The Physics of Potholes.

I'm not scraping the bottom of the road here to find this story (pun intended). Still, this news article does have a fairly accurate description of the formation of potholes that you often see on the street, especially in areas of the world that have freezing climates during certain times of the year.

Pothole formation comes down to basic physics. Water gets into the subsurface below the pavement, often through cracks, and expands as it freezes.

If everything freezes in a consistent way, it's not as much of a problem, Berry said. But often water distributes itself unevenly through the subsurface, meaning some areas expand more than others.

Then, when the ice melts, the pavement contracts and weakens. Add the weight of heavy vehicles to the mix, and the weak spot can become a hole.

That hole, in turn, can grow as car and truck tires chip away at the damaged asphalt.

Actually, there is also another factor to this. I often see potholes a couple of days after a snow storm. Why? All those freezing and thawing tends to loosen clumps of asphalt and concrete, especially those that were used to patch up a street. When a snow plow comes along to plow away the snow, these loose patches also tend to get caught in the plow and voila! You have a pothole. So while the weather certainly plays a factor in creating potholes, snow plowing simply accelerates such creations.

Didn't think you'd read about potholes in a physics blog, did you? :)

Zz.

Direct Measurement of Critical Casimir Forces

This is an amazing work. A group of physicists in Germany has made a "direct" measurement of the critical Casimir forces[1]. I suppose this is as direct as it can get, as of now.

There is a News and Views coverage of this paper in the same issue of Nature, and also on the Physics World website.

Zz.

[1] C. Hertlein et al, Nature v.451, p.172 (2008).

Illinois Governor Writes To Pres. Bush To Restore Science Spending

Illinois Governor, Rod Blagojevich, wrote a letter to President Bush urging him to restore the intended budget for Argonne and Fermilab, both national laboratories in his state. This is just after Bush visited an elementary school in Chicago.

Yesterday, as you visited Chicago, you toured Greeley Elementary School and saw first hand the success we’ve had in promoting math and science based education. Ironically, because of major funding reductions to some of the nation's leading research facilities within the Department of Energy’s budget, the students you saw today may have a hard time starting a technical or scientific career in Illinois.

The omnibus spending bill that you recently signed could cause dramatic funding cuts at Argonne National Laboratory, one of the nation’s largest and most important research centers. In addition to these cuts, the bill includes significant cuts to Illinois’ other federal research facility, Fermi National Accelerator Laboratory. These two institutions put Illinois and the United States at the forefront of scientific research. Without adequate federal funding, hundreds of people will lose their jobs while the United States will risk falling behind in science and technology leadership.

When politicians starts wondering why we seldom believe in what they say, point them to this debacle. Not even 6 months after they all agreed that more funding should be given to science via that joke America COMPETES Act, what did they do? They cut science spending, and cut it with impunity. Essentially, THEY LIED! They plainly lied in front of our faces, and knew that they'll get away with it too!

Of course, you could say "What else is new?" Maybe this is their standard operating procedure. I can only hope that one day, one of these lies would really come back and haunt them.

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Science, Evolution, and Creationism

If you haven't found this and downloaded it yet, you might find it useful. This is the document produced by the US National Academy of Sciences addressing the Evolution vs. Creationism in terms of science. It addresses things in a straight-forward manner, and produces not only rebuttals against several popular points brought up by creationists, but also points to several strong evidence in support of evolution that many people may not realize.

Most of the documents and reports can be obtained for free.

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When Superconductivity Became Clear (to Some)

I mentioned last October (2007) of the conference being held at UIUC to commemorate the 50th Anniversary of the BCS Theory of Superconductivity. Well now the NY Times has an article related to that, and includes a delightful anecdotal history on how Bardeen recruited Cooper to come to UIUC to work on the superconductivity problem. I think most people are not aware that some of the giants in physics at that time had tried to solve the superconductivity problem and failed!

After wrapping up special and general relativity, Albert Einstein tried, and failed, to devise a theory of superconductivity. Werner Heisenberg, the physicist who came up with the Heisenberg uncertainty principle, struggled with the problem, as did other pioneers of quantum mechanics like Niels Bohr and Wolfgang Pauli. Felix Bloch, another thwarted theorist, jokingly concluded: Every theory of superconductivity can be disproved.

You seldom hear in any of Einstein biography of him dabbling in trying to solve this.

This is a terrific story. Don't miss it.

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What Is It That Makes Us Believers?

This article examines the possible reason that people believe so strongly on things that have no scientific evidence for being valid.

The first reason magical beliefs continue to exist is it feels good to believe in them. It’s a sort of mental stimulation when one thinks there is something magical out there that can’t be explained that is going to show ‘them’ that they’ve been wrong all along.

It’s pleasing to believe that you know of some alternative medical practice that, while irreproducible in science, miraculously heals people while tens of thousands of physicians worldwide ignore it. These things don’t have to be medical, they could even be knowledge of a ‘magnetic’ hill where cars in neutral roll UP hill instead of down. Magic!

The second reason is that once a person buys into many of these beliefs their ego prevents them from deviating from this line of thinking. This is especially true if fundamental religious beliefs tie into these belief systems. Don’t get me wrong, I’m certainly not knocking religion, but in the case of faith healing (I’m talking about the televangelist type of money-grubbing stuff) there is a familiar thread of magical thinking involved.

For me, there's another reason - the inability to differentiate between a valid scientific evidence, versus anecdotal evidence. They don't know the criteria on what constitute a scientific evidence, and WHY we have such criteria.

Zz.

Japanese Particle Physics Is In Good Health

At least we have some positive news for the high energy physics community. The Japanese high energy physics lab, KEK, has revealed its future roadmap that certainly is more optimistic than what is going on with the UK and US budget debacle.

The 20-page roadmap report outlines an ambitious five-year plan that includes a major upgrade to KEK’s flagship "B-factory" and a strong commitment to the proposed International Linear Collider (ILC) — two areas that have suffered greatly as a result of the recent cuts in the UK and US.

I'd say along with China that continues to pour money into various areas of physics, that part of the world may end up with future high energy physics projects (ILC anyone?)

Zz.

"Absolute Zero" on NOVA Tonight

If you are in the US or could receive the US Public Broadcasting stations, here's an announcement that I received from NOVA about the program premiering tonight on PBS:

Starting tonight, January 8, NOVA will be presenting the first part of a two-part series on low-temperature physics. "Absolute Zero" explores four centuries of cold science, opening in the 1600s, when the nature of cold was a complete mystery, and continuing on to the modern race to create the first Bose-Einstein condensate in the laboratory. We think readers of the Physics and Physicists blog will be interested in the show!

Tonight's episode, "The Conquest of Cold," includes Cornelius Drebbel’s spooky trick of turning summer into winter for the English king, achieved in much the way that homemade ice cream is produced; Antoine Lavoisier’s battle with Count Benjamin Rumford over the caloric theory of heat, an intellectual contest set against the backdrop of the French Revolution, in which Lavoisier unfortunately lost his head to the guillotine and his wife to Rumford; and Michael Faraday’s explosive experiments to liquefy gasses, which established the principles that make refrigerators possible.

Next Tuesday, NOVA will air "The Race for Absolute Zero," which picks up the story in the late 19th century, with James Dewar and Heike Kamerlingh Onnes racing to liquefy hydrogen and helium, before moving a century ahead to meet the scientists who competed to produce a Bose-Einstein condensate, including Eric Cornell and Carl Wieman of the University of Colorado at Boulder and Wolfgang Ketterle of MIT.

You can watch a preview of this show at http://www.pbs.org/wgbh/nova/zero/. "Absolute Zero: The Conquest of Cold" will premiere tonight at 8PM ET/PT on most PBS stations. Please check your local listings to confirm when it will be broadcast near you: http://www.pbs.org/wgbh/nova/schedule-local.html.

It sounds fascinating. Hopefully, if you do watch this, that you'd write back with a comment.

Zz.

Big Trouble For Big Science

Alan Boyle at MSNBC has essentially given a summary of all the major research areas affected severely by the recent Omnibus budget. It covers essentially what I have highlighted separately here.

The cuts came in the omnibus spending bill patched together by Congress and signed by President Bush just before Christmas. Among the institutions hit hardest were Fermilab and Argonne National Laboratory in Illinois; and the Stanford Linear Accelerator Center, or SLAC, in California.

It is INSANE!

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The Quantum Spin Hall Effect: Theory and Experiment

More review article. This is a rather extensive overview of the quantum spin Hall effect. This effect has similarities to the traditional quantum Hall effect that involves charge transport. Coupled with the review article on spintronics that I highlighted recently, the QSHE shows how spin current is now a rather important factor not just in the possible application in advanced electronics, but also in fundamental understanding.

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Quantum Behavior of Light In Undergraduate Laboratory

While the Compton effect and the photoelectric effect are often used as "evidence" of photons, they actually cannot rule out completely the wave picture. The more definitive experiment would be the which-way experiment or the coincidence experiment. I find it rather amazing that such experiments are now within the realm of an undergraduate laboratory exercise.

There were 2 papers published in the American Journal of Physics that provided a very detailed description of such experiments suitable for such undergraduate laboratory. The first one is by J.J. Thorn et al. Here, they did the coincidence measurement that basically reproduced (with better equipment) an earlier Graingier et al. experiment. The second one by C.H. Holbrow et al. describes 5 different possible experiments (and theory to accompany them) to illustrate the photon pictures. No experimental result was reported in this paper.

Both papers contain a wealth of references, especially to other similar experiments that have already been done. That alone is worth keeping these two papers handy.

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SLAC Facing Budget Cuts and Layoffs

I reported last Friday of the impending consequences of the recent budget cuts at SLAC. They had their all-hands meeting today, and the anticipated scenario has become true.

Stanford Linear Accelerator Center (SLAC) staff learned in an "all-hands" meeting today that its budget is being cut by Congress and the center will have to reduce its workforce by 15 percent, or the equivalent of 225 full-time positions.

High energy physics in the US is dying.

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Atomic Force Microscopy and Spectroscopy

Wow. This is one of the most comprehensive overview (other than buying a book on AFM itself) of Atomic Force Microscopy and Spectroscopy.

Yongho Seo and Wonho Jhe, Rep. Prog. Phys. v.71 p.016101 (2008).

It would certainly be something one should read if one intends to use this technique.

Zz.

Science and the Presidential Election

The the tedious US Presidential Election in full swing right now with the primaries and caucuses for each party, science continues to take a back seat in terms of importance. I'll have more to say on this later, but for now, it might be useful to see if there's anything we can infer regarding each candidate's view on science. The Jan. 4th 2008 issue of Science has a summary for the leading candidates in each party regarding their views of science, and possible science policy. Hillary Clinton turns out to have the most detailed and comprehensive policy on science, which isn't surprising since she probably got the same network of advisers that Bill Clinton had. Still, she has stated that the Presidential Science Adviser will report directly to her, and not through several layers of commands the way George Bush currently has it.

Anyhow, you might want to pick up this issue of Science. This might be one of the few places that have such a concise description of the candidates' views on science and science policy. It is also why we should have a presidential debate on just science.

Zz.

The Spintronics Challenge

If you haven't read this yet, then you should click the link PhysicsWorld has a good article on Spintronics and the challenges it still has to face in producing something that can be used. It's a good article to get you up to speed on this amazing area of study.

Because the spin of an electron can be switched from one state to another much faster than charge can be moved around a circuit, spintronic devices are expected to operate faster and produce less heat than conventional microelectronic components. One of the ultimate goals is to build a spin-based transistor that would replace conventional transistors in integrated logic circuits and memory devices, thus allowing the miniaturization trend to continue. However, spintronics also opens the door to entirely new types of device, such as a light-emitting diode (LED) that generates left or right circularly polarized light for use in encrypted communication (see "Spin-based devices"). Looking further into the future, spintronic devices could even be used as quantum bits, the units of information processed by quantum computers.

It is also interesting to note, with ties to the previous blog entry that I made on the theoretical possibility of monopoles in a strongly-correlated magnetic system, that the spin current can move separately than the charge current in certain conditions. This fractionalization is expected to occur in 1D system, and could even possibly occur in 3D system. So this area is certainly not just an active area in the possible application of it, but also a hotbed in basic, fundamental physics studies.

Zz.

Alternative Medicine and the Laws of Physics

Another classic text on debunking many aspect of alternative medicine. This time it is an essay written by Bob Park, who I will freely admit, is one of my "heroes".

He and Richard Dawkins should get together. :)

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The Physics Behind Four Amazing Demonstrations

Skeptical Enquirer has listed 4 amazing demonstrations and gave each one of them a plausible and reasonable physical explanation. This should be quite handy if you ever encounter anyone using any of them as "proof" of some supernatural phenomenon.

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SLAC Cuts May Be Near

I've already highlighted the debacle with the budget cuts at Fermilab and Argonne. Next comes the news report about the possible cuts at SLAC. A all-hands meeting is scheduled for this coming Monday, and most are expecting rather gloomy news similar to that received at Fermilab.

Y'know, at some point, someone will wake up and realize what is going on. Still, I wouldn't hold my breath on that happening.

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Budget Cuts to Hit Argonne

The devastating budget cuts will impact almost every single US National Lab. We have see how this will almost cripple Fermilab with its planned layoffs of 200 people. It may even hasten its demise.

This Chicago Tribune article focuses on the other lab in the Chicago area besides Fermilab - Argonne National Laboratory. The premature shut down of the IPNS and the reduced operations at the APS are just the beginning of the awful mess created by this thoughtless omnibus bill.

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Physics World's "Physics Quiz of 2007" Contest

Do you want to a chance to win £50? Then be the one who gives the most correct answers to this quiz organized by Physics World.

Closing date is Jan 14, 2008. So you don't have that much time left!

Zz.