiential evidence is NOT RELIABLE as valid evidence. It is certainly less reliable when a person is under medical/physiological duress that he/she is near death! So to use those as justification for anything is extremely dubious.

It is ironic that he said that "... The afterlife may go against common sense, but twentieth century physics has taught us that common sense is often a poor guide to truth...." yet, he somehow ignored the rest of what physics has taught us of the nature of scientific evidence and what is valid. You'll notice a common thread here when someone who doesn't know much about physics will pick and choose what he/she wants to take from physics. The author of "The Secret" wants to use quantum mechanics to justify various part of it, and ignores the rest that will render the argument false. The same thing is occurring here. If this person is so respectful of what "twentieth century physics" has to teach us, then take the whole thing, rather than just what's convenient for him.

The fact that something like this continues to be presented as valid argument, and published in popular media without any hesitation, shows that (i) such fallacy is not seen as problematic to be accepted, and (ii) the readers and the general public probably won't catch what I've just mentioned here. Try reading the papers or watching TV. You'll see many more arguments being made that is based on simply a matter of opinion, or based on non-existent evidence, or an incomplete understanding. In many cases, no one is asking for evidence or justification of the point being made. So these things are being said as if they are "facts".

The nature and validity of the evidence being presented to support an argument is something that has been emphasized very little in public discourse. That is what is so discouraging.


Tuesday, April 15, 2008

Renewed Call for Science Debate

I mentioned earlier that the planned for the Science Debate 2008 among the US presidential candidates has been postponed due to lack of interest among those candidates. There is now a push for 3 possible dates in May.

While I think this is very important debate not just in terms of the issues, but in terms of a way we can judge how these candidates arrive at what they believe to be a valid opinion, I am not that optimistic that they will agree to this. Why? Because unlike most of the other debates, one actually need to have some knowledge of facts in this debate to be able to form an opinion. If you look closely at all the other debates, one can almost make things up as one goes along at answering the questions or discussing the issues. In those debates, style mattered more than substance. In a Science Debate, substance will take precedent over style. And for most politicians, that is very difficult to do.

So I am not going to hold my breath for this to happen...


Monday, April 14, 2008

More On The Physics Of Baseball

I mentioned earlier of the talk and demonstration on the physics of baseball presented by Paul Doherty, senior scientist at the San Francisco's Exploratorium. Wouldn't you know it, there's a video on this very topic staring this scientist.

It's not that in-depth, but its still fun.


RIP John Wheeler

John Wheeler, the legendary physicist that gave us the term "black hole", has died at the age of 96.

I am sure this will be mentioned during the APS April meeting going on right now. He certainly is a legend.


April 14, 1932 : The Era of Accelerator-Based Particle Physics is Born

A good piece of history in this article on the historic occasion that happened today in 1932.


The Extreme Deficit of Physics Undergraduates

David Harris is posting his report from the APS April Meeting going on this week in St. Louis. He is reporting on a session on physics education presented by Ted Hodapp from the APS. A listing of the issues involved in the shortage of physicists were given.

* The nuclear power industry will soon be suffering a shortage of qualified physicists to work for them. About 33 new power plants have been approved in the United States and will be starting up from 2010. That industry needs people with good science/math/problem solving abilities and physics graduates are an obvious choice.
* The medical physics industry employs about 3200 physicists, and have about 300 new jobs each year more than the current capacity for people with undergrad physics degrees. 78% of those people work in radiation oncology, and 16% in medical imaging.
* The growth of occupations requiring science and engineering undergraduate degrees has much higher growth than the civilian labor force but S&E enrollments are not growing anywhere near that fast.
* School principals rated physics and maths teachers about the hardest to recruit along with special needs teachers, primarily due to a shortage of qualified people.
* Math and computer science have about 70,000 undergraduate degrees granted each year, life science about 260,000. Physics has a mere 5000.
* Unemployment for physics graduates is very low, and for physics PhDs is an all-time low of 2.5%
* There is a need for US citizens with advanced physics degrees to work in classified areas. Hodapp says that Cherry Murray called the lack of US citizens with advanced degrees as “a national crisis.”
* The Rising Above the Gathering Storm report, the America COMPETES act, and the Tapping America’s Potential report all call for large increases in science, technology, engineering, and mathematics graduates.

Of course, there is a different viewpoint to this. You can read the comments posted to that blog entry, and also to the post that I made earlier that challenges the "Gathering Storm" report of the NAS.

Still, I have my own comments here.

1. The shortage being experienced by the nuclear industry is a direct consequences of the closing down of many nuclear engineering program in universities throughout the country during the past couple of decades. This is due to the lack of demand for nuclear engineers since the industry hasn't built a new commercial nuclear power plant at least during that time period. I don't think this can be attributed directly to the lack of physics majors.

2. While the employment may be "low", one also needs to look at what areas of physics that are more in demand than others and which areas of physics managed to get their graduates to land a job related to physics.

3. Traditional physics education needs to pay more attention to non-traditional jobs that may be available to physics graduates. I've seen school programs that are preparing their physics students to go into other areas upon graduation, rather than sticking with the traditional B.Sc-Ph.D-Post Doc-Faculty career tracks. Many smaller schools are at the forefront of that.

I still believe that a physics degree can still provide a rewarding career. However, I don't think that a lot of students are well-prepared to face the reality of employment after they graduate.


Sunday, April 13, 2008

Freeman Dyson to Give Public Lectures at Yale: "Three Myths in the Public Perception of Science"

If you are in the New Haven, CT area, you might want to consider attending this series of lectures given by Freeman Dyson.

• “Science Coming to an End,” on Monday, April 14, 2008 — Dyson will explain why he does not agree with some intellectual humanist scholars, most prevalent in Europe, who believe that science was a passing fad that is fortunately now over. This is a joint Leigh Page-Tetelman lecture, sponsored by the Physics Department and Jonathan Edwards College.

• “The Mathematician as an Automaton,” on Wednesday, April 16, 2008 — Dyson will talk about some mathematicians he has known and the different kinds of thinking they do. He divides them into “birds” and “frogs.” Birds fly high and survey the landscape out to the horizon. Frogs live in the mud below and enjoy the beauty of the creatures that they meet there.

• “The Selfish Gene on Thursday,” on April 17, 2008 — Dyson will talk about the relative importance of the individual and the community in language, in law and in science. He asserts that the clash between individual and community values in all three contexts is at the root of many of our ongoing quarrels.

They all sound fascinating. If you attended any or all of these lectures, I'd love to hear a comment from you here.


Friday, April 11, 2008

No "Glue" For Cuprate Superconductors?

There are finally some startling evidence that points to the very unconventional nature of the cuprate superconductors. A paper just published in Science[1], heading by Ali Yazdani, has found that while there are coupling between the electrons and a bosonic mode, this coupling may not be responsible at all for superconductivity.

You can read a review of this at the Science Daily website. This discovery certainly is consistent with what Phil Anderson has been trying to push. It also could mean that the "kink" in the ARPES spectrum that I've mentioned may be another red herring that isn't directly connected to the superconducting mechanism.

But as always, this isn't the first time something of this nature has occurred in the study of high-Tc superconductors, to later turn out to be insufficient in formulating a theory of these material. So to say that this is still a controversial (in terms of interpreting what it means theoretically) result is to put it mildly.


[1] A.N. Pasupathy et al., Science v.320, p.196 (2008).

Thursday, April 10, 2008

Argonne Tests Find Near-Zero Emissions for BMW Hydrogen 7

A while back, I mentioned about the Argonne Green Transportation event. It displayed several hybrid and hydrogen vehicles that supposedly have better millage and/or very little polluting emission. The star of that event were a number of BMW vehicles that ran on hydrogen.

These cars have been tested at Argonne, and it appears that it is the only public facility that can test vehicles with that low amount of emission. The testing project has now been summarized on video that's available on YouTube.


Wednesday, April 09, 2008

Revamping Intro Physics Laboratory - Part 5

{Note: If you wish to follow what has transpired so far in this series, here are Part 1, Part 2, Part 3, Part 3-Follow-up, and Part 4}

I read this post in PhysicsForums and immediately realized that this is an excellent laboratory experiment and a perfect one to follow what I've described in Part 4. This was done as part of a test, but I can see this as being quite suitable for an intro undergraduate lab, especially after they had just done springs and Hooke's law.

Again, this gives them a task, rather than an explicit set of instructions on what to do. They will need to know about the elastic spring extension and also simple, basic mechanics. So this may not be that suitable to be done at the very beginning of the course, but maybe after a couple of weeks or so to make sure the students have been introduced to simple 1D kinematics. But the fact that this student could have done it, and done it well, indicates that this is certainly doable.

BTW, do most "elastic bands" obey Hooke's law rather well? I remember testing a typical rubber band one time, and it deviated from linearity rather easily. It would be a cruel thing to do to give the students such elastic bands! :)


The Physics of Baseball

OK, I've posted many entries related to physics on this blog. Someone might have the impression that I'm a big baseball fan - I'M NOT! :)

Still, this is a rather fun and exciting news report on the physics of baseball. It was a talk and a lot of demonstration given by Paul Doherty, senior scientist at the San Francisco's Exploratorium. It sounds like it was a lively and somewhat "interactive" presentation, even if one could get hit on the head with a foam ball. :)


Tuesday, April 08, 2008

Unfortunate Acronym

First of all, this is not an attempt at being politically correct. I'm not criticising anything or asking for something to change. It is just that I find it a bit "amusing" some time, and wonder if anyone else spotted it, especially those who came up with it.

Often people come up with very cute acronym for many things. I can think of WIMP and MACHO, etc. in physics. These are catchy acronym that many people, including the general public, catch on. However, sometime, they come up with rather unfortunate acronym. I came across this one several years ago, and somehow, after reading an article this morning, it popped up again. The acronym is "FFAG", for Fixed-Field Alternating Gradient accelerator. I'm sure that most people reading this can guess what is unfortunate about this acronym (remove one of the "F"s and it becomes a short form of a derogatory word).

Of course, the first thing that came to mind is if the people who came up with the acronym actually realized this. The second thing that came to mind is on how this acronym is pronounced. Usually, acronym that can form a "name" that can be pronounced is usually refered to by that pronounciation. One would refer to WIMP as "wimp", not "W - I - M - P". So do people refer to "FFAG" as "F - F - A - G" or "F-fag"? I don't know about you, but I would feel rather uncomfortable to say the latter, even if nothing bad is intended.

I haven't had the opportunity yet to be in the circle of people that actually discussed this subject area yet, so I'm a bit curious on their view on this, or how they go about mentioning this word. Of course, I certainly wouldn't discount the fact that most of the people who do use this acronym aren't even aware of this angle, especially since there are many non-native English speakers involved in this field of study and the social/cultural connotation involved in that word doesn't mean anything to them.

Have you come across any similar acronym in physics/science that has the same unfortunate connotation?


ScienceDebate Announces Shift to Oregon

The initiative to hold a Science Debate among the US Presidential candidates is not going well. The planned debate to be held in Philadelphia has been canceled, and the organizers hope to schedule another one later in Oregon.

At this stage, I'm skeptical that it will occur. As the article stated, the candidates at this point are "well-defined" and don't need any more publicity. And science isn't anywhere near the important factor that the general public would consider in making their decisions on who to vote for.


Monday, April 07, 2008

Thousands Showed Up for CERN's Open House

Fifty thousand, to be exact. It was the last time the public will get to see many parts of the facility before they are closed down for the expected start-up in July. I suppose all the brouhaha about CERN and the black hole creation created even more publicity and even more interest in it.

And now, ladies and gentlemen, start your engine!


Sunday, April 06, 2008

'The Physics of NASCAR' Lecture

I mentioned earlier on the physics involved in a NASCAR race. Now there is an announcement of a lecture on the Physics of NASCAR tomorrow (Monday, April 7, 2008) at the University of North Carolina - Charlotte. It will be given by Diandra Leslie-Pelecky, the author of "The Physics of NASCAR".

If you get to attend this, could you write something about it?


Saturday, April 05, 2008

Follow-Up To The LHC Lawsuit

I was reading Bob Park's entry (April 4, 2008) of this LHC lawsuit yesterday, and it brought back memories of the almost-identical issue being faced when RHIC was about to start up. It was such a brouhaha that even Comedy Central covered it! :)

It is worthwhile to note of the in-depth study that was done at that time to dispel the myth that RHIC would create not only black holes in its collisions, but a catastrophic one. And unlike the joker who filed that lawsuit, this scenario was brought up not by an ignorant individual, but rather by a few physicists themselves. So certainly it warranted a careful consideration.

However, there were two different issues involved here. The first was the careful study of the claims made within the scenario, i.e. can there be a catastrophic creation of blackholes that could spell disaster. This was easily dispelled because of the existence of the moon (you'll have to read the full report). The second one was more difficult to explain to the general public. In many instances in physics, we see different phenomena that share the same mathematical description or formulation. The similarities of the mathematics from some aspect of condensed matter physics and elementary particle physics is one example. This is again what happened in a RHIC blackhole scenario. The problem here is that once that comparison got out, it caught fire among the media and the general public, who weren't able to know the significance of such a comparison. All they see is the "headlines" of blackholes being created, and that's that.

Again, this is where, if one doesn't have the necessary knowledge to decipher the information, one can be easily mislead by news reports. Sometime, it is the fault of scientists themselves for sensationalizing the issue (example: quantum teleportation, and anything Michio Kaku has written in his latest pop-science book). The public does not have the understanding and the formalism in mind when they read these things, unlike physicists. All they can do is associate what they read with what they know, and what they know come mostly from the media, TV, movies, etc. So it should not be a surprise that they can't tell the different between the "quantum teleportation" as a demonstration of quantum entanglement, and the teleportation they saw in Star Trek. When you use the same word, you should expect the pedestrian meaning of it to dominate, where it is accurate or not.


Addendum: Looks like the Editorial in the NY Times has it right.

More than once over the years we have felt as if we were transported to another universe listening to lawyers and judges wield the complexities and arcana of their trade. It would be fun to watch them struggle with theoretical physics. But if the courts have any sense, they will drop this suit into the nearest black hole.

Friday, April 04, 2008

More CP Violation

On the heels of the KEK report that I mentioned earlier, here comes the analysis of the data from the Tevatron at Fermilab that point to the same conclusion.

The amount of CP violation observed in experiments (and enshrined in the standard model), however, is far too little to explain why matter should have prevailed in its ancient war with antimatter. To get a clean look at CP symmetry, DZero and its sibling detector, CDF, focus on the BS, which consists of a bottom quark and a strange antiquark. (Quarks are components of protons and neutrons.) Working independently, the two detectors both found an extra dose of CP violation beyond what the standard model predicts.

Neither result on its own was very convincing, so a team of Italian researchers combined the data, similar to the way medical researchers cull information from independent clinical trials, to look for rare side effects. Together, the data make it 99.7 percent likely that the discrepancy is real, not due to chance, says physicist Luca Silvestrini of the National Institute for Nuclear Physics in Rome, who took part in the study submitted to Physical Review Letters.

Looks like both the CDF and D0 got similar things, which is always good.


Thursday, April 03, 2008

Q&A With Bill Foster

As the newest member of the US Congress, and the 3rd physicists in Congress, Bill Foster has a short Q&A session with Nature.


Feynman and the Music of Physics

Symmetry Breaking has an interesting, short article on Feynman and his bongo-playing. If you've read any of Feynman's biography (Glick's "Genius" is a good one), you'll know that he doesn't like any kind of "structured" music, but rather the more primitive, tribal rhythm.

So here's the video of Richard Feynman during one of his finest hours. :)


Wednesday, April 02, 2008

High-Tc Superconductors Are Very Kinky

In trying to decipher the mysteries of the mechanism that causes superconductivity in high-Tc superconductors (HTS), we have to characterize and understand the many-body interactions that influence the behavior of the charge carriers in these material. In a standard Fermi Liquid theory, these charge carriers are called quasiparticles, and their behavior are described by what is known as the spectral function A(k,E) (i.e. the imaginary part of the single-particle Green's function). The interactions that influence the behavior of these quasiparticles are quantified in the spectral function via the complex self-energy term Σ. The real part of the Σ shows how these collective interactions influences the dispersion relations/band structure of the material (i.e. the E vs. k curves), while the imaginary part of Σ indicates the scattering rate or lifetime of the quasiparticles. For an idealized metal having a non-interacting free-electron gas, the self-energy term is zero. This means that there's no deviation from the non-interacting electronic band structure/dispersion (ReΣ=0) and it has zero scattering rate/infinite lifetime (ImΣ=0).

So if one can actually measure this A(k,E), one can gain a lot of insight into the interactions that influence the behavior of the quasiparticles that are responsible for superconductivity in high-Tc superconductors. One of the ways to make a direct measurement of the spectral function (at least the occupied side of the band) is by using the angle-resolved photoemission spectroscopy (ARPES) technique. In an earlier post, I have highlighted a review of this powerful technique and how it can directly measure A(k,E). This technique has produced very clear signature of the various interactions in a typical metal such as Be[1] and Mo[2], showing very clearly the electron-electron interaction, the electron-phonon interaction, and electron-impurity interaction, all based on the self-energy obtained from ARPES measurement. The parameters obtained from the results, such as the electron-phonon coupling strength, all agree with existing theoretical predictions and previous measurements. So we know that such a technique works.

Because of that, ARPES has been extensively used in the study of HTS. This family of material is high suitable for this technique because of its layered, 2D structure. Furthermore, HTS compounds such as the BSCCO family are easily cleaved in situ along these 2D planes, exposing a pristine surface perfect for photoemission studies. A major progress in ARPES technique came in 1999 whereby not only the energy distribution curve (EDC) at a particular momentum are collected, but also the momentum distribution curve (MDC) at a particular energy can also be obtained simultaneously! This resulted in the collection of a 2D raw data of energy distribution and momentum distribution of the photoelectrons within an energy and momentum window[3]. What is essentially obtained is the dispersion curve. When this technique was done on the BSCCO family, a distinctive feature of a "kink" in the dispersion with an energy scale of around 50 meV was clearly observed[4]. This kink is the deviation of dispersion curve from the non-interacting dispersion, which signifies a coupling to some bosonic mode. By 2001, the race was on to analyze the nature of this kink to see if one can identify this "bosonic mode" that affects the electronic dispersion. This bosonic mode might be the "glue" that holds the Cooper pairs together in the formation of superconductivity.

[Figure shows the "kink", i.e. the deviation from the non-interacting dispersion (Campuzano et al. in The Physics of Superconductors, Vol. II, ed. K. H Bennemann and J. B. Ketterson (Springer, New York, 2004), p. 167-273., or at]

There were three important papers that were published in 2001 that were the first to analyze the origin and nature of this kink[5,6,7]. Two different groups arrive at roughly the same conclusion - that the kink seems to indicate a coupling to a magnetic (spin) bosonic mode[5,6], while the Stanford group[7] proposed the phonon as the origin of the kink. There have been many publications since then arguing for various scenario for the origin of this kink and until today, there is no overwhelming consensus for either the magnetic, although my quick review of this matter seems to indicate that there are more publications related to ARPES experiment in favor of the magnetic channel [8,9]. Still, the phonon picture has many strong advocates and the issue isn't settled even to this date.

But that is not the end of the story. It appears that the high-Tc cuprate familyis even kinkier than first thought. There seems to be, in addition to the low energy kink (now regarded to be between 50 to 70 meV scale), a higher energy kink in the dispersion has been discovered. It was reported, in succession within the span of a couple of weeks, by 2 papers in Phys. Rev. Lett.[10,11]. This new kink occurs at an energy scale of around 340 meV, so it is considerably larger than the low energy kink. The latter concluded that this new high energy kink is consistent with coupling to the magnetic (spin excitation) mode.

Since then, there have been even more reports on high energy kink[12], and this one is even at a different energy scale (115 and 150 meV) and the authors are suggesting that these may be due to neither spin fluctuation nor phonon modes.

Moral of the story: the high-Tc family of material is very kinky, and that the study on the origin of these kinks could hold a vital clue on the mechanism of superconductivity in these materials. However, the issue is highly complicated, especially when new discoveries are continually being made as one tries to solve the old ones. Whether these kinks are due to coupling to the magnetic mode, phonon modes, or neither, remains to be seen. A lot more work is still to be done.


Edit (04/10/08): A new preprint on arXiv[13] has appeared that studied the phonon mode in La doped Bi-cuprate compound. The result supports the electron-phonon coupling as the source of the kink in the cuprate superconductor.

Edit (06/10/08): A new preprint on arXiv[14] has studied the phonon dispersion in on of the Bi cuprate family using inelastic X-ray scattering. They found a significant phonon softening that's consistent with the same energy and momentum scale as the kink observed in the ARPES result. So this argues for the phonon origin of the kink.

Edit (07/02/08): This is getting to be quite interesting. A new PRL paper[15] has just been published, arguing that the high energy kink is more of an artifact of the MDC analysis, and that the EDC spectra provides a more accurate information about the band dispersion in high-Tc superconductors. So this certainly calls into question the conclusion made in previous papers on this high-energy kink.

Edit (12/22/08): A new theoretical analysis using parameters from the inelastic neutron scattering experiment has produced a model that can explain all the ARPES results[16]. It points to the incommensurate spin excitation as the dominant scattering mechanism.

Edit (02/26/09): A new manuscript has just appeared that compares the high energy kinks between the electron-doped cuprate with the hole-doped cuprates[17].

Edit (04/14/09): A manuscript has appeared that discussed the possibility that the high energy kink in the Bi-cuprates might be due to an artifact of the matrix element. The calculation produced showed that it isn't, and that this kink points to the coupling of the quasiparticles to the electronic mode [18].

Edit (06/16/09): A manuscript appeared today calculating the phonon contribution to the kink[19]. They concluded that phonons only contribute ~10% to the kink, while non-phonon sources contribute to the other 90%.

Edit (08/05/09): A PRL paper on ARPES measurement of single layer, bilayer, and trilayer Tl-family of high-Tc cuprate[20] shows that the kink has a momentum dependence as one changes the number of CuO planes per unit cell. The authors claim that this is not consistent with magnetic coupling scenario, and thus, seems to point to the electron-phonon coupling as the origin of the band renormalization (i.e. the kink).

Edit (02/02/10): A preprint on arXiv has reported a high-resolution, laser-based ARPES measurement on heavily overdoped (Bi,Pb)2Sr2CuO6. The report claims that the 70 meV kink along the nodal direction is due to coupling to multiple phonon modes[21].

Edit (02/15/10): 2 new reports on a new kink in the band dispersion of Bi2212. This kink is ~8 meV below the gap energy and may be tied to the optical phonon mode[22,23]

Edit (05/24/10): A new theoretical analysis of the low and high energy kink in the cuprates have revealed that these kinks can be reproduced by phonons using the extended Eliasberg theory [24]

Edit (01/10/11): An analysis of the low energy kink has attributed it to an in-plane acoustic phonon branch[25].


[1] S. LaShell et al. Phys. Rev. Lett. v.61, p.2371 (2000).
[2] T. Valla et al., Phys. Rev. Lett. v.83,p.2085 (1999).
[3] T. Valla et al., Science v.285, p.2110 (1999).
[4] P.V. Bogdanov et al., Phys. Rev. Lett. v.85, p.2581 (2000).
[5] P.D. Johnson et al., Phys. Rev. Lett. v.87, p.177007 (2001).
[6] A. Kaminski et al., Phys. Rev. Lett. v.86, p.1070 (2001).
[7] A. Lanzara et al., Nature v.412, p.510 (2001).
[8] A.A. Kordyuk et al., Phys. Rev. Lett. v.92, p.257006 (2004); A.A. Kordyuk et al., Phys. Rev. Lett. v.97, p.017002 (2006).
[9] A. Macridin et al., Phys. Rev. Lett. v.99, p.237001 (2007).
[10] B.P. Xie et al., Phys. Rev. Lett. v.98, p.147001 (2007).
[11] T. Valla et al., Phys. Rev. Lett. v.98, p.167003 (2007).
[15] W. Zhang et al., Phys. Rev. lett. v.101, p.017002 (2008).
[16] T. Dahm et al.,
[17] M. Ikeda et al.,
[18] S. Basak et al.,
[19] E. Schachinger et al.,
[20] W.S. Lee, Phys. Rev. Lett. v.103, p.067003 (2009).
[21] L. Zhao et al.
[22] J.D. Rameau et al. Phys. Rev. B v.80, p.184513 (2009)
[23] I.M. Vishik et al., Phys. Rev. Lett. v.104, p.207002 (2010)
[24] E.A. Mazur
[25] S. Johnston et al.,

Statistical Evidence Consistent With Performance-Enhancing Drugs in Professional Baseball

It seems that the use of statistical analysis has been quite prominent in the controversy surrounding the use of performance-enhancing drugs in baseball. Roger Clemens had a team trying to use such statistics in his favor, but it has now been discredited by a team of Ivy League professors.

Now comes even more support for the Mitchell Report. A team from Boston University has analyzed the statistics in baseball, and applied the power law density distribution from complex systems. They arrived at the conclusion written in the title.

So far, the scientific and statistical aspects of this controversy do not support the innocence of the players involved.


Tuesday, April 01, 2008

Bush to Science: "Let's be friends"

Holy Cow! This must be an April Fools joke!

Bush also plans to relax his stem cell policy. Although he has twice blocked congressional bills that would have expanded federal research on embryonic stem cells (ScienceNOW, 20 June 2007), he said today that such vetoes were a mistake. Bush said he now regrets having placed more value on a destined-to-be-discarded embryo than on a 30-year-old mother with multiple sclerosis--not to mention Michael J. Fox. "Why wait for a new president?" said Bush. "Let's get these embryos into the hands of scientists who can use them for good."

In a final concession, Bush promised to be a better steward of the planet. "I haven't always been clear about the threat global warming poses," he said. "In retrospect, having oil industry lobbyists edit our climate reports was probably a bad idea." He also admitted that initiatives such as "Healthy Forests" and "Clear Skies" had led to excess logging and air pollution, respectively. To make amends, he has appointed former rival and Nobel laureate Al Gore to head his new conservation initiative, which calls for mandatory cuts on greenhouse gas emissions and rigorous protection for species classified as threatened or endangered. "We're calling it 'Pristine Planet,' " said Bush. "And this time we mean it."

I would say that that last part kinda gave it away, really. Who would believe such a thing? :)


Sea Perch is a Fun, Hands-On Approach to Teaching Science

This Physics Today article highlights a project called Sea Perch, a hands-on approach to getting schoolchildren interested in science and technology.

For 10 weeks, Anderson will be showing the 10 students who stay after school for a couple of hours how to assemble their ROVs from kits consisting of such everyday items as PVC pipe and electrical tape. When the students are finished, they'll get to take the electrically powered vehicles to a test tank at the US Naval Academy, where they'll maneuver them by remote control. Throughout the process, the students will learn about buoyancy, displacement, and other physics principles through simple, well-crafted experiments. They also learn how to operate an electric drill and a soldering iron. Best of all, they're having fun doing it.

This is similar to my philosophy on the revamping of the undergraduate intro physics labs. Don't give some rudimentary exercise for them to do. Give them a TASK in which they have to build something or figure out something to accomplish that task. Along the way, they will need to learn certain techniques, or learn certain reason why something should be done in a certain way, just like the kids on this program:

As the children await their turn with the drill, they tested Archimedes' principle by fashioning crude model ships out of aluminum foil. Their goal was to see how many marbles they could load into the makeshift hull before it sank from the weight. By maximizing the length and width of their boats, they learned, they could increase the marble count. They recorded observations in laboratory logbooks. Asked by Anderson to explain how repeated trials are necessary in science, one savvy student explained the importance of changing a single variable at a time.

Reviewing what they had learned that day, Charlie Youngman observed, "the more weight, the more water it displaces," while Matt Rinaldi explained that if a vessel has "solid walls," it's less likely to sink. For R. J. Neal, the biggest lesson was "safety first; always use goggles when drilling."

If these are the lessons that the students learned from the program, then I would say that in my eyes, it has accomplished what many undergraduate intro physics labs have failed to accomplish or reinforce into the students. The ability to know the relationship between what we manipulate and what the corresponding outcome is one of the most important aspect of science, and certainly, experimental science. The students in this program obviously are getting that without even having to be taught of it. Why can't we do the same thing with the undergraduate intro physics labs?


Moore Looks Beyond the Law

Gordon Moore, the legendary Intel cofounder, and the originator of the "Moore's Law" for the semiconductor industry, sat down with the editors of Physics Today for a very insightful interview. Read about his contribution to various scientific projects through his foundation.