Giant Magnetoresistance

The 2007 Nobel Prize in Physics was awarded to Albert Fert and Peter Grünberg for the discovery of the Giant Magnetoresistance, as reported earlier. I had also given a good link that explains what GMR is. Still, one can never have too many good explanations of what it is, so here's another one, this time, it's an article from Physics Central.

This is actually quite appropriate because it is another example on how basic research in strongly-correlated electron systems can produce something that becomes important in our daily lives. It is why basic research is important. One would hope that this message gets across to those people making funding decisions.

Zz.

Webcast: Nobel Laureate to lecture on "Blind Chance or Intelligent Design: The Need for Basic Research," April 8, 2008

Here is the announcement for the next series of Honeywell-Nobel Initiative lecture series:

Some scientific advances, such as the discoveries of X-rays and penicillin were stumbled upon through serendipity. Others, like streptomycin and nuclear reactors, resulted from targeted and specific research. Honeywell will be presenting a lecture and Webcast by Nobel Laureate Dr. Sheldon Glashow on “Blind Chance or Intelligent Design: The Need for Basic Research" at 9:00AM on April 9, 2008 in Beijing (9:00PM pm April 8, 2008 in Eastern Time).

Dr. Glashow’s many research accomplishments in theoretical physics include his prediction of the charmed quark (for which he was awarded the Oppenheimer Medal) and his seminal contributions to the unified theory of weak and electromagnetic interactions (for which he shared the 1979 Nobel Prize in Physics).

For the past quarter century, while he has continued his fundamental researches in particle physics and cosmology, Dr. Glashow has also focused on stimulating interest in science among high-school students and encouraging scientific literacy among non-science students at the university level.

Dr. Glashow will be delivering a lecture to students at Beihang University, Beijing, China on April 9. A live Webcast of his remarks, as well as related content, will be available for viewing from Honeywell Science.

The video of the recent lecture on Cosmic Background Radiation by George Smoot is now available online.



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Under Control: Keeping the LHC Beams on Track

While people do have some idea of the size and the complexity of the LHC, most do not have a good 'scale' of the issues involved here. There are some astounding issues and problems that they have to deal with. Keeping the LHC beam under control, and what to do when it veers off course is a major issue.

This article tries to impart some idea on the control and contingency issues of the LHC beam. For example:

The complexity means that repairs of any damaged equipment will take a long time. For example, it will take about 30 days to change a superconducting magnet. Then there is the question of damage if systems go wrong. The energy stored in the beams and magnets is more than twice the levels of other machines. That accumulated in the beam could, for example, melt 500 kg of copper. All of this means that the LHC machine must be protected at all costs. If an incident occurs during operation, it is critical that it is possible to determine what has happened and trace the cause. Moreover, operation should not resume if the machine is not back in a good working state.

So this is not case where you can just simply pull the switch if something goes wrong. They have to make sure they dump the beam properly without causing damage to all the components along the ring.

This is, of course, a common issue at large particle accelerator facilities, including the Tevatron. I am still at awed at some of the things they are able to do, and at the scale that they are doing in. I some time wish the most of the general public has some clue on the level of complexity and the accomplishments at just being able to run such an experiment.

Zz.

Accelerator in a Bowl

This is a cool demonstration to illustrate how they accelerate particles at the Tevatron at Fermilab.



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Ettore Majorana And His Heritage Seventy Years Later

For those who are not familiar with the story of Ettore Majorana, this is probably a good introduction to his life, and his contribution to physics within such a short period of time till he mysteriously disappeared some 70 years ago. I consider him the Emelia Earhart or the Jimmy Hoffa of physics because of this disappearance, which still has not been solved.

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An Inquiry Into the Reproduction of Physics-Phobic Children by Physics-Phobic Teachers

I know! I was intrigued by the title as well! :)

First of all, this is a paper that was originally published in Japanese, and this English version is, what appears to be, an almost direct translation. So there will be some awkward passages here and there. If you keep that in mind, everything should be OK (just think of literal translation and you'll be fine).

The authors studied the effect of teachers who themselves have little understanding or interest in physics on students. Somehow, the teachers disinterest in physics can (surprise!) transfers itself to the students.

It is interesting to note that, with the budget crisis in physics in the US and UK, we tout the high investments in science in Europe and Asia, particularly Japan, China, and Korea. But it is obvious from this report that even in Japan, they also face, to a lesser degree, problems in getting students to do physics, not just as a career, but in terms of being educated or literate in it.

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Considering Science Education

There has been only one essay so far in which I flat out tell everyone to go read it. It was the Helen Quinn essay "Belief and Knowledge - A Plea About Language".

OK, so here comes another one. In the March 21, 2008 issue of Science, an editorial by Bruce Alberts is a MUST READ by everyone and anyone (Science, v.319. p.1589 (2008)). He argues why science education is important to everyone, and not just science students.

I consider science education to be critically important to both science and the world, and I shall frequently address this topic on this page. Let's start with a big-picture view. The scientific enterprise has greatly advanced our understanding of the natural world and has thereby enabled the creation of countless medicines and useful devices. It has also led to behaviors that have improved lives. The public appreciates these practical benefits of science, and science and scientists are generally respected, even by those who are not familiar with how science works or what exactly it has discovered.

But society may less appreciate the advantage of having everyone aquire, as part of their formal education, the ways of thinking and behaving that are central to the practice of successful science: scientific habits of mind. These habits include a skeptical attitude toward dogmatic claims and a strong desire for logic and evidence. As famed astronomer Carl Sagan put it, science is our best "bunk" detector. Individuals and societies clearly need a means to logically test the onslaught of constant clever attempts to manipulate our purchasing and political decisions. They also need to challenge what is irrational, including the intolerance that fuels so many regional and global conflicts.

I totally agree. If you have read the beginning of my series on revamping the intro physics labs, I've always argued that these labs can be a valuable tool to these students (the majority of whom are not physics majors) as an illustration on how we accept something to be valid, or how we arrive at some of our knowledge. We should emphasize the idea that using scientific technique to verify something is the strongest degree of certainty that one can have in any endeavor. It is why scientific evidence is different than anecdotal evidence. It is why astrology is not a science, whereas astronomy is. The fact that many still can't tell the difference is an important reflection on how these arrive at what they perceive to be true. This means that many of the decisions they make may not be based on valid information or evidence.

So think of what happens when they vote for their political leaders....

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The Squeeze at Argonne And Fermilab

.. and this "squeeze" comes both in terms of funding and science.

Three months into the disastrous Omnibus bill, this article looks at the impact on the two national laboratories in the Chicago area - Fermi National Accelerator and Argonne National Laboratory.

To say that the mood and the morale are low is to put it mildly. One good thing about this article is that it highlights each of the facility that has been affected, and what kind of science and impact it has.

As far as I can tell, the outlook for the immediate future isn't rosy either. Even though the president's FY09 proposal calls for immediate increase in all affected areas, everyone here is almost certain that Congress is not going to pass this budget any time soon and will wait instead until after the general election. This means that we will be saddled with a continuing resolution, and will adopt the disastrous FY08 budget for the remainder of the year and into next year.

Things are not looking good for science in the US, despite all the lip service that has been given about its importance.

Zz.

The Science of Tangled Cord

Next time you have to untangled the cords from your electronics, you can at least think of it as a complicated physics process. :)

This news article describes a recent PNAS paper on this very issue.

Knot formation had been studied a lot by mathematicians, but not much by physicists. Smith was worried that the work wouldn't be taken seriously, but it ended up being published in the prestigious Proceedings of the National Academy of Sciences.

"The way that you get a knot is the string has to bend back on itself, coil back on itself," Smith said. As a string or cord tumbles, the end of it has a 50 percent chance of weaving to the left or the right of the coils, and under or over the coils, sort of like random braiding, Smith said.

The exact citation for this paper (which none of these popular newspapers ever give) is:

Dorian M. Raymer and Douglas E. Smith, PNAS v.104, p.16432 (2007).

Don't get all tied up with it.

:)

Zz.

Interpretation of Quantum Mechanics - The New Religion

First of all, a clarification and a qualification. Most physicists (at least the ones that I come in contact with throughout my years as a student and as a physicist) don't really care about the various interpretations of quantum mechanics. It really is a non-issues 99.9% of the time. So essentially, we practice Feynman's "Shut Up And Calculate" philosophy where the formalism and what empirical evidence that it can produce is what we care about.

Now, in one of my rants in "Imagination Without Knowledge is Ignorance Waiting to Happen", I mention about many crackpots who have argued that physicists simply want to keep the status quo as far as our understanding of the universe goes, that all we care about is upholding the current laws and theories. We can't, as some put it, work "outside the box". Some even compare to our "devotion" towards not wanting to drop our current understanding as a "religion".

This, of course, is stupid, and false, on many different levels, as I've mentioned in that blog entry. Still, there is one aspect of physics in which, I hate to say, is starting to look like a religion, and it has nothing to do whatsoever with what these crackpots have in mind. In fact, I don't think any of them could even comprehend these things well enough to know any better.

What I find in physics to be no different than a religion is the rabid devotion of some people, physicists included, to the various interpretation of quantum mechanics. These interpretations could range from the "popular" Copenhagen Interpretation (CI), to Many-World Interpretation (MWI), to Bohm Pilot Wave (BPW), etc.. etc. Now, again, to be fair, this issue comes up only in a very small percentage of practicing physicists. I tend to find more of these discussions on physics forums rather than in prominent physics journals. And certainly, amateurs and philosophers tend to be more fascinated by this issue than the overwhelming majority of physicists. So in physics, this "religion problem" isn't a widespread epidemic.

Still, those who are devoted to this is not doing physics any favor. I find that the rabid devotion to such various interpretation (rather than just a casual attitude about it) rather puzzling and contrary to how one accepts something to be valid in physics. This is why I find that the devotion to any such interpretation as being no different than a religion:

1. There's no empirical evidence that shows one being "better" than the other. All of them come up with the same analytical form within the formal QM. The similarities with religion is obvious here. This means that there's nothing to support which is better, and they all come up with the same answer, at best, so far.

2. Yet, the devotees in each camp tout why such-and-such is more "logical" or "rational" or "conceptually sensible", etc. Without empirical evidence to support such claim, this is nothing more than a preference based on a matter of tastes! We might as well argue for our favorite color, or, in this case, our favorite religion. This is no different than the different religions and the many followers that they have. Each one will tout the superiority of its belief system, or why it is the "truth", etc. Yet, in none of these are there any empirical evidence to separate and support these claims.

Now one could argue that isn't what is being taught in QM classes more along the lines of adopting the CI? I don't believe so, because in the end, it is the formalism that is more important, and there's no ambiguity at all there. And if it really is CI that is being instilled into these students, how come most of them grow up and adopt the "Shut Up and Calculate" point of view and not become a CI devotee?

I'm not saying that at some point, there won't be a "tie-breaker", be it a further refinement to these various interpretations that make them distinctly different from each other, and/or new tests would come out to allow for direct verification of each one. But until then, why are people "believing" in something that, at the very foundation, is simply a matter of tastes?

Zz.

Iron-Based High-Tc Superconductors

This certainly came out of nowhere.

There's another "high-Tc" superconductor joining the fun. This time, unlike the cuprates, it consist of iron-arsenic planes, and is doped with fluoride atoms. Currently, it has a Tc of 26K, but that would probably change.

From preliminary report, it seems that it is not phonon-mediated, but rather via spin-fluctuation. It would be interesting to see if it has the same phase diagram as the cuprates and if it also has a pseudogap state.

Update 04/18/08 : There's a rather good summary on this in a Science daily news.

Zz.

What is the Matter with the Uuniverse?

More CP violation results out of KEK on the B meson.

To find out the team created pairs of matter and antimatter particles, called B mesons and anti B mesons, and measured how they behaved. The study has come up with a better estimate of earlier measurements that suggest that there is a difference in the rate of decay (they decay into a kaon and pion).

"We have measured two differences of decay rates between b and anti-b," says Prof Hou. " It is around 9 per cent for neutral B and anti-B, and 7 per cent for charged B and anti-B. The bigger mystery, and gist of our paper, is posing the question of why there is this difference."

But the end of the article mentioned about waiting for more results out of BaBar at SLAC. I thought SLAC is no longer doing any particle collider experiment and is already being converted into the LCLS? Did something changed? Or are still going to do limited collider experiment in between LCLS runs?

Zz.

Addendum: I just finished reading the paper in Nature (Lin et al, Nature v.452, p.332 (2008)) and the Perspective on this work by Michael Peskin in the same issue of Nature. The BaBar result they are expecting is the analysis of the large, existing data that have already been collected. So it isn't from any future BaBar experiment. That clears things up a bit, at least for me.

More Addendum: See a report on this in PhysicsWorld.

HiRes Confirms GZK Cutoff

This could be one of HiRes last triumphs. It has now down a "negative result" experiment and confirms the GZK cutoff (link may be open for a limited time), signifying a threshold of energy for cosmic rays.

This energy ‘cut-off’ was predicted in 1966 by Kenneth Greisen of Cornell University in Ithaca, New York, and in the same year by Soviet physicists Georgiy Zatsepin and Vadim Kuzmin of the Lebedev Institute of Physics in Moscow. They predicted that there would be very few cosmic rays with energies greater than about 6×1019 electronvolts (eV) because of energy losses through interactions with the ubiquitous photons of the cosmic microwave background, the radiation that fills the Universe.

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The Hummer is NOT More Environmentally-Friendly Than a Prius

It's amazing how a report that is full of holes can gain such a foothold once some talking heads on TV adopted it.

A while back, there was a rather dubious report called "Dust to Dust" that essentially drew up a conclusion that the monstrous Hummer is more "environmentally friendly" than the Prius, based on all the energy accounting that is being used to research, manufacture, and run the vehicles. Slate.com has a brief synopsis of the whole thing. Luckily, they also tackled the validity of that claim and cited several prominent (and certainly, NOT dubious) research work. It essentially debunked that myth.

Moral of the story: never accept the validity of science/engineering issues from politicians, TV personalities, or popular news media.

Zz.

More Challenges Against Non-Local Hidden Variables Theory

Science Daily is reporting a new experimental measurement out of NIST and Maryland that challenges the validity of a certain aspect of non-local hidden variables theory.

Experiments so far have ruled out locality and realism as a combination. But could a theory assuming only one of them be correct" Nonlocal hidden variables (NLHV) theories would allow for the possibility of hidden variables but would concede nonlocality, the idea that a measurement on a particle at one location may have an immediate effect on a particle at a separate location.

Measuring the polarizations of the pairs of entangled particles in their setup, the researchers showed that the results did not agree with the predictions of certain NLHV theories but did agree with the predictions of quantum mechanics. In this way, they were able to rule out certain NLHV theories. Their results agree with other groups that have performed similar experiments.

I may have missed it, but I don't recall ever seeing any experiment on entanglement that hasn't produced any result that's consistent with QM. One can argue that such-and-such an experiment doesn't rule out that and that theory, but QM is batting with 100% hits here with zero strike-out. I find that rather impressive, and impressively convincing.

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Public Impatience With Science

Argonne's Director Robert Rosner spoke to the Chicago Council on Science and Technology, a not-for-profit organization is committed to promoting science and technology in the greater Chicago area. Some of the things he said bears repeating here, especially on the part where it takes decades for a basic scientific breakthrough to make it to the consumer.

Computers were around for 30 years before they became useful to business, and solid-state electronics consumer products didn't catch on until a generation after the transistor was discovered, said Rosner, director of Argonne National Laboratory.

"When a basic discovery is made, no one has any idea what it will lead to," said Rosner. And this disconnect is behind the financial crisis now afflicting Argonne and its sister institution, Fermilab.

"People believe that basic science can wait," said Rosner, "but the truth is that if you don't do the basic research today, you won't reap the fruits in 20 to 30 years. We have to invest now to benefit our children and grandchildren. But to a culture that expects instant results, such patience is a hard sell.

I think most people do forget that. Even within the sciences themselves, many forget that some of the advancement in biochemistry, for example, were brought about because of something that was developed in physics years before. Synchrotron light sources came out of research in high energy physics, and it took many decades before the field of biochemistry, medicine, and pharmacy realized that such facilities can be valuable to their work. This is just one example of something that came out of basic research that appeared to have no direct application at that time.

Just how do we convey that to the public and, especially, those politicians?

Edit: The original link appears to no longer work. However, there is a link directly to the Chicago Council on Science and Technology with a video of the talk.

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What Makes A Successful "Letters"?

The "Letters" in this case is the Physical Review Letters (PRL), one of the top 3 most prestigious publication for physics papers. The Physical Review website has an editorial on what makes a suitable and successful PRL paper. With the criteria for acceptance being more tight, and with the editors at PRL now having a larger role in weeding out submission, it is more important to pay attention to these guidelines on what they are looking for.

A successful Letter of course begins with a valid result, one that is important and interesting. This is glib, however, because it lacks explanations of “important” and “interesting.” So, here are attempts to define each, in single sentences: An important result provides insight that changes the way others view and understand the topic, allows them to improve their own approaches, and thus leads to substantial progress. An interesting result will make readers glad to learn of it, because it is important to their own work or the work of others, or because it is science of uncommon beauty, aesthetically. In the context of a manuscript there is a third element: accessibility. Regardless of its content, a manuscript will be of lesser interest if it is impenetrable, and a manuscript that attracts fewer readers will be less important.

Present PRL policy incorporates these three concepts by seeking to publish work that should not be missed by researchers in the given field and also those in at least some related fields. Broader interest, in general, is better, as is greater importance, but the two are not independent. Work that is extremely important to a few might be as worthy as work that is moderately important to many, which again leads directly to presentation. A manuscript that can be understood only by a narrow audience will be less likely to be suitable for PRL, because it will lose its chance to be moderately important to a wide audience.

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How Fundamental Particles Lose Track Of Quantum Mechanical Properties

We have another report on the study on the mechanism of the differences between the quantum world and our classical world. This is another study on the effect of decoherence on a quantum system that couples to an external "bath".

It would be interesting to compare this to an earlier report on the emergence of a classical system from a single-particle state after just one interaction. It is also interesting to see how Roger Penrose would handle this. He seems to think that our classical world emerges due to some coupling or interaction between the quantum systems and gravity, and that eventually destroys the quantum system and out comes the classical system. These two papers above seems to indicate that the mere act of decoherence might be sufficient to produce the classical world.

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Revamping Intro Physics Laboratory - Part 4

Continuing with this series, here's another experiment that I would propose. This would still be something that can easily be done at the beginning of the semester, which means it doesn't require that the students would have already learned any physics related to it. BTW, in case people think that all the experiments that I'm going to propose are this "simple", that is not going to be the case. These "no physics" experiments are aimed only at the beginning of the semester and where we want to introduce to the students that physics is nothing more than a systematic way of deriving what is valid and how to figure out a way to understand the relationship between things. It reinforces the idea that one doesn't need to abandon all that we already know to understand physics. In fact, we need to bringing in our "common sense" and the sense of "play" to do physics, or at least, these physics experiments. As the semester progresses and, presumably, the students' understanding gets more sophisticated, the experiments should also evolve the same way.

OK, for this experiments, we will deal with springs and masses, so again, it shouldn't be something difficult. The task this time is simple:

You will be given a "mystery" object in which you need to determine its mass. You are given a set of springs, and a set of calibrated masses. In addition, you will also have access to a ruler and a stopwatch if you need them. Figure out how you can determine, as accurately as possible, the mass of this mystery object. You must describe explicitly how you go about doing this determination.

Now, of course, in many intro physics class, this type of experiment typically requires that they find the spring constant by looking at the extension versus force or mass applied to the spring. I'm going about this the other way. Forget about the spring constant for now. The key thing here is that the student learns about the relationship between the spring extension as different masses are added to the spring. This to me would be the most obvious technique that most of the students would do. They would find the extension of the spring with different masses. Then, when given mystery mass, they may have to do some interpolation or extrapolation to estimate the mass of that object.

Now, there's also a possibility that some students may do this differently. They could, instead, let each of the known masses oscillates one at a time and find the relationship between the mass and the period of oscillation. They won't end up with a straight line, but as in the previous suggested experiment, this is OK. While we tell them they need to do this as accurately as possible, in the end, we really don't care as long as they explain what they did and how they did it. So even if they had to extrapolate/interpolate by hand, this is perfectly fine.

Now, what we can do further is this. For the students that did the first method (hanging the mass and finding the spring extension), we can ask them this:

Now, often it is difficult to get the spring to be very still - the mass tends to oscillate up and down. So maybe it might also be a good idea to see if we can make use of this property to see if there's an additional relationship here between the mass on the spring, and the period of oscillation. Can you determine the mass of the mystery object this way? Does it give the same answer? It is always more convincing when two different methods give consistent answers.

For those who did the the second method (oscillating the mass and finding the period), you then say:

Oscillating the spring doesn't allow you to read off the mass very quickly, which is something you need quite often. So is there another way to determine the mass quicker? How about looking at how much the spring extends as you hang different masses? Can this lead you to a different way to measure the mystery mass? Does this value agrees with the one you got earlier? It is always more convincing when two different methods give consistent answers.

.. and voila, you've gotten them to do this in both ways! They also learn that in science, it is always more convincing when you can show a consistent result from two different techniques (although, to be technically accurate, these are not really two different techniques, but this is a good enough demonstration at this level). Now the fun starts if they come up with very different answers. This is where they need to figure out (with the help of an instructor) on what went wrong. To me, figuring out what went wrong is as important and what went right.

After the students have done both, you then can pose an additional question such as this:

What you have now is a graph that you always need to use whenever you want to determine a mass. Is there a way to know the mass of something without having to resort to using such a graph? Can we figure out a way in which, if we know how much the spring extends, we can simply punch that number in and out comes the mass?

I think you know where I'm going with this, don't you? Considering that the students should have a background in sufficient mathematics, they would have seen a straight line equation. If not, a bit of help and hand-holding is called for, which, at this point, should be alright.

So in essence, we have done the mass-spring experiment, but done in a different manner. Rather than giving out the necessary steps that the students have to do, we instead "coerced" them into doing them by a series of questions and tasks that we want them to accomplish by themselves. Inadvertently, they "discover" Hooke's Law by themselves.

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"This Coincidence Cannot Be Accidental"

That's the most dramatic statement coming out of a newly-published paper in Science, and that was the title that Doug Scalapino used in his Perspective article on this paper in the same issue.

Just when we think that we know everything there is to know about conventional, metallic superconductors, Mother Nature throws a wrench at that fallacy. Reported today by Ayanajian et al.[1], metallic superconductors such as Pb and Nb still holds a mystery. This time, it appears that the exact phonon energies of the Kohn anomalies happen to coincide with the superconducting binding energies of the cooper pairs of that particular metal. This is something that was not expected, and current formalism of conventional superconductivity says nothing about such a thing. As Scalapino pointed out his is Perspective article[2],

... although the polarization created by the conduction electrons and the response to the ionic lattice contribute to determining both the Kohn anomaly and the pair binding energy, there must be something else at work that locks (the superconducting gap) to (Kohn anomaly energy). As noted, this could mean that there is some new physics that is not captured by the Eliashberg formulation.

I love it! I love unexpected surprises like this!

Zz.

[1] P. Ayanajian et al., Science v.319, p.1509 (2008).
[2] D.J. Scalapino, Science v.319, p.1492 (2008).

Dark Matter Music From CDMS

This is a bit out of the ordinary.

This is taken from Fermilab Today newsletter for March 13, 2008:

Karl Ramberg sometimes incorporates music into his artwork. But a trip with his brother, Fermilab physicist Erik Ramberg, added science to his palette. Karl, with the help of scientists, produced a full-scale, plastic model of a dark matter detector that translates its data into light and sound.

"The end result is that you get an experience, aurally and visually, of subatomic affects," Karl said. "You get a better understanding of what the data is saying."

The musical detector, a YouTube sensation, is modeled after the real Cryogenic Dark Matter Search, an underground experiment searching for dark matter particles. The actual CDMS experiment detects and records the energies of particles that strike its five towers. The model takes that one step further, expressing the data in color and tone according to particles and their properties. The idea for the model was inspired by a trip to the Soudan, Minn. mine that houses the CDMS experiment, where Erik, a CDMS collaborator, took shifts.

So this is essentially data translated into music.



It could pass for a New Age music, I would think. :)

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Revamping Intro Physics Laboratory - Part 3 (Follow-Up)

OK, I got some very interesting responses to my suggestion of an experiment that can be done for an intro physics lab. I think I didn't explain myself too clearly on the premise and how I'm going to present it on here, so I should do that now.

While I tried to be explicit in describing the experiment and what would be a good way to do it, I don't actually want to reveal the whole hand. That's why I went along with the idea that there could be a dependence of the period with varying weights, because that is a very likely path that the students might attempt. If someone is thinking of actually trying to introduce this experiment in an intro lab, I don't want the possibility that some student might google it and find my blog where the whole thing has been revealed. :) That would defeat the purpose of them doing this without any kind of "previous knowledge".

So while I'm trying to be as clear and complete as possible in the experimental description, and the "philosophy" behind it, I don't really want to reveal everything either. In fact, I'm hoping that there WILL be students who decided to figure out if they can do it by changing just the weights. I consider discovering something that cannot work to be very educational. In fact, in science, knowing what doesn't work can be quite important (re: Michaelson-Morley experiment). They at least now know that changing the weights would not work. If they are curious enough, they'll try to find out WHY it doesn't work, and this is where the physics can be introduced.

Note that the experiment that I had suggested does NOT require that they have learned anything in intro physics. It is quite independent of the lesson they might have received in class. So in principle, this experiment could be done even during the first week of class. It doesn't require that they had learned about simple pendulum.

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New WMAP Data Once Again Agrees With Cosmological Model

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

The new report out of the new analysis of WMAP data on the neutrino background has again produced a result consistent with the Big Bang Nucleosynthesis.

As such, the cosmic microwave background provides an independent estimate of the number of neutrino “families” in nature: 4.4 ± 1.5. Despite having been inferred from a totally different cosmological epoch, this value agrees with constraints from Big-Bang nucleosynthesis, the first few minutes of the universe during which light nuclei were manufactured, and with precision measurements at particle accelerators which fix the number of families at three. The WMAP5 data also constrain the combined mass of all types of neutrino to be less than 0.61 eV.

“The discovery of the neutrino background tells us that our models are pretty much right,” says cosmologist Pedro Ferreira of the University of Oxford. “Stuff from particle physics that you’re not putting in by hand just drops out of them — that’s pretty cool if you ask me.”

Yes, very cool! :)

Zz.

Revamping Intro Physics Laboratory - Part 3

OK, I haven't forgotten this yet.

To me, the biggest problem with the current structure of intro physics lab is that we give students a list of things they have to do and measure, and hand-hold them into getting the result. In other words, they don't have to think too much to complete the exercise. They may have to do a bit of thinking and understanding of physics to complete the write-up, but the actual part of performing the experiment requires simply the ability to follow instructions.

I believe that we should have a more open-ended experiment to be given to the students. So I'll give an example. Note that while thing is something that I've thought about for a while, I'm still writing this off the top of my head. So there may be other problems with it that I haven't carefully considered.

Give them a problem to solve such as something like this:

Construct a pendulum clock. To make this clock useful, it would be helpful if the pendulum can swing back and forth once as close to 1 second as possible. Then each complete oscillation will take just one second. That way, this clock and measure time in increments of one second. You may use a stop watch to calibrate your pendulum to verify that it makes a one-second swing. Try to build this as accurately as possible. You must describe in detail in your lab report how you accomplish this task and why you chose to do it this way.

Now, as apparatus, give them a length of string, a set of weights, and a stop watch, plus other necessary items for them to be able to mount the pendulum on something.

Here's what I expect to occur. You'll have some students doing this by trial-and-error. They'll mount a length of string, and then start changing the weights to change the period of oscillation. Of course, there's no guarantee here that there is JUST the right weight for that length of pendulum to produce a 1-second period of oscillation. So students doing it this way may face a problem, but that's OK, because at the end when we discuss on to do such a thing, they'll discover why their technique isn't the best way.

You'll also get a bunch of student who would use a fixed weight, but tries to vary the pendulum's length. Again, they may try this simply by trial-and-error, adjusting it a little bit at a time until the period is close to 1-second interval. This technique is of course, more "refined" than the earlier one, since there's a high possibility of getting the right period.

Of course, what should be done, rather than simply doing a trial and error method, is simply to use a fixed weight, then measure a set of period corresponding to a set of pendulum lengths. Using the table, one can plot period versus lengths, and from there, interpolate (or extrapolate, depending on the range of lengths that were used) the exact length to produce a period of 1 second can be read off. So after the experiment is done and the students write their report, the lab instructor can start a discussion on the best possible technique to get the most accurate result. One can even make it a bit more complicated and ask the students how accurate is their clock as they let it swing for a length of time. This is where if they constructed a clock that swings over a large angle of oscillation, they may discover that it doesn't keep time very well.

What this type of lab forces them to do is think on the relationship between two measured variables. The first group had to figure out how the period changes as they change the weights. The second group is finding out the relationship between the period and the length of the pendulum. There may be a 3rd group that may be changing both the length and the weights simultaneous. If they do, and they're doing this by trial-and-error, god help them! :) But no matter what, the students are forced to think of what to do, and why they're doing it, to accomplish the task. They are not told how to do it. The experiment and the equipment give are familiar enough to them that this isn't something out of the ordinary. In fact, when they were kids, they probably played with something like this. The curiosity with finding how to do things is the purpose of the lab exercise. It is really playing, it is just that now, they have to think on what they are doing, why they are doing it, and how to present it in writing.

Next time, I'll try to present another possible laboratory exercise along this line.

Zz.

New Video on "Dark Matter" With Teacher Notes to Benefit Students, From Perimeter Institute

Hum.... a video on "dark matter" for high school students? With teacher's notes?

I haven't seen this yet, but this was the press release from the Perimeter Institute on something they are producing. If you have time and want to view it, you can directly go to this link.

Tell me what you think after viewing it. Do you think this can be an effective tool to introduce dark matter to students at that level? Would the teachers be able to understand it, even with the teachers guide?

A More Accurate Clock, and Fine Structure Constant Isn't Changing

Talk about killing 2 birds with one stone.

A new paper out of physicists from NIST has managed to accomplish to very important task. The first is the use of an optical clock that is way more sensitive and accurate than the atomic clock. Secondly, due to the highly sensitive and accurate nature of the clock, they have shown essentially that the fine structure constant isn't changing over time.

I wonder if the J.K. Webb camp will be responding to this report....

Zz.

Review: The Mystery of the Missing Antimatter

This is a book review of Helen R. Quinn and Yossi Nir's "The Mystery of the Missing Antimatter". As the reviewer has noted, there are only 3 major mysteries in cosmology today: the nature of Dark Energy, the nature of Dark Matter, and why matter dominates antimatter in our universe today.

This might be something I might try to get in the next few months. Helen Quinn, if you've read this blog for any considerable period of time, wrote a while back an article that I had characterized as something all scientists and science students must read. So she certainly has a clarity of thought and a concise use of words.

Zz.

'Expatriates' From Physics Careers Find Funding, Fulfillment in Medicine

I think the field of Medical Physics has not been getting enough publicity among incoming students, which is too bad considering the graduates from this field continually fetch good starting salary and continue to be highly sought after.

This news article highlights the migration into Medical physics by students who suddenly face funding shortage and cutbacks. Considering the economic outlook especially in the rest of physics, these setbacks may be a blessing for these students going into this field of study.

Zz.

Bill Foster Wins Election

It's no secret that I've mentioned about physicist Bill Foster campaign to win the House of Representative seat vacated by Dennis Hastert. He has done the upset and won the special election yesterday against Republican Jim Oberweis. So we have another physicists in Congress.

Unfortunately, this is only to serve the remaining term that was vacated by Hastert. We will have deja vu all over again this coming November when the two of them fight it out for the full term.

Zz.

The Wave-Particle Duality of Light: A Demonstration Experiment

Other than the fact that I don't quite like the title, this is an excellent demonstration paper that was published recently in AJP. Very much like the J.J. Thorn et al. paper on the which-way experiment, these profound phenomena can actually be performed in an undergraduate physics lab.

First, the exact citation:

T.L. Dimitrova and A. Weis, Am. J. Phys. v.76, p.137 (2008).

They basically performed a Mach-Zehnder interferometer experiment using very low intensity light so much so that only one photon is in the apparatus at any given time. They also have a second stronger laser beam that traverse the same apparatus, but slightly displaced that exhibit the clear wave-like interference pattern.

So far, this is fine and dandy, and it would not have caught my eye because it would be a nice, undergraduate physics lab exercise. But at they end, they did something simple, yet, can be quite profound to a student. I'll quote what they said:

The demonstration, whose result is astonishing for students, is realized in the following way. First the fringe pattern is locked to a photodiode as explained in Sec. IV B, and the photomultiplier is moved to a fringe minimum, as characterized by a low photon count rate which can also be displayed acoustically. If now path A of beam 1 is blocked inside the interferometer, it is possible to hear (and see) a distinct increase of the click rate. This result demonstrates that if we give each photon the choice of taking either path A or path B, it has a low probability to appear at the detector. In contrast, if we force the photon to follow a specific path by blocking the other path, then the probability to arrive at the detector is much higher. The puzzling fact that a two-path alternative for each photon prevents it from reaching the detector, while blocking one of the paths leads to a revival of the clicks, is most intriguing for beginning students. This experiment is well suited for illustrating this remarkable quantum mechanical effect, which can be explained only if we assume that each photon simultaneously takes both paths A and B; that is, each photon, in the phrasing of Dirac, "interferes with itself."

Gorgeous!

It is something we know would happen, but the way this is demonstrated is so clear that I would say this is an experiment worth doing at every undergraduate level. Well done to the authors!!

Zz.

Campus Ceremony Will Celebrate New Stamp for Physicist John Bardeen

I mentioned about the new US Post Office stamps set celebrating American scientists which includes a stamp of John Bardeen. Well, if you happen to be at the University of Illinois campus today (March 6), there is a small ceremony to mark the unveiling of the stamp.

The U. of I. physics department will host Urbana Postmaster Kathleen J. Burr, regional U.S. Postal Service officials, university administrators, and family and friends of Bardeen (1908-1991) at the ceremony. The event is free and open to the public. It will begin at 12:15 p.m., in room 144 of Loomis Laboratory, 1110 W. Green St., Urbana.

I can only hope that those who don't know much about him will now have the impetus to learn more about what Bardeen has done and how he has directly influenced how we live today.

Zz.

Follow-Up On Fredrick Seitz

I mentioned in a previous blog entry of the passing of Fredrick Seitz. Someone asked me why I didn't mention anything about his later-years opposition to Global Warming. After all, he was one of the more prominent skeptic of that effect.

I'm not sure why that would be relevant, frankly. The Fredrick Seitz that I know and admire came from his work on Solid State Physics. That was how he made his name, and that was how he became prominent. I'm sure he has his reasons for looking at the available data to be convinced that global warming isn't what it has been claimed. He's entitled to that. It's not as if he's supporting massive human extermination, which was the issue surrounding most German scientists during World War II.

So even though I don't agree with him regarding the issue of global warming, it remains a fact that he has a major influence in the field of solid state physics/condensed matter. Just for that, he deserves to be saluted.

Zz.

Frederick Seitz Dies at 96

The name "Frederick Seitz" should be very familiar to anyone who has studied Solid State Physics. Seitz is one of the instrumental figures in Solid State Physics and may even be one of its founding fathers.

This distinguished physicist passed away this past March 2nd, 2008. Our modern civilization, in no small part, has be shaped by his work.

Thank you, and rest in peace.

Zz.

The Best Years of Your Life?

It may not feel that way when you're embarking on pursuing your Ph.D, but it can be. This is an article from PhysicsWorld that reviews several students in the middle of their Ph.D program in physics. It has several good advices for anyone thinking of pursuing a physics Ph.D, especially if you are in Europe. This should plug some holes in my "So You Want To Be A Physicist" essay that essentially focused mainly on the US Ph.D program. Note the important difference between the US and UK/Europe program:

Having a research topic in mind is absolutely essential when applying for PhD positions in the UK and elsewhere in Europe, since you will usually begin working on your chosen research problem straight away. In the US, however, PhD students spend two years doing coursework and exams in all areas of physics and only then begin proper research.

“Most physics students in the US start their PhDs without a specific research field in mind,” says Jayatilaka. This adds at least an extra year to the process, but it makes the US a good option for those who want to learn a bit more physics before choosing an area to specialize in, or for students who want to undertake a PhD project in an area that they do not have much experience in.

Zz.

Journal Club For Condensed Matter Physics

This is such a terrific idea.

The Division of Condensed Matter Physics of the American Physical Society (APS) has sent out e-mail highlighting the existence of a "Journal Club for Condensed Matter Physics". This is where prominent physicists recommend papers and preprints that they find important, fascinating, or have a passion for. You get a more in-depth review of the paper/preprint, especially a discussion on the salient point being made.

I will include this link in the Blog's Physics Links collection.

Zz.

Physicists Successfully Store and Retrieve Nothing

This could easily fit in as an episode of the Jerry Seinfeld series.

It appears that there is such a thing as a "squeezed vacuum", and it takes some effort to store and retrieve this "nothingness".

To see what this is, begin with a normal light wave. Classically, this is a smooth wave of electromagnetic fields with equally spaced peaks and dips. But throw in quantum mechanics and things get more complicated. The precise height of the wave becomes uncertain, so the wave gets fuzzy (see figure). Physicists have learned how to manipulate that inevitable uncertainty--for example, making it smaller at the peaks and larger in between. That makes "phase-squeezed light." Now imagine turning down the intensity of the phase-squeezed light to zero. The wave itself goes away, but the waxing and waning uncertainty remains, creating a squeezed vacuum.

It's interesting that two separate groups produced work on this at almost the same time. This, of course, is not unusual, and PRL, Nature, and Science have been known to put such things in the same issue. It serves to reinforce the discovery.

Zz.

I'm Back!

I'm back from a short vacation. It was great to be away for a while, but now I feel so out of touch with what has been happening. So I'll need at least a couple of days to get back up to speed. Hope I didn't miss any earth-shattering "we found proof of aliens" or "convincing evidence for the mechanism of high-Tc superconductors" news.

Zz.

Barry Barish and the GDE

Barry Barish of Caltech heads the Global Design Effort (GDE) for the International Linear Collider (ILC). As anyone who has followed the news since December 2007, the ILC has had two major, and possibly fatal blow to its plan: the UK pull-out and the drastic reduction in funding in the US.

This is a good article on Barish and his effort within the GDE, including his take on the future of the ILC. I think most people kinda agree that even if the ILC gets built, it will probably be the last of its kind because the cost to go beyond that is no longer realistic. Unless new acceleration schemes that are currently still in basic, fundamental research stages (such as plasma wakefield, etc.), particle accelerator for high energy physics will probably not get any bigger than the ILC-like design.

Zz.

Theistic Evolution - The New Theology?

This is a rather fascinating article from, of all places, the Chicago Tribune. It detailed the "inquisition" being faced by a physicist at Calvin College in Michigan for a book that was published years ago. In it, Howard Van Till dares to propose that his religious belief can be reconciled with the evolution.

Van Till roused a small but fervent pack of enemies at the conservative college with his book, "The Fourth Day," in which he argued that the stories of the Bible and science's account of evolution could both be true. His critics on the school's board of trustees had no interest in reconciling the religious account of creation with a naturalist explanation of how life and the universe have evolved over the ages. For years after the book's release in 1986, Van Till reported to a monthly interrogation where he struggled to reassure college officials that his scientific teachings fit within their creed.

Now that's an interesting tactic.

I suppose that many people do accept both, and I suspect that there are a lot more of them than those who are reverently anti-evolution or anti-religion. This is because many people of faith accepts that what they believe in is simply a matter of faith - devoid of physical and empirical evidence, and they're willing to accept that. They still continue to accept science as the workings of the world that they live in. I don't see anything wrong with that kind of a "compromise".

But this attempt at reconciling religion (or in this case, Christianity) with evolution is certainly interesting. It does mean that many who accept both don't have to feel any discomfort for an apparent contradiction.

A good article!

Zz.

Revamping Intro Physics Laboratory - Part 2

So what is the main purpose of intro physics laboratory?

Keep in mind that MOST students in such courses are NOT physics majors. In fact, for many, these are the only physics courses they'll ever take. So I see it as the best opportunity to introduce to the students how physics actually work. How exactly do we consider something to be valid in physics? After all, anyone and everyone can come up with some "theory" to describe something (and in the age of the internet, everyone does!). How do we select which ones are valid and which ones aren't? It all comes down to experimental verification. How we know something to be valid come from our empirical observations. Therefore, proper experimental techniques must be crucial since it can determine what is valid and what isn't. This is where the acquired skills come in.

When I say "skills", I don't just mean physical skills, such as the efficient way of using an oscilloscope, or one's agility in soldering a piece of wire. It also includes mental skill, which is the ability to think through a problem, or a nagging feeling that something isn't quite right. It also includes the ability to know what is the best and most accurate way of doing something. For example, why can't a student simply make one measurement of the restoring force of a spring, make the corresponding measurement of the spring extension, and then plug those values into the Hooke's law equation to find the spring constant? Why do we have to make a series of measurements instead? The ability to know why we need to do that is an acquired skill in proper technique to test a particular relationship of two different variables. One acquire such skill after consciously and repeatedly learning ways to make such tests. However, the students need to be told that these are the skills they are being taught, so that they are consciously aware of what they are doing and why. So often, in the usual physics labs, this awareness is lacking and not being emphasized.

What the labs can do is reveal in a very direct way how we gain and verify knowledge. What exactly is the relationship between variable x and y, and how do I test it? How do I know my result is valid? In the end, without one having to tell them point blank, they learn the difference between "scientific evidence" versus other forms of evidence, and they get a glimpse of some form of what people like to call "the scientific method". Considering that most of them will go on to do other things in life beyond just doing physics (or even science), I would think that this ability to have them understand what is involved in determining what is valid is something extremely valuable. This lack of understanding can easily be the cause of why people accept pseudoscience and other flaky ideas. That is why I consider these physics labs as extremely important not just in physics, but as part of a general education of the population.

Since I've already mentioned what is wrong with the current way of doing intro physics labs, I should put my money where my mouth is. What exactly should we do in such courses? In the next part, I will give an explicit suggestion on how to revamp these lab sessions.

Zz.

Webcast: Nobel Laureate on the History and Fate of the Universe, March 4th, 2008

Here's an announcement for the upcoming Honeywell-Nobel Initiative:

Honeywell will be presenting a Webcast – The History and Fate of the Universe – by Nobel Laureate Dr. George Smoot of the University of California, Berkeley. His talk will focus on the present status of cosmological observations and will make a forecast on things soon to come. It’s a big topic but one Dr. Smoot is well qualified to address.

In 1992, Smoot and his team detected and mapped tiny variations in the radiation from the early Big Bang. Gravity worked on these variations to grow the galaxies, clusters of galaxies and clusters of clusters that are found across the universe. For this work, Smoot was co-awarded the 2006 Nobel Prize in Physics.

Smoot will be delivering this lecture to the students and faculty of the Government College of Engineering in Pune Maharashtra, India on March 4th. A live Webcast of his remarks, as well as related content, will be available for viewing from Honeywell Science.

You can also find more information and details on our MySpace page.

Zz.

Revamping Intro Physics Laboratory - Part 1

I used to hate doing the lab in First Year college intro physics classes. It would be 2 hours of torture, and at that time, I didn't see the point. Unless things have changed, most students taking such classes would tend to feel the same way as I did. And I think this is a waste of opportunity to really get through to the students of THE most important aspect of science, and of physics in particular - the empirical testing of physical concepts, and how we arrive at our knowledge to accept something as valid. This is what separates science from pseudosciences (and even religion).

The problem here starts from the very beginning. When I was that freshman undergraduate, no instructor ever spent time explaining why the laboratory sessions are important, why it is crucial that we actually DO things, rather than just read or watch what is being done. No one was explaining to me the fact that the SKILLS that I could get out of the physics lab may turn out to be a rather important aspect of my education that transcends beyond just physics, but into other parts of my life. This means that it doesn't matter if you're a physics major or not, the physics labs can be quite beneficial as one progresses in one's education, career, and life. I strongly believe students should be made aware of this in no uncertain terms. The physics instructors must impress upon the students why doing these laboratory experiments is important, what kind of skills are being practiced, and why this is different than just sitting and reading. I would think that the students would at least become aware that there is a rational reason for forcing them to do such a thing, rather than just them being told that they need to do this for no valid reason.

When I was a lab TA years ago, I tried doing just the very thing. More than 3/4 of my students at that time were not physics majors, and I flat out told them that in the lab sessions, it was more important to pay attention to what they were doing, and reporting what they were doing, rather than the final "answer" or results that they were trying to measure. I was more interested in what they were thinking as they were doing the experiment, reporting accurately their observations, and if the results looked weird, to notice that they did look weird rather than just reporting the number and did not realize something was not quite right. In other words, I was more interesting in the doing of the experiments themselves rather than testing if the students understood the physics theory or idea that was being tested. I was more interested that the student acquire proper experimental skills. They can learn more effectively about the theory and principles in class. I wanted the lab session to be more "hands on" on how to think and conduct an experiment to measure something.

So already my philosophy in what an intro physics lab session should be was different than what I encountered during my undergraduate years. And after being in this profession for many years, and being an experimentalist, I am even more convinced that this is what such lab sessions should be.

Zz.

Unitarian Physicist to Speak on Separation of Church, State

This is a piece of news announcing a speech by a physicist. It would have been a rather innocuous announcement, except for one, historically-important fact about the person delivering this speech.

Schempp, a Unitarian, was the subject of a 1963 Supreme Court case banning school-sponsored Bible readings in public schools. While a high school student in Abington Township, Pa., in 1956, he and fellow students were required by state law to read 10 Bible verses every day. He protested and was disciplined at school. He and his father, with the help of the American Civil Liberties Union, sued the school district.

I tell ya, even as a child, physicists can be a pain in people's butt, aren't they? Still, I'm proud to know that a physicist (or in this case, an eventual physicist) was the one responsible for this. :)

Zz.

A Day In The Life Of Brian Cox

If you are ever curious to know the typical day of a well-known physicist working at CERN, you can't get any better than reading this about Brian Cox. Long periods of time away from home can some time be the less rewarding part of the job.

Still, this is a fascinating and amusing account of a day in his life.

Zz.

Leap Year Has a Long and Complicated History

This year, February will again have 29 days, making 2008 a leap year. This article describes the reason and history behind the leap year.

“Everyone knows that the calendar year shows it is 365 days, but it really isn’t. Really, it is 365 and almost-one-fourth days.”

According to Infoplease.com, the actual time for Earth to travel around the sun is 365 days, 5 hours, 48 minutes, and 46 seconds, to be precise, marking a full year for us.

Zz.

Panel Picked to Review UK Physics

The health of physics in the United Kingdom will be the subject of this review by a panel appointed after the Science and Technology Facilities Council (STFC) budget shortfall.

I thought there has been a number of previous studies already on this issue. I suppose this study is to evaluate the future impact of the budget cuts that has been done to UK physics. Still....

But some physicists are sceptical that the review will do anything to reverse the current situation in any case. “It is likely the review will just say that this shouldn’t happen again,” says Mark Lancaster, a particle physicist at University College London.

Having a review and pledging support for basic physics are one thing. Not providing enough funding to pursue it is another. This can be said to the US physics budget situation as well.

Zz.

A Deeper Look at Student Learning of Quantum Mechanics: the Case of Tunneling

This preprint, co-authored by Nobel Laureate Carl Wieman, looks at the difficulties that students had in understanding quantum tunneling.

Abstract: We report on a qualitative study of student learning of quantum tunneling in traditional and reformed modern physics courses. In the reformed courses, which were designed to address student difficulties found in previous research, students still struggle with many of the same issues found in other courses, but the reasons for these difficulties are more subtle, and many new issues are brought to the surface. By explicitly discussing how to build models of potential energy and relate these models to real physical systems, we have opened up a floodgate of deep and difficult questions as students struggle to make sense of these models. We conclude that the difficulties found in previous research are the tip of the iceberg, and the real issue at the heart of student difficulties in learning quantum tunneling is the struggle to build the complex models that are implicit in experts' understanding but often not discussed explicitly with students.

It's a lengthy paper, and I'm still reading it. But it is interesting that you get to learn quite a bit more about quantum tunneling in here, especially on aspects that are quite subtle.

Let me know what you think...

Zz.

Preparing for Your Post-Ph.D. Career

The Science Career webpage has another great article on preparing for life after getting a Ph.D. As I had mentioned in my "So You Want To Be A Physicist" essay, at some point, one has to prepare oneself with the reality that the traditional path of a physics career may either not be suitable, or not available to be pursued. And with the dwindling job opportunities in universities and research labs (especially after the recent budget cuts in the UK and US), other alternatives should seriously be considered.

Zz.

Lord Kelvin's Follies

Now I don't know if what has been quoted here as being from Lord Kelvin is accurate or even true. So let's get that out of the way first of all. Still, this webpage lists several erroneous statements that is attributed to Kelvin that obviously aren't true, or even accurate, anymore. Certainly the part about physics being a dead subject isn't true (if only he is alive today to see how that is so not true).

Still, how is that any different than the grandiose claim that some physicists have made regarding "The Theory of Everything", even when, admittedly, such a theory can't come up with a description of everything, such as many emergent phenomena.

Zz.

The Big Bang Implosion of Physics

This is a terrific essay that expresses what I've been saying all along on why research on basic physics is important enough not to be abandoned.

In truth, fundamental research is a necessity, not a luxury. Most of the technological developments made in the past 100 years have been fuelled by fundamental research into science. Albert Einstein famously dismissed Enrico Fermi’s idea that massive amounts of energy could be released by splitting the atom. The unintended consequences of the theory of relativity gave us nuclear power. Similarly, from the esoteric beauty of the theory of quantum mechanics has emerged electronics, computing and laser optics, to name but a few developments.

We cannot foretell where research into the fundamental constituents of matter will take us, but to not travel down that path is to shut the door on the future. Our ability to understand and control nature is what gives us the capacity to carve out a different future not constrained by the fetters of the immediate problems of finite resources. It is our lack of vision and our preoccupation with the limitations of our society that holds us back from venturing further.

As physicists, we need to carefully list out ALL of the "applications" that came out of what was originally thought to be nothing more than "pure knowledge". This, to me, is the most effective means of countering the notion that pursuing basic knowledge for knowledge itself has no direct, beneficial outcome to human civilization. We should no longer talk about "spin offs" of science projects. We have to go right down to the nitty-gritty and use concrete example. That's the only way the general public and the politician can understand.

Zz.

UK Still Hopeful of Participating in Gemini Project

There is a glimmer of hope that the UK would not have to withdraw completely from the Gemini Project due to the recent budget constraints.

But last week it emerged that the council was now in discussions with the observatory about future collaboration.

Prof Michael Rowan-Robinson, president of the Royal Astronomical Society (RAS), welcomed the news that "the stand-off between the STFC and the board of the Gemini Observatory has been replaced by constructive discussion".

If this is true, it offers one very rare piece of good news, considering that a week ago, the STFC reaffirmed UK's withdrawal from the ILC collaboration, putting the whole effort into jeopardy of being abandoned.

Zz.

The Most Intense Laser in the Universe - So Far

This is where if anyone doesn't understand physics, or the language being used in laser optics, one could easily get misled by the title.

The people on HERCULES laser at the University of Michigan has claimed to have created the most intense laser pulse in the universe {link may be available for free only for a limited time}.

The intensity of a laser beam is the amount of energy it delivers per unit time per unit area. This record-breaking beam actually has very low energy — at just 20 joules, it is less than the 8,000 joules stored in a tic tac — but the energy is squeezed into a tiny spot (1.3 micrometres in diameter, about a hundred time thinner than a human hair) for a very short time, just 30 femtoseconds (10-15 seconds). So the beam has an intensity of 2 x 1022 watts per square centimetre: two orders of magnitude more intense than achieved before.

It will be nice if there's an immediate application for it.

Zz.

The Science of the Perfect Souffle

I'm always happy when I can combine things that I love into one, such as Disney and Physics, or food and Physics. This is the latter. It discusses on the chemistry and physics of making the perfect souffle.

Science in the kitchen is largely the chemistry kind — the properties of two liquids mixing, the transformation of bread into toast, the breakdown of starches into sugars. But do you ever think about velocity or gravity in your cooking? It turns out, beating eggs is all about science — and it's physics and chemistry that make a souffle rise or fall.

I don't think this will make physics a requirement subject for anyone wishing to graduate from a culinary school, but it is still entertaining in the Elton Brown sort-of way.

Zz.

Presidential Campaigns Call for Big Boosts to Research Funding

At the AAAS annual meeting this past week, representatives from the Clinton and Obama campaign presented their candidates' views on science policy.

Representatives of the two remaining major Democratic candidates for U.S. president both endorsed big budget increases for federally funded basic scientific research at a debate before hundreds of scientists today, with Senator Hillary Clinton's (D–NY) team offering decidedly more specifics on their plans.

Still, what was glaring here is that not a single Republican candidate sent a representative.

The presumptive Republican candidate, Senator John McCain (R–AZ), was invited but sent regrets, said Albert Teich of AAAS. "They apparently would have liked to come." Representative Ron Paul (R–TX) and former Arkansas Governor Mike Huckabee did not respond to AAAS's invitation.

Take that however you wish.

Zz.

Snowmobiles Faster Than A Speeding Bullet, Maybe, But Not Light

I'm glad this writer spotted something fishy about the accident report.

Mr. ... and his brother ....were traveling across (the) lake around 10:30 p.m. at an apparent high rate of speed when (they) came upon the shore and hit a maple tree ... 'He was overdriving his headlights. The shore came up too fast and he hit a maple tree

The writer certainly questioned, and rightly so, the phrase "overdriving his headlights", because it implied that the snowmobile was moving faster than the headlights! Awful! :)

Still, this accident report is practicing what I wrote earlier about the propensity of news editors and other "official-type" reports of using the phrase "rate of speed", when all they meant was just "speed". If all they meant was that the vehicle was moving fast, then "rate of speed" is the wrong expression, because this is acceleration. An object could have an instantaneous speed of 0 and yet, still have the highest "rate of speed" it will have in its motion (example: oscillating mass on a spring).

More media writers need to have better physics education. Unfortunately, based on this news report, so do people in a Department of Inland Fisheries and Wildlife

Zz.

Dark Energy and the Accelerating Universe

This resource letter has appeared online in the March issue of the American Journal of Physics[1]. It is written by one of the leading experts in this field, Eric Linder. If you don't have access to AJP, you can get the arXiv preprint of this paper here. Reading the abstract alone should be sufficient motivation on why anyone would want to keep a copy of this paper.

Abstract: This Resource Letter provides a guide to the literature on dark energy and the accelerating universe. It is intended to be of use to researchers, teachers, and students at several levels. Journal articles, books, and websites are cited for the following topics: Einstein's cosmological constant, quintessence or dynamical scalar fields, modified cosmic gravity, relations to high energy physics, cosmological probes and observations, terrestrial probes, calculational tools and parameter estimation, teaching strategies and educational resources, and the fate of the universe.

Zz.

[1] E. Linder, Am. J. Phys. v.76, p.197 (2008).

Shortchanging Science

This is an editorial in a Toledo newspaper that essentially echoes what have been said of the budget disaster that has befallen science funding.

LAMENTS in the scientific community about hundreds of millions of dollars in federal funding cuts for research highlight yet another example of government saying one thing and doing another.
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But for now, scientists rightfully feel betrayed over the ditching of the government pledge to boost funding for research, and they worry what will befall their most talented colleagues as government investment in their projects wanes. In Congress, Rep. Judy Biggert of Illinois predicts a sure brain drain among scientists if government continues to deliver only nominal support.

I think the jokes that are often being made about politicians speaking from both sides of their mouth aren't that funny anymore when it reflects reality.

Zz.

American Institute of Physics Announces Awards for Best Science Writing

This is a press release from the AIP announcing the winners of the awards for best science writing. There are some really good science essays here. I would bring your attention to Tim Folger and his award in the Journalist category. The article, published in Discover, is actually quite interesting and provocative. It was based on an interview with Roger Penrose, and of course dealt with one of the most fundamental issues surrounding quantum mechanics. It also contains a description of one of his proposed experiment at detecting the quantum superposition using mirrors, which is currently being tested by Dirk Bouwmeester at UCSD.

The proposal for this experiment was published a while back in PRL, and you can find the arXiv version here.

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Violation of the Zeroth Law of Thermodynamics in Systems with Negative Specific Heat

I must admit that I am not that familiar with this topic. I've paid attention to the research surrounding materials with negative index of refraction, or right-handed materials, that have been made recently using metamaterials. However, I have not paid any attention to materials having a negative specific heat.

It appears that such material can be shown to violate the Zeroth Law of Thermodynamics, as shown in this preprint that is to be published in PRL. Obviously, systems that exhibit such specific heat are not something one encounters everyday (are these systems even under what we generally consider to be a thermodynamic equilibrium?). Still, it is nice to see how we continue to understand the limits of the principles that we have in physics. At the very least, this paper has a wealth of references to these exotic systems exhibiting such negative specific heat. That alone is enough for me to keep a copy of this paper. :)

Zz.

Dark Physics Beats Light Limit

If you haven't read this Physical Review Focus story, you might want to do that. This is an ingenious technique of trying to beat the diffraction limit in optical lithography on electronic chips by using so-called the "dark states". It doesn't use a multiphoton effect, and thus, does not require a high-powered laser.

The photoresist molecules would be activated by coherent population trapping (CPT), a process used in slow light and other atomic experiments. In the simplest case, two lasers drive two transitions from different lower energy states to a common excited state, but due to a quantum interference effect, the molecules are never excited. Instead they evolve into a so-called dark state--a stable combination of the lower states that is unaffected by light. With additional upper and lower states, there may exist more complex dark states that combine several low-energy states and that could be populated using additional lasers tuned to the different transitions. CPT does not require multiphoton absorption, so it can work at relatively low intensities.

This is such a clever scheme. Of course, there's still a long way to go before such a technique can be used in an industrial setting.

Zz.

Report Backing Clemens Chooses Its Facts Carefully

So, you didn't think that Roger Clemens and the alleged steroid use from the Mitchell Report would be on a physics blog, did you? Bear with me. This has everything to do with data analysis and statistics, something many of us physicists, especially experimentalists, have to do.

For those who don't know about this (especially those from outside North America or don't follow US baseball), there is a major scancal in the sports of US baseball. The recently released Mitchell report, commissioned by the Major League Baseball association has implicated many high-profile players of using steroids during their professional careers. One of them is Roger Clemens, a well-known baseball pitcher who was well on his way to the baseball Hall of Fame in a few years.

Clemens has vehemently denied such practice. He has gone on the "offensive" of trying to produce "evidence" for his innocence. One of the things he (more likely, his defense team) has done is to produce a set of statistics showing that his performance late in his career (during the period that he was accused of using human growth hormone) is not unusual. So his camp actually tried to produce some quantitative analysis to proclaim his innocence.

This is fine and dandy. Unfortunately, his "data analysis" is being disputed by no less than three Ivy League academicians. Three professors from the University of Pennsylvania has challenged the validity of the analysis and wrote an article in the New York Times to rebutt the conclusion from Clemens statistics. The most damaging conclusion they gather out of a more thorough analysis of the statistics was this statement:

Other measures suggest Clemens performed similarly to his contemporaries. But these comparisons do not provide evidence of his innocence; they simply fail to provide evidence of his guilt.

Our reading is that the available data on Clemens’s career strongly hint that some unusual factors may have been at play in producing his excellent late-career statistics.

In other words, if the Clemens camp was hoping that the statistics show his innocence, they are wrong. It certainly doesn't show that he has used any performance enhancing drugs, but it certainly also can't be used as evidence for his innocence like they had hoped.

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Profile of Harry Lipkin

This is an interesting profile of theorist Harry Lipkin. While many of his colleagues certainly know him due to his body of work, many others certainly know of him due to his highly provocative essay in Physics Today several years ago titled "Who Ordered Theorists?" In it, he argued that many of the discoveries and amazing advances in elementary particle physics (and possibly physics in general) have not be due to theorists, and in fact, might have been hindered by them.

Of course, being an experimentalist, I'm not going to argue with that. Still, it brought out a lot of "heated" discussion and rebuttals after the letter was published. Still, I can say with definite certainty that many of the emergent phenomena in condensed matter, for example, such as superconductivity and fractional quantum hall effect, were never predicted by theory. The experimental discovery of the phenomena inevitably always came first.

Zz.

More Bad Physics - Part 2

Again, this is possibly nitpicking. But really, something this elementary should not be done incorrectly. You have read previously how someone mistaken energy as mass*velocity. We have another one of the same degree.

I think this is nothing more than an advertisement, which makes it worse since it shows that whoever is peddling this doesn't know much about what he/she is talking about. There are two very strange physics in here and they both occur in the same paragraph.

Being Able to slam dunk is almost as much in the mind than it is in the legs but in the end it comes down to one thing – power. In physics power is strength x speed. Strength is the amount of energy that your legs can push up with and speed is how long it takes to push out the strength.

Close, but no cigar.

In physics, Power = Energy/time, or Force*speed. And "speed" isn't "how long it takes to push something", which is really a quantity of time, not speed. It is really the time rate to move something.

Again, this is basic, intro physics that first year college kids, or even high school kids, would have come across. The terms "power", "energy", and "speed" are very well-defined at this level. One simply can't just mix things up as one pleases. So for this person to invoke "in physics...." and then proceeded to mess things up is really astounding.

I don't know about you, but I certainly won't buy whatever it is that is being peddled here. :)

Zz.

The Physics of Sandcastles

Lots of stuff on granular physics in here. This short article gives you a brief intro on the physics of sandcastles, or more specifically, the ratio of sand to water to give you the most stable sand structure.

Of course, the practical application of this goes beyond just building castles in the sand at the beach.

The results provide understanding of the complex physics of more than just sandcastles: they could shed light on landslides, which have killed hundreds of thousands over the past century.

This again is another example where many people do not realize of the practical application of physics, and that there's a lot of physics involved here.

Zz.

Where Science, Religion Meet?

This news article reports on a noble effort of trying to present the middle ground between science and religion as part of what they call the Evolution weekend. I'm sure they had good intentions here in doing this, and certainly, having such dialog could possibly help. However, and maybe this is simply the skeptic in me talking, I think they're missing a lot of important aspect here, which is understandable if they only think of "religion" as being "christianity".

For example:

"Neither science nor faith can fully prove how the world came to be, so they are complimentary to each other," said Bennet Brabson, a professor of physics at Indiana University in Bloomington.

"(Religion and science) have a shared inquiry, not necessarily a shared certitude," said Mark Engle, a retired rector from a Marquette church. "The journey of truth in scriptures is never done without science."

Whenever someone says something like this, he/she is forgetting one important thing. In science, when something is accepted to be valid, there is usually ONE set of formulation or description that we all agreed on. It doesn't matter if you are an American, a European, a Russian, a Chinese, a christian, a buddhist, a muslim, an athiest, etc... It is the SAME scientific theory and description. The theory of conventional superconductivity, for example, isn't different for a Canadian than it is for a Japanese, no matter what their social and cultural differences are. Even something that is still being highly studied, such as the Big Bang Theory, has a rather large and uniform consensus, even though there are small groups of cosmologist that may disagree with it. What may differ, for instance, among those who do accept the Big Bang, is the details. They may disagree on the "exact" age of the universe, let's say, but it's a matter of it being 4 billion, 6, billion, of 12 billion years old. The difference certainly not between 10 billion and 10,000 years old. If better evidence come along, accepted science evolves to match the evidence.

The same can't be said about religion and its view of the universe. The Judeo-Christian-Islam view of the universe varies WIDELY from the Hindu/Buddhist/Taoist/etc. view of the universe. One can also say that even within the Judeo-Christian-Islam religion, there are also significant differences in the description of the universe. Don't believe me? Read Maurice Bucaille's "The Bible, The Quran, and Science". They do not agree on the fundamental formation of the universe and its age. Even among the Christians themselves, you get one that accepts the age of the universe from Cosmology as being in the billions of years, while there are these "Young Earth" followers who still think the earth is only of the order of 10,000 years old! That's a major, major discrepancy in my book.

So I find it strange that whenever people say that both science and religion can meet, and that one compliments the other in our understanding of the universe, this major disagreement between various religious views are never mentioned, as if "religion" is only one version of Christianity, and as if "religion" means "Christianity" only. There is NO ONE ACCEPTED VERSION of the universe in religion. That's a fallacy.

Not only that, the other reason why I think events like this may not be that effective is because you get someone like this who can't see the fault in what they believe in:

Fred Betz, 63, of Galesburg told the panelists he took the words of the Bible at face value, and his understanding of scripture disproved evolution.

"What's wrong with my simplistic view of reading the Bible?" Betz asked.

Panelists said nothing was wrong and pointed to the central themes of Evolution Weekend: open-mindedness and discussion.

"The way we deal with each other is more important than any of our individual theories," Brabson answered.

Betz wasn't convinced.

"It's sad we're having (this discussion) in a church," he said after the event. "The Bible is the inherent word of God. It's sad I had to explain the same things to them I had to explain to my atheist friend."

How come no one points out that what this guy accepts "at face value" is nothing more than a product of SEVERAL TRANSLATIONS of human memorization over hundreds of years? Did he think that the bible was written in English outright? How secure are you at accepting "at face value" something that had been translated from several ancient languages across several different cultures? How many languages does this guy know? Has he ever done any kind of translation and see how a lot of meanings get lost when one does that? I mean, c'mon! Why are we missing something this obvious here?

When all the religions of the world get their act together and come up with a coherent picture, when maybe this "science meet religion" affair might produce something worthwhile. Till then, all this is doing is trying to merge science with something that is ill-defined. I see this as a futile effort.

Zz.

Physicist Discovers How Sax Players Hit High Notes

Many physicists either study, or try to investigate things that may not be strictly in the traditional area of physics. I mentioned one earlier on the study of the most optimal way to load passengers onto an airline. Now comes a study by a physicist to investigate how a professional saxophone player can hit the high notes that many people cannot. They somehow are able to adjust their vocal tracts to resonate at the same frequency as the sound they're trying to make with the saxophone.

But for the highest notes, the vocal tracts of professional saxophonists did something special.

"In those higher frequencies up there, the saxophone's own resonances are relatively weak, so that's why it's hard to sound those notes," Mr Chen said.

"By adjusting your vocal tract resonances to match those in the saxophone, they add up. That allows them to play the notes."

Interesting!

Zz.

Layoffs At Cornell

I've mentioned of the effects of the disastrous Omnibus budget that was passed recently, and have highlighted how it has severely affected operations and staff at several US Nat'l Labs. But the casualty isn't just restricted to these places. Cornell University has had to lay off about 10% of its workforce at its Laboratory of Elementary-Particle Physics.

The 11 job cuts represent 10 percent of the lab's 110 employees. The laboratory, which studies the laws that govern atoms and molecules, has lost 30 percent of its funding in the last 2 1/2 years, said lab director Maury Tigner.

“The support of physical science throughout the United States has been falling victim to the latest congressional action in which the American competitiveness has not been supported,” he said.

So not only is there a real impact beyond just the high energy/nuclear physics programs, there are also impacts beyond just the Nat'l Labs. I wouldn't be surprised that there are more of these stories around in the months to come, because I don't see the president's FY09 budget proposal being passed, certainly not this year.

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The LHC As A Time Machine?

Report on this has been circulating the news wire for a few days ever since the silly editors at New Scientists proclaimed that it can happen (shall I mention for the gazillion'th time why I consider New Scientist as the science's supermarket tabloid?). I suppose when colliders like RHIC didn't actually produce blackholes, some people need to come up with other more creative ways to get them free publicity. So why not a wormhole?

We finally have a sensible article that discusses this. Still, the crackpots of the world are already rejoicing and jumping all over this.

Zz.