Vacation

I've been on vacation since May 25th, and won't be back till June 4th. So there will be no new updates and reports till then.

The physics world will just have to move on without me.

:)

Zz.

Weinberg Cancels UK Trip

Physics Nobel Laureate Steven Weinberg has canceled an invited trip to the UK to honor Abdus Salam. This cancellation was due to his perceived view of the UK's growing anti-Isreal movement.

In the letter, the professor said his decision was triggered by an agreement by the National Union of Journalists at its national conference to boycott Israeli products.

He wrote: "I know that some will say that these boycotts are directed only against Israel, rather than generally against Jews.

"But given the history of the attacks on Israel and the oppressiveness and aggressiveness of other countries in the Middle East and elsewhere, boycotting Israel indicated a moral blindness for which it is hard to find any explanation other than ant-semitism."

Zz.

JPL Open House

I've highlighted the Open House at both Argonne and Fermilab. Now it is the turn of the Jet Propulsion Lab.

While I'm sure we didn't copy each other, it is great to hear that we both have similar open house presentations. For our HEP division here, we had a "As A High Energy Physicist" booth where people can ask almost any physics question that they have. At JPL, they had "Ask A Martian". Cute!

If you attended this open house, or if you were involved in it, I'd like to hear from you.

Zz.

Organizing the Universe

This is a terrific interview with physicist Neil DeGrasse Tyson. I especially like the part where he started off with something that is exactly how I feel about the whole Pluto issue:

Neil DeGrasse Tyson is an astrophysicist who doesn't believe in planets. Of course he knows that there are large objects circling the Sun. He just doesn't believe that picking out nine of them -- or eight, now that Pluto has been demoted -- has any scientific basis. There are far more interesting ways of dividing up the universe. For example, there are four bodies in our solar system that have atmospheres -- three planets and one moon of Saturn -- and having an atmosphere is far more interesting scientifically than simply being a big object because having an atmosphere raises lots of questions and possibilties. Being big raises nothing but the question, "Well, so how exactly big are you, anyway?"

It was rather sad that out of all the amazing development out of astronomy and astrophysics, the recategorization of Pluto got such a huge news and such large amount of effort among even astronomers. Compare that to what exactly is such an impact on the physics and astronomy content - NOTHING. That is why I said that this is an exercise in something that is utterly useless.

Zz.

Left-Handed Natural Material

Left-handed material are those that have a negative index of refraction. It means that both the permittivity and permeability of the material are both negative.

Till now, such material have been man-made, and they are called meta-material. This is because the material consists of structures made that is considerably smaller than the wavelength of interest. In this way, the EM wave does not see the material as consisting of discrete structures.

However, there is now a new report that showed for the first time that a natural material can have a negative refraction. Physicists in Germany has shown that metallic ferromagnet can exhibit such property up to the GHz range. This astounding result was published in PRL[1]. A summary of this discovery can be found at PhysicsWeb (requires free registration)

Zz.

[1] A. Pimenov et al. Phys. Rev. Lett. 98, 197401 (2007).

Physics For Future Presidents

This is a serious class at UC Berkeley, but that is essentially the title and the aim. The instructor of the class, Richard A. Muller, certainly has a well-defined goal in mind. It covers many important issues that are related to physics, but in a non-trivial manner. Essentially, if you become the President, or leader of a nation, these are the physics that you should know for you to be able to make an intelligent decision, rather than delegate it to someone else.

They got a bit of publicity on this also, which they deserve. There are also other free online lessons that are listed on the ABC7NEWS webpage that you might want to look for.

I'd go even further if it isn't explicit in that webpage. It is essential for EVERYONE to understand the material being covered here. We all have to be able to decide on these issues. Without proper skill and background knowledge, one will be making guesses based on ignorance, rather than a rational decision. Many of our problems we face today are simply too important to be decided based on guess work.

Zz.

The Wrecking of British Science

This is a terrific opinion piece written by Nobel laureate Harry Kroto. While it focuses on the problems in the UK with regards to physics education and enrollment, many parts of what he said applies everywhere in the world. In particular, he made a compelling argument while the study of science is valid for everyone, no matter what area they are going into.

The scientific method is based on what I prefer to call the inquiring mindset. It includes all areas of human thoughtful activity that categorically eschew "belief", the enemy of rationality. This mindset is a nebulous mixture of doubt, questioning, observation, experiment and, above all, curiosity, which small children possess in spades. I would argue that it is the most important, intrinsically human quality we possess, and it is responsible for the creation of the modern, enlightened portion of the world that some of us are fortunate to inhabit.

Curiously, for the majority of our youth, the educational system magically causes this capacity to disappear by adolescence. Without it, we have no instinctive ability to assess the importance of the technical issues that impinge on our everyday lives. We are unable to gauge accurately the validity of fears over such issues as climate change and the looming energy crisis, or grasp the socio-economic and humanitarian importance of new genetic technologies.

Scientific education is by far the best training for all walks of life, because it teaches us how to assess situations critically and react accordingly. It gives us an understanding based on reverence for life-enhancing technologies as well as for life itself. If we do not know how things work, how can we fix things? And how are we going to use these powerful technologies wisely?

I've always argued that more than the material itself, the ability to analytically think things through, and to analyze the validity of a result/conclusion, are more important, especially for people who are not going to be scientists and engineers. Such skill is severely lacking in many people, because they seldom look behind the statements being made, often by politicians and talking heads on TV.

Zz.

Cathodes for Photoinjectors

A while ago, I did a table listing various "family" or types of photocathodes that are used or might be used in an accelerator photoinjector. It was one of the first thing that I did after I changed field and went into accelerator physics. The table made its debut at our Theory Institute workshop on high brightness photoinjector, and it has appeared in the workshop's White paper, but also in several other presentations. So I consider it as the very first impact that I had on a field that I was still trying to learn.

The table is quite brief and obviously omits a lot of other material. I'm working on expanding it to include as many photocathode material that I can find that are either suitable, or being considered as viable candidates for this application. Just because something can photoemit, it doesn't mean it can automatically be used in a photoinjector setting, especially an RF photoinjector. The material must be robust because it will be under high, alternating gradient (often up to 90 MV/m peak field), and it must be able to withstand back bombardment of electrons that are sloshing in the photoinejctor cavity, and must be able to perform for months without significant degradation. All of these are strict requirements of a photocathode for an accelerator photoinejector.

So here is the table that I made years ago. Hopefully, an updated version will be out soon.



Zz.

20 Years of Physics at Kennywood Park

With summer rolling around and amusement parks in high gear all over North America, many schools/physics classes are starting their "amusement park" physics. I suppose it is one way to illustrate various principles of physics to the students while they have fun at the park.

Still, one park in particular is marking its 20th Anniversary of students doing their project there. The historic and lovely Kennywood Amusement park in Pennsylvania this year welcomes thousands of students over a 2-day Education Days at Kennywood.

Twenty years later, Kennywood welcomes approximately 14 thousand students over two “Education Days” at Kennywood. On Tuesday, May 22, thousands of students will participate not only in Physics, but also in other Math and Science programs. Programs include: Physics, Mathematics @ Kennywood, Math & Science Passport, the Pittsburgh History & Landmarks Foundation’s Architecture Program, Phipps Conservatory’s worksheets entitled Plants at Kennywood, Space Exploration a NASA demonstration, Carnegie Science Center’s program Fire & Ice, Understanding our Watershed presented by RiverQuest & 3 Rivers Wet Weather and, in celebration of Pittsburgh’s 2007 Year of Glass, the Pittsburgh Glass Center will present Hot Glass Demonstrations.

Applause to both the organizers and the park officials for sustaining this activity into a huge event.

Zz.

Wilczek's Wife Put A Stop To The Destruction Of The Universe

This is a rather hilarious anecdotal account. I'm not sure if it is true or not, but hey, it's an amusing story nevertheless.

Reported in this blog is the account from Frank Wilczek's wife on how she put a stop to the destruction of the universe. Back in 1999, Wilczek published a letter in Scientific American that cause quite a ruckus. He was examining the possible scenario that the about-to-be-commissioned Relativistic Heavy Ion Collider (RHIC) at Brookhaven might create a black hole and destroy our world. He later studied it a bit deeper and concluded in another report that the possibility of it happening is minuscule to negligible.

But while this is going on, his wife Betsy recalls how she put a stop to it:

Cambridge's Betsy Devine's husband is Frank Wilczek, an MIT professor who shared the Nobel Prize in physics in 2004. On her eponymous blog, Divine recalls how, in 1999, he seemed to have been quoted as suggesting that a planned "heavy ion collider" could possibly trigger a reaction that would destroy the universe. And she recalls how she put a stop to it:

"Betsy: But the universe is not going to blow up, right?

Frank: Of course not.

Betsy: You really thought about it and it's not.

Frank: Yes, I did. And no, it's not.

Betsy: Good, because if it blew up I'd be so mad at you . . .

That is just precious!

Zz.

Lawyer-Scientists Cash In

Want to make big bucks?

[No, this is not a SPAM for a get-rich quick scheme]

One of the hottest and most lucrative field right now is someone who understands both science and law and can explain it very clearly to a jury. Many physics degree holders go on to law schools after their undergraduate degree and become experts in patent law.

Demand for these specialists is being driven by an explosion in patent applications in recent years and a growing need for lawyers to protect old patents or challenge new ones. The U.S. Patent Office estimates 450,000 patent applications will be filed this year, up from about 350,000 five years ago.

Law professors say they're seeing more students with strong science backgrounds make the leap to law, where recruiters are snapping them up.

So there you go.

Zz.

New Push for Nuclear Power

Considering that many countries in Europe has a higher proportion of electricity generated from nuclear power (France is a prime example), the US lags far behind in this area. It is only now is there a push to build more nuclear power plant for power generation.

Of course, whenever you talk about nuclear energy in its present form, you'll have enviromentalists arguing against it. Any form of energy generation will have trade-offs. It is just a matter of what is acceptable and what isn't. For every "accident" you can point to with nuclear power, one can also point to France and Japan that have impecable records. So it CAN be done.

It is just a matter of to what extent one wants to do it.

Zz.

Plaque Marks Victim of 1970 Bombing at U. of Wisconsin

As someone who went to the University of Wisconsin-Madison, I of course heard about the event that led to the tragic death of a physics graduate student back in 1970 during the antiwar movement. In fact, one of the popular movies shown on campus at that time was The War At Home, which had a coverage of that event.

It appears that finally, upon the consent of the victim's family, a plaque commemorating that tragedy has been unveiled. I also didn't realize that one of the bombers is still at large and one of the most wanted man.

Zz.

Hockey Player Blames Physics

Even when physics isn't involved, it STILL gets the blame.

This hockey player has this excuse for his punishment:

"It's a nothing play if Robbie doesn't hit him," Pronger said, stressing that he did not intentionally hit Holmstrom in the head. The contact, he said, was partly because he is 6-foot-6 and Holmstrom is 6-foot-1. Of course I'm going to hit him in the head," Pronger said. "He's quite a bit shorter than me. It's just law of physics."

Er... Hello, Mr. Einstein, I think you probably have had several hits on the head as well. The fact that you are taller and will hit someone on the head has nothing to do with physics, but rather it has everything to do with GEOMETRY, as in Mathematics!

In one of the chapters in my essay "So You Want To Be A Physicist", I mentioned the fact that for many intro physics students, many of them actually have more of a problem with the mathematics than they do with the physics. When they try to tackled a physics problem, they often get stuck somewhere, and then blame physics for being "difficult". I've seen many instances where the students actually are not well-prepared mathematically, and therefore, they got stuck with the mathematics, often with basic trigonometry. But most don't realize this, so they attribute the difficulty to physics.

Physics can be tough, sure. But it will become impossible if you don't have the tools (mathematics) to use.

Zz.

Canadian PM Puts Spotlight on Scence Funding.

Canadian Prime Minister Stephen Harper spoke yesterday at the Perimeter Institute on his government's effort to bolster science and technology funding in Canada.

The money that will pay to keep Canada's science and technology competitive was announced in the March federal budget. It amounts to $9.2-billion in this fiscal year — $1.9-billion of that is new and the rest was carried over from previous years.

Humm... is it too late to move to Canada?

:)

Zz.

The Longest Carbon Nanotubes You've Ever Seen

Researchers from University of Cincinnati have created the worlds longest carbon nanotube. It is so long, it isn't "nano" anymore! :)

It's pretty neat. They use a CVD technique at a company's facility that specializes in such a thing.

So what do you use something this big for?

Zz.

A Bang, A Cloud, A Delay

I thought that this was a rather amusing title. It is a news report with first hand account of what happened when the Fermilab-built crygenic system to cool the LHC magnets failed.

Of course, those people involved, especially at Fermilab, don't see any humor in all of this.

Zz.

Stanford Science Labs Burglaries

Whoa! I didn't know such things occur in Palo Alto! :) It seems that Stanford has been burglarized lately, with a thief or thieves stealing science equipment.

The physics lab has lost $400,000 worth of equipment, not counting break-ins at other nearby labs, including the astrophysics and biology buildings, according to Mike Killian, facilities manager of the Hansen Experimental Physics Laboratory.

But the students are trying to fight back in their own ways...

When a thief began stealing high-end science equipment from Stanford University labs this year, a group of graduate students struck back using tools of their own.

About 5:30 a.m. Sunday, a camera rigged by the students caught 20 seconds of footage of a man breaking into a Stanford physics lab - information that is now a part of the campus investigation, said Mike Killian, facilities manager of the Hansen Experimental Physics Laboratory.

If I were the thief, I'd watch my back. These are not your run-of-the-mill smart kids, and if they want to, they can rig almost anything.

Zz.

Ca Phonons Responsible For Superconductivity in CaC6

The possible mechanism for superconductivity in the layered compound CaC6 (Tc~11 K) may have been solved. Reported in Argonne News today, it seems to indicate that the Ca phonons are responsible. This is detected via the well-known isotope effect.

Recently superconductivity was discovered in a new compound composed mostly of graphite layers and a small amount of calcium, CaC6. Its transition temperature of 11.5 Kelvins is nearly twice the transition temperature of the previously known layered graphite compounds. The immediate question raised by this discovery is the mechanism for superconductivity in this compound.

Materials Science Division scientists have now found the answer. They found a downward shift of the transition temperature on substituting a heavier isotope of Ca for the naturally occurring lighter one, showing not only that superconductivity is due to the conventional electron-phonon interaction, but also that the low-energy Ca phonons and not the high-energy layered C phonons are responsible.

This is opposite to the behavior of another famous superconductor, MgB2, where the high-energy layered B phonons drive the superconductivity, producing a record-setting transition temperature of 40 K for the electron-phonon mechanism. This work demonstrates the remarkable scope and variety of superconductivity that, despite scientists' considerable knowledge, remains a tantalizing challenge for modern science to explain.

The result was published in PRB:

"Large Ca isotope effect in the CaC6 superconductor", D. G. Hinks et al., Phys. Rev. B 75, 014509 (2007).

Zz.

Dark Matter "Seen" By Hubble Telescope?

Came across this news report in, of all places, the Economist. It seems that the "ripples" of matter due to the collision of two galactic clusters may be the tell-tale signature of dark matter. The observation was announced today.

By looking at how the faint light from galaxies behind the cluster they were studying was distorted by that cluster, Dr Jee and his team created a map of the distribution of its mass. They then compared that with what they could actually see. Instead of finding that the mass coincided with the location of the ordinary matter of stars, as had been seen in observations of other clusters, they found a distortion.

After trying—and failing—for many months to explain this distortion away, they accepted that it was real, and sought to explain it. The most plausible explanation is that the cluster contains a distinct ring of dark matter without any accompanying ordinary matter.

While this may not identify exactly what dark matter is, if confirmed, then it means that both Newtonian and Einstein's gravitational laws are accurate without any need for modification, at least not based on this.

We must still wait for the paper's publication and the scrutiny of people in this field.

Edit: This is the NASA Press release related to this.

Zz.