Laser - The First 50 Years, And The Next 50 Years

A perspective on the first 50 years of the laser, and what we might possibly look forward to for the next 50 years.



Zz.

Ignitor to Challenge ITER

Italy and Russia are poised to build a new fusion facility called Ignitor.

Russia and Italy announced on Monday that they will collaborate to build a new tokamak fusion reactor called Ignitor. Following talks between Italian Prime Minister Silvio Berlusconi and his Russian counterpart Vladimir Putin, other ministers signed a memorandum of understanding to work together on building the Italian-designed device on Russian territory.

The reactor is the brainchild of Bruno Coppi of the Massachusetts Institute of Technology who worked on MIT's Alcator tokamaks from the 1970s until the present day.

This is certainly a legitimate alternative to the budget-busting ITER that has been beset by delays and cost over-runs. Whether they can actually achieve the goal is another matter and the whole reason why this is being built in the first place.

Zz.

Meet WANDA

WANDA at Berkeley Lab is ".. one of the world's first nanomaterials synthesis robots... "



Too bad WANDA doesn't look as attractive as EVE from "Wall-E".

Er... I need to get out more often....

Zz.

Wichita State University Physics Dept. On The Chopping Block

Here comes another physics program that is slated to be "reoriented". The physics department, and degree program, at the Wichita State University in Kansas is being considered to be eliminated. I suppose if this is a school that emphasized mainly liberal arts subject areas, it is understandable. But WSU kinda sold itself as a school with a strong engineering program. So it is a bit confusing how they could hope to continue selling itself as that but lacks a physics department.

One also wonders if the data being used to argue for its elimination is outdated, as stated in the article.

But supporters of the physics department say demoting physics from a major to a grouping of courses would damage WSU's national reputation. The department chairman, professor Nick Solomey, said Miller's numbers are way out of date in that February study, and that Miller's proposal is destructive.

All the problems Miller cites did exist two years ago, Solomey said, when he was hired by the administration to revive the department. But he did revive it, he said; there are now 38 majors, and eight students graduating; there will be larger numbers in the year to come. The problem is well on it's way to being solved; the numbers trend is up, test scores are up, he said.

Other physics programs have had to face similar fate, with varying degree of success. We'll have to see how this turns out.

Zz.

April 2010 Issue of Physics and Society Newsletter

The April 2010 issue of Physics and Society Newsletter is now available online.

In particular, one of the issues that could be a major problem some time soon and have not received the publicity that it deserves, is the issue on the isotopes production, especially the medical isotopes that will experience a severe shortage. This is discussed in a brief article in the newsletter, so it will give you a quick intro and update on the problem if you're not aware of it already. I've mentioned this potential problem in relation to particle accelerators.

Zz.

Hubble Telescope Turns 20

Happy 20th Birthday, Hubble Telescope.

This is one of the workhorses of astronomy/astrophysics. This "thing" has advanced so much of our knowledge of other parts of our visible universe.

Zz.

Making Einstein's Idea Real

This is a very fascinating and informative Q&A with Charles Townes as part of the celebration of the 50th Anniversary of the laser. There's a lot of historical background information here on his effort in the invention of the maser, and later on, laser.

Several people at Columbia in the early 1950s, including physics Nobel laureate I.I. Rabi, told you that trying to build a maser was a waste of time. What made you disregard that advice?

I’m accustomed to being myself, being independent, and that’s a very important part of creativity. My parents taught me that, too. Don’t do what other people are doing; you do what you think is really right. I had to think about what these people were saying, yes, but it wasn’t troublesome or upsetting when someone disagreed with me. Luckily, I had tenure at Columbia. If I didn’t have tenure, that would have been a bigger problem certainly, whether I would have taken a chance or not [to build the maser], I’m not sure. After we built the maser, Rabi didn’t exactly apologize, but he did congratulate me on my work.

See? Even Nobel Laureates can be wrong! :)

Zz.

Tales from the Quantum Frontier

This is an unusually good article on quantum physics aimed at the general public. It is unusually good because (i) it doesn't go overboard with all the weirdness of QM, and (ii) it actually provides links to actual physics papers as references! How many times have you seen article aimed at the general public, and published in the mass media do the latter?

No wonder Alan Boyle, the author of that article, has received all kinds of recognition.

Zz.

Teaching Science to Nonscience Majors

A very nice article in Science Career section about various instructors teaching science topics to non-science major. A quote from a physics instructors reinforced what I've said earlier regarding communicating physics to the general public.

Teaching nonmajors has much in common with the work of science communicators. You have to learn something about a range of disciplines and social issues and stay current on "what's on the news," Moctezuma says. "I love science, but I'm also interested in other fields, and this allows me to explore some things beyond science and also how science influences and affects many different fields of study," he adds. Also important is not to fall into the trap of thinking it's easier than teaching majors. "There are probably some people who think ... if you can teach classical mechanics to physics students, you should be able to teach motion at a lower level," Schwarz says. "It's actually harder."

It definitely is. This is because, more often than not, what you think you are communicating or trying to convey is not what they understood. This makes it harder because you have to choose your words very carefully, and always have to realize the "pedestrian" meaning of the words and phrases that you chose. This pedestrian meaning is what the general public will attach these words and phrases to, not the physics definition. So this makes the job of communicating science (and physics) significantly harder.

Zz.

Unconventional s-Wave Superconductivity in Fe(Se,Te)

This is an amazing experiment in more ways than one.

Abstract: The superconducting state is characterized by a pairing of electrons with a superconducting gap on the Fermi surface. In iron-based superconductors, an unconventional pairing state has been argued for theoretically. We used scanning tunneling microscopy on Fe(Se,Te) single crystals to image the quasi-particle scattering interference patterns in the superconducting state. By applying a magnetic field to break the time-reversal symmetry, the relative sign of the superconducting gap can be determined from the magnetic-field dependence of quasi-particle scattering amplitudes. Our results indicate that the sign is reversed between the hole and the electron Fermi-surface pockets (s±-wave), favoring the unconventional pairing mechanism associated with spin fluctuations.

T. Hanaguri et al., Science v.328, p.474 (2010).

What is amazing is that they not only managed to determine the pairing symmetry for this family of superconductors, but also were able, using STM no less, to detect the s±-wave pairing symmetry, which is not easy! See J.E. Hoffman article reviewing this work in the same issue of Science to understand why.

Is this the first ever experiment to actually make an observation of this pairing symmetry? I'm sure that it is the first ever using an STM.

Zz.

LCLS Achieved Completion Milestone

Congratulations to all the folks at SLAC's LCLS for completion of CD4 Milestone just today! Here's the official announcement.

Today at approximately 1PM, LCLS achieved its project completion (CD-4) milestone of delivering first photons to the Far Experimental Hall. This is a tremendous day for SLAC! I congratulate all of you who have worked so hard to make this happen. Above all, I want to congratulate and thank John Galayda for delivering this wonderful machine on time, on budget and with outstanding performance!

Persis

Well done, folks! This was one tough beast to construct, especially with such tight tolerances. It is an amazing accomplishment.

Zz.

Physics and the 6-Day of Creation

It is a very clear example on what I mean by a good intention with a not-so-good outcome. The intention to educate the public in physics may be good, but often it leads to an unwanted bastardization of the physics itself. Deepak Chopra is one very good example. This is another.

This appears to be a Letter to the Editor by someone who learned about Relativity rather superficially.. "... especially in the Discover magazine with Einstein on the front cover... " no less. The writer seemed to be referring to one of the consequences of SR, which is time dilation. This "knowledge" was used to somehow justify the biblical description of the creation of the universe in 6 days.

And one thing struck with the theory that was shown in an illustration of a boy standing in the center of a circle with an old man riding around him at the speed of light. The theory shows that within a few minutes the young boy in the circle would be older than the man riding around him on the bike.

After we talked about that for a while, everything got plugged in. Time is different with speed and gravity and all those crazy variables. If this type of theory scientifically would exist, it blows the mind with the possibilites of everything else. If the universe is expanding, then if we rewind far enough back, the time dilation would be different. If that boy in the middle is older than that man on the bike, then he still went through the aging process, much like Earth going through the billions of years of aging.

Maybe a day really was nearly a billion years and maybe not much was lost in translation.

It is one thing to actually think and wonder about such a thing, especially considering that one only has a superficial understanding of the physics, it is another to have no qualms to actually write to a paper and let it be known to the world about it. There doesn't seem to be any kind of "quality control" on the part of many, especially in double-checking to see if one has fully understood what one is about to use and present to the "world".

The flaw in this argument, of course, is the very common mistake that almost everyone makes when they first encounter SR. Time dilation is the apparent slowdown of time in ANOTHER REFERENCE FRAME AS VIEWED BY SOMEONE IN A DIFFERENT REFERENCE FRAME. If A views the clock of B, where B is moving relative to A, then A sees B's clock as being slow. A doesn't see HIS clock as being any slower or different. And the same could be said from B's point of view. B sees clocks in A reference frame as being slower than his. B doesn't see his clock being any different.

Now, unless the author is implying that the universe literally has a motion that is VERY fast when compared to "God", so much so that god sees the clock in the universe as being time dilated, then the whole argument above makes no sense. Furthermore, why would god describes the formation of the universe from that point of view? After all, everything else about the genesis was described from the point of view within the universe itself, so the proper time to be used here is the local time of the universe. This, of course, is ignoring the lack of definition for "6 days", considering that Earth didn't come into existence until the final days.

While we can't stop some poor misguided souls from taking something and completely bastardizing it, as science writers and communicators to the public, we should always, in the back of our minds, think of what we say and how the public might understand what we say, because when they do this to physics, it isn't progress, but rather a step backwards. They understood the WRONG THING. I've often wondered in cases like this whether no knowledge is better than having the wrong knowledge. Having the wrong knowledge can often be dangerous.

Zz.

Yoctonewtons Of Force Measured

The smallest ever measurement of a force has reported {link open only for a limited time}.

The result, measuring mere yoctonewtons (10–24 newtons), beats previous record lows by several orders of magnitude. The group behind the measurements, based at the National Institute of Standards and Technology in Boulder, Colorado, hopes that the technique can eventually lead to new tools for measuring the minuscule features of materials' surfaces.

The preprint cited can be found here.

Zz.

A New Limit on the Light Speed Isotropy

All those theories that have the possible Lorentz violation will have to deal with a new lower and more stringent limit on light speed isotropy. A new study base on the Compton edge measurement at the ESRF has imposed a new limit on such isotropy.

Abstract: When the electrons stored in the ring of the European Synchrotron Radiation Facility (ESRF, Grenoble) scatter on a laser beam (Compton scattering in flight) the lower energy of the scattered electron spectra, the Compton Edge (CE), is given by the two body photon-electron relativistic kinematics and depends on the velocity of light. A precision measurement of the position of this CE as a function of the daily variations of the direction of the electron beam in an absolute reference frame provides a one-way test of Relativistic Kinematics and the isotropy of the velocity of light. The results of GRAAL-ESRF measurements improve the previously existing one-way limits, thus showing the efficiency of this method and the interest of further studies in this direction.

The new limit is Delta(c)/c of less than 1 e-14.

Zz.

The Day Einstein Died

For 55 years, many of these Ralph Morse pictures never made it into print at the request of Albert Einstein's son. Only now is Life Magazine printing out the pictures of Einstein's office other related scenes. All of them were taken on the day that Einstein died. A bottle of scotch got him access to Einstein's office.

"I grabbed my cameras and drove the ninety miles to Princeton," Morse recalls. "Einstein died at the Princeton Hospital, so I headed there first. But it was chaos -- so many journalists, photographers, onlookers milling around outside what, back then, was a really small hospital. 'Forget this,' I said, and headed over to the building where Einstein's office was. On the way there, I stopped and bought a case of scotch. I knew people might be reluctant to talk to me, and I knew that most people were happy to accept a bottle of scotch instead of money if you offered it in exchange for their help. So, I get to the building and nobody's there. I find the superintendent, give him a fifth of scotch, and he opens up Einstein's office so I can take some photos."

Zz.

Soudan Lab Open House

Oh, I would go if I could!

The Soudan underground lab will be having its Open House on May 8, 2010.

The public is welcome to travel a half-mile underground and visit the Soudan Underground Physics Lab at an open house set for May 8.

Participants will discover the data collected during the years that the MINOS detector has been operating. The Fermi National Accelerator Lab has been sending a beam of neutrinos to the Soudan Lab since the first one was detected March 20, 2005. It will also be an opportunity to ask the experts about the new project, NOvA, a 15 kiloton detector under construction on the Ash River Trail to study other characteristics of the neutrino. The third major experiment is the Cryogenic Dark Matter Search.

When was the last time you get to visit a half-mile-underground physics lab? That in itself is a good-enough incentive.

Zz.

Can We Be Moral Without Science?

The answer is no, at least, from this essay that argues that a society needs science to maintain moral values.

Can science help us be moral? Yes, science frees our intellect from inadequate morals which have impeded humanity and provides knowledge from which we make better moral decisions. We should not perceive science and religion as opposing principles, but as complementary choices - compatible pathways to progress. Perhaps a more important question is, can we be moral without science? In today's scientific era, I think not.

I haven't decided if I quite agree with the whole essay. I've never thought of science in this light before, so this is something new.

Zz.

LHC Q&A

The abbreviation alone is enough to confuse anyone.

This is a valiant attempt at answering some of the general questions regarding the LHC. Still, there are quite a few errors or inaccuracies. The two glaring ones are:

Q. What does the name Large Hadron Collider mean?

A. The LHC is "large'' because it's the biggest assemblage of scientific tools ever gathered in one place. It works with "hadrons'' — physicist jargon for protons and neutrons that make up the nucleus of an atom. It's a "collider'' because it smashes protons — tiny subatomic particles — together so that scientists can peer at their shattered innards.

Hadrons are not a physicist jargon for protons and neutrons. It is essentially anything made up of quarks, which means they could be baryons and mesons.

Q. Will the LHC help explain how quarks combined to create matter?

A. That's one of the major goals of the project. Scientists hope they will find in the debris of the collisions evidence of an as yet undiscovered subatomic particle called the "Higgs boson,'' named after a Scottish physicist who predicted such a particle in 1964. Like the gluon, bosons are particles that have no mass but carry a force. Scientists think the Higgs boson, if it exists, is the particle that allows energy to turn into mass. The theory is that Higgs bosons are spread throughout the universe, like flowers in a field. Particles acquire mass — in other words become matter — by interacting with the Higgs field. That's why physicist Leon Lederman called the Higgs the "God Particle'' in a 1993 book of that name.

Bosons are particles with integer quantum spin. That's it. It happens that all our "force-carrying particles" are also boson, but all bosons are not "force-carrying particles".

While these errors are not as horrible as the one we've seen previously, one again is left to wonder why they don't have a qualified physicist go over these things before they publish it. These errors are not something that is so highly specialized or so subtle. They are often something even an undergrad can spot from 10 miles away.

Zz.

Watch Out For A Nobel Prize At Your Local Pawn Shop

This is utterly bizarre!

A man broke into Nobel Laureate Roy Glauber's home and not only slept in his bed, but also possibly took his Nobel Prize medal!

Stephen Beaulieu, 42, of Skowhegan, Maine - a disheveled drifter with champagne tastes - broke into Harvard University Professor of Physics Roy J. Glauber’s home overlooking Spy Pond in Arlington last month, slept in one of his beds, stubbed out a cigarette on a nightstand and stuffed his face with imitation lobster and smoked oysters bought with his food stamp card, investigators said.

Police, meanwhile, are trying to track down Glauber’s Nobel Prize for his work on the behavior of light, as well as a Nobel replica and a Spanish Academy of Sciences Gold Medal he has been unable to locate since the break-in.

“Obviously, they mean a great deal to me,” the 84-year-old brainiac said. “I cannot imagine what good they would be to anybody.”

I definitely hope they recover the medal.

Zz.

Random Numbers Certified by Bell’s Theorem

Haven't had time to closely read this yet, but it is a good one.

Abstract: Randomness is a fundamental feature of nature and a valuable resource for applications ranging from cryptography and gambling to numerical simulation of physical and biological systems. Random numbers, however, are difficult to characterize mathematically, and their generation must rely on an unpredictable physical process. Inaccuracies in the theoretical modelling of such processes or failures of the devices, possibly due to adversarial attacks, limit the reliability of random number generators in ways that are difficult to control and detect. Here, inspired by earlier work on non-locality-based and device-independent quantum information processing, we show that the non-local correlations of entangled quantum particles can be used to certify the presence of genuine randomness. It is thereby possible to design a cryptographically secure random number generator that does not require any assumption about the internal working of the device. Such a strong form of randomness generation is impossible classically and possible in quantum systems only if certified by a Bell inequality violation15. We carry out a proof-of-concept demonstration of this proposal in a system of two entangled atoms separated by approximately one metre. The observed Bell inequality violation, featuring near perfect detection efficiency, guarantees that 42 new random numbers are generated with 99 per cent confidence. Our results lay the groundwork for future device-independent quantum information experiments and for addressing fundamental issues raised by the intrinsic randomness of quantum theory.

S. Pironio et al., Nature v.464, p.1021 (2010).

A news report on this paper can be found here.

Zz.