Friday, February 27, 2009

Should Students Be Allowed To Vote?

No, not that kind of vote, but more like using this "clicker" during a lecture.

This article describe this teaching aid where students are given clickers and at certain points during the lecture gets to "vote" on the answer to certain question. Many of these have been tested in physics lectures. So the article explores if they are as effective in mathematics lectures.

The bottom line at the end of the article summarizes what I think is a more accurate reflection of this whole thing. And as has been mentioned before in other entries here on teaching, a lot of this depends very much on the instructor and how he/she is engaged in teaching the material.


Thursday, February 26, 2009

High-Tc Superconductors Are Very Kinky - Update 4

Another manuscript appears today addressing the high energy kinks found in the cuprate superconductors. This time, they compare the high energy kinks observed using ARPES between the electron-doped cuprates and the hole-doped cuprates[1].

Abstract: We have performed an angle-resolved photoemission spectroscopy (ARPES) study of Nd$_{1.85}$Ce$_{0.15}$CuO$_{4}$ (NCCO) in order to elucidate the origin of the high-energy kink (HEK) observed in the high-$T_{\rm c}$ superconductors (HTSCs). The energy scale of the HEK in NCCO is large compared with that in hole-doped HTSCs, consistent with previous ARPES studies. From measurement in a wide momentum region, we have demonstrated that between the hole- and electron-doped HTSCs the energy position of the HEK is shifted approximately by the amount of the chemical potential difference. Also, we have found that around $(\pi, 0)$ the HEK nearly coincides with the band bottom while around the node the band reaches the incoherent region and the HEK appears at the boundary between the coherent and incoherent regions.


[1] M. Ikeda et al.,

IceCube Building Goals Exceeded at South Pole

This is a very good article that gives you a brief summary of IceCube, the project to detect and characterize extra-terrestrial neutrinos that hit our Earth.

The observatory is an enormous telescope designed to capture evidence of elusive subatomic particles called neutrinos released by distant cosmic events like exploding stars. Built directly into the ice covering Antarctica, IceCube uses the Earth to filter out lower-energy particles and focus instead on the highest energy neutrinos that carry information about supernovas, dark matter, gamma-ray bursts and other exotic cosmological mysteries.

Such neutrino studies, including MINOS, Numi, NOvA, etc. are all part of the cross-breeding between high energy physics and astrophysics, forming what is now known as "Particle Astrophysics". It could also be what made a few traditional astronomers a bit pissed as well since the study of the heavens and far regions of space have shifted more and more away from classical astronomy and more and more into physics and particle physics.


Wednesday, February 25, 2009

Physicists Playing Cards

OK, this is too nerdy to pass up!

I just found this today. The AIP store is selling 2 sets of playing cards with pictures of prominent physicists on them. One set is "Historic", featuring 54 physicists prior to 1960, while the other deck features 54 physicists after 1960. I wonder who they put as the "Joker"? :)

Each deck includes a complete companion biographical booklet.

Hum... I guess some of my friends now know what they will get for Christmas this year! :)


X-Ray Diffraction of III-Nitrides

This is a terrific review of not only the x-ray diffraction of III-nitrides, but also a lesson in x-ray diffraction in general[1].

Abstract: The III-nitrides include the semiconductors AlN, GaN and InN, which have band gaps spanning the entire UV and visible ranges. Thin films of III-nitrides are used to make UV, violet, blue and green light-emitting diodes and lasers, as well as solar cells, high-electron mobility transistors (HEMTs) and other devices. However, the film growth process gives rise to unusually high strain and high defect densities, which can affect the device performance. X-ray diffraction is a popular, non-destructive technique used to characterize films and device structures, allowing improvements in device efficiencies to be made. It provides information on crystalline lattice parameters (from which strain and composition are determined), misorientation (from which defect types and densities may be deduced), crystallite size and microstrain, wafer bowing, residual stress, alloy ordering, phase separation (if present) along with film thicknesses and superlattice (quantum well) thicknesses, compositions and non-uniformities. These topics are reviewed, along with the basic principles of x-ray diffraction of thin films and areas of special current interest, such as analysis of non-polar, semipolar and cubic III-nitrides. A summary of useful values needed in calculations, including elastic constants and lattice parameters, is also given. Such topics are also likely to be relevant to other highly lattice-mismatched wurtzite-structure materials such as heteroepitaxial ZnO and ZnSe.

It is also a good introduction to the various level of complexities and capabilities of x-ray diffraction. One can get a good understanding of what the fuss is all about when a new synchrotron center opens, and why having a light source like that that produces such quality of x-rays (and other range of light) is so important.


[1] M.A. Moram and M.E. Vickers, Rep. Prog. Phys. v.72 p.036502 (2009).

Tuesday, February 24, 2009

"Green" Energy Initiative Needs A Big Leap

A very good article that discussed the issues surrounding energy efficiency and renewable energy research in the US. It has as much to do with the organizational problems of coordinating and directing such research efforts as it is with the science involved.

There are also roadblocks within the federal government, the Energy Department report and two other new studies suggest. Experts from the Brookings Institution said this month that the way federal energy research was being managed was "holding back innovation and rapid deployment of clean energy technology."

And Harvard researchers said the government had "fallen short in what it can do to promote the development and deployment of advanced energy technology."

All three reports call for more research funding, and they suggest institutional changes to spend research dollars smarter.

Especially when there's a lot of money to be spent after the stimulus package has been passed, it is imperative that some coordinated effort is in place to figure out where the money should go to.


Is There Evidence for God in the Often Strange Things That Happen in World Around Us?

This is a very good and concise article that address this question very succinctly. The author tackles several often-mentioned phrases and claims of "god" or a miracle whenever something unexplained happened.

I often wonder if, when people say something like that, that they completely forgot about history, or are totally ignorant of the progress in knowledge. There are many things that were attributed to "acts of god", such as eclipses, earthquakes, volcano eruption, etc. Now, no one (other than Pat Robertson maybe who still attributes these natural events as "punishments" from god) would seriously claim such a thing.


Monday, February 23, 2009

LHC Performance Workshop - Chamonix 2009

Here's the website that has practically all the info you want to read regarding the status of the LHC and what to expect next.

It's wonderful that they're making this available to everyone. This is becoming more and more of a common practice for many prominent research facilities.


Saturday, February 21, 2009

FSU's Mag Lab Has High Hopes For BigLight

This news report describes the effort to build a facility called "BigLight" at Florida State University's National High Magnetic Field Laboratory.

Unfortunately, this news piece is big on fluff, but totally devoid of substance. I kept wanting to know what is this "BigLight" facility. But the best that I can come up with from the article is this:

Boebinger, the lab’s director, described BigLight as a 40-meter by 10-meter loop of electrons. It would add a valuable tool to be used in concert with the magnetic fields as scientists study any range of materials, he said.

The article is full of accolades for the yet-to-be-built facility, but has no description of what it is. A "..... 40-meter by 10-meter loop of electrons.... " is the best it can do?

So after doing some investigating, I discover that this is a free-electron laser (FEL) facility. One can view a Powerpoint presentation of the proposal for the facility here. An FEL facility isn't unique. The LCLS being built at SLAC is one such facility that should break a whole bunch of records when it is being built. What is probably unique for the BigLight facility is the frequency range (IR?) that it will be dedicated to operating.

I know the public can't understand such a thing, but I certainly didn't expect a news report to be THIS superficial in reporting news. One should look at the news article on science coming out of the NY Times and see how science reporting should be done as far as including relevant details that almost anyone can understand.


Friday, February 20, 2009

Shaping Attitudes Toward Science in an Introductory Astronomy Class

Here's a rather brief but interesting paper. Maybe students can have a very effective and positive attitude towards science from taking just one class in astronomy!

At many universities, astronomy is a popular way for non-science majors to fulfill a general education requirement. Because general-education astronomy may be the only college-level science course taken by these students, it is the last chance to shape the science attitudes of these future journalists, teachers, politicians, and voters. I report on an attempt to measure and induce changes in science attitudes in my general-education astronomy course. I describe construction of the attitude survey, classroom activities designed to influence attitudes, and give numerical results indicating a significant improvement. In contrast, the literature on attitudes in introductory physics courses generally reports stagnation or decline. I briefly comment on some plausible explanations for this difference.

I think, and I truly believe this, that it really doesn't matter if it is astronomy, chemistry, physics, etc. It has more to do with the quality of the teaching, and the instructor him/herself. I have met instructors who are so talented, they could read a phone book and make it mesmerizing, and on the other end, I've encountered instructors who can make the most fascinating material sound downright dry and boring. Until and unless scientists and college instructors realize that it is THEY who hold the biggest influence in shaping a student's attitude towards physics, things will simply continue the way they are regardless of all the modern instruction techniques that everyone seems to be introducing.


Science and Religion Able To Coexist Only Via Ignorance?

One would think that no one right now would dare to use the tired and faulty argument of using the 2nd Law of Thermodynamics (Entropy) to try to debunk evolution. But nooooooooo...... Human stupidity and ignorance can never be underestimated.

This writer is trying so very hard to justify creationism by picking apart not only evolution, but what "scientists" do. This is, of course, assuming that Mr. Anthony Nocket has actually seen and understood what and how scientists actually work. But that's not the reason why I'm picking what he wrote apart. If he wrote this garbage on his own personal webpage, I wouldn't have bothered. There's way too much crap out there to waste precious seconds of anyone's life to comment on. But this apparently is some small news organization, and unless someone actually debunk this, the same misinformation gets perpetuated.

He repeated the same, erroneous attack against evolution:

So as not to open a veritable Pandora’s box, I’ll close with a parable from Thermodynamics Laws: Verse 2. Disorder (or entropy — for those concerned with vernacular) always increases.

How then does life stay together and function, when it’s thermodynamically unfavorable even to keep water from evaporating?

From a physical standpoint, judicious invocation of “intelligent design” appears more legitimate than randomness.

This is a very clear example of "Imagination without knowledge is ignorance waiting to happen". I've already debunked this kind of argument (and so has many others if one cares to actually LEARN. In fact, there have been papers that showed HOW the 2nd Law actually works in promoting evolution! Another paper describing entropy and evolution by Dan Styer describes it even more succinctly. Do you think Mr. Anthony Nocket read them before he made this silly comment? No prize for getting the right answer.

But what is also incredulous is how he is able to fool himself. He applies some set of "law" onto others, but he then sidestep it for himself. For instance:

Here’s the scenario as I see it: God creates physics, physics dictates chemistry and chemistry dictates the rest —including evolution.

The problem is that scientists studying a particular branch of science get bogged down in the minutia, not contemplating the bigger picture. This is precisely why evolutionary biologists have taken flak before, and will, no doubt, continue to do so.

A scientist tries to understand nature empirically, but not its physical origin; this is, for now, the realm of pseudoscience.

So if his "scenario" requires something to create something, then the logical question one would ask is, "Who created God?" If one replies that God doesn't need to be created, that it can simply exist, then what's to prevent us from saying the same thing about the origin of the universe, that the beginning of the Big Bang, for example, had no creator, that it simply existed?

He is correct in one aspect, though. That this is now in the realm of PSEUDOSCIENCE! I bet he didn't exactly look in a dictionary or figure out what "pseudoscience" actually meant before he used it. Wait till he found out that it is more of a derogatory description of what he is believing in! :)


Thursday, February 19, 2009

What Did Galileo Actually Do? Most People Don't Know

There are some things that you JUST expect that a functioning human being should know. For example, if you live in the US, you should really know the name of your current President, and where Washington DC is roughly on the map of the US. You should know the name of the two big oceans flanking the east and west coast of the mainland, and you should really know the two neighboring countries to the north and to the south. One would be severely ignorant to not know any of them and, in my opinion, someone who does not know that shouldn't be allowed to vote!

There are certain things in science that even most the general public is rather expected to at least be aware of. Even if they don't understand science, they should at least have heard of certain names and words due to their importance or prominence. After the great tsunami disaster from a few years ago, almost everyone on earth learned about the word and what it is, even if the overwhelming majority of the public were never schooled in that area of study.

The name "Galileo" is one of those names that should be familiar with people, especially in light of the historical significance, not only in science, but also in christianity. So 400 years after his courageous work that shows that the Earth revolves around the sun, do people actually know what he did? Most apparently do not.

To mark the UK launch of the International Year of Astronomy (IYA 2009) in the UK, the Royal Astronomical Society (RAS), the Institute of Physics (IOP) and the Science and Technology Facilities Council (STFC) have surveyed the UK public to ask what Galileo is remembered for... and most people don’t know.
The results show that nearly one third (29 per cent) of the UK is just as likely to associate the name Galileo with wine, fashion or a famous ship before associating him with astronomy. Also of concern, almost three quarters of the UK (73 per cent) credit Galileo with erroneous discoveries, such as Neptune or the black hole at the centre of our Milky Way Galaxy, or simply don’t know what he discovered – the four large satellites of Jupiter.

But really, is this really a surprise? It isn't to me. Practically all surveys of the public's knowledge of science have shown a rather depressing result. In the 2008 Science and Engineering Indicators, a survey of the public's knowledge of basic science knowledge showed a miserable result. Almost half, for example, thinks that the electron is LARGER than an atom (see Appendix table 7-5).

The public's support for science, strong as it may be, is built not due to an thorough understanding and appreciation of what science is, but rather based on a perceived importance of science. While this may not be a problem most of the time, it will rear its ugly head when the "reputation" of science is under assault either by some scandal, or when it is being challenged by well-managed entities that can distract the public with delightful bells and whistles. The Discovery Institute is one such entity that can propagate zero substance, but disguise it via attacking Evolution.

It is why science cannot be done via public polls. When the majority of the public thinks that a laser is nothing more than a focusing of sound waves, this is not the group of people that should decide science content, or what scientific idea is valid and what isn't.


Wednesday, February 18, 2009

High-Energy Physics Probes Ancient Fossils

First of all, there's nothing wrong with this article. It describes how x-ray from a synchrotron facility is used to study ancient fossils. All fine and dandy, and I can point to another application of synchrotron centers.

What is misleading is the title. "High-Energy Physics Probes Ancient Fossils". "High energy physics", at least in physics circles, means "elementary particles, particle colliders, etc. A synchrotron center is NOT a "high energy physics" facility. There's no particle collider there. In fact, in the US, synchrotron centers are not funded by the High Energy Physics office in the Office of Science, but funded under the Basic Energy Sciences office.

So synchrotron facilities are not "high energy physics" facility. What is more appropriate here is to attribute it to "Accelerator physics". I've attempted several times on here to indicate that accelerator physics is not the same as high energy physics, and remove many misconception about it.

The problem here is that this isn't just a cosmetic issue. Accelerator physics doesn't get the same recognition, and certainly does not enter into the consciousness of students when they choose a specialization. Yet, if you look at many of the advances in physics, both in high energy and in x-ray/light sources, it is the advancement in accelerator physics that made all of those possible. High energy physics, for example, will cease to have any more advances in experimental capability beyond the ILC (if it gets built at all) if those in the accelerator physics community do not come up with new physics to accelerate particles more compactly and cheaper than the current methods. No one is going to want to spend $20 billion or more to build a 100 km particle accelerator. Without any new innovation in accelerator physics, the next frontier of energy in experimental high energy physics will never be realized.

So no, this article has nothing to do with "high energy physics". It has, however, everything to do with accelerator physics and the various uses one can get out of it.


The Absurdly Artificial Divide Between Pure and Applied Research

This is a valiant essay at trying to convince people of the artificial divide between pure and applied physics. However, I think the author didn't go far enough and didn't do it that well because he missed many important examples. I also didn't quite understand how his point is strengthened by the example he gave towards the end of the essay.

What could have been more illustrative is the "feedback mechanism" that is involved between what is typically considered as "fundamental, pure physics" such as elementary particle, field theory, etc. and what is considered to be "applied physics" such as condensed matter physics. I've mentioned several examples, such as the Kondo effect and the principle of spontaneous broken symmetry, that actually came out of condensed matter that have now become part and parcel of "pure physics". The study of magnetic structure in materials CAN and HAS been shown to provide insight into fundamental questions of our universe.

These are the example the author should have shown. I think he missed a golden opportunity.


The Benefits of Particle Physics

To a large extent, it has always been very difficult to point to the "economic benefits" for esoteric areas of physics, such as particle physics, astrophysics/astronomy/cosmology, and even to some extent, nuclear physics (example: RHIC). It is always a tough sell to the public when one is asked "Well, how does that affect my well-being?". Unlike, say, condensed matter physics, where one can always find a direct benefit that translates into various consumer electronics and application, the areas that I've mentioned above has more to do with seeking basic understanding of fundamental knowledge, rather than seeking direct application of that knowledge.

Yet, no one can deny that the efforts in building particle colliders, etc. have resulted in tangible benefits to humankind. But quantifying such benefits have been very difficult, especially if it wants to be used as the selling point. Still, maybe it is time for the particle physics community to actually do careful analysis of this factor to used as a selling point to the politicians and the general public. This is the main point that David Harris over at Symmetry tries to make. After all, it is this lack of selling point that could easily be the root-cause on why physics, and high energy physics in particular, is always the first one to get short-changed whenever there is a pressure on the budget to cut cost. Most do not see any harm in not funding such an area.

If all the politicians can understand is how such-and-such impacts their way of life, then you TELL them. Having such a proper study done on the economic impact of particle physics may be the worthwhile endeavor in selling the importance of the field of study.


Tuesday, February 17, 2009

Looking At Single Electrons

This is a review of the recently published paper in PRL by physicists from Brown University on their ability to track the motion of single electrons. These electrons form bubbles in liquid helium that can be tracked (and videotaped apparently).

It's a very fascinating and clever experiment, and I will qualify that I haven't fully read the PRL paper yet (I've only read the PHYSICS article that reviews this work). However, while I was reading it, I had a distinct deja vu feeling that I've seen this before and have written about it. Sure enough, a quick search of my blog (it's amazing the amount of crap.... er ... stuff I've written over the years in here) produced this entry:

Single Electron Motion Caught on Video

It also appears that these two were done by the same group of people. Can anyone familiar with this work (and have read both papers) tell me the difference between these two?


Tom Hanks To Restart LHC?

Hum... while I think this is a brilliant marketing/publicity strategy, I don't think people have thought this thing through.

It appears that while visiting CERN for the filming the upcoming Dan Brown's "Angels and Demons", Tom Hanks was invited to "throw the switch", so to speak, when the LHC restart later this September {link open for free only for a limited time}.

Hanks was at CERN promoting his new film Angels & Demons, in which he plays Harvard University symbologist Robert Langdon, who is investigating a plot to annihilate the Vatican with 0.25 grams of antimatter stolen from CERN. His co-star Ayelet Zurer, who plays a brilliant CERN physicist, and the film's director Ron Howard, were also present at the unusual junket.

"I asked Hanks if he'd like to come back for the switch-on and he said 'yes'," says Steve Myers, CERN's director of accelerators and technology, after giving him a guided tour of the LHC's 7,000-tonne ATLAS experiment on 13 February.

As if the LHC is not already under a severe media scrutiny, do they need another attention being drawn to the restarting of the LHC? All I can say is, they'd better get this one right.


Monday, February 16, 2009

The Saga of Gravity Probe B

This is a fascinating coverage of the history of the Gravity Probe B and also the tenacity of its champion, Stanford physicist Francis Everitt, in keeping it alive and running.

I continue to be amazed at something like this. You have a science experiment that is trying to test one of the most fundamental and important aspect of our universe, and it struggles to continue to exist while operating under such puny budget when compared to the cost of other things (I believe you can come up with your own list of what these "other things" are). So you force the researcher to go begging for money just to continue with the original mission. This partial funding of something and cutting it of before it completes its mission is INSANE!


String Theory Predicts an Experimental Result?

A rather fascinating item that came out of the 2009 AAAS Meeting in Chicago. A panel discussion during one of the session presented a possible explanation out of String Theory that could describe two very widely separated experimental observations from 2 very different field of study.

First came out of condensed mater from the observation of the behavior of supercooled lithium 6, producing a strongly interacting Fermi gas that behaves like a superliquid. The second came from nuclear physics with the observation of the quark-gluon "liquid" from collisions at RHIC.

It appears that a claim has been made that the holographic principle of String Theory can produce a description that mimic these two phenomena. So in essence, you have the convergence of condensed matter, nuclear physics, and string theory.

So does that mean that string theory finally has an experimental verification? Hardly.

Not to say that string theory has been proved. Clifford Johnson of the University of Southern California, the string theorist on the panel, was very clear about that. All the arguments about whether nature is composed of unimaginably tiny vibrating strings and multiple dimensions, and whether this will eventually explain the basic workings of the universe, are still unresolved.

Furthermore, we also do not know if there aren't any other better explanations, i.e. is the string approach really unique? After all, condensed matter theory already has a well-established line of formulation for the Fermionic gas. If string theory claims to have a more fundamental theory, then it will have to reproduce all of those other observations as well, and not just this.


Sunday, February 15, 2009

Teaching Science: Is Discovery Better Than Telling?

Hum... this new research result should create more questions and also answers some others in the teaching of physics to students in middle/high school.

Western Michigan University researchers have discovered that in the academic debate over whether young science students learn more through experimenting or direct instruction, there's little difference.

Neither teaching approach provides a significant advantage for middle school science students, according to research by three Western Michigan University faculty who will present their findings at the American Association for the Advancement of Science Annual Meeting Feb. 12-16 in Chicago.

So what would be the most important factor in students understanding the material?

In comparing the two methods of instruction, they found there actually was no significant difference in learning by students. More important, they say, was having a positive attitude toward science, a well-designed curriculum and good teachers.


Saturday, February 14, 2009

The Stimulus Bill Approved

The stimulus bill was approved by both the US House of Representatives and the Senate yesterday. It will now be on President Obama's desk to be signed, which he planned to do.

While the bill was as generous with physical science funding as in the original congressional bill, both the DOE and NSF came out of it with substantial money to spend, many on shovel-ready and approved projects just waiting for the money to arrive. This is the most favorable outcome of a budget/funding bill for the physical sciences that we have seen in quite a while. So I'm pleasantly shocked.

The interesting thing left to see is how the money is going to be allocated. While details are still sketchy, it appears that specific provisions have been made for different areas of physics. I wonder if High Energy Physics, for example, will get to restart the ILC effort, and if ITER funding gets a boost.


Friday, February 13, 2009

Bouncing Atoms Measure Gravity

This is one of those amazingly clever experiment. Physicists in Virginia have managed to trap atoms with magnetic field and then cause them to bounce when they collide with an upward laser light.

Initially held up by a magnetic field, the atoms fall when the field is switched off. As they drop down, most of the atoms collide with photons emitted by a laser diode placed directly under the trap, which emits pulses of light in an upwards direction about once every 2 ms. When the atoms collide, they each receive a precise amount of momentum, which knocks them back up. These atoms then fall down again, only to collide with the next laser pulse.

They can make very accurate measurement of the gravitational acceleration, and supposedly, plan to increase its accuracy.


Thursday, February 12, 2009

Stimulus Bill - Almost There!

It's been quite a roller coaster ride for Science in the Stimulus bill. First we got good news with the version that passed though the House of Representatives. Then DOE and NSF got zeroed out in the version that passed through the Senate. And now after the negotiations, there's a lot of hope for funding for the physical sciences after all!

While details are sketchy (meaning we won't know for sure till this thing is approved), the summary of the current version that will make it through the House today and the Senate tomorrow is like this:

NIH: $8.5B for research; $1.5B to renovate university research

DOE: $1.6B for Office of Science, $400M for ARPA-E, and $30B across
DoE for smartgrid/advanced battery technology/energy efficiencies

NSF: $3B for basic research

NASA: $1B, including $400M for climate change research

NIST: $580M

However, as we have seen the the past, these things can change just like THAT, and we have seen how support for the physical sciences have NOT translated into equitable funding. I'll believe it when I see the funding money in research accounts, and not a second till then.


The NSLS-II at Brookhaven

I mentioned earlier of the construction go-ahead received by Brookhaven to build the NSLS-II. Robert Crease has a terrific piece on what this machine is and why it is important, especially to that region of the country.

First, research at NSLS-II will not be in the esoteric domains of particle physics or cosmology, but in areas with significant, practical applications: energy production, materials science and nanotechnology. Large corporations such as GE, IBM and Corning will use its unique resources to address problems they could not before. Helped by Stony Brook University's efforts, a nexus of 400 companies, universities and government labs has begun to collaborate in a way that will fundamentally restructure relations between these institutions.

I think everyone that works at a synchrotron light source can testify to the fact that almost everything that is done at such facility has an immediate impact or benefit.


Wednesday, February 11, 2009

Nanocrystals Shown to Generate More Than One Electron Per Absorbed Photon

This is rather interesting, especially when I missed all the controversy regarding the earlier, similar claim.

Scientists out of Los Alamos have reconfirmed their findings that in certain nanocrystal, one absorbed photon can produce more than one free electron in the conduction band.

When a conventional solar cell absorbs a photon of light, it frees an electron to generate an electrical current. Energy in excess of the amount needed to promote an electron into a conducting state is lost as heat to atomic vibrations (phonons) in the material lattice. Through carrier multiplication, excess energy can be transferred to another electron instead of the material lattice, freeing it to generate electrical current—thereby yielding a more efficient solar cell.

Klimov and colleagues have shown that nanocrystals of certain semiconductor materials can generate more than one electron after absorbing a photon. This is partly due to strengthened interactions between electrons squeezed together within the confines of the nanoscale particles.

If this finding is true, then one immediate direct implication is that one could produce a more efficient solar cells.

I'll try to hunt for the exact reference (I hate press releases like this since they do not include the exact citation) and post it here when I find it.


Tuesday, February 10, 2009

Conflict Brews Over Science in US Stimulus Package

With the stimulus bill passing through the US Senate already, it is now the tedious and difficult task to reconcile the bill's version that passed though the US House of Representatives early. The differences are still quite big as far as funding for science is concerned.

Overall, science fared well in the Senate. According to an analysis by the American Association for the Advancement of Science (pdf format), the Senate bill includes $17.8 billion for research and development, including $2 billion for new facilities and equipment - compared to $13.2 billion in the version previously passed by the House of Representatives.

This boost is mostly due to an extra $6.5 billion provided by the Senate for biomedical research at the National Institutes of Health. But the two main agencies that support the physical sciences - National Science Foundation and the Department of Energy's Office of Science - were not so favoured. In the Senate bill, they get only $1.2 billion and $330 million respectively, compared to $3 billion and $2 billion in the House version.

So how come the physical sciences ALWAYS get the short end of the stick? I've never had any politician flat out explain this. It's not something they can't deny since we have all the evidence these past few years.


University of Idaho Physics Not Going Without A Fight

I highlighted earlier of the news that the undergraduate physics program at the University of Idaho is one of those on the chopping block of programs for elimination. It appears that this past week, there was a public hearing on the proposal, and there was a unanimous support for the program to continue.

More than a dozen students and faculty members made their plea to keep the physics program to the committee members. Members outside of the physics department, including faculty from the College of Education and the College of Engineering, also offered their requests to “save” the program. A high school student who is interested in studying physics also asked the committee to reconsider the current proposal.

No one spoke in favor of cutting the program.

There's nothing much for a blogger like me can do other than voice my support and hopefully publicize it.


Monday, February 09, 2009

AAAS Annual Meeting

The annual meeting of the American Association for the Advancement of Science (AAAS) is meeting in Chicago this week. If you are in the area, there are plenty of activities for you and/or the whole family either at the conference itself (the Exhibits area in the Hyatt Regency hotel) or at various locations around the city. Click on the program at the webpage or the Family Science Days.


Science and Astrology: the Proof in Astrophysics?


This article shows exactly why astrologers have no clue on how things are accepted to be valid in science. This person is trying to grasp as the flimsiest straw based simply on one, ONE, hypothetical musings on a "theoretical astrophysicist". I'll let you read the rest of the article, which really provides ZERO evidence to accept the validity of astrology. But what gets my goat is what was said at the end of the article:

Thus far, the few scientific studies that support astrology have shown significant correlations, but correlations are measurable observed links between one happening and another....they don't reveal predictable outcomes. So, perhaps astrology will never be confirmed by the majority of scientists, but even Seymour points out that scientific thought...both ancient and fallible due to preconceptions and that astrology is dismissed without study by the average scientist.

But what about not accepting something FIRST before valid and convincing evidence are presented? It is NOT the job of science to prove that you are wrong, it is the job of whoever is trying to show that something is valid to find convincing evidence. Every single scientific discovery and new ideas have to go through that process. Einstein had many doubters to all of his idea when presented. Quantum mechanics had a lot of challenges against it. It is when these ideas are backed by overwhelming body of evidence (as in empirical evidence), only THEN are they accepted to be a scientific idea and considered to be valid. Not before then.

Yet, so many people, including this "astrologer" have already accepted astrology to be valid, despite the lack of any valid evidence. Astrology is dismissed because of that. And considering that such a belief has been around for hundreds of year and it still can't get beyond the phase of trying to prove its existence, it has been understandably categorized as crackpottery. A valid phenomenon never languishes in the land of "is it true, or is it not true" for that long. Our understanding of every single valid phenomenon improves with time, from the moment of discovery to making even more careful measurement of its various properties. We know more about the top quark mass now when compared to when it was first discovered at the Tevatron. We know more about the behavior and puzzling properties of high-Tc cuprate superconductors, even though we still don't quite fully have a valid theory for it. All of these phenomena have gone way past the "discovery" phase and into more detailed studies. One cannot say that about "astrology", that is still stuck at first base.

It is crackpottery.


Sunday, February 08, 2009

A Musical Tribute To Einstein Inspired By Mozart

Unlike the very puzzling "Einstein's Physics on Violins", this one is actually kinda interesting and creative.

Einstein's love of Mozart, and the inspiration it provided him, is the theme behind ''Einstein's Mozart: Two Geniuses'' by Kate Light. The composition -- an integration of two of Mozart's great string works with the narration of Light's original poetry and prose -- will be performed today at the Zoellner Arts Center by the Serafin String Quartet, with Light as narrator.

See, something like this, I can sit through, mainly because it is more of an entertainment. And they don't try to "interpret" physics into music, especially by musicians who are not trained in physics, which is rather pretentious.


Saturday, February 07, 2009

The World's Top Ten Telescopes

Based on science impact, the Sloan Digital Sky Survey is the top telescope of the year {link open for free only for a limited time}. The list of the top 10 telescopes was compiled in this report.


Physics vs. Medicine in the Stimulus Bill

It may have happened again.

Remember all those optimism regarding funding for DOE and NSF in the Stimulus bill? And remember when I said that I am not going to buy all this until I see the money? Well, my pessimism may be justified.

The bill that has been agreed to may have cut the money going to DOE and NSF.

According to a version of a memo describing the cuts, the stimulus for N.S.F. and the energy department’s Office of Science would be cut to zero and there would be cuts to the NASA and NIST portions as well.

Clay Westrope, Sen. Nelson’s spokesman, said the senator was not anti-science, but that he felt the stimulus bill was the wrong place to add financing for long-term research. “If they were in a spending bill, he would probably support them,” Mr. Westrope said.

Mr. Westrope said he could not explain why biomedical research was regarded as a stimulus, but physics research would not.

The NIH should be given the responsibility to construct its own synchrotron centers and use some of the obscene amount of money it gets, rather than benefiting from the physical sciences and their facilities. Maybe then, the people in congress can get their heads out of the hole in the ground and see who supports what.


Friday, February 06, 2009

CERN to Set Goals for First LHC Physics

This is the latest press release out of CERN regarding the start-up of the LHC. It includes not only the plan for the start-up, but also on the cause of the shut-down.

At the conclusion of a workshop held in Chamonix this week, recommendations have been made to the CERN1 management for the restart schedule of the Large Hadron Collider (LHC). If accepted in a management meeting on Monday, these recommendations will ensure that the LHC starts to produce physics data in late 2009, running through the winter and on to autumn 2010 at an energy of 5 TeV per beam and ensuring sufficient data for the experiments to produce their first new physics results.


Thursday, February 05, 2009

IoP President Gives Her Thoughts

The current president of the UK's Institute of Physics, Jocelyn Bell-Burnell, gives her thoughts on the state of physics, physics education, and IoP's function in this video.


Wednesday, February 04, 2009

Neal Lane Warns of Science Gaps

Neal Lane, the former Presidential Science Adviser for Bill Clinton, was interviewed recently. In this news article, he expressed his opinion on the current state of science in the US, the damage done to science, and what he expects from the Obama administration. In particular, he echoed what I have been saying on here all along:

Q. Are there other areas of concern within science where the United States is losing ground relative to the rest of the world?

A. There are other examples of where we have started to fall back from a position of leadership because of many years of under-investment in basic research, particularly the physical sciences.

Q. Can you give me an example?

A. High-energy physics. Over 1,000 U.S. physicists are now going with their students to Switzerland to work on the Large Hadron Collider, the high-energy accelerator. That’s partly because Congress killed the Superconducting Super Collider a number of years ago, a terrible mistake in my view. Had that not happened, scientists from all over the world would have been working here, along with the small companies that grow up around these large experiments. If we don’t provide these experimental facilities, eventually people just aren’t going to come here, and we’ll be left in the dust.


The Seeker of Novel Materials

There are MANY well-known physicists among other physicists who are not well-known to the public. In fact, in each of the different field of studies in physics, there are plenty of "giants" in those fields who are quite well-known and prominent.

This is one such physicist in the field of condensed matter. Practically everyone in that field know Paul Canfield pretty well. And now it is your turn. This news article profiles this prolific physicist and what he does well.

There are many people who are not household names, but are significant contributors to the body of knowledge that we call Physics.


Dynamics of Coin Tossing is Predictable

Y'know, sometime when I'm bored, I browse various journals that I seldom read just to find something I could occupy my time, or even something to read in bed that can put me to sleep! :) It is during such browsing time that I often find many articles that often is more interesting than what I anticipated.

This could possibly one such article, and I find that I'm spending way more time than I should reading it. The article discusses in great detail the dynamics of coin tossing[1], and that, as we expected, it isn't random once we know the initial condition even when we include various other complexities such as air resistance, and the various strange trajectory and spinning motion.

Abstract: The dynamics of the tossed coin can be described by deterministic equations of motion, but on the other hand it is commonly taken for granted that the toss of a coin is random. A realistic mechanical model of coin tossing is constructed to examine whether the initial states leading to heads or tails are distributed uniformly in phase space. We give arguments supporting the statement that the outcome of the coin tossing is fully determined by the initial conditions, i.e. no dynamical uncertainties due to the exponential divergence of initial conditions or fractal basin boundaries occur. We point out that although heads and tails boundaries in the initial condition space are smooth, the distance of a typical initial condition from a basin boundary is so small that practically any uncertainty in initial conditions can lead to the uncertainty of the results of tossing.

Sometime it is nice to see what we know should happen, and someone else did all the dirty and tedious work to show this. :)


[1] J. Strzałko et al., Phys. Rep. v.469, p.59 (2008).

Debating the Source of a Rare Particle

This is a very good comprehensive review of the recent excitement surrounding the PAMELA results that may have detected dark matter. Not only that, the article contains FREE access to the actual PAMELA paper published in PRL. What more could you want?


Edit: a review of this publication can also be found at PhysicsWorld.


Invisibility Umbrella Would Let Future Harry Potters See the Light

This is a report on a very clever scheme where an object is placed next to a left-handed material, resulting in both having a "cloaking" property.

The trick, they report in a paper to be published in Physical Review Letters, is to embed a matching "antiobject"--the metamaterial equivalent of a voodoo doll--in the outer layer of the post. The scattering from the embedded antiobject exactly cancels the scattering from the object, Chan says, "so it looks as if there is nothing there." Because the hidden object remains outside the post or umbrella, it can detect light from its surroundings.

The scheme does have limitations, Pendry notes. The umbrella works for only a single frequency, has to be specifically tailored to the object to be hidden, and won't completely hide something that absorbs light. Still, Pendry says, "that's carping on my part--it's really a neat idea."

The application for left-handed materials is very vast. I just wish that we don't attach it to such popularization and suffer from the same misunderstanding as the "teleportation" phenomenon.


Tuesday, February 03, 2009

Sudden Death of Entanglement

This is a very nice review of essentially the phenomenon of decoherence[1]. I finally had a chance to read through it. If nothing else, it has a wealth of references that I find highly valuable. What the review indicates is that the loss of quantum correlation (or decoherence) can occur a lot faster than "half-life decay".

What is more important, at least to me, is that this clearly shows why all the pseudoscience, mystical claims, and other crackpotteries that attempted to use QM and entanglement in particular to justify their claims completely and clearly show their ignorance of the subject matter. Many claims, such as this and this, only apply the physics that was probably gathered from popular science sources without understanding the physics, and without getting the whole picture. They only hear about "entanglement", without realizing what it is, how difficult it is to maintain, and how it can easily be destroyed. So they attempted to use it to justify something else without knowing all the "ground rules".

One would hope that these people would read a paper like this, but that's asking way too much, I'm sure. So if you encounter another of these crackpots trying to sell you on how we are all "entangled" with each other because QM says so, show him/her this paper.

Edit: a press release of this publication can be found here.


[1] Ting Yu and J.H. Eberly, Science v.323 p.598 (2009).

Monday, February 02, 2009

Einstein's Physics on Violin

Einstein's physics on violin..... Er.... what?

Professor Brian Foster of the Experimental Physics department at the University of Oxford will deliver a lecture on Einstein’s contribution to physics, including his Theory of Relativity.

Violinist Jack Liebeck will join Professor Foster on stage at various points to provide musical analogies to some of the points raised by the lecture.

Er.... what?!

I'm going to stop scratching my head before I go bald. But what the hey....? It is difficult enough to explain such a thing in plain English, but this? I'd like to know what is expected out of such "musical analogies". Or maybe I don't understand and appreciate something like this because I am musically illiterate?

If you get to go to this one (and it should be a doosey), can you please tell me how the photoelectric effect analogy sound? I'm awfully curious with that one.


Gender Bias Found in Student Ratings of High School Science Teachers

OK, so we have gender issues with female students in science and engineering. Now, even the students themselves are showing gender bias against female science teachers!

Most notably, say the researchers, the physics students in the survey showed the largest bias toward female physics teachers. In biology and chemistry, male students tended to underrate their female teachers, but female students did not. In physics, both male and female students tended to underrate their female teachers.

I don't have access to this publication since my institution doesn't subscribe to it, so I could not tell you more about the content than what's being reported here. If you do have access to it and have read it, I would like to hear a bit more on the content, especially if they have made any proposal on the possible reason for such a bias.

My initial inclination is that in physics, the predominant "role model" of a physicist is typically a "nerdy man" with ruffled hair, a lab coat, and may be horribly absent-minded. So a female physics teacher doesn't fit into what these students probably think a physicist should look like and so, give them less credibility.

We need not only more female physicists to be pushed to the limelight (I guess that's what Lisa Randall is doing), but also more studly and handsome male physicists to dispel the nerdy myth! :)


Google Has Gone "Psychic"

I harped on Yahoo search a while back for displaying not only crackpot websites when one does a search on "physics", but also listing psychic websites, which is the antithesis of physics. So now, to be fair, I will have to whine also at Google search for doing almost the same thing.

It appears that lately (or it could just be my imagination), that the psychic websites are appearing more frequently when one does a "physics" search. I don't remember this occurring this often before. Did something changed? Here's an example:

Of course, as with the result of a Yahoo search, this is annoying but not unexpected. These search engines are trying to be too clever and anticipate all possible spelling mistakes that might people make. In the process, it'll list things that are of a complete opposite to the subject matter that one is looking for. As intelligent as they try to make it to be, this shows that the search logic is still pretty dumb.


More On The Physics Of Basketball

Here's something that sorta re-enforced what was mentioned earlier. John Fontanella, the author of "The Physics of Basketball", explains why tall men in the game seems to have more problems in making either a jump shot or a free throw. It has to do with the angle and trajectory of the ball.

“This gives an extra reason that Wilt and Shaq are poor free-throw shooters,” Fontanella wrote in an e-mail. “If they were trained by people of average height, they were probably trained incorrectly. They were probably taught to shoot like a shorter person and that’s wrong. A big man needs to shoot the ball in a slightly different way in order to take advantage of the physics.”

Fontanella said that launch angle and angle of approach of the ball are pivotal in free throw shooting. Angle of approach is the angle between the horizontal and the velocity of the ball when the ball is directly above the front of the hoop. It’s the angle in which a basketball “sees” the hoop at its largest opening as opposed to a ball coming toward the hoop at an acute angle.

It also means that to improve the "effective surface area" of the hoop that the ball sees, one might want to consider shooting the ball underhanded, which was the argument used earlier. Unfortunately, this might work only for free throws, because doing such a shot during the rest of the game is just inviting it to be blocked way too easily.