Interface Between 2 Insulators Becomes Superconducting

As Alice in Wonderland says "things are becoming curioser and curioser".

First there was a report that the 2D interface between 2 insulators can become metallic[1]. Now a new report in Nature has indicated that such interface can in fact become superconducting, albeit at 200 mK[2]. Fantastic!

This interface is a 2D thin region (~10 nm) and evokes exotic transport mechanism, I would assume. There's still considerable work in coming up the theoretical explanation for this phenomenon. So there's plenty of work left to be done.

Zz.

[1] A Ohtomo, H.Y. Hwaing, Nature v.427, p.423 (2004).
[2] N. Reyren et al., Science v.317, p.1196 (2007).

SNS: America Regains Leadership with World Record

This appears to be a breaking news from Oak Ridge National Lab regarding the Spallation Neutron Source.

Lab officials have announced that the Spallation Neutron Source, the Department of Energy’s $1.4 billion research facility at the Oak Ridge National Laboratory, has established a new record as the world’s most powerful accelerator based source of neutrons for scientific research.

The SNS surpassed the previous record for beam power 160 kilowatts, held by the United Kingdom’s ISIS facility, while operating at 183 kilowatts.

I wouldn't stamp it with the "leadership" medal yet, because the usefulness of such source depends more than just this parameter. Still, it is a good start at justifying all that money spent on building it.

Zz.

String Theory Might Provide Insight Into High-Tc Superconductors and Quark-Gluon Plasma?

Say it isn't so!!

:)

Jan Zaanen's article in this week's Nature (Nature v.448, p.1000; 30 August 2007) highlights an ArXiv preprint by Hartnoll et al. that seems to have made a connection between one aspect of String Theory called the anti-de-Sitter/conformal field theory correspondence(AdS/CFT), and the heat and charge transport in high-Tc superconductor called the Nernst effect.

Hartnoll et al. push what one might term the 'AdS-to-high-Tc correspondence' to its logical conclusion. They study its application to a particular, rather recondite transport phenomenon known as the Nernst effect — the crosswise flow of heat and charge currents in the presence of a magnetic field7 — in the nearly quantum-critical matter of a two-dimensional cuprate system. In a theoretical tour de force, they use the physics of a black hole in a three-dimensional anti-de-Sitter space that carries both electrical and magnetic charge to guide them in the very complex derivation of the relevant transport equations directly from quantum field theory. They show that these theoretical results are seemingly consistent with a number of hitherto unexplained features of the Nernst effect in a high-temperature superconductor7.

Man, that takes a lot of balls to do that! :) And what about the quark-gluon plasma that has been studied at RHIC?

Here, the AdS/CFT correspondence comes to the aid of the experimentalists in a similar way. The background is the observation that quark–gluon fireballs, as have been created in the Relativistic Heavy-Ion Collider at Brookhaven National Laboratory on Long Island, behave in a remarkably simple way, but one that current theories find difficult to explain — they are governed by normal hydrodynamics, but have extremely low viscosity. Quite simply, the AdS/CFT correspondence tells us that when the quantum physics is scale invariant, the viscosity of such a system can be as small as it is. This result is far from obvious given our current understanding of quantum chromodynamics, the standard-model quantum-field theory of the strong nuclear force that governs interactions in the quark–gluon plasma.

I'm not going to jump onto the String Theory bandwagon and proclaiming it as the next best thing since sliced bread, but this is getting to be rather interesting.

Zz.

Yukawa's Gold Mine

This is an excellent article on the historical significance of Yukawa's hypothesis of the pion. It is simply amazing how this theory has legs, even till today.

Zz.

Illusion Mimics Out-of-Body Experiences

So now we can manipulate the brain enough that we can even mimic the so-called "out of body" experience (link open for free for a limited time only).

The effect was created in two separate experiments described in Science1,2 this week, both of which used a simple method to fool volunteers into thinking that their minds had been displaced outside their bodies. In each case, participants wore virtual-reality goggles hooked up to cameras trained on their own bodies.

In one study, carried out by Henrik Ehrsson at University College London, volunteers were then prodded in the chest at precisely the same moment that an object approached the camera. In this scenario, the volunteers identified strongly with the location of the camera, thinking that this is where their true self was — the view of their body was like a view of someone else.

In the other experiment, led by Olaf Blanke of the Swiss Federal Institute of Technology in Lausanne, patients viewed a camera image of their own back being stroked, while their own back was stroked too. In this instance, volunteers identified strongly with the picture of their back, thinking that this was their location - again outside their own body.

So again, something that was "mystical" and supernatural actually is nothing more than our minds playing tricks on us, as in the case of many other examples (placebo effect). It is why valid evidence cannot be based on just anecdotal evidence. Our minds can be easily susceptible to illusions that we think are real. Scientific evidence requires a lot more rigorous testing to ensure that we do not fool ourselves.

Zz.

[1] H. Henrik Ehrsson Science v.317, p.104824 (2007).
[2] Bigna Lenggenhager et al. Science v.317, p. 1096 (2007).

Nuclear Reactions in the Lab Mimic Supernovas

This is one way to create a controlled "supernova" in the lab.

RESOLUT is not the only facility in North America using a beam of atomic particles to isolate rare nuclei in a particle accelerator, but it is unique in its flexibility. The TRIUMF Accelerator at the University of British Columbia and the ORELA facility at the Oak Ridge National Laboratory in Tennessee have, Wiedenhöver admits, "better beams, but we can select more freely which isotopes to study."

So how come we don't get people complaining about a doomsday scenario for such an experiment? They seem to be coming out of the woodwork with the LHC collider creating blackholes. You don't hear people complaining about blowing ourselves up by creating a supernova.

Or maybe they aren't quite sure yet what a "supernova" is. :)

Zz.

The Unreasonable Effectivness of Mathematics in the Natural Sciences

This is a rather old essay written by Eugene Wigner. However, it is still as relevant today. This is one of the best essays that I've ever read. He gave a rather practical definitions of Mathematics and Physics, and what mathematics means to physics.

This was already implied in the statement, made when discussing the role of applied mathematics, that the laws of nature must have been formulated in the language of mathematics to be an object for the use of applied mathematics. The statement that the laws of nature are written in the language of mathematics was properly made three hundred years ago; [ It is attributed to Galileo.] it is now more true than ever before.

And as I've indicated in my own essay on why QM is so difficult, in such a case, the mathematics of QM is the main connection we have between it and what we already understand, even when there is no conceptual connection between classical and quantum mechanics. It is the bridge and thus, if one does not understand the mathematical formulism of QM, one hasn't understand QM at all but rather has a superficial idea of what it is.

If you haven't come across this yet, I would certainly highly recommend that you read it.

Zz.

Living Is "Riskier" Than Nuclear Power

Y'know, I've seen this kind of claims forever. Newspaper column and people on the street often argue about something having a risk, or no amount of radiation is "safe", etc.. etc., without realizing quantitatively what they are saying in comparison to others that they have accepted. The case in point is the "risk" associated with nuclear power. It seems that the LA Times editorial has concluded that nuclear power is "extremely risky". That, in itself, is extremely irresponsible if one doesn't compare the risk involved with the risk others have accepted.

So it was good that R. Stephen White, emeritus professor of physics at University of California, Riverside, wrote back to blast such claims.

Really, how risky is nuclear power? The Three Mile Island meltdown was the worst accident in the history of U.S. commercial nuclear fission electricity generation. It occurred at a time when about 100 U.S. commercial reactors were generating electricity, with an average life span of about 30 years. Yet it caused no injuries or deaths. The emitted radiation was so low that it could hardly be measured. In the 20 years before and 28 years after that accident, no deaths from other U.S. commercial reactor meltdowns occurred.

But let's assume that three people had died in that emergency, and from that hypothetical make a simple estimate of the risk of death to a person in the United States by the operation of 100 reactors. We will assume a U.S. population of 300 million, and a person's lifetime of 75 years. Dividing the three deaths by the population of 300 million, we find the chance of a person's death over his/her lifetime is 1 in 100 million.

We now compare that risk to those a person may take every day, like riding in a vehicle or walking along the street. In the United States, about 40,000 people are killed each year in vehicle accidents. Five thousand of these are pedestrians. In the 28 years since the Three Mile Island accident, over 1 million people have been killed in U.S. vehicle accidents. In a person's 75-year lifetime, 3 million people will die. Thus, the chance of any one person being killed in his or her lifetime is 3 million divided by the 300 million population, or about 1 in 100. Driving is 1 million times more risky than nuclear fission generation of electricity. Riding in vehicles, even walking, with a risk of about 1 in 800, might be called "extremely risky."

Again, there is often a disconnect (hypocracy) between what people claim and do. They claim such-and-such is risky, yet they are practicing and accepting something even riskier. And note that this is the same pattern that can be applied to other things as well, such as the proclaim that "time is an illusion", without bothering with the fact the criteria being used to make such a claim can also be used to assert that "space is an illusion" as well. Yet, no one seems to be making such a claim. So why did they just pick on time?

Often, human actions are inconsistent.

Zz.

Clavius.org

We continually see discussion on various conspiracy theory on the moon landings. Very much like the claim that the 2nd Law of Thermodynamics falsies the theory of Evolution, the people who make these claims are either simply proud of their ignorance, or simply won't learn (or both). This is despite the fact that there have been many explanation for the various claims made by these conspiracy theories.

One such website that has collected many of these claims and has debunked them meticulous is Clavius.org. There is a tremendous wealth of information here, and everything one can think of or has been made against the moon landings, one can find it here and see it smashed into bits. It's a great site to have in your Bookmars/Favorites because, inevitably, these "conspiracists" will pop their ugly heads again, and you'll know where to look for your ammunitions.

Zz.

Astronomers Puzzled by Cosmic Black Hole

OK, so the title is rather misleading because this isn't a "Black Hole", but rather a void in the universe.

Astronomers have stumbled upon a tremendous hole in the universe. That's got them scratching their heads about what's just not there. The cosmic blank spot has no stray stars, no galaxies, no sucking black holes, not even mysterious dark matter. It is 1 billion light years across of nothing. That's an expanse of nearly 6 billion trillion miles of emptiness, a University of Minnesota team announced Thursday.

As an experimentalist, I love it when we discover unexpected or new observations. So this is really something right up my alley. :)

Of course, I could make some dumb jokes about this void being the possible origin of dark matter, but I won't. :)

Zz.

Medical Linear Accelerator Celebrates 50 Years of Operatons

This is a bit late, but better than never.

I wrote an entry earlier on Accelerator Physics, and how many people do not actually understand what it is and why it is different than particle smasher. I have examples where linear accelerators can in fact already be present in your hospitals. It turns out that the medical linear accelerator celebrated its 50th Anniversary this past April.

This is one very clear example where the advancement made in one field provides a new opportunity and technique in another. And no one reading this should make the mistake anymore of confusing "particle accelerator" with "particle collider". :)

Zz.

Light Collapses Step-By-Step

This is such a cool experiment. They are able to make non-destructive measurement of the photon number in a superconducting cavity, and then as they successively make this measurement, they begin to see the result converging (collapsing?) to a single number. Just exactly what quantum mechanics described!

The exact citation for this paper is C. Guerlin et al. Nature 448, 889 (2007).

Zz.

Enemy of Reason Part II Video

Thanks again to Moridin at PF for pointing this out. Part 2 of Richard Dawkins's "Enemy of Reason" video has now appeared online. The first part of this series can be found here, if you missed it.

Let the fall-out begin!

:)

Zz.

'X' Marks Fermilab Future

With the Tevatron shutdown looming and the International Linear Collider still a dream away, Fermilab is making its own effort to survive by proposing an intermediate project called Project X. It is meant to be a project that allows for the lab to remain in operation, continues to produce fundamental science, and also allows for the engineering expertise that is eventually needed for the ILC to be tested.

Fermilab's long-range ambition is to host a mammoth project called the International Linear Collider, but that idea will take decades to bring to fruition. Project X would incorporate many of the technologies needed for the ILC, yielding new experimental opportunities and potentially strengthening Fermilab's chances of landing the bigger device.

"This would be a world-class machine at a cost that is much lower than the ILC," said Fermilab Director Pier Oddone.

Of course, as the article has stated, everyone, including Fermilab officials, are aware of the possible downside to such a proposal and especially if it gets built. Certainly there's a perception that Fermilab may not get the ILC if this gets built, and that Project X may be a "light" version of the ILC, the same way RIA got downsized by half of the cost and morphed into an "Advanced Exotic Beam Laboratory".

Zz.

Scientists Confirm Long-Held Theory About Source of Sunshine

It is always good to confirm a long-standing understanding of anything. This is such a case done at Gran Sasso National Laboratory near L'Aquila, Italy. By observing the low-energy neutrinos from the sun, they have verified the type of nuclear reaction going on inside the sun that generates all of the energy.

"Our observations essentially confirm that we understand how the sun shines," said Frank Calaprice, a professor of physics and principal investigator of the Princeton team. "Physicists have had theories regarding the nuclear reactions within the sun for years, but direct observations have remained elusive. Now we understand these reactions much better."

Bravo!

Edit: this is the news article from Nature on the same experimental work. Again, the link is open for free only for a limited time.

Zz.

Galactic Collision Challenges Dark Matter Theories

What? We may have to change our "understanding" of the property of something we barely know anything about? This is unacceptable! :)

All kidding aside, this observation by the Chandra X-ray Observatory could be BIG! (Open, free link available only for a limited time.)

The images depict hundreds of galaxies merging into a huge cluster called Abell 520, located about 2.4 billion light-years away. As astronomer Andisheh Mahdavi of the University of Victoria in Canada and colleagues will report in the 20 October issue of The Astrophysical Journal, some of the galaxies have moved as far away as 2 million light-years from their dark matter anchors, far enough that gravity will never bring them back. Perhaps just as incredible, the clouds of hot interstellar gas formerly contained by the galaxies--and superheated by the collision so they glow in x-ray light--seem to have been grabbed by the dark matter instead of being flung into space.

Dark matter remains mysterious, which also means that there's going to be a lot of jobs for a long time for people studying this.

Zz.

Science and the Islamic World

This is just an excellent article in Physics Today by Pervez Hoodbhoy, who is the is chair and professor in the department of physics at Quaid-i-Azam University in Islamabad, Pakistan. I think for people who are not aware of how muslims have contributed to the advancement in science, and why they are not so far lagging in it, this is an eye-opening essay from someone from the inside of the battle lines. For many of us, such restrictions and hand-cuffing of what we do or how we go about practicing our profession are unimaginable.

Zz.

The Mystery of Dark Matter and Dark Energy

For a Yahoo News article, this isn't a bad overview of the hunt for dark matter and dark energy.

I've attended seminar given by both Michael Turner and Scott Dodelson, who were both interviewed for the article. These are certainly two of the well-known names in this field of study. So they have certainly go to the experts to get information for this article.

Zz.

More and More Bastardization of Quantum Mechanics

It never ends, does it?

This one is even hilarious. It is advertising a free "tele-seminar" on how QM can affect your consciousness.

Speaker, Thomas Herold will discuss how quantum physics can help individuals manifest their life dreams. Calling on the findings of Sir Issac Newton, the Wave/Particle Duality quantum paradox and the paradigm of space, time and matter, this seminar will illustrate how good old fashion science coupled with a strong belief system provides evidence that your thoughts create your reality.

Pardon me, but Isaac Newton had findings on wave/particle duality? No kidding!

So besides that fact that there are no clear link and evidence to extrapolate QM's formulation with "consciousness" and "belief system", they also can't get the history of physics correct. This is a first for me in seeing Newton being associated with this QM "paradox". Of course, they neglected to study QM and realize that there is NO paradox at all, and that the wave-particle duality is only something used to explain one part of an observation (not formulation) to the general public. There's no wave-particle duality in the formalism of QM. Honest! Look for yourself if you don't believe me!

Zz.

Nature Collections of Energy Papers

Nature has compiled a list of their papers and articles related to our Energy issues and problems. Most of these papers are being made available FREE online. So take a look if you're interested (not sure why you won't be since this affects all of us).

Zz.