Bill Foster To Run For Congress Again

Physicist and former US Congressman Bill Foster is mounting a campaign to win a congressional seat at the next election.

Foster represented the 14th Congressional District for nearly three years after winning a high-profile special election in March 2008 to take the seat that had been held by Republican Dennis Hastert, the longtime House speaker who retired several months after Democrats took over the House.
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But Foster’s time in Congress came to an end after last November’s Republican tidal wave, when Randy Hultgren, a state senator from Winfield whose supporters included tea party activists, reclaimed the seat for the GOP.

The number of physicists in the US House of Representatives dropped quite a bit this time with Foster's loss and the retirement of Vern Ehlers. Last count, I think Rush Holt might be the only one left! And he's the only one who could beat Watson!

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Slow Recovery of Japanese Physics Facilities

I just found this report on the current recovery progress in Japan after the recent earthquake/tsunami. It looks like in some facilities, significant work still has to be done. This is discounting the infrastructure issues of the surrounding areas that provides water, electricity, and access/roadways.

The recovery will be very slow. I know of many colleagues who thought they would be busy with work and/or travel to Japan this summer who suddenly find themselves having a wide-open few months due to conference and work cancellations.

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Freezing Liquid Nitrogen

Those fun people at JLab are at it again. This time, they freeze liquid nitrogen using evaporative cooling.



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No Electric Dipole Moment For Electron Yet

The most accurate experiment to detect any electric dipole moment for an electron has detected none[1]. Don't miss also the News and Views article of this work in the same issue of Nature.

This experiment has received quite a bit of media coverage (see here, here, here, and here).

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[1] J.J. Hudson et al., Nature v.473, p.493 (2011).

Where Do Tears In Zero-G Go?

Nowhere! They just stay in front of your eyes!

That's what happened to astronaut Andrew Feustel during a space walk when his eyes got stung by something and started to water.

NASA's lead spacewalk officer in Mission Control, Allison Bolinger, later identified the irritant as an anti-fogging solution that had been applied to the inside of Feustel's helmet. It's essentially off-the-shelf dishwashing soap and occasionally flakes off, if not buffed properly, and can get in a spacewalker's eye.

Feustel managed to rub his eye against a foam block in his helmet — normally used for clearing ears — and said that helped. The spacewalkers noted that tears in space "don't fall off of your eye ... they kind of stay there."

Yup! Another property of gravity that we take for granted.

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The Physics of Drinking Dogs

We have now firm confirmation that dogs and cats drink alike!

Earlier on, there was a study on the mechanics of cats drinking water. It turns out that in a new study of dogs drinking water using high speed camera and x-ray images, dogs drink the same way as well!

This footage shows that as the tongue touches the surface of the water, the liquid adheres to it, creating a water column as the tongue is drawn back towards the mouth. The dog then snaps its mouth closed just as the water begins to fall backwards towards the bowl.

The research, published in the journal Biology Letters, has surprised scientists because it reveals that cats and dogs drink in the same way.

I'll post the exact citation to the paper when I find it.

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Argonne on "Jeopardy" Again

Seems like the lab is quite popular whenever there is a category on cars. It was on Jeopardy earlier this year, and it is on Jeopardy again this past week.



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The Physics (Or Lack Thereof) Of Souls

I've tackled the subject of "afterlife" and "life after death" before on here. But Sean Carroll took it a step further and really examined it with respect to what we know of today in terms of the physics. He even brought out the Dirac equation.

If you believe in an immaterial soul that interacts with our bodies, you need to believe that this equation is not right, even at everyday energies. There needs to be a new term (at minimum) on the right, representing how the soul interacts with electrons. (If that term doesn't exist, electrons will just go on their way as if there weren't any soul at all, and then what's the point?) So any respectable scientist who took this idea seriously would be asking -- what form does that interaction take? Is it local in spacetime? Does the soul respect gauge invariance and Lorentz invariance? Does the soul have a Hamiltonian? Do the interactions preserve unitarity and conservation of information?

What it means is this. If one wants to argue that our current understanding actually SUPPORTS the existence of souls and afterlife, then one MUST reformulate this equation and show exactly the physics and dynamics of such entities the way we understand all other parts of physics. Now this is very important because to CLAIM that current science are consistent with such phenomenon, or even explained it, one must provide such formalism, or else, it is just a handwaving speculation. The latter is something that Deepak Chopra has been doing, which is piggy-backing onto modern physics without providing any valid formalism for it.

But if one claims that souls and afterlife are BEYOND current-day physics, then one has to throw out everything that we know (and know to be valid since we are USING them in our everyday lives) and come up with something new. This will present a very daunting task.

We don't choose theories in a vacuum. We are allowed -- indeed, required -- to ask how claims about how the world works fit in with other things we know about how the world works. I've been talking here like a particle physicist, but there's an analogous line of reasoning that would come from evolutionary biology. Presumably amino acids and proteins don't have souls that persist after death. What about viruses or bacteria? Where upon the chain of evolution from our monocellular ancestors to today did organisms stop being described purely as atoms interacting through gravity and electromagnetism, and develop an immaterial immortal soul?

We simply can't manipulate or change one part of physics, without affecting other parts. If one proposes a new physics, then it is a valid to look at consequences of that physics and see how it affects other parts. And this is where many new theories will have problems because it has to not only predict new things, but also be consistent with others that we have verified. That's why I said it is a daunting task.

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Brookhaven Lab Wins PR Award

In another example of a scientific organization really putting in thoughtful effort to convey news and messages to the media and public, Brookhaven National Laboratory has won two "Bulldog" awards for excellence in media and public relations.

The Brookhaven Lab campaign won a Gold award in the “Best Campaign Under $25,000” category, and a Bronze award in the “Best Not-for-Profit/Association/Government Campaign” category. In 2010, the campaign also won a Bronze Anvil Award of Commendation from the Public Relations Society of America.
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In the award-winning campaign, Brookhaven Lab and its communications counsel developed and executed a strategy to announce two major results related to RHIC scientists’ quest for the primordial matter known as quark-gluon plasma (QGP) through RHIC’s high-speed collisions of heavy ions. Scientists believe such a quark-gluon plasma filled the early universe some 14 billion years ago, before ordinary constituents of matter such as protons and neutrons — let alone stars, planets, and galaxies — ever formed.

Well done!

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The Physics of Blue Jeans

Here's something to show that there's physics in everything. This article covers the physics of blue jeans - everything you wanted to know about the physics aspects of blue jeans but were afraid to ask!

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The Physics of Sailing for Pirates

Now, we're not talking about the nasty pirates off the coast of Somalia that have been hijacking ships. We are talking about the romanticized version of pirates here, and since this weekend is the opening weekend of Disney's "Pirates of the Caribbean - On Stranger Tides", this is a good time to talk one aspect of the physics of sailing.

The fastest way to sail is at a forty-five degree angle to incoming wind. I know! Ye minds have been blown! But it works. the best way to understand is to think of the wing of an airplane. It has a flat side an a rounded side. The rounded side is tough for air to get around - it has to move quicker, and there's less of it making the dash - so the air pressure is lower on that side of the wing. The flat side is easy for air to move by, and so the air pressure is higher. That pushes the plane upwards. When wind hits the sail, it puffs out, making one side rounded like an airplane's upper wing, and the other side a hollow. The air pressure in the hollow is high and in on the puff is low. The keel keeps the boat from drifting sideways, and so it moves the only way it can - forward.

So the expression "may the wind be at your back" may not be such a good thing in sailing.

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Introducing Synchrotrons Into the Classroom

A neat video that describes a program at Brookhaven Lab that allows high school teachers, and their students, the opportunity to make a proposal for an experiment.



I wish they revealed the results of the experiment! That's the only part missing in here.

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AMS Attached To Space Station

Finally, after such a long wait, the ISS is now actually a useful scientific laboratory! The AMS has been successfully installed to the International Space Station.

The task was done over several hours in the middle of the night as astronauts used robotic arms from both the shuttle and the space station to lift the AMS out of the shuttle’s cargo bay then maneuver it into place and install it on the station. They were finished by 5:46 a.m. Eastern time.

The report also stated that it has already been "turned on", whatever that means. I'm sure there's a lot of diagnostic checks and calibration being done before actual data-taking.

Check out the AMS on-orbit images at the AMS homepage.

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Probing Potential PhDs

Oh, if you missed this article when it appeared last week, don't miss it now! It's a fun article to read about an interview process conducted in China to find potential PhD candidates for SUNY-Stony Brook University. Many of us even with PhDs can learn a thing or two of the conceptual questions that were asked.

I like Crease's expression for making sure that what you are conveying is at the same level that the intended audience can understand:

The challenge questions that one looks for are those that do not involve calculation but conceptualization, or a general sense of the physics involved. The student must then convey the conceptualization and how it settles the problem swiftly and succinctly at the undergraduate level. These questions therefore test what I like to call "impedance matching", or the ability to match the "load" of one's explanation to the environment in which it must be understood.

I like that expression: impedance matching. I think I'll copy it! :)

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Back From Vacation

Just got back from a week-long vacation. It'll take me a few days to catch up with what's been going on. At least the AMS lifted off with the space shuttle and will be installed today. After such a long wait, it is now finally up where it belongs. Hopefully, it won't be too long before we start to get data from it.

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A Brief Introduction to Band Structure in Three Dimensions

This is a very handy and quick tutorial on the calculation of band structure in solids. It's useful to see how QM principles is applied to our understanding of solids such as semiconductors, etc. which leads to our ability to know how to make our modern electronics.

Abstract: Without our ability to model and manipulate the band structure of semiconducting materials, the modern digital computer would be impractically large, hot, and expensive. In the undergraduate QM curriculum, we studied the effect of spatially periodic potentials on the spectrum of a charged particle in one dimension. We would like to understand how to extend these methods to model actual crystalline materials. Along the way, we will explore the construction of periodic potentials in three dimensions, and we use this framework to relate the single-particle Hamiltonian to the potential contribution from each atom. We then construct a crude model system analogous to the semiconductor silicon, and demonstrate the appearance of level splitting and band gaps as the strength of the potential is varied, in accordance with our intuition from the one-dimensional case. We discuss refinements of the model to include many-particle effects, and finally we show how a careful choice of the potential function leads to good agreement with the correct band diagram for silicon.

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The Road To Discovery Of Atom's Nucleus

This is an interesting and brief historical account Ernest Rutherford's discovery of the nucleus.

The one interesting part that I read is how shrewd he was.

With blossoming international scientific fame, Rutherford was regularly offered posts in America and elsewhere. He accepted none because McGill had superb laboratories and support for research, but he was wise enough to let the McGill authorities know of each approach; they increased his salary each time. However, Rutherford also wished to be nearer the centre of science, which was England, where he would have access to excellent research students and closer contact with notable scientists. His desire was noted. Arthur Schuster, being from a wealthy family, said he would step down from his chair at Manchester University provided that it was offered to Rutherford, and in 1907 Rutherford moved to Manchester.

As always, in reading historical account such as this, it continues to amaze me how many "household names" are involved, either directly or indirectly. We see the involvement of Geiger, Marsden, Bohr, etc...

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Willard Boyle: 1924–2011

We note today the passing of a Physics Nobel Laureate, and someone whose discovery/invention is certainly influential in our lives. Willard Boyle, a co-inventor of the CCD, passed away at the age of 86.

Like many Nobel laureates, the prize came late in Boyle's life, when he was 85. As his long-time friend and Nova Scotia local councillor Ron MacNutt told the Canadian Broadcasting Corporation yesterday, Boyle "had some regret that that recognition came a little bit late for him to get out and do more of that, to talk to younger children in school". An earlier award, MacNutt added, might have let Boyle influence even more people in his life.

Still, I'm glad that the Nobel committee gave him his award and that he gets the recognition, even late in life. BTW, here's another example you can give to people who thinks that physics and physicists only deals with esoteric, no-application knowledge.

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Particle Physics Fights Cancer

Jennifer Ouellette has a wonderful article on a new method to fight cancer, using knowledge that we gained from high energy/particle physics. In this case, one is using an imaging technique from a Cerenkov radiation.

This is just one more example of the benefits one obtain (and taken for granted) from so-called esoteric fields such as elementary particle/high energy physics. I've mentioned earlier about such benefits that many people are not aware of. This is in addition to the fact that basic knowledge is so valuable, even when we initially do not realize its potential benefits and application later on. And let's not forget that out of all of this is the advancement in accelerator physics that continues to produce numerous crucial benefits.

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Scotland's Bid To Honor Its Only Nobel Prize Winner In Physics

As customary of my effort in highlighting the legacy of physicists who we all should know but get very little mention, especially in the popular media, here is a news report of Scotland's effort to honor its only Physics Nobel Prize winner - Charles Thomson Rees Wilson - who was given the Nobel prize for the invention of the cloud chamber.

Now a group of prominent scientists and politicians who believe his achievements rank alongside those of Albert Einstein and Marie Curie are to launch a campaign to have issued a commemorative banknote to honour long-forgotten inventor CTR Wilson. Wilson was awarded the world's most prestigious science prize in 1927 for his invention of the cloud chamber, inspired by the optical effects he saw in the sky in the Highlands. His invention was pivotal in the development of particle physics and has been described as "the most original and wonderful instrument in scientific history".

The cloud chamber, of course, was one of the earliest particle detector that was used, and featured prominently in the early high energy physics experiments. I still use a cloud chamber whenever we have visitors, and it is amazing how many have never see such a thing. People continually are amazed when they see all of these tracks zipping around in the chamber. It reinforced the idea that we are surrounded by cosmic/terrestrial "radiation", and something this visual tends to stick in people's head faster and easier than simply telling them, or showing them on posters.

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Gravity Probe B Confirms Einstein's General Relativity

There are many news article on the latest report from Gravity Probe B stating how the results are consistent with predictions from Einstein's General Relativity (see here, here, and here). But the one I will highlight here is from Jennifer Ouellette who started out her article with ...

It's a sad day for physics crackpots bent on disproving relativity, because once again, it turns out that Einstein was right.

I love it!

Obviously, she had encountered, as I have, all of these sad creatures who continue to want to bash Einstein's Special and General Relativity.

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What Students Learn When Studying Physics Practice Exam Problems

A rather interesting study on a topic that I don't think have been looked at much. This group of researchers try to evaluate what students understand and gain when they were given past, old exams (some with solutions) to practice and study on[1].

Abstract: We developed a web-based tool to provide students with access to old exam problems and solutions. By controlling the order in which students saw the problems, as well as their access to solutions, we obtained data about student learning by studying old exam problems. Our data suggest that in general students learn from doing old exam problems, and that having access to the problem solutions increases their learning. However, the data also suggest the depth of learning may be relatively shallow. In addition, the data show that doing old exam problems provides important formative assessment about the student’s overall preparedness for the exam and their particular areas of strength and weakness.

In particular, they were trying to address these questions:

How much do students learn from doing a multiple-choice exam problem and getting feedback about the correct answer? Does providing students with a complete solution improve their learning? How accurately does student performance on practice exam problems predict their performance on actual exam problems? In particular, can it help predict areas that a student should spend more time studying?

Going over the paper, I first had a chuckle when looking at Fig. 1 which shows that most of the students tried the practice exams within 24 hours of the exam! Typical last-minute cramming! :)

It appears that these are "multiple choice" tests. Although the authors don't think that this may make a significant difference, I'm not so sure about that, because one also can't discount random selection, or at least, a student making an educated guess without actually knowing the correct answer.

Still, it's an interesting study to read.

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[1] W. Fakcharoenphol et al., Phys. Rev. ST Phys. Educ. Res. v.7, p.010107 (2011).

Bosons In High Temperature Superconductors: An Experimental Survey

This is a wonderful review article on the issue of the bosonic mode that couples to the quasiparticle in the cuprate superconductors[1]. Deciphering the nature of this boson is THE key issue in the mechanism of superconductivity for this family of material. This article compiles the relevant experimental data from angle-resolved photoemission spectroscopy (ARPES), optical measurement, and tunneling spectroscopy, to present the state of knowledge about this bosonic mode.

What makes this article even more useful is that, if you're not familiar with the physics surrounding these techniques, especially for ARPES and optical conductivity, it provides a nice brief summary of these techniques and what they actually measure that can provide the information needed.

A highly useful article, in more ways than one.

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[1] http://arxiv.org/abs/1105.0726

309 Antihydrogen Trapped for 1000 Seconds

This made the news at least a week ago, but only now has the story appeared on PhysicsWorld, so here it is.

The ALPHA team produced the antihydrogen by merging two clouds of cold plasmas: one containing positrons and the other antiprotons. By improving their trapping techniques, the researchers managed to hold the antihydrogen for more than 1000 s. These advances also meant that five times as many atoms were trapped per attempt. Calculations based on data from the experiment suggest that after about 0.5 s, most of the trapped antihydrogen atoms reach their lowest energy or ground state. As a result, the team says that its trapped sample is the first antihydrogen obtained in the ground state.

As in this group's earlier attempt, this is such an amazing accomplishment. The fact that they can hold these that long opens up a whole slew of tests that one can conducts on very fundamental aspects of physics. So this isn't just an astounding accomplishment, but also a tool to investigate other things. That is why this is so important.

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New Light On Dark Energy

If you have 2 hours (yowzah!) to spare, here's a video of a panel discussion on the latest development in our understanding of Dark Energy.



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Publishing A Turd Is Still A Turd

OK, I've made wholesale judgement of something that I haven't read, and something I don't have a very good knowledge of. In other words, I'm doing exactly what I've criticized crackpots for doing. I fully admit it, and I'm fully owning it! So there!

But really, as I've mentioned earlier, you can only counter crackpottery with another crackpottery. And I'm going to judge this with the same level of superficial knowledge as this person is doing by invoking his superficial level of knowledge of quantum mechanics. I think that is a fair deal, no?

This article out of Cornell highlights a series of publication on ESP and other paranormal phenomena. Oh yes, that again! Supposedly, this series of publication is based on new research that somehow shows "convincing" evidence for it. But just in reading this article, are you truly convinced?

In one experiment, Bem asked students to pick one of two curtains as the one they thought contained a picture behind it. Although the students correctly chose the correct curtain 53.1 percent of the time, which appears to not be too different from the expected 50 percent, Bem believes this value is, in fact, statistically significant and unlikely to appear by chance.

A paper published by researchers at the University of Amsterdam suggests that Bem uses incorrect statistical methodology by using one-tailed tests instead of two-tailed tests, which would be more difficult to prove significance for. By re-analyzing Bem’s data using a different set of statistical analysis tools, however, the researchs show that Bem’s data is not statistically significant. Bem believes this claim is “an absolutely ridiculous argument to be making” and that the assumptions used by the University of Amsterdam researchers are “unrealistic.”

Er... yeah! Of course!

But it gets better when physics is invoked.

It is Bem’s belief that there is “nothing in physics that is contradicted” because although ESP might not be in line with Newtonian physics, it is in line with quantum physics.

He added, “The fact that we do not have a mechanism to explain it is a major deterrent. But almost every theory first started out as an unexplainable phenomenon.”

Er... what is it with "quantum physics" that is consistent with this cra... er ... study? Let me guess. He's invoking quantum entanglement? Superposition? The Cat? If he is, he is barking up the wrong tree, very much like Deepak Chopra. And thus, my point about superficial understanding of something. But what is funny is the gall he had to say that " ... almost every theory first started out as an unexplainable phenomenon.. " Since when is this something new to be "first started out"? Claims of ESP and such have been made for decades, even longer! In all of those years, they still can't get out of first base, out of the "discovery" mode. Other legitimate phenomena have gone beyond the discovery/confirmation phase and now have proper theoretical descriptions.

This thing cannot get beyond the fact that they can't differentiate their signal from random noise. The statistical analysis of such a thing is suspect. It is why the effect is not convincing.

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Michael Tinkham

OK, I completely missed the passing of Michael Tinkham last year. I only heard of the news when I read his obituary in latest edition of Physics Today.

I did not have the privilege to have known him, or to have met him, unlike his students, postdocs, and colleagues. However, he certainly made a huge impact on me professionally. His "Introduction to Superconductivity" book was my "bible" when I was in graduate school. In fact, his derivation of the BCS Theory was the one I studied from very closely, above all others. I would not have grasped the theory of superconductivity as well and as fast as I did if it weren't for this book.

So thank you, Michael Tinkham. I think your legacy, through your work and your books, will live on.

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2011 APS Apil Meeting Presentations Available Online

Viewgraphs of selected talks from the 2011 APS April Meeting are available online. This could be useful to those who can't make it to the April Meeting, so this is definitely a good idea. It appears that this is still in a trial basis, but I hope it continues.

Now, they need to do the same for the March Meeting.

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The First Year of the LHC

This is a technical/scientific overview of the first year of the Large Hadron Collider at CERN.

Abstract: The first year of LHC data taking provided an integrated luminosity of about 35/pb in proton-proton collisions at sqrt(s)=7 TeV. The accelerator and the experiments have demonstrated an excellent performance. The experiments have obtained important physics results in many areas, ranging from tests of the Standard Model to searches for new particles. Among other results the physics highlights have been the measurements of the W-, Z-boson and t t-bar production cross-sections, improved limits on supersymmetric and other hypothetical particles and the observation of jet-quenching, elliptical flow and J/Psi suppression in lead-lead collisions at sqrt(sNN) = 2.76 TeV.

It still amazes me how much they accomplished in the first year alone, considering the technical challenges that something of this size can have. It is an astounding machine in many ways, and it will provide us some of the most profound knowledge during its lifetime.

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Quantum Entanglement "Detected" By Human Eye

I'm not sure what to make of this.

This report describes a new and elegant experiment by the Gisin group. In this experiment, they have 2 entangled photons. One goes to a detector, the other gets amplified and generate a lot of photons with the same polarization state. In essence, the large number of photons are now a "macro" photon that is still entangled with the first photon. What they are doing is a micro-macro photon entanglement. This large number of photon is then detected by the human eye.

Using a similar set-up to that of Sciarrino, Gisin and his team entangled two photons. One was sent to a standard photon detector, while the other was amplified using a machine that generated a shower of photons with the same polarization, thereby, in theory, generating a micro–macro entangled state.

But Gisin replaced the photon detector Sciarrino used for the light field with a human. The beam of light produced by the amplifier could appear in one of two positions, and the location of the beam reflected the polarization state of the photons in the field. Gisin and his team sat in the dark for hours, marking the position of the light spot over repeated runs of the experiment, for the first time seeing the effects of quantum entanglement with the naked eye.

But then, they decided to check this by measuring the photon before it gets amplified, thereby destroying the entanglement with the first photon. Strangely enough, they get a false positive result!

But there was a hitch. What Gisin's team saw was not micro-macro entanglement. Gisin had a nagging suspicion that the Bell test may not be valid for macroscopic objects, so he deliberately set up the experiment so that the state of the second photon was measured before it was amplified. According to the rules of quantum mechanics, this act of measurement would break the entanglement, meaning that the first photon and the light field could not be in an entangled state. The system should not have passed the Bell test.

So essentially, they argued that the micro-macro entanglement isn't that convincing due to some issues. So I'm not sure how to spin this.

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The Alpha Magnetic Spectrometer Is About To Fly

With a few days left before takeoff, space shuttle Endeavour's last flight will carry with it the Alpha Magnetic Spectrometer that will, finally, turn the International Space Station into a scientifically-significant facility, rather than a glorious piece of orbiting "motel".

This news article highlights this upcoming event, but it started out all wrong.

Scientists believe anti-matter exists, and they said the alpha magnetic spectrometerhas been packed away in the space shuttle Endeavour in search for it.

Er... hello? We don't just believe that anti-matter exists. We KNOW they do, or else the Tevatron has been colliding imaginary particles, and PET scans is based on hypothetical ideas.

Providing evidence for the existence of antimatter is NOT what the AMS is for. It is a lot more subtle than that. The AMS webpage (link given earlier in this blog entry) should tell you what it is for. News article like this does a disservice because it makes it sound as if antimatter is still something unverified, and that "scientists" merely "believe" in its existence.

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Teach Physics The Proper Way, You Might Get Complaints

Sometime, you just have to shake your head when you read stories like this.

This writer talk about one possible reasons (out of many) of why we often have problems with the quality of our education - Parents! Parents often put low priorities on academic excellence.

Ever notice how parents line up around the block to get into the schoolhouse meeting that's to discuss the cellphone policy, the dress code, bullying or the teaching of evolution? But I don't ever recall any parental protests about mediocre TCAP or ACT scores.

Ballgames bring the crowds by the hundreds (if not thousands), but how many parents showed up on parent-teacher conference day? In my 14 years of teaching high-school math, I typically had a handful on those days, when I needed to see dozens.

But the saddest part of this article is the description of what happened when a physics high school subject was taught properly:

In January 2008, the News Sentinel published my Citizen's Voice column, in which I complained that the typical kid was a million times more interested in his vast entertainment and social worlds than he was any academics.

One of the 26 replies I got was from a guy who was sent to an East Tennessee high school to strengthen its physics program. He was from the Distinguished Professionals Education Institute, meaning that he was top-notch.

Upon investigating, he discovered that his physics enrollment was much higher than would be ordinarily expected, that the previous year the class was taught by a coach and that almost every kid got an A. Physics should be one of the hardest classes in any high-school's curriculum. If taught correctly, few will take it, and they'll expect to work very hard. If kids eagerly sign up for physics, then the class is probably a joke.

Well, our serious teacher taught his physics class the right way: homework, labs and (oh, my goodness!) rigor. By mid-October, he was removed from the class, so widespread and vehement were the complaints from students and (surprise) parents.

This, of course, is the reverse in countries such as China, Singapore, South Korea, India, etc. There, students and parents do not dare complain about a subject being taught as being too "difficult" or demanding.

I would love to hear the "excuse" being given by the schools and the parents for removing that teacher.

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"What Is The Most Important Thing You Learned In Becoming A Scientist?"

I get asked that question frequently. Whenever I do an outreach project with either high school or college students, or even sometime even when I talk to the general public, I often get asked the question on what I think was the most important thing that I learned in becoming a scientist, or in this case, a physicist.

Now, I've mentioned a while back that I believe that the transition from being a "student" to being a scientist is when you learn the difference between what is "interesting" and what is "important. This is because what is interesting need not always be important, and making that realization is the first step towards becoming a scientist. So certainly, that realization and the ability to distinguish between the two is an important lesson in becoming a scientist.

But is that the most important thing that I've learned in becoming a scientist? When students asked me that question, they often expect that I would say that learning quantum mechanics, or electromagnetism, etc. would be the most important thing. So it comes as a surprise to many when I told them what I believe is the most important thing that I learned in becoming a scientist: Learning To Learn!

One of the things about being a scientist is that we always have to learn new things all the time! There's always something that we haven't heard of, something that is new, something we have never quite fully understand, or something puzzling. You are always faced with tying to find out about something. What we have acquired along the way, starting from undergraduate years to graduate school to postdoctoral work, and even through our early careers, is the ability and skill to learn. I'm not just talking about reading a book or paper and trying to understand something. I'm talking about knowing WHERE to look, WHO to ask, WHAT do I need to do to understand that, HOW do *I* understand something? We all work in different ways. Knowing how I, personally, comprehend something is very important, because I have consciously tried to discover when I can make something click in my head, and when it can't. How the material is presented, how I organize my thoughts in my head, how I work things out on paper, etc. are all my own personal preferences and skills that I know help me to understand something. In other words, at some level, I know what makes me tick and how I can grasp something. To me, this is the most valuable and important thing I learned in becoming a scientist.

So why is this the most important thing I learned? Besides the fact of what I've mentioned earlier about scientist always having to learn new things, it is also an important factor career wise. Not many of us are lucky enough to know what we want to do, and get to do it. Often, we have to make career changes, often changing field of studies due to one reason or another. Switching fields is not as uncommon as one would think, and in such cases, you definitely are faced with new knowledge to understand and comprehend. This is where the ability to learn becomes invaluable because in many situation, you are almost starting from scratch. This is where the skill that you used to obtain that PhD could be employed to get you up to speed in another field. The subject matter may be different, but if you've honed your skills properly, it is the same set that you will need to use to learn the new subject matter. It certainly happened to me when I switched from condensed matter physics to accelerator physics.

So yes, learning how to learn is the most important thing I learned in becoming a scientist.

Zz.

The Higgs Rumor - You Won't Find It Here

Oh no! I'm not falling for that thing again!

If you wish to read about the rumors that ATLAS may have see the Higgs, go read it elsewhere, or do a search. This is all over the web. You can't miss it. But you won't find any comments on it here.

I will wait only for the official word, either from CERN, or from someone I trust, not someone who has cried "wolf" before.

Zz.

The Far-Reaching Theory of Superconductivity

The celebration of the 100th anniversary of the discovery of superconductivity still continues. If you've read the Adrian Cho's piece in Science (Science April 8, 2011, p.190), you'll discover how superconductivity has influenced ideas in a wide-ranging field in physics. This is widely acknowledged by non other than Franck Wilczek in his contribution to the 50th anniversary of the BCS theory. He reinforced it here in this video on how our knowledge of superconductivity has a far-reaching impact.

It's a rich mix that the theory of superconductivity has given us," he says, referring to concepts such as pairing and symmetry breaking as applied to topology. "All those ideas really have their deep roots in work on superconductivity and they've become dominant tools for fundamental physics.

The point that is being stressed here, and which I've repeatedly mentioned, is that it is no longer a valid point to labelled areas of study such as condensed matter physics as being "applied physics". The knowledge gained, especially on the theoretical aspect of it, is as "fundamental" as anything. It is plainly apparent here in the case of superconductivity, but it can easily be said about the physics of graphene, topological insulator, BEC-BCS crossover, etc. It is in this field where various aspects of quantum field theory comes to life with utmost clarity. It is not pure fallacy that Carver Mead would say that "... Nowhere in natural phenomena do the basic laws of physics manifest themselves with more crystalline clarity...." regarding superconductivity.

So if anyone claims that anything other than high energy/particle/astrophysics/string/etc. is merely "applied", show him/her this.

Zz.

Lessons from Fukushima

There will be a panel discussion on the Fukushima nuclear disaster today at 4:00 pm US CDT. The live webcast can be followed at that web link.

Japan's Tohoku earthquake and tsunami in Japan have caused the world to reconsider nuclear energy and its place in global energy policy. The University of Chicago Alumni Association, in conjunction with Argonne National Laboratory and the Harris Energy Policy Institute, invite you to join us for a live discussion and simultaneous webcast that will explore the impact of nuclear energy, now and in the future. The discussion will explore the topic from a variety of perspectives, including climate and ecology, economics, history, policy, safety, and science and technology. The panel includes:

* Mark Peters, Deputy Director of Argonne National Laboratory (Moderator)
* Kennette Benedict, Executive Director of the Bulletin of Atomic Scientists
* Hussein Khalil, Director of the Nuclear Energy Division at Argonne National Laboratory
* Robert Topel, Isidore Brown and Gladys J. Brown Distinguished Service Professor in Urban and Labor Economics, Chicago Booth School of Business, and Director, University of Chicago Energy Initiative.

Zz.

Why Are Feynman's Lectures Still Mesmerizing?

Here's a brief Q&A with MIT's Robert Jaffe on why videos of Feynman's lectures still are popular with a lot of people.

Q. Nearly 50 years after Richard Feynman gave these lectures, why are they still relevant today?

A. Feynman brought a level of insight, enthusiasm and trenchant wit to the exposition of the fundamental laws of physics that is unsurpassed. These lectures come from the height of his “pedagogical period,” shortly after he finished his “Feynman Lectures” books. As for why they are still relevant, I addressed that in one of my commentaries. Here is a quote from my commentary on the last lecture:
“The laws of physics that Feynman has been describing are just as fresh and powerful as they were in 1964, or indeed decades earlier, when they were first discovered. In contrast a 50-year-old lecture series in biology, chemistry, computer science or the social sciences would be of historical interest only. For better or worse, the laws of physics don't change (no matter how much we may sometimes wish they would). Now, as in Feynman's day, they form the basis of all the other sciences, and Feynman's explanations are as fresh as any lectures in a classroom today. From time to time, I've added some modern perspective, occasionally correcting one of Feynman's remarks that proved incorrect in later years.”

There are also people who I think follow the cult of "celebrity". A lot of people who have very little inkling of understanding of Stephen Hawking's work, for example, still buy his books and flock to his appearance as if he's a rock star. I would think that Feynman legend continues to grow even after his death, and that helps to cultivate more "cult" following.

In any case, if you missed it, I reported on the availability of the Feynman lectures online a while back, thanks to Bill Gates.

Zz.

Profile of Clifford Will

I've mentioned Clifford Will's name before in my blog entries (see here and here). He is certainly one of our most preeminent expert in General Relativity.

PNAS March 29, 2011 issue has published his inaugural article, along with a wonderful profile of this distinguished physicist. It contains not only information about him, but we also get a bit of a history lesson on the experimental tests of General Relativity.

Zz.

Neutron Gravitational Quantum States Probed

Several years ago (in fact, close to 10 years ago), we read about an amazing experiment that showed for the first time the gravitational quantum states done by using a neutron free fall experiment. Now long comes an experiment, almost 10 years later, that probed these quantum states, again using neutrons, but with an induced frequency in one of the plate[1].

The new work by the ILL team has added what is known as a piezoelectric resonator to the bottom plate; its purpose is to jiggle the bottom plate at a very particular frequency.

The researchers found that as they changed the bottom plate's vibration frequency, there were distinct dips in the number of neutrons detected outside the plates - particular, well-spaced "resonant" frequencies that the neutrons were inclined to absorb.

These frequencies, then, are the gravitational quantum states of neutrons, essentially having energy bounced into them by the bottom plate, and the researchers were able for the first time to force the neutrons from one quantum state to another.

This then could be used as an extremely sensitive device to measure gravity at atomic scale.

Fascinating experiment.

Zz.

[1] T. Jenke et al. Nature Physics doi:10.1038/nphys1970 (online publication - full citation not available yet).

Another Tragic Death of US Science Student

The tragic death of a US undergraduate physics student at Yale this past week brought back memories of another tragic death a couple of years ago at UCLA. In that earlier blog entry, I mentioned that, due to the less stringent training and safety review process at most universities, I'm surprised that such an accident doesn't occur more often. Unfortunately, they are.

I think everyone working in the field, except for theorists, needs to be told that there are aspects of doing science that can be dangerous if one isn't paying careful attention. A simple rubbing of one's eye while doing laser alignment can cause an accidental exposure of one's eye to that laser light. Many things can go wrong, and many times, they do when one isn't properly trained or be made aware of of the hazards. Luckily, most of the accidents are minor, but some time, it takes only one mistake to result in such tragic consequence.

As an experimentalist, my main focus has always been the work. But luckily, even though it can be annoying, the constant hammering of safety issues and the hazards that I face each day while at work do result in my conscious awareness of what I do and how I do it. When you deal with something where a serious mistake can lead to a life-or-death situation, you tend to want all the information you can get before doing the work.

One would hope that with this latest accident, universities will pay even more attention on how graduate students are trained to safely do their work.

Zz.

Quantum Superposition, Using Atoms and Mirrors

This appears to be a very clever experiment. However, I still have a bit of a problem understanding it completely, and I haven't had time to read the actual paper. Still, some of you may want to read it ahead of me, and might even be able to provide a clearer explanation before I can get to it.

By placing an atom very close to a mirror, and having the atom emits a photon either away, or towards the mirror, physicists at Heidelberg University, TU Munich, and TU Vienna have shown a superposition of an atom that is moving simultaneously in two opposite directions.

“If the distance between the atom and the mirror is very small, it is physically impossible to distinguish between these two paths,” Jiri Tomkovic, PhD student at Heidelberg explains. The particle and its mirror image cannot be clearly separated any more. The atom moves towards the mirror and away from the mirror at the same time. This may sound paradoxical and it is certainly impossible in classical phyiscs for macroscopic objects, but in quantum physics, such superpositions are a well-known phenomenon. “This uncertainty about the state of the atom does not mean that the measurement lacks precision”, Jörg Schmiedmayer (TU Vienna) emphasizes. “It is a fundamental property of quantum physics: The particle is in both of the two possible states simultaneousely, it is in a superposition.” In the experiment the two motional states of the atom – one moving towards the mirror and the other moving away from the mirror – are then combined using Bragg diffraction from a grating made of laser light. Observing interference it can be directly shown that the atom has indeed been traveling both paths at once.

I still have trouble understanding how the interference pattern can infer the superposition motion of the atom. To me, the photon itself will "self-interfere" since each one of them are in superposition of both paths (i.e. emitted away from the mirror and emitted towards the mirror and gets reflected back). Thus, when combined, they will self-interfere, very much like the double slit. So why the need for the Bragg diffraction grating?

Like I said, I definitely need to read the paper, since I am obviously missing something here.

Still, being able to show the atom having that opposite motion simultaneously is amazing. It is very much like the Delft/Stony Brook SQUID experiments, where the supercurrent was moving in two opposite directions at the same time.

Zz.

A Light Diode?

A very interesting review of a new theoretical work proposing a device that will allow the efficient transmission of light in only one direction, without having to generate any higher harmonics.

The solutions showed that waves are best transmitted when their frequency matches a "resonance" value for the nonlinear layers, but as with many nonlinear systems, this frequency depends on the wave's amplitude. However, the dependence is different for oppositely-directed waves because of the asymmetric set-up. So for some amplitudes, if identical waves come from opposite directions, only one of them can have the right combination of frequency and amplitude to be fully transmitted, while the other is largely reflected. They found similar results with larger numbers of nonlinear layers.

Because Lepri's system doesn't rely on harmonics, as the photonic crystal system did, it can transmit light much more efficiently, says Panayotis Kevrekidis of the University of Massachusetts at Amherst. The amount of light that makes it through depends on the properties of the nonlinear material, which means you can tune the system to block some or all of the light. "What the nonlinear medium allows you to do is create perfect transmission," Kevrekidis says.

And it appears from this article that the test to show this isn't going to be too complicated. So it shouldn't be too long for us to hear the first experiment on such a system.

Zz.

Fukushima: Fact Versus Fiction

A video of a panel dialog on the nuclear disaster at the Fukushima nuclear power plant.



Zz.

DOE Office of Science Sparred Severe Cuts

The tentative agreement on the US 2011 budget presented the most optimistic scenario that one could ever imagine in this climate. It is reported that the DOE Office of Science budget will be cut only by 0.6% from 2010 level, when compared to the originally-proposed 18%. One can hear a collective sigh of relief from not only the National labs, but also a lot of universities and industries that make use of the many user facilities within those labs.

However, this is only a temporary reprieve. We are already in the battle for the 2012 budget, and a lot of people, especially politicians of a certain persuasion, simply are ignorant of the value of basic research and how it affects the economy. This is a continuing effort and a continuing struggle to make people be aware of such impacts.

In particular, DOE-funded scientists are worried about the office's 2012 budget request, now before Congress. "It's been an educational year," Isaacs says. "We learned that the argument [about the value of basic research] is still on the table and that we still have to make that argument."

So if you had written to your representatives during this last budget debacle to support science funding, thank you! But please, do not let up your support for basic science research if you truly believe in it. Continue to write to your representatives and ask them to consider what drives our economy and how science research has been a major player in that.

Zz.

A Different Perspective on Science

If you've read this blog for any considerable period of time, you would have noticed that I've highlighted several of Robert Crease's articles from time to time. So now, instead of him writing an article about something, this article is all about him, the main behind the story. Read his infamous encounter with Richard Feynman.

“So we aren’t any closer to unification than we were in Einstein’s time?” Crease asked. He and Feynman had been discussing the Standard Model, a cornerstone of modern particle physics that is considered to be almost a theory of everything, but still quite there be- cause it leaves out principle subjects like general relativity.

“It’s a crazy question!” Feynman said in anger. “We’re certainly closer. We know more. And if there’s a finite amount to be known, we obviously must be closer to having the knowledge, okay? I don’t know how to make this into a sensible question…it’s all so stupid. All these interviews are so damned useless.”

It was at that point that Feynman got up from his desk and cut the inter- view off. Crease heard Feynman yell from the corridor, “The history of these things is nonsense! You’re trying to make something difficult and complicated out of something that’s simple and beautiful.”

For a philosopher, he isn't that bad in dealing with science (is that a back-handed compliment?). A lot of his writing, especially his historical accounts, are very informative and entertaining, and I've always look forward to those.

Zz.

More Updates On Fire At Soudan Mines

A confirmation of the initial good news out of the Soudan Mines. As reported earlier, fire broke out at the underground laboratory that housed several important research projects. This could potentially be disastrous to the only underground research facility in the US. Luckily, the damage so far appears to be minimal.

Although the fire cut short by a month tests on detectors for the follow-on experiment, SuperCDMS, for which Cushman is co-spokesperson, she says those engineering tests will be "declared done" and the physics run will start this summer as planned.

Several smaller experiments in the underground lab, such as dark-matter search CoGeNT (Coherent Germanium Neutrino Technology), still have to be checked to see if their detectors have been compromised by having tiny amounts of material deposited on them due to the warming.

The Main Injector Neutrino Oscillation Search, a detector for neutrinos beamed from Fermilab 735 km away, has to be dried and its electromagnetic coil and other parts assessed. The MINOS lab needs a good cleanup from the firefighting foam and debris that got pulled in with it.

Like I said earlier, PHEW! This could have been a serious setback.

Zz.

Luttinger Liquid Behavior For Photons In 1D?

This is a very intriguing theoretical idea.

Luttinger liquid is usually a property of correlated electron (fermion) systems when confined to 1D. But in this latest scheme, a proposal has been made to confined photons in 1D that could exhibit the same spin-charge separation of Luttinger liquids.

Thus the suggestion by Angelakis et al. [1] that spin-charge-separated Luttinger liquid behavior could occur for photons in a one-dimensional nonlinear medium opens the door to a host of potential new studies and applications of spin-charge separation in one dimension. The basic idea is to employ a one-dimensional nonlinear optical media with two species of atoms to create a gas of strongly interacting polaritons of two “types,” which will become the analogs of spin and charge. The proposal draws on earlier work by Chang et al. [6] in which it was shown that a regime of very strongly interacting polaritions could be achieved in a single-component one-dimensional nonlinear optical media. In the single-component case, the strongly interacting polariton system was shown to realize a Tonks gas, a strongly interacting system of bosons with contact (zero range) interactions [6], which has already been observed in cold atomic gases (as opposed to photons) of bosons [8, 9]. When the interactions in a system of bosons are very strong, particles tend to avoid the same spatial location, which mimics the Pauli exclusion principle for fermions. Of this effect, one sometimes says that the strong interactions have caused the boson system to “fermionize.” Once a one-dimensional bosonic system reaches this regime, the connection to interacting fermions becomes clear, and the mathematical descriptions of the low-energy behavior are identical.

You may obtain the paper in question at the link given above.

Now, let's see who will be the first to validate this experimentally.

Zz.

The Odyssey Of The Alpha Magnetic Spectrometer

With Endeavor's last trip into space, it will carry a very important piece of experimental equipment for the International Space Station that might make the ISS finally becoming an important scientific facility - the Alpha Magnetic Spectrometer.

The idea for the AMS came from Samuel Ting, a Nobel Prize laureate out of MIT. This article documents his "odyssey" to have this built.

Starting in 1994, he threw himself into a project he called the Alpha Magnetic Spectrometer (AMS), a device of nearly eight tons that would be attached to the International Space Station. Essentially a giant magnet for sifting apart the particles in cosmic rays, the AMS will look for evidence of the mysterious dark matter that some physicists believe makes up more than 80 percent of the matter of our universe.

It is quite an informative article, not just about the AMS, but also about Samuel Ting. It also conveyed a very fascinating story on the discovery of the J/psi particle, and how it is another one of those "Who Ordered That?" situation.

Like I said, a very entertaining article. Don't miss it.

Zz.

Q&A With Philip Phillips

This is an interesting Q&A with UIUC theorists Philip Phillips. While it focused mainly on his career path to how he got to where he is now, it also contains some insight into various issues in condensed matter physics, especially on how some condensed matter system can actually test other fundamental physics.

[In 1998, Argentinean physicist Juan] Maldacena made a conjecture in which he argued that there is a relationship between a strongly coupled quantum mechanical system and a gravitational system [that] is entirely classical Einsteinian gravity. So in fact, strongly coupled quantum mechanical systems that are charged are equivalent to a curved space-time with a black hole in it. We showed that if you just introduce some probe fermions and these probe fermions are coupled to the space-time in a particular way, that system looks identical to the normal [nonsuperconducting] state of high-temperature superconductors.

Others have used this mapping before. What we did that was new is that we used a particular interaction between the probe fermions and the black hole that is really irrelevant to the physics of the black hole but changes the physics at the boundary of the space-time [which is where the quantum mechanical theory lives]. No one suspected it.

With such a model, you can just forget about trying to figure out what the basic building blocks are, just go and solve this geometry problem and extrapolate it to what's going on at the surface of this geometry, and you'll see what the quantum mechanical system is doing.

A fascinating career arc.

Zz.

The Knowns And Unknowns of Physics

A rather entertaining audio interview with Sean Carroll on what we know and what we don't know in physics.

Physicist Sean Carroll probes fundamental physics by studying the structure and evolution of what he calls the 'preposterous universe'.

He says we've solved nearly all the problems of everyday life, scientifically speaking, but the rest? It's a mess.

Physics is in a bind because so much of its classical theory doesn't match what has been discovered recently. Have they hit the physical wall?

Zz.

Hard Lesson In Physics

OUCH!

I saw this report and video just now, and holy cow! I hope she's OK!

The article is a bit misleading in the sense that it's saying that "Gravity wins". It really has nothing to do with gravity, but rather, conservation of momentum.



Say the guy has mass M, and the woman has mass m, with m < M. For simplicity sake, let's assume that they both had the same velocity (but in opposite direction) before the collision Momentum before collision is Mv - mv = (M-m)v Momentum after collision is: MV_f + mv_f (I'm not making any assumption yet on the directions of the velocities after collision.) Applying the conservation of momentum, we get (M-m)v = MV_f + mv_f This means that mv_f is mv_f = (M-m)v - MV_f or v_f = (M-m)/m * v - (M/m) V_f Now, from the video, V_f (the velocity of the man after collision) appears to be in reverse, but very small, so V_f is negative, but small. So the 2nd term in the last equation is negative, making the equation to be v_f = (M-m)/m * v + (M/m) V_f Now, if M is substantially greater than m, M/m >1, and so (M-m)/m is also >1.


This means that v_f, the velocity of the woman after collision is greater than v, the initial velocity. She will recoil after collision with a greater speed than when she came in. This is what happened in the video.


One can also add another assumption of elastic collision, assuming the exercise balls didn't absorb too much energy in the collision. But I think the point has been made here. :)

Zz.

Mathematics And Science - A "Waste Of Time"

Trent Lott, former US Senate Majority Leader (and, a Republican, but you can draw your own conclusion there), proudly declare that, for an lawyer-to-be, studying mathematics, science, and especially physics, is a ".... waste of my time, waste of my teacher's time and a waste of space... "

Which, of course, didn't preclude him from deciding if something is worth funding or not. That then calls into question on how he would decide such a thing if it is a science/technical field. Did he simply delegated it to his minions? Or did he not based on scientific/technical merits, but rather purely on political issues? This type of attitudes, and lack of knowledge, explains why there were really astoundingly silly actions that have taken place.

It is one thing to be ignorant of what you don't know. It is another to actually be PROUD of such ignorance. I am not surprised if a large percentage of current crop of politicians (Tea Party, anyone?) have equal view on science.

Zz.

Q&A With Richard Muller

ScienceInsider had a Q&A session (or more like two from the way they described it) with Richard Muller after his congressional testimony on Global Warming and the "surprising" result that he presented during that testimony.

After that, I am certainly curious as to what else he would come out with out of this Berkeley project. But the bigger question here will be, will the Koch foundation continue to fund this project? It will look very bad for that organization to stop funding just because the initial result just didn't match what they had hoped for. Will the Republican party continue to call on him to more congressional hearing on this topic? Hum?

Zz.

Fermilab's "Big Bump" Announcement

So, did everyone get to digest the news from yesterday out of Fermilab? What do you think?

The paper on the Technicolor at the Tevatron can be found here.

Rumor has it that a result out of the ATLAS detector at the LHC making the rounds right now did not see such a bump. So stay tune! Things might be bumpy!

Zz.

The "Mysterious Bump" In Tevatron Data Could Be Big, If It Holds Up

OK, so the buzz around this mysterious bump in the data out of the Tevatron will be announced to the public today.

The results, if they hold up, could be a spectacular last hurrah for Fermilab’s Tevatron, once the world’s most powerful particle accelerator and now slated to go dark forever in September or earlier, whenever Fermilab runs out of money to operate it.

“Nobody knows what this is,” said Christopher Hill, a theorist at Fermilab who was not part of the team. “If it is real, it would be the most significant discovery in physics in half a century.”

It is way too soon to for something like this to have such profound impact and declarations. As stated in the news article, if it is real, the LHC would be able to spot this quite easily. So as exciting of a news this could be, we just need to step back a little bit, give it some time, and let the scientific process works itself out.

Zz.

Schrodinger's Cat Becomes 430 Atoms Fat

That cat is becoming fatter and fatter.

We have heard several years ago of quantum interference with C60 buckyballs, which are molecules containing 60 atoms. Now comes a new report of quantum interference of molecules, each containing 430 atoms, at around 6 nm in length!

In the team's experiment, the beams of molecules are passed through three sets of slits. The first slit, made from a slice of silicon nitride patterned with a grating consisting of slits 90 nanometres wide, forces the molecular beam into a coherent state, in which the matter waves are all in step. The second, a 'virtual grating' made from laser light formed by mirrors into a standing wave of light and dark, causes the interference pattern. The third grating, also of silicon nitride, acts as a mask to admit parts of the interference pattern to a quadrupole mass spectrometer, which counts the number of molecules that pass through.

The researchers report in Nature Communications today that this number rises and falls periodically as the outgoing beam is scanned from left to right, showing that interference, and therefore superposition, is present.

A very, very clever experiment, and it shows that if one can maintain coherence, size really doesn't matter in the manifestation of quantum effects.

Zz.

Geo-neutrinos

Looks like it's a day of neutrinos.

A very good summary on the search and study of geo-neutrinos in this month's issue of CERN Courier.

Geo-neutrinos are the (anti)neutrinos produced by the natural radioactivity inside the Earth. In particular, the decay chains of 238U and 232Th include six and four β− decays, respectively, and the nucleus of 40K decays by electron capture and β− decay with branching ratios of 11% and 89%, respectively. The decays produce heat and electron antineutrinos, with fixed ratios of heat to neutrinos (table 1). A measurement of the antineutrino flux, and possibly of the spectrum, would provide direct information on the amount and composition of radioactive material inside the Earth and so would determine the radiogenic contribution to the heat flow.

It's interesting that the article mentioned that the Earth emits mainly electron antineutrino, while the sun emits mainly electron neutrino. In light of the recent possible error in estimating the amount of electron antineutrino that is emitted from such nuclear reaction, I wonder if this makes the study of geo-neutrinos even more difficult. Or maybe the 3% difference doesn't matter.

Zz.

The Neglected Neutrinos

... or in this case, the uncounted for antineutrinos, but not on purpose.

It seems that neutrinos are still missing in one form or another. A new calculation has reported that we may have underestimated, by roughly 3%, the amount of antineutrinos generated out of nuclear power plants.

Experiments that measure the rate of antineutrino production from the decay of uranium and plutonium isotopes have so far produced results roughly consistent with this theory. But the revised calculation1 accepted this week by Physical Review D suggests that it's not the whole story. While waiting for the Double Chooz neutrino experiment in France to become fully operational, Thierry Lasserre and his colleagues at the French atomic energy commission(CEA) in Saclay set out to check predictions of the rate of antineutrino production by nuclear reactors. They repeated a calculation first done in the 1980s by Klaus Schreckenbach at the Technical University of Munich, using more modern techniques that allowed them to be much more precise.

Their new estimate of the rate of production is around 3% more than previously predicted. This means that several generations of neutrino and antineutrino experiments have unknowingly missed a small fraction of the particles. "It was completely a surprise for us," says Lasserre.

A possible mechanism for the non-detection of these antineutrinos could be the possible oscillation into "sterile" neutrinos.

The result may be pointing to evidence of neutrinos and antineutrinos oscillating into a fourth kind of neutrino or antineutrino, a so-called 'sterile' version that doesn't interact with ordinary matter, says Carlo Giunti, a physicist at the University of Turin in Italy. Other experiments have previously seen evidence for sterile particles, including the Liquid Scintillator Neutrino Detector at Los Alamos National Laboratory in New Mexico and the Mini Booster Neutrino Experiment, or MiniBooNE, at Fermilab in Batavia, Illinois, and the search to confirm their existence is a hot area of physics.

With several neutrino experiments going online soon, one would think that this would be something that might looked at. So stay tuned!

Zz.

Brainwashed By Newton?

It is very seldom that I read something and then say "Whoa! This person is writing exactly what I have been thinking of, or what I've been saying all along!" Maybe it is why I found this preprint so entertaining to read.

I don't know if this has been submitted anywhere for publication. It doesn't matter. It is still something that should be read. Z. K. Silagadze from the Budker Institute wrote a very illuminating (and, of course, entertaining) article on how our insistence on describing everything based on classical notion is probably the cause of a lot of misconception (and apparent trouble) of modern physics[1]. In particular, he picked the outdated idea of "relativistic mass", especially in the teaching of relativity.

The concept of mass in modern physics is quite different from the Newtonian concept of mass as a measure of inertia. However, this does not mean that we should throw out mass as a measure of inertia. Simply modern physics framework is more general and flexible and it explicitly indicates the context under which it is fairly safe to consider the mass as a measure of inertia. The problems begin when things are turned upside down and the Newtonian physics is considered as a basic truth and modern physics as some derivative from it. “Objectivity of Classical physics is some sort of half-truth. It is a very good thing, a very great achievement, but somehow it makes it more difficult than it would have seemed before to understand the fullness of reality”.

Note that this is of course consistent with previous papers that I've highlighted on here on this idea of "relativistic mass" and why it should no longer be used in such a fashion today. See the coverage on "Rest Mass Versus Relativistic Mass", "Einstein on Mass and Energy", and "The "Relavistic" Mug".

There are several things that he mentioned in that article that sounded as if *I* was writing it. So we certainly seem to share the same sentiment with regards to the continuing confusion of modern physics and the various terminologies used.

Maybe we are twins separated at birth! :)

Zz.

[1] http://arxiv.org/abs/1103.6281

Japan's Nuclear Crisis - Steven Chu Interview

Newsweek interviewed US Dept. of Energy Secretary, Steven Chu, on the aftermath of Japan's nuclear crisis. It didn't just cover his job, but also him being a physicist and still producing his own research work.

Last summer you wrote a paper called “Subnanometre Single-Molecule Localization Registration and Distance Measurements.” When asked about it, you said, “I consider it my equivalent of vegging out in front of the TV.”

The first 80 hours a week of my time go to my full-time job at the Department of Energy. But in the wee hours of the morning, on airplane trips, I can go back and forth. It doesn’t take much time, and it’s a good release.

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Physics World's "Superconductivity - The First 100 Years"

With the IoP celebrating the 100th Anniversary of the discovery of Superconductivity, Physics World has a special issue on the first 100 years of Superconductivity. You can receive a free copy of this issue by clicking on the link here. You will have to register with them first, though. Still, a small price to pay for getting a commemorative issue of this anniversary.

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150 Years of Maxwell Equations

We seem to have a lot of anniversaries in this year of 2011. I already mentioned of the 100 year anniversary of the discovery of superconductivity. There is also the Physical Review Landmark paper from 30 years ago of Alan Guth's expanding universe paper. It seems that we almost overlook another significant birthday, and that is the 150th anniversary of the beginning of the first "unification" idea of electricity and magnetism by James Clerk Maxwell.

To much fanfare, Italy celebrated 150 years since its unification two weeks ago. Less exuberantly, America is commemorating the 150th anniversary of the outbreak of the civil war, a failed attempt to undo its union. Amid this flurry of historical fissions and fusions it is easy to overlook another, arguably more significant unification set in motion in spring 1861. In March of that year James Clerk Maxwell, a Scottish physicist (pictured above), published the first piece of a four-part paper entitled "On physical lines of force". Sprinkled amid the prose in the Philosophical Magazine were equations which revealed electricity, magnetism and light to be different manifestations of the same phenomenon.

Read the entire article on why this is more than just an important event for the study of electromagnetic theory.

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Berkeley Earth Group First Data Analysis

I mentioned a while back about the Berkeley Earth Group's project that was headed by Richard Muller, that aims to collect an extensive amount of data on the Earth's global temperature. The project and the group are not without controversy (as is the case with something within the area). There are skepticism surrounding the effort, especially considering some of the sponsor of the project. Still, as I wrote in one of the blog entries, I'm still curious to see what they would have come up with.

Well, we now have an initial indication of what they are finding, and it happened during a "charged" congressional hearing on Earth's climate.

Let's just say that those who were hoping that Muller's project would debunk climate warming took a severe blow with this one.

There are two separate issues here that should be considered:

1. When you have different studies considering different things, and then they ALL came up with very consistent results (see the graph), it is very difficult not to be convinced of the validity of the conclusion. I'd like to see similar consistencies in results that led to various policies in politics, economics, social sciences, etc.

2. It is of course unfair to simply label Republicans in the US Congress as being "anti-science", or have very little regards for scientific opinions that are contrary to their own beliefs. However, when there is a pattern of disregard, starting from Presidential candidates past and present, and when you think a lawyer, an economist, and a professor in marketing can actually provide meaningful evidence (rather than persuasion) with regards to scientific policies, it is very difficult for me to overlook such a thing and fall into such unfair label for that party. The blatant disregard for the importance (both scientific and economic) of science funding with a catastrophic budget bill proposal simply reinforced such a view.

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Earth's Lumpy-Like-Play-Doh Gravity

Oh, this is not only informative, but also way cool!

The latest survey of earth's gravity done by the European Space Agency produces a picture that makes our home planet looks like a lumpy ball of Play-Doh! You can also link to the original report here.

I am guessing that this might be published somewhere, but I wish the report would indicate what the color scales mean in terms of actual quantity.

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Rivalry To Find The Higgs

Typically, when there's news about the rivalry to find the Higgs, we often see this rivalry between the LHC at CERN and the Tevatron at Fermilab. But in this case, it is the "internal rivalry" between two giant detectors at the LHC - ATLAS and CMS. The article describes the friendly rivalry between these two detector groups, and it also has a short video of it.

Be it a rivalry or not, both detectors need each other (and other detectors situated at the LHC) to verify what the other discovers. This is no different than the situation at the Tevatron with CDF and DZero. They may have a friendly rivalry, but in the end, one needs the other to validate discoveries and measurements. The rivalry serves to keep each other honest and on their toes, which is good for science.

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Interference Between Electric and Magnetic Concepts in Introductory Physics

I only had time to read this rather quickly, so I can't make any kind of intelligent remarks on it. But it is fascinating, mainly because I don't realize that such an "interference" could occur. I don't recall making that type of mistakes when I was an undergraduate, and I'm not claiming that I'm smart either!

The study looked at how students learning electrostatic and magnetostatics answered questions on electric field force and magnetic field force acting on a charge particle[1]. You'd be surprised that the understanding is non-commutative!

Abstract: We investigate student confusion of concepts of electric and magnetic force. At various times during a traditional university-level course, we administered a series of simple questions about the direction of force on a charged particle moving through either an electric or a magnetic field. We find that after electric force instruction but before magnetic force instruction most students answer electric force questions correctly, and we replicate well-known results that many students incorrectly answer that magnetic forces are in the same direction as the magnetic field. After magnetic force instruction, most students answer magnetic force questions correctly, but surprisingly many students incorrectly answer that electric forces are perpendicular to electric fields, as would happen if a student confused electric forces with magnetic forces. As a further indication of interference between electric and magnetic concepts, we also find that students’ responses depend on whether electric or magnetic force questions are posed first, and this effect depends on whether electric or magnetic force was most recently taught.

It's astonishing that some students can get that confused. I have to read the paper closer to see if they came up with a rational reason why it occurred.

If any of you teach intro E&M, do you see the same thing in your class?

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[1] T.M. Scaife and A.F. Heckler, Phys. Rev. ST Physics Ed. Research v.7, p.010104 (2011). You may obtain the paper for free here.

The Amazing World of Iron-Based Superconductivity

We all know that the cuprate superconductors continue to give condensed matter physicists fits even more than 20 years after its discovery. Now the iron-based superconductors look like another candidate to provide a lot of delicious puzzles for experimentalists and theorists alike to ponder upon for many years to come.

This wonderful article provides a comprehensive review of the progress in our understanding of the nature of superconductivity in this family of material since its discovery in January of 2008. Other than the topological insulator, the iron-based superconductor could be the hottest topic in condensed matter physics at this moment. The best part about it is that, the story is still unfolding, but at such a rapid rate. It seems as if almost every month (week?) that we see astonishing new results that boggle the mind. For physicists, this is what we became scientists for.

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LHC's Search For SUSY

I mentioned a news report a while back on the search for SUSY at the LHC, and the null results so far. We now have the published paper available, with a very nice commentary accompanying it. For someone who doesn't quite understand what "Supersymmetry" is, this is another article that might elucidate what it is, and why it is a big deal.

At the cost of predicting a whole set of new particles, SUSY provides a fix for a number of the standard model’s problems. For example, the standard model predicts a divergent value for corrections to the Higgs boson’s mass, but SUSY offers a way around this problem, provided the sparticles aren’t too heavy [4]. Another exciting possibility is that SUSY provides a way to unify the different forces coupling constants at very high energy. There is no a priori requirement that this must happen, but the potential unification of the electroweak and strong forces has an elegance that is tantalizing [5]. Many versions of SUSY have an extra conservation law that would prohibit the decay of the lightest SUSY particle. Not only would this particle become a dark matter candidate, but in this context SUSY can be used to provide both a full calculation of early universe physics and the dark matter relic density, a central problem in modern cosmology [6]. Finally, SUSY allows a possible connection to quantum gravity through superstring theory.

All that, and it might even clean your windows!

Still, we do live in a very exciting time, and the LHC will discover (if not already) new physics even if we don't find the Higgs or any SUSY's sparticles. Considering that no new particle colliders are in the books to being built, we will have to live with the LHC for quite a number of years from now.

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The Inflationary Universe

This is another Physical Review Focus Landmark article that highlights a historically-significant paper published in the Physical Review journals. This time, it is the landmark paper by Alan Guth that gave a significant push on the idea of an inflationary universe.

You should be able to get a copy of that important paper from the article, if you're so inclined.

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Mind The Pseudogap

If there is a sequel to "Beware of the Pseudogap", this would be it.

In the earlier paper, they reported observing two distinctive gaps for the cuprate superconductors - one that is associated with the superconducting gap, while the other is of a different nature and thus, competes with superconductivity. Finding the true nature of the pseudogap is extremely important, since it can be determined, once and for all, if this gap that exists above Tc, the critical temperature, has anything to do with superconducting mechanism at all - is it a precursor to superconductivity, or is it competing with it. This paper said yes to both.

Now comes another interesting report[1]. This time they studied the optimally-doped cuprate superconducting compound Bi2201 using three different techniques: ARPES, polar Kerr effect, and time-resolved reflectivity. What they discovered is quite interesting. They claim that the onset of T* (the pseudogap temperature) is a phase transition into a non-superconducting broken-symmetry state.

But then, what about the question on whether there are two distinctive gaps in the superconducting phase, as claimed in the earlier paper? This is what they have to say:

Below Tc, the nodal arc is gapped with a dwave–like structure suggestive of a dominantly superconducting origin (38). In contrast, in the antinodal region, rather than one order being dominant, or the two gaps of both orders adding in quadrature, the spectral function develops a complex structure with two energy scales below EF of mixed origin, a larger one being primarily associated with the pseudogap order and a smaller one with the superconducting order.

Fascinating! Essentially, they observe the same thing, i.e. two different gaps, albeit it in the antinodal region of the Brillouin zone. So there is some consistencies here with this respect.

I certainly don't doubt that more studies on this will be forthcoming. But at least now we can start to consider separating the two different origins of the gaps this amazingly-complex material.

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[1] R.-H. He et al., Science v.331, p.1579 (2011).

Smell Might Be A Quantum Physics Phenomenon

Fancy that!

I've heard of this idea before, but now it beginning to gain some traction a bit. I don't know how it will work out in the end, but in the mean time, it is nice to follow the progress on this idea.

This news article reports from the ongoing APS March Meeting in Dallas, TX, where the idea that our sense of smell might be explained using quantum mechanics.

Dr Horsfield's research centres on demonstrating how the vibration might be detected.

The idea is that an electron on one part of a protein may move, and arrive at another part lacking a quantum of vibrational energy.

"The electron starts at one end of the room, if you like, and it can only make it to the other end if it gives up energy to the molecule in the middle of the room," he explained.

"Once it's arrived, you say 'Aha! The fact that it's here means that somewhere beteween where it started and where it is now there's a molecule with the right vibrational frequency'."

This might be a good excuse for physics instructors to wake up sleepy students in the class while teaching the topic on quantum harmonic oscillator. Those Hermite polynomials might be responsible for all our smell senses! :)

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Traces of Radiation from Japan?

So I read this CNN news this morning about slightly higher radiation levels that could possibly come from Japan.

But, on a portion of its website dedicated to tracking such radiation, the Environmental Protection Agency noted Wednesday that these and other readings "show typical fluctuation in background radiation levels" and -- thus far -- "are far below levels of concern."

Sampling from a monitor in Colorado -- part of a national network of stations on the lookout for radioactivity -- detected miniscule amounts of iodine-131, a radioactive form of iodine, the state's public health and environmental department said Wednesday in a press release.

On the same day in Portland, Oregon, tiny quantities of iodine-131 were also detected by an Environmental Protection Agency air monitor, Oregon public health officials said.

Now, the physicist in me started asking "It's one thing to detect slightly higher-than-normal radiation, it is another to actually know the source of such radiation." How can one verify a statement that says ".. trace amounts of radioactive particles that have likely drifted about 5,000 miles from a quake and tsunami-damaged nuclear power plant in Japan.. " Is the detection of such iodine isotopes rather uncommon, so much so that their detection now can be plausibly linked to the nuclear accident in Japan? Can someone who is an expert in this field clarify this?

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Congressman Randy Hultgren Visits Fermilab

This is a video of a short speech by US Congressman Randy Hultgren when he visited Fermilab.

Hultgren is one of the large number of Freshman Republican Congressman who won the last election. He defeated the incumbent (and physicist) Bill Foster for the Illinois 14th District.

It is too bad that the video didn't carry the question-and-answer session. I'm sure there was a question on his support for the Republican-controlled Congressional budget proposal that severely cut money to the DOE Office of Science. None of what he has said in his speech in this video is consistent with the budget proposal. In fact, he made zero mention of the budget bill and how it could cause places such as Fermilab to have massive layoffs, furloughs, and even a premature shutdown of the Tevatron. I'd like to hear how he would spin this and still maintain that he supports science, and Fermilab in particular.



.... and people wonder why I seldom listen to political speeches.

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Metrology Overhaul

A fascinating article and a closer look at how we arrive at the various SI units and quantities that we have accepted for granted. It reports on the meeting to possibly overhaul the 7 SI units that we currently use.

Over the two days of the meeting, participants expressed varied opinions about the force and urgency of these reasons. One of the chief enthusiasts and instigators of the proposed changes is former BIPM director Terry Quinn, who also organized the meeting. "This is indeed an ambitious project," he said in his opening remarks. "If it is achieved, it will be the biggest change in metrology since the French Revolution."

Leading the way is the overhaul of our definition of a kilogram, which is still defined by an "object" rather than based on a fundamental constant. There certainly have been a ground swell to redefine this quantity.

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