## Friday, June 28, 2013

### Psychophysics Is Psychobabble?

This is a spot-on article on the seemingly fashionable practice nowadays to make some quantitative description of various ideas in social science.

Psychophysics secretly dominates our social sciences. Such physics-ing often improves experimental practice, but its mathematical methods face new challenges. As every infant knows, but too many scientists ignore, people aren’t biological billiard balls.

I'd go even further and say that people aren't even quantum balls.

Clearly, people are subject to the laws of physics. But nothing in physics chooses. Physics needs no strategies or game theory. Its main business is mechanical causation. Physics has no future. Like the best Buddhists, it feels only the forces of the present. Human psychology is different from physics precisely because it evolved to weigh and choose between forces from different possible futures.

Physics developed in situations like this: Everything of type X always does Y under conditions Z, where X, Y and Z are mathematically related. And simple scenarios such as: Every action has an equal and opposite reaction. Some people behaviors are like that. But many are not.
And I've lost count how many times I've seen discussion on the economy or in politics that kept on using various physics terms such as "every action there must be a reaction" in trying to justify or strengthen their arguments.

This topic is no different than the "Physics Envy" topic that I've posted quite a while back. The problem with adopting physics concepts in describing areas involving human actions and interactions is not just based on what has been said here in this article, but also the fact that many of the people who are adopting these physics concepts are not physicists, and have only a very superficial understanding of what they are adopting (think Deepak Chopra). So they may be using the same words and phrases, but they are severely bastardizing the concept.

Zz.

## Thursday, June 27, 2013

### Opportunity's Improbable Anniversary

Happy 10th Anniversary, Opportunity! This is am amazing rover that could!

Zz.

## Wednesday, June 26, 2013

### Tabletop Accelerator To Create Ultra-Relativistic Positron Beams? Sure, I'll Take One!

I had just finished reading this new paper that appeared in PRL this week. Using a high-powered laser, they shoot the light beam to a He gas jet to create a beam of high-energy electrons (exceeding 80 MeV). These electrons are then shot at various high-Z material, and this is where the electron-positron pairs are created. The authors stated two separate processes for these pair production:

In these experimental conditions, the positrons inside the high-Z target are mainly generated via either direct electroproduction (trident process), in which pair production is mediated by a virtual photon in the electron ﬁeld [25], or via a two-step ‘‘cascade’’ process where the electron ﬁrst emits a real photon (bremsstrahlung) [26], which then produces an electron-positron pair via the Bethe-Heitler process [27].

It looks like the could get positrons with energies in the range of 90 to 120 MeV.

Now, while I'm sure the size of this whole contraption can be considered as "tabletop", it doesn't include the laser source, which is a petawatt laser, something that is not trivia and not easily available to everyone, much less having it fit onto a tabletop size (at least, for now).

Zz.

## Monday, June 24, 2013

### Revamping The DOE Labs

A new report produced by an interesting group of organizations has recommended sweeping management changes at DOE in the structure and running of the US Department of Energy's non-weapons laboratories.

One jolt would be to name a single DOE undersecretary for science and technology to oversee the 13 nonweapons laboratories, instead of the two that do the job now. Another recommendation would remake how the department evaluates the contractors that run the labs for the federal government. The labs should also have more flexibility to set their own spending priorities, charge fees for the use of their facilities, and develop broader entrepreneurial partnerships with industry, the report asserts. The goal, the authors write, "is not to just tinker around the edges but to build policy reforms that re-envision the lab system."

The current system is enmeshed in red tape, reporting requirements, and program directives, according to the report. "Decisions that should be made by research teams and lab managers are instead preapproved and double checked by a long and growing chain of command at DOE," it notes. "At the smallest level, DOE, in concert with [the White House Office of Management and Budget] and Congress, micromanages internal lab-directed investment decisions."
This is fine and dandy, but I echo the comment by former Lab Director Burton Richter:

One former DOE lab director, however, is skeptical that implementing the report's recommendations will produce lasting change. "The report is very good in many respects, and I'm delighted to see these issues being discussed out in the light of day again," says Burton Richter, the director emeritus of DOE's SLAC National Accelerator Laboratory in Menlo Park, California. He supports many of the recommendations but says that the report doesn't "explain how you would actually achieve the culture change within DOE and Washington you'd need to persuade Congress and the bureaucrats to loosen the reins." He believes that a return to micromanagement is inevitable without a fundamental change in the culture.

In other words, one has to point the finger at Congress as well, who seem to think that they know the science priorities to set, and therefore, do their own micromanagement. If the report does NOT address that and ignore this huge component, then the DOE can make as many management changes as they want and nothing will actually change.

As a former physicist that has worked at a US Nat'l Lab, I can tell you that, while adopting to the maddening array of DOE regulations and redundant directives can be a huge pain, I'd rather deal with that than the uncertain, meandering, and ill-conceived funding directives from Congress. With DOE regulation, one at least knows what what is getting into, and the bureaucracy made them slow to change. So you can expect almost the same thing year in, year out. With the politicians, who knows! It is significantly more difficult in dealing with uncertain priorities and not knowing what will happen in the next few months.

So how come no organization is doing any kind of study on how politicians screw the US science effort, huh?

Zz.

## Sunday, June 23, 2013

### How The Penguin Diagram Got Its Name

Some time, one just never know if a folklore that gets spread around is actually true. But this one seems believable enough that it might just be.

One of the more famous Feynman diagram in particle physics is the "penguin diagram". This news article describes the origin of this name. It appears that it came about because of a lost bet!

In 1977 John Ellis made a bet with a student named Melissa Franklin at a bar. “If you lose this game of darts,” Franklin said, “you have to use the word ‘penguin’ in your next paper.” Ellis took the bet, and lost. The result can be seen in physics classrooms all over the world: the penguin diagram.

You can read the rest of the hilarious article, especially on why Franklin came up with "penguins". I suppose one can ask directly the participants involved and see if this story is true.

Zz.

## Saturday, June 22, 2013

### Fermilab Has A New Director

Nigel Lockyer will have the unenviable and difficult task of guiding Fermilab through its most challenging period in its entire history of existence. He has just been named as the new Fermilab Director, taking over from the retiring Pier Oddone.

Times are tough at Fermilab, which employs roughly 1700 people. Its budget for this year is $366 million, down from$397 million in 2010. The lab has cut staff members in recent years. Most important, although Fermilab has a number of intermediate scale projects going on now, its future a decade down the road remains uncertain.

I don't know to what extent many of these things are within his control. He has to work and guide the lab with whatever the politicians throw at him. It is the politicians, and to some extent, the public, who need to realize the importance of such science and want to fund it.

But to ask the politicians and the public to think about long-term benefits rather than short-term, instant gratification is almost an impossible task.

Zz.

## Wednesday, June 19, 2013

### Neutrinos: Nature's Ghosts?

A short video to introduce you to neutrinos, if you haven't heard about them.

I guess you will have to wait for Part 2 of the video to hear about the flavor-changing neutrinos.

Zz.

### Flames In Microgravity

This is actually an interesting video on the physics of flames, and the physics of flames in microgravity. It shows a flame experiment on the International Space Station.

Zz.

## Monday, June 17, 2013

### Hints At The Existence Of A 4-Quark Matter

Two papers published in PRL this week report on the possible discovery of a 4-quark matter.

Two separate groups, both reporting in Physical Review Letters, have seen evidence for this strange particle, called Zc(3900). Although the data is open to other interpretations, it’s clear that our understanding of quarks has a long way to go.

The evidence for Zc(3900) comes from two independent groups: the BESIII Collaboration at the Beijing Electron Positron Collider, China, and the Belle Collaboration at the High Energy Accelerator Research Organization in Tsukuba, Japan. It is the business of both labs to accelerate electrons and positrons to nearly the speed of light, smashing them into each other and carefully analyzing the resulting debris. Taken together, the two collaborations have uncovered 466 events that appear to have a Zc(3900) in their debris.

BTW, if you're paying attention, none of these facilities are in the US because ..... altogether now .... the US no longer has any electron-positron colliders or any high energy physics colliders! What we have left are nuclear physics facilities such as RHIC, which is scheduled to shut down due to budget cutbacks.

Zz.

## Friday, June 14, 2013

### Not All College Degrees Are Created Equal!

I read this report either earlier in the year, or late last year, but forgot to write about it till now.

I know that I've written several "philosophy-bashing" posts in this blog. It's not that I was trying to pick a fight against philosophy in general, but rather I'm trying to tackle the often overblown perceived-importance of this field in its contribution to science as it is practiced today (I profess zero knowledge of its importance in other fields).

While those discussions are based on opinions, to some extent, this one isn't. A study done out of Georgetown University has listed Philosophy/Religions Studies major as one of the worst major in college based on the unemployment rates of its graduates and the starting salary. The only major that's worse is a degree in Fine Arts. A summary of the report can be found in this news article.

Physics/Physical Science didn't fare that badly in this study. Of course, the unemployment numbers do not clearly say if those who are employed are working in their chosen fields, or if they are employed doing other things. Previous statistics from the AIP indicated that a lot of physics degree holders outside of Academia and Research Lab are employed as "engineers, computer programmers", etc.

Zz.

## Wednesday, June 12, 2013

### Solving A Simple Simultaneous Equation Using Quantum Computer

This work appears in this week's PRL. A group of scientists have managed to solve a rather simple simultaneous equation with two variables using a quantum computation scheme proposed back in 2009.

The computational feat has been carried out by Jian-Wei Pan and colleagues at the University of Science and Technology of China, the University of Toronto and the National University of Singapore, who used a quantum algorithm created in 2009 by Aram Harrow, Avinatan Hassidim and Seth Lloyd. For simple systems of linear equations, Harrow and colleagues showed that their algorithm can be exponentially faster than the best solving methods that use a classical computer. One important caveat, however, is that the algorithm does not find an exact solution, but only the most likely answer.

Most likely answer, eh? Not sure how good that will be especially when we use computers to solve already-uncertain situations such as weather forecasting and other phenomena.

Still, this is merely a baby step in the evolution of quantum computers.

Zz.

## Tuesday, June 11, 2013

### What Is An Electron?

I get asked that question surprisingly often. It is understandable because of all the mysterious, unseen subatomic, elementary particle in our everyday lives, electrons are the ones we either encounter or deal with the most. It is the predominant carrier of electricity, and it used to be what caused our TVs to display images in the old days when we still used cathode ray tubes. So naturally, many of us are familiar with the presence of electrons, but we don't quite know what it is.

This is especially true in light of quantum mechanics. QM has made all subatomic particles, including electrons, mysterious. What we thought we knew, now seems to exhibit behaviors that are rather strange.

Frank Wilczek has a very nice article in last week's issue of Nature addressing "The Enigmatic Electron"[1]. He said something that people who are not trained in science should pay attention to:

Modern quantum theory reinforces Bohr's conclusion that what you see depends on how you choose to look. Electrons are both ideally simple and unimaginably complex. They are understood with precision yet remain mysterious. Electrons are stable bedrock in physicists' world picture, and are playthings that we are learning to fragment and transform.
And that is the central theme here. Something can appear to be mysterious, appear to have strange behavior, etc., but it doesn't mean that we know nothing about that. We have such huge and vast knowledge about electrons, their behavior (especially their collective behavior), etc. This is what drove advances in modern electronics. Yet, based on QM and QFT, there are a lot of things we either don't know, or can't quite reconcile with our classical understanding of the world. So being mysterious is NOT synonymous to not understanding anything about it.

I am emphasizing this because this is identical to what I mentioned earlier when I keep hearing people claim that no one understands quantum mechanics. This is, of course, utterly silly considering that we have a formal theory of quantum mechanics, and we have used it to produce useful applications! This ability is MORE than what can be said about many other things that people seem to think they understood.

Zz.

[1] F. Wilczek, Nature v.498, p.31 (2013).

## Monday, June 10, 2013

### "The Theoretical Minimum: What You Need to Know to Start Doing Physics"

One of the questions I get asked a lot online by members of the public is "what do I need to know if I want to be an amateur physicist?" There are many people who obviously are interested in "doing physics" without making a career out of it. While I am not quite sure what an "amateur physicist" actually do, or what they can accomplish, I can certainly understand why those who have a keen interest in physics but with an already-established career, might want to know that they need to be equipped with to continue trying to understand physics. This is especially true if one wants to know beyond the superficial level all the interesting discoveries and news from the world of physics.

So it is with that in mind that I'm highlighting a new book written by Leonard Susskind and George Hrabovsky that attempts to address that very issue. A review of this book appears in this month's issue of Physics Today.

Enjoyable it was, but its utility is narrower than I might have hoped. In fairness, it seems to be excellent for its stated purpose: as a first textbook for the “ardent amateur” who is perhaps taking a continuing education course or seeking to learn about physics at a level a bit higher than in the usual gee-whiz, calculus-free course. I, however, was eager to analyze the book as a supporting resource for mechanics courses for two different classes of amateurs: life-science students taking physics as a premedical requirement and engineering or physics students with a comparatively weak background. There is a chronic need for a clearly written “theoretical minimum” textbook to help the many students who try to learn physics but cannot remember, or who never properly learned, the necessary elementary math skills—not to mention students whose high school physics course was so poor it actually obstructed their conceptual understanding.

A few minor issues notwithstanding, it does sound as if this is a worthwhile book to have especially if one is a physicist in academia.

Zz.

## Thursday, June 06, 2013

### Staging the Drama of Quantum Physics

This news report presents an account of the staging of the infamous battle between Bohr and Einstein that is forever linked to this history of quantum mechanics.

At the center of the drama was the rivalry and grudging friendship between Albert Einstein and Niels Bohr, two brilliant physicists who fell on opposite sides of the new debate that came to be known as quantum theory.

Did you attend this? If you did, I'd like to hear your view of this play.

Zz.

## Wednesday, June 05, 2013

### The Physics Of Toasty Buns

It's summer (at least, here in the northern hemisphere), and lots of outdoor grilling goes on. So what a timely article on the secret to getting proper grilling of food.

At high temperatures -- about 400 degrees and up -- a substantial part of the heat that reaches the food arrives in the form of infrared light waves rather than via hot air or steam.

The higher the temperature, the bigger the part that radiant heat plays in cooking. But this form of heat interacts with color in a profound way.
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A silvery, mirror-like fish skin is even more reflective than a white car. About 90 percent of the radiant heat striking it simply bounces away. Because only around 10 percent of the energy sinks in and warms the fish, cooking initially creeps along slowly but steadily.

That changes rapidly, however, as soon as the food gets hot enough to brown. It's like changing from a white shirt to a black shirt on a sunny summer day.

As the food darkens, that 10 percent of energy absorbed rises by leaps and bounds, and the temperature at the surface of the food soars.

So learn your physics to understand how to be good in grilling! :)

Zz.

### Interview With David Gross

Wired as an interview with Nobel Laureate David J. Gross.

I think the title of the piece is misleading. It seems that he is urging more of a 'revolution' in theoretical physics, not ALL of physics.

These days, Gross enjoys challenging young physicists as they chalk equations at the Kavli Institute for Theoretical Physics, the think tank funded by the National Science Foundation that he ran from 1997 until stepping down last year. He is eager for younger scientists to surpass his achievements, to break the impasse of under-determination that currently troubles particle physics, whereby competing theories predict the same physical results and may therefore be immune to experimental verification within the lifetime of the universe.

Gross characterizes theoretical physics as rife with esoteric speculations, a strange superposition of practical robustness and theoretical confusion. He has problems with the popularizing of “multiverses” and “landscapes” of infinite worlds, which are held up as emblematic of physical reality. Sometimes, he says, science is just plain stuck until new data, or a revolutionary idea, busts the status quo. But he is optimistic: Experience tells him that objects that once could not be directly observed, such as quarks and gluons, can be proven to exist. Someday, perhaps the same will be true for the ideas of strings and branes and the holographic boundaries that foreshadow the future of physics.
He has an interesting, but not surprising, take on String theory:

Simons Science: Is it possible to falsify string theory/quantum field theory? Or is that a purely philosophical question?

Gross: The question of how we decide whether our theories are correct or wrong or falsifiable has a philosophical aspect. But in the absence of empirical data, can we really judge the validity of a theory? Perhaps. Can philosophy by itself resolve such an ontological quandary? I doubt it. Philosophers who contribute to making physics are, thereby, physicists!

Now, in the last century, great physicists such as Ernst Mach, Bohr and Einstein were also philosophers who were concerned with developing theories of knowledge. Einstein famously criticized Heisenberg for focusing only on observable entities, when there can be indirect evidence for entities that cannot be seen. It may be the same with string theory.

Zz.

## Tuesday, June 04, 2013

### Sonoluminescence

Here's Minute Physics description of sonoluminescence.

Zz.

## Monday, June 03, 2013

### Theorists And Experimentalists

Hey, this is a rather good article on why many in the public seem to know more about theorists than experimentalists, and know more about theory than experiments.

Similar themes proliferate throughout the popular view of physics. Everyone knows Paul Dirac who conjectured the existence of the positron, but how many know Carl Anderson and his collaborator Seth Neddermeyer who actually found it? People similarly know about Wolfgang Pauli and Enrico Fermi stating the requirement for a ghostly particle called the neutrino in the 30s, but ask popular science enthusiasts if they are aware of the dogged pursuit of the neutrino by Raymond Davis for over 30 years and you will likely see knitted brows. Finally, even today, a schoolchild would likely know Einstein’s prediction of the bending of starlight by the gravitational field of a star, but Arthur Eddington’s verification of this fact would be little known.
The author produced a not-so-well-known quote from Feynman on the importance of experiments:

In general we look for a new law by the following process. First we guess it. Then we compute the consequences of the guess to see what would be implied if this law that we guessed is right. Then we compare the result of the computation to nature, with experiment or experience, compare it directly with observation, to see if it works. If it disagrees with experiment it is wrong. In that simple statement is the key to science. It does not make any difference how beautiful your guess is. It does not make any difference how smart you are, who made the guess, or what his name is – if it disagrees with experiment it is wrong.
For many physicists, this is the main issue surrounding String/Superstring, etc.

The author produced a number of reason why the public are more inclined to be fascinated by theorists/theory than by experimentalists/experiments.

It seems to me that there are at least two important reasons why the public, in spite of tacitly appreciating the all-important role of experiment in physics, fails to give experimentalists their due. First is the sheer success of theoretical physics in uncovering the deepest mysteries of the universe through armchair speculation. Nobody can fail to gasp in awe at an Einstein or Bohr who, working with a few facts and pencil and paper, divine grand operating principles for the cosmos in short order.

Compared to their efforts based on pure thought, the corresponding efforts of experimentalists who get down on their knees, liberally coat their hands with grease and spend most of their time soldering electronic circuits and fashioning precision machine parts on a lathe sounds humdrum and boring.
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Secondly, there are also outstanding example of discoveries made by experimenters which really had no theoretical precedent. That is what makes Rutherford and Faraday the two greatest experimental physicists in history. Rutherford discovered the atomic nucleus in 1908, but it took thirty years for physicists to develop a concrete theory of the nucleus. Similarly Faraday discovered the seamless relationship between electricity and magnetism – one of the very few examples of unification by experiment – but it took until after his death for Maxwell to come up with his pioneering theory of electromagnetism. Experimentalists  often follow in the steps of theorists, but the instances in which they lead the way are as full of creativity and achievement as the work of an Einstein, Bohr or Feynman. And even when they follow, they are the ones who bridge the gap between idea and hard fact.
Hum... OK. I don't quite agree with the 2nd part, even when the author gave some examples on when experiments produced something that hasn't been predicted by theory. I would say that in physics, it is more of a rule that the major advancement were made DUE to the unexpected discovery found from experiments, not the other way around.  Superconductivity, fractional quantum hall effect, dark matter, dark energy, the whole field of electromagnetism, etc.. etc. all came about out of observations first. In fact, one only needs to read Harry Lipkin's provocative essay in Physics Today from a few years ago when he asked "Who Ordered Theorists?" One can even say that Gell-Mann's often-used exclaim of "Who ordered that?" is a direct result of many experimental discoveries that no one expected or anticipated.

Zz.

## Saturday, June 01, 2013

### Why Supersymmetry?

OK, so we had a video out of Fermilab explaining to us what Supersymmetry is. Now comes a video on WHY.

Zz.