Wednesday, September 30, 2009

Hawking Steps Down From Cambridge Post

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

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

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


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

Zz.

Tuesday, September 29, 2009

Quantum Entanglement Visible to the Naked Eye?

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

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

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

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


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

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

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

Zz.

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

Happy Birthday, Enrico Fermi

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

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

Zz.

Monday, September 28, 2009

Unintelligent Design

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

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

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


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

Zz.

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

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

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

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

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


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

Zz.

Sunday, September 27, 2009

UK's Science Figures Are "Science Fiction"

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

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

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

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


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

Zz.

Friday, September 25, 2009

2009 Nobel Prize Predictions

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

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

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

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

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


All of them are good and worthy choices.

Zz.

Thursday, September 24, 2009

Is George Smoot Smarter Than A 5th-Grader?

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

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

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


Luckily for us, he crushed the challenged.

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

Zz.

Mildred Dresselhaus

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

Zz.

Wednesday, September 23, 2009

More on Spin-Charge Separation

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

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

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


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

Zz.

Tuesday, September 22, 2009

Cornell Synchrotron Center

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

Still, what's wrong with this picture?

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


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

Zz.

Monday, September 21, 2009

Science and Technology Policy in the Obama Era

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

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


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

Zz.

Sunday, September 20, 2009

FY 2010 US Defense Science and Technology Appropriation Bill

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

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

Zz.

Friday, September 18, 2009

Einstein's Nobel Prize

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

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

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


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

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


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

Zz.

Thursday, September 17, 2009

First Detailed Photos of Atoms

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

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

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


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

Zz.

Wednesday, September 16, 2009

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

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

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

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

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


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

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

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


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

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

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

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


So I gasped a bit when I read that.

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

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

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

Zz.

Tuesday, September 15, 2009

ATLAS Multimedia Contest Winners

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

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

Zz.

Monday, September 14, 2009

Best Morley-Michelson Experiment Yet!

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

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

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

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


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

Zz.

Sunday, September 13, 2009

Steven Weinberg: Master Builder of the Standard Model

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

Zz.

Saturday, September 12, 2009

Is Physics iPods, or the LHC?

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

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

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

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


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

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

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

Zz.