Measurement of Electron Electric Dipole Using Solid State Experiment

Another example where the so-called "applied" physics field can make as fundamental of a contribution to physics knowledge as any other "pure" field.

A while back, a new and improved measurement of the electron dipole moment using beams of electrons reveals that there is still no internal structure to the electron. A new experiment has significantly improved the ability of a solid state experiment to measure the electron dipole moment.

The electron’s EDM must be collinear with its spin. Solid-state EDM searches, therefore, typically apply an electric field to a sample and try to measure the induced magnetic signal. Stephen Eckel and colleagues at Yale University in Connecticut perform such an experiment with Eu0.5Ba0.5TiO3, a ceramic with a high density of unpaired, unordered spins, and a sizable ferroelectric response. This means that an external electric field creates an even larger internal electric field for the spins. The authors place a sensitive magnetic pickup loop between two 12-mm-diameter, 1.7-mm-thick disks of Eu0.5Ba0.5TiO3 and apply a series of short electric field pulses to modulate the signal from the EDM and cancel out stray fields.

Eckel et al. conclude that if the EDM is nonzero, it cannot be greater than 6.05 x 10−25ecm. Compared with the best limit of 1.05 x 10−27ecm from atomic beam measurements, it may seem like a losing battle to continue with a solid-state approach, but the prospect of new materials and lower noise measurements motivates continued research.

With the discovery of the same physics for a magnetic monopole in the spin-glass system, possible discovery of skyrmions, and the recent discovery of Majorana fermions, condensed matter experiments are producing a lot of fundamental results that used to be the sole realm of particle physics. The myth that condensed matter physics does not produce "fundamental knowledge" should be thoroughly destroyed by now.

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Another Physicist In the US House of Representatives

Physicist Bill Foster won the seat to the US House of Representatives, beating incumbent Judy Biggert. He will be back in the House after losing his congressional seat 2 years ago.

I mentioned earlier if his talk at last year's TIPP conference on the life of a scientist in the US Congress. Here's a link to the power point document of that talk. Click on his talk titled "Applications of Analog Circuit Design to Life as a Scientist in the United States Congress".

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Edit 11/9/2012: More coverage on this can be found at PhysicsWorld.

Can We Predict Everything?

This is quite consistent with the very latest result from last week.

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"Ridges" In High-Energy Collisions

It looks like Ruffles potato chips are not the only ones that have ridges.

New results out of the CMS detector at the LHC seems to produce "ridge"-like structure in the collision data between proton-lead. This observation has been detected before.

The first data from proton–lead collisions at the Compact Muon Solenoid (CMS) experiment at the Large Hadron Collider (LHC) at CERN include a "ridge" structure in correlations between newly generated particles. According to theorists in the US, the ridge may represent a new form of matter known as a "colour glass condensate".

This is not the first time such correlations have been seen in collision remnants – in 2005, physicists working on the Relativistic Heavy-Ion Collider (RHIC) at Brookhaven National Laboratory in New York found that the particles generated in collisions of gold nuclei had a tendency to spread transversely from the beam at very small relative angles, close to zero. A similar correlation was seen in 2010 at CMS in proton–proton collisions and then later that year in lead–lead collisions.

Of course, as expected, theorists are already out in force presenting various scenarios to explain this phenomenon. We simply have to wait for more data to come in before we can make any kind of rational decision on this.

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Oliver Heaviside

This month's issue of Physics Today has a terrific brief biography of Oliver Heaviside. If you've studied physics, mathematical physics, or even electrical engineering, then you would have encountered and used the fruits of his labor.

In physics, there many many of these unsung heroes that do not get the public recognition that they should. It is only through articles such as this, and highlighting them in blogs such as this one, that these figures will at least be known to a few more people that have never heard of them.

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So Light Is A Particle In This Demo?

I love these videos coming out of JLab's Forstbite theater. They're hilarious and usually quite educational as well.

However, this time I think the "evidence" that they are using to show that light is a particle isn't that obvious.



Certainly their conclusion is correct that (i) no matter how bright (intense) the red laser is, it cannot activate the fluorescence and (ii) the green laser has a higher energy and thus, can cause the fluorescence, no matter how weak the intensity. However, all this does is show that the intensity does not correlate to the energy.

Now, if one understands the photoelectric effect picture and the Einstein's model, then one can see that this is ONE aspect of that model, which points to the photon picture. But this is just ONE aspect of the model. By itself, it isn't obvious from this experiment that light is a particle.

I think experiments such as the which-way experiment are the ones that would have a more solid claim of showing that light is a particle.

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The Case Against Cold Fusion

If there ever is a blog article that has compiled an amazing history of Cold Fusion, this one could be it. Jennifer Ouellette at Cocktail Physics has updated an article on this topic due to a new film called "The Believers". This article is full of other links and references that you might also want to read, and it also includes description and comments on the effort to separate "cold fusion" from low-energy nuclear reaction (LENR).

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E=mc^2 Is Incomplete

I wonder if people who do not study physics actually realize that the actual equation has another term in it?



I lost count how many times someone has told me that since E=mc^2, and photon has energy, then it MUST have mass!

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The Beginning and End of the Universe

If you have 1 hr and 10 minutes to spare, you might want to watch/listen to this video (you can play it in the background - there's not that much to see). Especially if you are a layman and want to know what physics says about the topic, this video will be of interest to you.



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Single-Pixel Digital Ghost Holography

Hey, just in time for the Halloween season, we see this paper being published in PRA.

Holographic imaging is typically done by splitting a laser beam in two, shining one beam on an object and then letting that modified light interfere with a reference beam that does not hit the object. The recorded interference pattern can be read out with another laser to form a three-dimensional real image. By using multipixel electronic cameras rather than photographic film, researchers can computationally analyze and process the data for better effect. Clemente et al. modify this setup for ghost imaging by replacing the camera with a single-pixel detector (as conventionally used in ghost imaging) by using a randomly structured optical beam and scanning for a set of discrete phase shifts in the reference beam (that is, the beam not directly influenced by the object).

Just don't do this while wearing you ghoulish costumes.

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More Evidence of No Hidden Variables

The idea of quantum and contextuality is being tested in this latest report.[1]

The experimental setup and techniques are simple, elegant, and quite well controlled. The research group had little room for error, since the discrepancy between the classical bound (or inequality) imposed by the Yu-Oh formulation of SIC and the value predicted by quantum mechanics is tiny (only about 4%). Despite unavoidable experimental uncertainties, the measurements by Zu et al. violated the classical bound (thus ruling out noncontextuality) by about 5 standard deviations, irrespective of the prepared system’s state. This statistically significant result sets a very good benchmark for experimental SIC with a single quantum system.

Of course, if you read further, it doesn't rule out all of the classical noncontextuality due to the nagging problem with many photon systems - the detection loophole. Still, if you go by the body of evidence, the QM scenario has shown perfect agreement with experiments so far.

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[1] C. Zu, Y-X. et al., Phys. Rev. Lett. 109, 150401 (2012).

Using Muons From Cosmic Rays To Peek Into Fukushima?

What a clever idea!

A PRL paper published last week[1] had an interesting proposal. Use muons generated in the upper atmosphere due to cosmic ray collisions to peek into the Fukushima reactors.

To radiograph inaccessible parts of Fukushima reactors, Borozdin et al. propose a similar approach based on muon detectors placed right outside the reactor building. The authors compared two imaging methods: attenuation radiography, which measures how muons are absorbed inside the reactor, and scattering radiography, which monitors how their path is deviated. They show that scattering radiography would deliver more reliable images of the nuclear core after only a few weeks of measurement, allowing the visualization of melted fuel as well as debris.

That report has a link to the PRL paper that you can get under the Creative Commons license.

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[1]K. Borozdin et al.,Phys. Rev. Lett. 109, 152501 (2012).

Is This What It Looks Like To "Learn" Quantum Physics?

When I first saw this piece, I didn't want to comment on this because, frankly, it's one of the most ridiculous, irrelevant, and inaccurate report that I've ever seen. But I couldn't help myself. So here it is.

This Gizmodo article highlights some "art", or photography snapshot of blackboards that supposedly show how it looks like when one "learns" quantum physics. The photos show various shots of messy, jumbled up scribbles all over the place. There was no explanation anywhere on where exactly these were taken, or under what circumstances (was it after a class, was it after two people discussing something, was it in someone's office?).

I will tell you why I consider this to be utterly ridiculous and irrelevant:

1. Everyone who does physics knows that we tend to have either blackboards or whiteboards in our offices. I have one. It is used quite a lot. In fact, we have white boards along the hallways of our offices. Frequently, when we talk and discuss things, we go to one of such boards to either illustrate our ideas, or work something out. Inevitably, after this is done many, many times, the board looks very much like the mess you see in those photos. It has nothing to do with learning quantum physics. It has everything to do with performing one's job. This is not philosophy where esoteric ideas are thrown out verbally. Physics (and sciences in general), mathematics, and engineering all require visual illustrations and descriptions. Any kind of discussion inevitably will require writing down something, be it a piece of paper, a board, or a cocktail napkin!

2. The point where these scribbles are indecipherable seems to imply that this is unique to physics, or to learning quantum physics. Nonsense! Put a bunch of musical notes on the board. I'm musically illiterate, and they might as well be a bunch of gooblygook. So why would a bunch of mathematical symbols be any different? This is not unique to physics. Look at something that you are not an expert in, and you should EXPECT to see a bunch of things that you don't understand. Is this that difficult to comprehend?

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Does The US Really Not Have Enough Skilled Workers?

This is a topic that is related to something that was talked about in the last presidential debate between Barack Obama and Mitt Romney. The moderator asked whether jobs in assembling electronics such as iPhone, iPad, etc. can be brought back to the US. You may read the responses on your own from that news link.

However, later on in the news article, this issue came up about the lack of industrial engineers in the US as one reason Steve Jobs gave for being unable to have such manufacturing jobs in the US.

There's another catch, and it's one that politicians don't like to talk about: China has many more skilled engineers than the United States does.

Steve Jobs, Apple's late CEO, brought the issue up during an October 2010 meeting with President Obama. He called America's lackluster education system an obstacle for Apple, which needed 30,000 industrial engineers to support its on-site factory workers.

"You can't find that many in America to hire," Jobs told the president, according to his biographer, Walter Isaacson. "If you could educate these engineers, we could move more manufacturing plants here."

Now this is interesting in the sense of timing, because last week, Science journal website published an interesting review of a book at attacks such a point of view and put the blame squarely on the industries that complained on such lack of expertise. The book is titled: "Why Good People Can't Get Jobs: The Skills Gap and What Companies Can Do About It." It was written by Peter Cappelli, a professor of management and director of the Wharton School’s Center for Human Resources at the University of Pennsylvania.

That's because the book resolves the vexing conundrum of how two conflicting narratives about high-skilled employment have coexisted in our national conversation. On the one hand, countless unemployed or underemployed workers with perfectly good skills, education, and experience are struggling through a severe job drought, many sending out hundreds of applications and resumes to no avail. On the other hand, employers (especially in technical fields) complain of great difficulty finding workers, citing serious gaps between the requirements of available jobs and the skills of the workforce. One company that Cappelli mentions didn’t find a single worker that it considered qualified among 25,000 applicants for a fairly ordinary engineering job. Employers and their organizations fault an inadequate school system that fails to prepare Americans and restrictive immigration laws that prevent employers from importing the skilled workers they need from abroad.

He wrote in particular about companies getting "lazy" in trying to not only hire someone with a potential to do an amazing job, but also the lack of patience in recruiting someone and providing adequate training.

The main reason that companies aren’t finding the workers they seek in an ocean of available ability, Cappelli believes, is that in recent decades, for reasons he explains, those companies have allowed their traditional human resources (HR) departments and training programs to atrophy. Another reason is that some complaining companies simply offer too little money to attract the people they want.

The current lack of adequately staffed HR departments, and companies’ refusal to teach workers on the job, have combined to produce what the book terms “a Home Depot view of the hiring process, in which filling a job vacancy is seen as akin to replacing a part in a washing machine. … Like a replacement part, job requirements have very precise specifications. Job candidates must fit them perfectly or the job won’t be filled.”

There's more, so you should either read the entire article, or get the book (which I intend to do). Now, wouldn't it be more interesting if reporters (or debate moderators) actually do their homework and read about these things way ahead of time before they ask politicians and CEOs such questions? I would love to hear these CEOs try to respond to what has been brought up in this book.

Interestingly enough, what industries seem to tend not want to do, those in Academia continue to practice such things. We seldom get postdocs who are completely compatible with the skills that we are looking for. So it is a given that we try to nurture and train them with new skills, so much so they become experts in those areas by the time they are done. This is one clear example on why certain organizations should  not be run like a business!

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Angry Birds Bumps With CERN

So I don't have any clue on what would be the outcome of such a "marriage". Still, it appears that Rovio, the makers of the wildly-popular Angry Birds (and Angry Pigs) games are teaming up with CERN to come up with some educational games.

Rovio told TechCrunch the collaboration will involve co-producing learning support materials with CERN — including, initially, books and a board game. More products will be added later, the company said. We’ve also reached out to CERN to ask for more details and will update with any response.

“Modern physics has been around for 100 years, but it’s still a mystery to many people. Working together with Rovio, we can teach kids quantum physics by making it fun and easy to understand,” said CERN’s Head of Education, Rolf Landua, speaking at the Frankfurt Book Fair where the Rovio launch took place.

 Er... ok. I am certainly curious to see what they come up with. Angry photons smashing into fat, lazy quarks?

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The Origin Of Quantum Physics

Another educational and entertaining video. This time, on the origin of quantum physics.



And to think that it all started by a light bulb!

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Felix Baumgartner's Supersonic Speed

Not that this is a puzzle, but here's a simple explanation on how Felix Baumgartner's achived a supersonic speed during his free fall.

I still think this is a crazy thing to do. Fascinating, sure, but still, CRAZY! :)

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No Supersolid In New Experiment

OK, there are two separate issues here.

First, a new experiment, done by the person responsible for the first announcement of the possible discovery of supersolid, has now shown no evidence for that.

Many other theoretical and experimental results finally convinced Chan to redo the experiments. With postdoctoral researcher Duk Kim, he completely redesigned the torsional oscillator, taking every precaution to eliminate space for elastic helium. This time, the changes in oscillation previously attributed to a supersolid state were completely absent.

Chan realizes that this almost closes the book on supersolid helium. ”I’m in an awkward position, since we started the whole damn thing,” says Chan. “But I’m glad we were the ones who found the explanation.” Beamish agrees that these are extremely subtle effects, which is why it took so long to sort them out: “I give Moses the greatest credit for all the years he spent trying to find out what it was, rather than trying to prove it was what he said it was.” He also notes that the hunt for supersolids actually seeded new research on what has become known as quantum plasticity—the tendency of a material to deform macroscopically based on its quantum properties.

Which brings me to my second issue here of the utmost respect we all should have to Moses Chan for illustrating what a true scientist should do when faced with a contradicting evidence. Here is a person who received quite a coverage and reception when the first supersolid discovery was announced. Yet, he continues to investigate the effects in light of the responses he got, and now, after redoing the experiment and found that his original conclusion was wrong, he went ahead and published it! (Taleyarkhan, are you paying attention to all this?)

Have any religious leaders nowadays done such a thing? And yet, there are still people out there who insist that science is a religion?

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Wineland and Haroche's PRL Papers

On the heels of AIP's free listing of the papers by this year's Physics Nobel Prize winners, the APS is making available for free the papers by these two authors that were published in PRL.

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Physics That You Already Know

Another good video.



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AIP Papers By This Year's Nobel Prize Winners

The AIP has generously provided a list of papers from their journals that were authored/coauthor end by this year' physics Nobel prize winners. I think you get all, if not most, of the papers for free.

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2012 Physics Nobel Prizes

This one certainly came out of nowhere.

The 2012 Nobel Prize for Physics has been awarded to Serge Haroche and David Wineland.

The Nobel citation said the award was for "ground-breaking experimental methods that enable measuring and manipulation of individual quantum systems".

... which is rather vague!

The Nobel website does have a more in-depth description of it for the laymen.

Still waiting for a woman to win the Physics Nobel Prize in my lifetime.

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Work Function And Photoemission Threshold

It is no secret to anyone who has read this blog for a while that I do not like Wikipedia. I think that there's a fundamental flaw with the whole concept and philosophy of it. While I think that it may be useful to many who need a quick lookup for something, it is unfortunate that even more are using it almost as their primary source of information. And this is scary considering that (i) the validity of the information being presented is never guaranteed and (ii) the pedagogical presentation of the material is often shoddy, making the subject even more confusing.

I often get asked to look at such-and-such Wikipedia entry, or someone is trying to convince me of something and using a Wikipedia entry as a "reference" to back up his/her argument. It is usually during such instances that I find inaccuracies, confusing statements, and something outright errors in such entries. I was doing my own search on something a few minutes ago, and I decided, out of curiosity, to see what Wikipedia has to say about "Work Function". Now, keep in mind that this is a common terminology, especially for physics students, since the photoelectric effect is a "must-know" topic for these students. One would think that this should be a topic that a Wikipedia entry would get it right, considering how many people would look up such a thing, AND, the fact that errors and inaccuracy would, by now, be ironed out.

WRONG!

This is what I saw on the Wikipedia page TODAY.

I posted today's date in the screen capture as a date stamp on when this was viewed.

The offending passage has been highlighted with a red box. Let's look at it closely, shall we?

The description here is on what happened for an insulator (or a semiconductor, for that matter). The figure shown is the simplified band diagram for such a system (i.e. an intrinsic semiconductor, for example), and defines the various quantities such as the work function, band gap, electron affinity, etc. The problematic statement says this:

For an insulator, the Fermi level lies within the band gap, indicating an empty conduction band; in this case, the minimum energy to remove an electron is about the sum of half the band gap and the electron affinity.

 The first part of that paragraph which says ".... For an insulator, the Fermi level lies within the band gap, indicating an empty conduction band ..." is OK. However, the second part is very puzzling and an outright error : "... in this case, the minimum energy to remove an electron is about the sum of half the band gap and the electron affinity ..."

Whoever wrote this is STILL thinking that the work function (Phi) is still the minimum energy needed to produce photoemission, as in the case of a metal. This is FALSE, and anyone who looks at the band diagram can tell. Half of the band gap plus the electron affinity is the work function Phi, but this is the energy between the vacuum level and the Fermi level. The Fermi level for insulator/semiconductor has NO STATES, and thus, no electrons to excite! After all, it resides in the band gap! So what is being excited here?

For an insulator/semiconductor, while the work function may still be defined as the energy between the Fermi level and the vacuum level, it no longer corresponds to the photoemission threshold! The photoemission threshold now is the full band gap energy PLUS the electron affinity. You need to excite, at the minimum, the electrons from the top of the valence band to the vacuum level. One can see this clearly by looking at the band diagram in the figure.

I hope no one was using on this Wikipedia entry for something useful or important.

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Real World Telekinesis

Despite the title, there's nothing "supernatural" about this video, and it might be useful for someone who just want some simple intro to electromagnetic field.



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"It Is Not Acceptable To Promote Bad Science"

This is a wonderful video of Brian Cox that you should sit down and spend some time watching and listening.



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From A Gymnast To A Physicist

Can't make it as a work class gymnast due to health issues? Why, study to be a physicist instead!



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The Standard Model

Here's an informative video for the general public on the Standard Model of elementary particle.



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First Images Of Landau Levels

Ok, I didn't realize that we haven't had a measurement of such landau levels till now. It appears that this has finally been imaged.

Using scanning tunnelling spectroscopy - a spatially resolved probe that interacts directly with the electrons - scientists at institutions including the University of Warwick and Tohoku University have revealed the internal ring-like structure of these Landau Levels at the surface of a semiconductor.

What is also interesting that this could tie in to the standard definition of a kilogram.

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The Physics Of Fittness - Getting It Not Quite Right

I'm always happy to see when physics is explicitly mentioned as being involved in many of our daily routine. Many of us know this in the back of our heads, but it is always educational when it is mentioned explicitly, especially to laymen, so that they are aware that physics isn't just something one deals in school.

Unfortunately, while the intention is good, the application of various physics principles can often be rather dubious, or filled with errors and misunderstanding. I have been known to nitpick (I fully admit that) stuff like this, not because I like to nitpick, but I think things can be done a lot better and clearer without having to resort to such errors.

This article is one prime example, where they could have gotten it right rather easily, but didn't. I suspect that there is a bit of unclear understanding of simple basic physics here, The writer is trying to point out how the 3 Newton Laws are at work in a fitness routine. Let's go over some of the puzzling aspect of this article.

The first law of motion dictates that an object at rest will stay at rest, and an object in motion will stay in motion. I use this for mental motivation and often say, a person on the couch tends to sit on the couch… but a person who gets up and moves around will keep moving around. An exercise example is the bicep curl. Until your biceps contract to pick up the weight it’s at rest, and gravity constantly tries to pull it back to  rest on the ground.

Right off the bat, the first law is stated in a rather incomplete form. The object will stay at rest, or will remain in motion unless there is a net force acting on that object. This is rather important omission. Furthermore, the object in motion will stay in motion with a constant velocity. The example given in this paragraph of " .... a person who gets up and moves around will keep moving around... " isn't quite accurate because we don't just move in a straight line with constant speed! Not only that, the example given with the bicep curl is a bit confusing. If you stop moving somewhere in the middle of your bicep curl and remain still, you are not doing any work mechanically, but your muscles are certainly doing work and burning calories to maintain that position. The "rest" position isn't just the weight resting on the ground!

Newton's second law of motion states that force equals mass times acceleration. A good example of this when exercising is illustrated when you perform a bench press. The amount of weight you can lift is directly related to the amount of force exerted on the weights by your muscles. Increasing the weight requires more force to lift it. Also, doing reps faster (increasing acceleration) requires more force to be exerted.

This is confusing because of the way it is stated. "The amount of weight you can lift is directly related to the amount of force exerted on the weights by your muscles." What should have been stated here is that the minimum amount of force one must exert to lift the weight must be equal to the weight itself (here, I'm using the term "weight" to mean W = mg, so this is where Newton's 2nd law comes in). The way the statement is stated, it is more related to the 3rd law, which comes next. The last part of the paragraph also has more relevance to the 2nd law than what was stated in the beginning of the paragraph. However, does lifting the weight faster a better way to build muscles? I've read many fitness instructions that insisted that one lift weights slowly and deliberately to really "push" the muscles involved.

When your foot hits the road (or treadmill) you apply a force to the ground, which responds with an equal and opposite force, helping to propel you forward. As you speed up, either the length of your stride or how frequently your foot hits the ground increases. Working to improve your running stride can help make every run feel less taxing, increasing both the speed and distance you can cover.

Again, this illustration of Newton's 3rd law is confusing. What propels you forward is friction, not the equal and opposite force that is the result of the force you apply to the ground. The equal and opposite force here means that you don't crash through the road or your treadmill. Rather, this is where the weight lifting example in the previous paragraph would have been more relevant.

The writer than has more confusing article on other issues of biomechanics.

Stability
The biomechanics of stability, the less an object’s surface area touches a solid base, the less stable that object is. Applying this basic principle into exercises makes our whole body work harder, meaning a higher calorie burn, plus a more challenged core.

Try This: Make any strength move more challenging by narrowing your base (bringing your hands closer together during pushups or feet closer together during squats), removing a point of support (doing single-leg dead lifts or planks with arm raises), or replacing your sturdy surface with a wobbly one (placing your hands on a stability ball during planks and pushups, or stepping onto a BOSU trainer during lunges).

Now, by bringing your hands closer together during the pushups, or your feet closer during squats, you have not changed the surface area between you, and the object in question (the ground), has it? After all, the contact surface area (your hands, or your feet) has not changed. Only the separation between your hands or your feet is the one that has changed. So the principle involved does not match the example. I'm not saying that the stability hasn't changed in those cases, but the reason why one scenario is more stable than the other doesn't match the explanation or principle given.

The lack of the subtle understanding of these basic physics concepts is what separates between a superficial knowledge of physics versus a deeper understanding of it. We hope that students that have gone through at least an undergraduate/intro level physics classes in college can acquire the latter and spot the differences in such subtle understanding.

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"String theory: big problem for small size"

This paper is an "intro" to String Theory. Well, at least that's what the paper claims.

Now, don't think you actually will learn much from it, because String Theory is highly mathematical, and this paper doesn't even present much, if any, of the theory. All it does is present a superficial argument for String Theory. So in that sense, this is as good of an intro to laymen as any. You'll get some general idea on what String theory is, but nothing substantial beyond that. I won't be surprised if, after reading this, you end up with more questions than you started with.

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More Evidence On Majorana Fermions

On the heels of the possible discovery of Majorana fermions earlier this year, along comes more evidence of their discovery, and this time, they came from a Josephson experiment.

Rokhinson observed a variation of the Josephson effect that is a unique signature of Majorana fermions. The effect describes the way an electrical current traveling between two superconductors oscillates at a frequency that depends on the applied voltage. The reverse also is true; an oscillating current generates specific voltage, proportional to the frequency. In the presence of Majorana fermions the frequency-voltage relationship should change by a factor of two in what is called the fractional a.c. Josephson effect, he said.

Rokhinson used a one-dimensional semiconductor coupled to a superconductor to create a hybrid nanowire in which Majorana particles are predicted to form at the ends. When alternating current is applied through a set of two such wires, a specific voltage is generated across the device, which Rokhinson measured. As a magnetic field was applied and varied from weak to strong, the resulting steps in voltage became twice as tall, a signature of the formation of Majorana particles, he said.

There ya go! So far, in the race to detect the existence of the Majorana particles, it is two for condensed matter physics, and zero for high energy physics.

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The Chemistry Of Cleaning

Yes, cleaning! Enough with the Higgs, and the Dark Energy, and the pnictide superconductivity. Let's get dirty and learn about the physics and chemistry of cleaning!

This brief overview actually came from a janitorial service company, but it has a nice article on the chemistry of cleaning, with lots of external links if people care to read more. It's one of those things that we use and encounter each day, but for many of us, we don't give a second thought on how or why it works. So wash your hands (with soap), sit down, and learn what you just did.

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What Is the Smallest Number Of Water Molecules Needed To Make Ice?

Answer: around 275.

This is a neat work that tries to answer that very question, and actually got the answer.

Zeuch and colleagues obtained infrared spectra for cluster sizes ranging from 85 to 475 molecules. As expected, there was a shift in the spectrum maxima towards lower wavenumbers as cluster size increased. The transition from 3400 to 3200 cm^–1 began at around 275 molecules, with the first crystalline ice occurring in the centre of the cluster, forming a ring of six hydrogen-bonded water molecules in a tetrahedral configuration.

As the cluster size increased further, the crystalline core gradually grew. By 475 molecules, the infrared spectrum was dominated by the ice structure: the formation of the ice crystal was all but complete. This behaviour matched theoretical predictions made by a different group of researchers in 2004.

You may read the rest of the article on the important implication of this work, especially in understanding ice nucleation.

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Nobel Prize For The Higgs? Maybe Not This Year

As always, come this time of the year, everyone (including me) starts making their own guesses on who will receive this year's Nobel Prize for physics. This year, the most obvious topic is the apparent discovery of the Higgs. However, I think this is way too new and requires more confirmation, and I think the others also see it that way.

In this year's predictions, "it's too early for the Higgs boson team," Pendlebury says, despite the attention paid to the "God particle," first predicted in the 1960's. Two large teams at CERN's Large Hadron Collider facility reported a "Higgs-like" particle in their data this year, making the Higgs boson's theorists look like Nobelists-in-waiting. The Higgs boson is a subatomic particle that provides mass to other physics particles in our current understanding of how matter behaves on the most fundamental level.

Instead, the prediction this year (of which they don't have a good track record of getting it right) seems to match mine to some degree:

Instead "quantum teleportation" inventors Charles Bennett, Gilles Brassard and William Wooters, or light-speed-slowing pioneers Stephen Harris and Lene Hau, look more like winners for the physics prize, he says. Those phenomena have been experimentally validated in recent years, while the CERN results are still new, with that lab calling their discovery "Higgs-like" in their announcement, hedging their bets for further tests to verify the find.

As far back as 2007, I've predicted that Lene Hau (and Deborah Jin of NIST) should win the Nobel Prize. It certainly would make the news since we haven't had a woman winning the physics Nobel Prize in such a very long time!

Zz.

Will Biology, Astronomy, And Physics Rule Out God?

More arguments on this very topic, and this appears to be a continuation of what Sean Carroll had stated earlier. So I'll let you read the article for yourself.

The one part that I think worth highlighting is towards the end:

Judged by the standards of any other scientific theory, the "God hypothesis" does not do very well, Carroll argues. But he grants that "the idea of God has functions other than those of a scientific hypothesis."

And I think, this is where a lot of the misunderstanding between both sides of the fence occurs. Those outside of science (theologians) appears to not realize that to counter a scientific argument, one must use another scientific argument. Simply arguing that such-and-such must surely point to the existence of "god", without offering evidence (rather than not being able to falsify it) simply isn't convincing, nor can it be used as an evidence. The "god of the gaps" should no longer be used at this point, because history has shown that these gaps continue to diminish over time!

Certainly a thought-provoking article.

Zz.

Paper or Electronic?

Do you remember being asked, when you are checking out at a grocery store, whether you want "paper or plastic"? (I'm guessing that this is probably unique to those in the US.) Well now, I'm asking you a similar question, but with some differences. This time, it is where you use paper or electronic, and you're not checking out at a grocery store, but rather you are in your laboratory.

This question came up because of an article last week on whether one still uses the old-fashioned lab notebook, or if one has moved on to an electronic notebook. For me personally, I still prefer the old-fashon paper notebook. I'm sure if I'm at a very large facility where dozens of people are working on it, and requires some sort of shared knowledge of the experiment, an electronic notebook would probably be more sensible. However, for small-scale experiments, I see the regular lab notebook as being more convenient and with very little fuss. Even though the collected data are in electronic form, as stated in the article, I only have to write down the file name to make a reference to it, or any other electronic files that I want to include in the lab book.

The only thing that I can see happening for me is the migration to make such note using a tablet such as an iPad. Considering that one can have the ability to do both handwriting and typing on such a device, making quick sketches or writing notes the same way one would do on a regular notebook might be the bridge between the old and the new.

So, do you still use the old-fashioned paper lab notebook, or have you migrated entirely into the electronic age?

Zz.

NOVA's "Making Stuff: Stronger"

If you are in the US or have access to PBS, this might be of interest to you.

The first part of a 4-part NOVA "Making Stuff" series will air tomorrow (Sept. 19, 2012). The first installment will be on the strongest material.

What is the strongest material in the world? Is it steel, Kevlar, carbon nanotubes, or something entirely new? NOVA kicks off the four-part series "Making Stuff" with a quest for the world's strongest substances. Host David Pogue takes a look at what defines strength, examining everything from steel cables to mollusk shells to a toucan's beak. Pogue travels from the deck of a U.S. naval aircraft carrier to a demolition derby to the country's top research labs to check in with experts who are re-engineering what nature has given us to create the next generation of strong stuff.

Zz.

How to Measure the Width of a Hair With a Laser!

Those folks at JLab are at it again. This time, they use a simple laser pointer to measure the width of a hair.



This is a fun project and suitable for high school classes.

Zz.

Vacation

I'm on vacation. I hope nothing important happens while I'm gone. :)

Zz.

Job Advertisements For Theorists and Experimentalists In Physics Today Apr-Aug 2012

Continuing with my survey of the physics jobs advertisements in Physics Today, here are the statistics that includes the Aug 2012 issue.

1. Number of jobs looking only for experimentalist = 43
2. Number of jobs looking only for theorist = 14
3. Number of jobs looking for either or both =31

The ratio of jobs seeking experimentalists only to the jobs seeking theorists only is still above 3.

Zz.

Theoretical Physics is NOT Always Esoteric!

This is another example where people think "theoretical physics" deals only in some esoteric, non-applicable physics such as elementary particles, high energy physics, etc.. etc. And unfortunately, people that were interviewed in this article didn't help much to kill the misconception!

"We're not going to see dark matter in Starbucks anytime soon," laughs Tim Meyer, head of Strategic Planning & Communications, adding it's okay to wonder if theoretical physics has practical uses.

Oy vey.

I've already made my reply to correct this misconception in another blog entry on people wanting to do "theoretical physics" but not realizing that that statement actually is rather vague. I think physicists should be quick to correct such misconception, because not only does it harm our field (i.e. a lot of theoretical physics HAVE direct implications to our everyday lives, AND have direct uses!), it also insults many theorists who are working on areas that have practical applications, which, the last time I checked, outnumbered those working in the esoteric fields.

We can correct things a little at a time, which is why we shouldn't miss such opportunities when they appear.

Zz.

A Tale Of 3 Photons

Not exactly similar to the 3 Wise Men, but these 3 photons could cause serious implications for many theoretical models that attempt to merge gravity and quantum field together.

Supposedly, the 3 gamma photons came from a gamma-ray burst, and were detected by the Fermi telescope within a millisecond of each other after traveling all that distance. The implication here is that if space isn't smooth, but rather quantized at the Planck scale, this "foam" would have affected how quickly photons can travel over some distance, and will be more apparent as the distance goes larger. The closeness of the time of arrival for these 3 photons appears to set the graininess of space, if any, at a scale lower than the Planck scale, which would ruffle the feathers of a lot of theorists.

Robert Nemiroff, an astrophysicist at Michigan Technological University, and colleagues recently took a look at data from a gamma-ray burst detected by the Fermi telescope in May 2009.

"Originally we were looking for something else, but were struck when two of the highest energy photons from this detected gamma-ray burst appeared within a single millisecond," Nemiroff told Life's Little Mysteries. When the physicists looked at the data more closely, they found a third gamma ray photon within a millisecond of the other two.

Computer models showed it was very unlikely that the photons would have been emitted by different gamma ray bursts, or the same burst at different times. Consequently, "it seemed very likely to us that these three photons traveled across much of the universe together without dispersing," Nemiroff said. Despite having slightly different energies (and thus, different wavelengths), the three photons stayed in extremely close company for the duration of their marathon trek to Earth.

Many things — e.g. stars, interstellar dust — could have dispersed the photons. "But nothing that we know can undisperse gamma-ray photons," Nemiroff said. "So we then conclude that these photons were not dispersed. So if they were not dispersed, then the universe left them alone. So if the universe was made of Planck-scale quantum foam, according to some theories, it would not have left these photons alone. So those types of Planck-scale quantum foams don't exist."

Oh, here's the reference to the PRL paper:

R.J. Nemiroff et al., Phys. Rev. Lett. 108, 231103 (2012).

Now, I could have sworn that a while back, I read a theoretical paper somewhere which indicated that photons traveling through such quantum foam may not show any change in travel time. Since the slowing down and speeding up over a Planck scale is random, after a while, the randomness washes out and the speed remains the same over very large distances. I can't seem to find that paper right now, but essentially, the result reported in this observation doesn't really rule out the existence of such quantum foam.... at least, not yet anyway.

Zz.

"Sticky physics of joy: On the dissolution of spherical candies"

Anyone reading this blog for any considerable period of time would know that I love reading or solving "mundane" problems. This one might barely qualify as one, I think. The authors are studying the "dissolution" of spherical-shaped candies.

Abstract: Assuming a constant mass-decrease per unit-surface and -time we provide a very simplistic model for the dissolution process of spherical candies. The aim is to investigate the quantitative behavior of the dissolution process throughout the act of eating the candy. In our model we do not take any microscopic mechanism of the dissolution process into account, but rather provide an estimate which is based on easy-to-follow calculations. Having obtained a description based on this calculation, we confirm the assumed behavior by providing experimental data of the dissolution process. Besides a deviation from our prediction caused by the production process of the candies below a diameter of 2 mm, we find good agreement with our model-based expectations. Serious questions on the optimal strategy of enjoying a candy will be addressed, like whether it is wise to split the candy by breaking it with the teeth or not.

In any case, I have to admit that I was snickering almost throughout the entire paper, especially the conclusion.

Finally we would like to address the question proposed in the very beginning of this study: What is the best strategy of eating such a candy? As so often, the answer depends on what the person enjoying the candy considers as the optimum. If the time the candy lives should be maximized, the eater of the candy should try to maintain the spherical shape of the candy by all costs. Since the e ect of mass transfer is driven by the surface, and the sphere possesses the smallest surface for a given volume among all possible shapes [5], any deviation of the spherical shape increases the process of losing mass. In particular, breaking the candy with the teeth enlarges the surface by a huge amount, making the candy vanish faster. Thus, from this point of view one should carefully try to keep the candy as spherical as possible. But there is another way to look at it: Suppose you break the candy with your teeth in many pieces. The surface becomes big, and in an instant the mass that is transferred away from the fragments becomes huge as well. This might amplify the effect of tastiness and joy, even though the life-time of the candy has become considerably short in this approach. Even though we now know how candies dissolve in time we stress that the best thing to do when eating a candy is to forget about these considerations, since they draw your attention away from what candies are made for: enjoyment.

C'mon, now. How could you not giggle when reading something like that in a physics paper? I'm only human! :)

I wouldn't be surprised if this gets nominated or even win the Ig Nobel Prize.

Zz.

Scaled-Down LBNE

After the full-blown LBNE was rejected by US DOE, Fermilab's official submitted a scaled-down version of LBNE to full review.

Kim presented the new plan for the first stage of LBNE. The preferred option calls for building a new beam line at Fermilab to fire neutrinos 1300 kilometers through Earth to a particle detector on the surface at the abandoned Homestake gold mine in Lead, South Dakota. That detector would contain 10,000 tonnes of frigid liquid argon. (The original LBNE design called for a larger, 34,000-tonne detector buried 1480 meters deep in Homestake and a smaller "near detector" at Fermilab.)

Let's see if this thing will fly, AND, with the $135 million from international collaborators.

Zz.

Rolling In The Higgs

OK, other than a bit of bad singing, this is utterly hysterical!

This is an a capella version of Adelle's "Rolling in the Deep", but with a tribute to the Higgs. This was done by "... 22-year old singer/arranger and theoretical physics masters student Tim Blair.. "



I wouldn't be surprised if this things goes viral, if it hasn't done so already.

BTW, this video is even funnier if you understand a bit about the Higgs physics. Just like "The Big Bang Theory" TV series, there's a lot of inside "jokes" and information that only someone who understands the material will get.

Zz.

Apps To Teach Kids Math And Science

I asked a while back on what physics apps do you people have, or like, for your smartphones or tablets. I certainly received quite a number of suggestions.

Today, the Wall Street Journal has an article on the best apps for your kids to learn math and physics. I think the suggested apps are too elementary for most (all?) of you reading this blog. But still, in case you have young ones under your care or supervision, these apps might be something you want to check out if you don't know about them already.

Zz.

Science Is Not Cool

Another entertaining article by Adam Ruben. This time, he is insisting that Science should not be cool, or "cool".

First of all, the word “cool” sells science short. Science is wonderful. Science is vital, science is fascinating, science is awe-inspiring, and science is praiseworthy. You know what’s been called “cool?” Parachute pants, slap bracelets, pogs, the Macarena, and Hypercolor shirts. (Maybe I’m unfairly picking on the early ’90s, but holy hell, what an awful lot of crap we liked.) Fist-pumping over science’s newfound coolness implies, it seems to me, that “cool” is a higher aspiration for science, and it isn’t.

Second, even when CNN said “cool,” it didn’t mean “cool.” The nomenclature gets tricky here, but they meant “cool-in-quotation-marks.” Without the quotation marks, the word means something completely different. It means Miles Davis and Johnny Cash in a ’76 Mustang. “Cool-in-quotation-marks” has a much broader connotation, as in, “Hey, that paper clip is shaped kind of cool.”

Third, are we supposed to be grateful that the world has once more seen fit to approve of what we do? Should we spin in ecstasy, shouting, “Cool again! We’re cool again! Put the little sunglasses on the Einstein doll, and let’s bop our heads to Moxy Früvous’s entropy song! Break out the Whole Foods sodas!”

But mostly, I don’t want science to be cool, or even “cool,” because cool is transient. People have to ask “What’s cool right now?” because trends constantly change. Is Gwen Stefani still cool? Is Facebook cool? Is Japan cool, or are we done with that?

I generally agree with that sentiment. Science should not be those things. Unfortunately, we live in an environment where (i) we need funding from politicians to accomplish what we need to do which (ii) requires popular support from the general public (iii) we have to appeal to an attention-deficit public that quickly move from one "cool" thing to another. When something is in the news, that's what is "cool" at a given time and for better or for worse, that's how you capture the public's imagination and maybe, support.

It shouldn't be that way, but unfortunately, that is how the game has to be played sometime.

Zz.

Sudden Approximation In QM Verified

It's always nice to see experiments that verify the basic, textbook stuff that many of us have used when we were students learning physics. This is one such case.

Experiments on singly-ionized 6He and observing the effect of the beta decay into 6Li has confirmed the quantum mechanical technique that we have used in QM classes - the superposition of the initial state with the final state, where the final state has a form that is an approximation of the initial state, i.e. the sudden approximation method!

Professor Patyk’s team has been collaborating with teams of physicists working in GAEN accelerator centre in Caen (Normandie, France) for several years. Calculations performed by NCBJ physicists to the accuracy of 4 significant places yielded the 2.3% probability that beta-decay will be liberating the sole orbital electron of the 6He ion, i.e. will be producing a totally ionized lithium atom. To a comparable accuracy that result was confirmed by some experiments performed at the French accelerator.

“Such a good agreement between theoretical predictions and experimental findings in such a simple (almost textbook) system is the first direct proof that the sudden approximation computational method utilized to solve quantum mechanics problems for almost a century is indeed correct” points out Professor Patyk.

 Good to know that a lot of the textbook materials can and have been verified, even if in many cases, these are "idealized" systems. Often, these idealized systems are not that easy to replicate and verified.

Zz.

In An Expanding Universe, What Doesn't Expand?

I just recently discovered this paper, and am still reading it. But I think if you have access to AJP, you might want to get a copy and read this too.

The paper addressed[1] the question that I've heard before. If our universe is expanding, does that mean that the atom is also getting larger?

Abstract:  The expansion of the universe is often viewed as a uniform stretching of space that would affect compact objects such as atoms and stars, as well as the separation of galaxies. One usually hears that bound systems do not take part in the general expansion, but a much more subtle question is whether bound systems expand partially. In this paper, a definitive answer is given for a very simple system: a classical “atom” bound by electrical attraction. With a mathematical description appropriate for undergraduate physics majors, we show that this bound system either completely follows the cosmological expansion, or, after initial transients, completely ignores it. This all-or-nothing behavior can be understood using analysis techniques used in junior-level mechanics. We also demonstrate that this simple description is a justifiable approximation of the relativistically correct formulation of the problem.

But what was equally interesting is the impetus for the authors to write this paper.

This paper is the result of a question posed by high school student Deepak Ramchand Mahbubani, Jr. at the University of Texas at Brownsville’s “21st Century Astronomy Ambassador’s Program,” and by the lack of a clear answer at the right level.

See kids? You ask an interestingly-enough question to the right person, you'll end up being cited by name in a physics paper!

So what's the answer to the question? It appears that if we adopt the realistic parameters, the atoms does not participate in the expansion.

We end with a practical consideration. Our quantification of the relative strengths of atomic and expansion forces is given in terms of a characteristic time Tatom for the motion of electrons in atoms, and a cosmological expansion time Texp (e.g., the Hubble time). Our analyses show that atomic forces are initially stronger if Tatom=Texp is less than order unity. Because Tatom ~10^ 16 s and Texp ~ 4x10^17 s, we see that atoms are in no danger of being disrupted by cosmological expansion.

In other words, you can't blame the expansion of the universe for your expanding waistline.

Damn it!

Zz.

[1] R. Price and J. Romano, Am. J. Phys v.80, p.376 (2012)

Energy Gained By Charge In Uniform Electrostatic Capacitor

I have seen this question being asked frequently, both online and from when I was briefly teaching physics. A lot of students have a bit of an issue in understanding why, if an electron is placed in a field with potential V, that the energy gain after going through the field is always eV, no matter how far away it has to move. For example, in a parallel plate capacitor situation where the potential across the capacitor is V, an electron that starts at one plate will gain an energy eV when it reaches the other plate, no matter how far away the two plates are separated (ignoring edge effects).

Certainly, when I first came across this as a student, it was a bit puzzling, but I remember working it out on my own and convincing myself this is correct. So I will show why this is so, both qualitatively and quantitatively.

We will do this qualitatively by applying an analogous situation. Say that you have a mass at a height h, and it rolls down an inclined plane to a horizontal distance of x=d (see Figure 1). Now, how much kinetic energy has it gained? You’ll notice that the height h provides the change in gravitational potential energy, mgh. When the object goes from high h to height 0, it would have lost mgh amount of potential energy, which is converted into kinetic energy. So the gain in kinetic energy is exactly mgh. I can vary x to any length that I want, and it would not change the amount of kinetic energy that it gains.

This is identical to the parallel plate capacitor problem.

So now, let’s prove this quantitatively. The scenario is sketched in Figure 2. An electron starts at one plate, and we want to find how much energy it has gained when it reaches the other plate.

For infinite parallel plate capacitor (ignoring edge effects), the electric field E is uniform and a constant. So in this case, E = V/d. We need E because this is the field that would produce the electrostatic force F = eE. Solving Newton’s equation,

F = ma = eE; a = eE/m = eV/(md)

Since the force is a constant (E doesn’t change), then the velocity of the electron when it reaches the other plate is

v^2 = u^2 + 2ad

For simplicity (since we want the gain or change in velocity/energy), let’s say the electron starts from rest, so u=0. Then

v^2 = 2ad = 2d* eV/(md)

v^2 = 2eV/m

The final velocity does not depend on d, the distance between the two plates! This means that the kinetic energy gain is also independent of d! QED!

So why is this? Note the the magnitude of E depends on d. For a constant V, the closer the two plates are together, the larger the magnitude of E. So even though the electrons only has a short distance to travel, the force pushing it to move is LARGE. If the separation between the two plates is large, the electron may be pushed for a longer distance, but the force acting on it is smaller. In the end, the effects balance out and the gain in energy remains the same. You can apply the same mathematics for the ball-inclined plane problem above.

Zz.

GRE Scores And Majors

The Buzz Blog has a very interesting breakdown and analysis of GRE scores correlated to the intended majors. Physics majors tend to do quite well in such test, especially in quantitative reasoning (not surprising, really).

What I find more fascinating is which majors did poorly in these categories. Political science majors did only half as well as physics majors in quantitative reasoning (again, not surprising), but they aren't even listed in the top 7 for the others! Are these the same people who will be part of our political system? Scary!

I've always believed that you don't elect someone simply because that person shares your point of view on certain things. You elect someone who has the ability to THINK things through and know how to see answers to those he/she doesn't know about. If you don't, you end up with morons such as Todd Akin who bastardize science to his benefit. How many times have we seen politicians unable to either look up some simple information, or think things analytically? People in politics WILL encounter unexpected, complex, and difficult issues. You want someone who has the ability to think rationally, not just someone who happens to agree with you on such-and-such. If not, you'll be lied to.

Zz.

Quantum Physics And ..... Golf?!

While article like this are often done tongue-in-cheek, I can't help feeling that it also helps to reinforce a tremendous misunderstanding of physics, especially quantum mechanics. What I dislike the most about this type of article is that they pick and choose certain aspects of physics, and then ignores others that could easily nullify the original assertion.

This "science fiction" writer is doing a "what ifs", applying certain aspects of quantum mechanics to see how it would work in the sport of golf. Yes, golf! Let's take a closer look at the  problems with each one of his ideas:

But if the golfer and the ball could somehow be entangled, then every movement the golfer makes would instantly have an effect on the golf ball. The golfer could literally steer the ball in midair.

Remember, quantum physics deals with teeny-weeny, itsy-bitsy particles that are smaller than atoms. Not macroscopic objects like golfers and golf balls.

However, both the golf player and the golf ball are composed of uncounted gazillions of subatomic particles. If it were possible to entangle one of the particles of the golfer's body with one of the particles of the golf ball, then the golfer's contortions would have an instant effect on the flight of the ball.

The body English would work!

No, it would not. Whenever people are using quantum entanglement, they often overlook one extremely important aspect of this phenomenon - the preservation of coherence of all the entangled particles! This is extremely important because in the destruction of the original entanglement is EXTREMELY EASY. In fact, even a single interaction has been shown to destroy the original piece of information! We only need to look at the gymnastics that we had to put a system through to preserve such entanglement and made such measurement - it isn't easy! We have had success with entanglement phenomenon with photons over long distances, because they weakly interact in air, but we certainly do not have a lot of success so far with  particle entanglements over long distances because they tend to interact very, very easily with their environment. So golf ball and golfer being entangled? I don't think so!

In quantum physics there's a phenomenon known as tunneling. An electron, for example, can run into a solid wall and come out the other side, seemingly without drilling its way through the wall or leaving a hole in the wall behind it.

Imagine a situation on a golf course where the golfer's ball had landed in the deep weeds or behind a rock or some trees. It might take several shots to maneuver the ball around such an obstacle and get back onto the fairway.

But if the ball could somehow be made to tunnel the way electrons do, the golfer could aim his shot at the pin and blast away. The ball would approach the obstacle, be it weeds or rock or tree, and come out the other side, free to sail unimpeded toward the green.

It sounds like magic, but that's the way electrons can be made to behave. Would it be impossible to make golf balls tunnel the way electrons do? It could take strokes off the golfer's score.

First, let's call on the inconsistencies in this scenario. If the golf ball can "tunnel" through the weeds or the rock, what is to stop it from tunneling through the ground as well and miss the hole completely? If it goes through things unimpeded, why would the ground be any different? So already he is expecting a law of physics that turns itself on and off on a whim. As someone once said "God is subtle, but not malicious".

The problem with the application of tunneling of macroscopic object is the same as in the previous point. For the entire macroscopic object to tunnel through a barrier, it must be in completely coherence with each other. If not, the probability of one part of the object tunneling through will be different than other parts of the object. An electron, or a quantum particle does not have that problem. We describe the electron using one coherent wavefunction. We can't do that for a golf ball.

We note that in experiments that showed how particles such as buckyballs can undergo quantum interferences, the experiments were done under extreme conditions such as very low temperature. This is to ensure that the entire buckyball are in coherence with each. Introduce thermal effects, and there goes your interference pattern!

An atom can gain energy by absorbing a photon, the basic particle of light. Or the atom can lose energy by emitting a photon.

Now picture a golfer faced with a long putt. If the ball is hit too slowly it won't make it to the cup. If hit too hard, it will go past the cup. Perhaps the ball might skim the rim of the cup and zip away instead of plopping in.

If the golfer could somehow induce the ball to gain energy or lose energy, depending on how the putt's going, the ball could be guided right into the cup every time. All you have to do is figure out how to make the ball gain or lose energy at your command.

This is where one thing does not have anything to do with the other. Induce the ball to gain and lose energy? How is this related to an atom absorbing and losing energy? It seems that this person seems to think he can violate conservation of energy with the golf ball. Unfortunately, even if he could do this, his ball is already busy tunneling its way to the other side of the earth.

Zz.

Biological Physics

... or Biophysics? You be the judge.

While all the attention in physics has been on the discovery of the Higgs and also the recent landing on Mars, it is important that we keep informing the public that physics, and physicists, are more than just these narrow areas of study. In fact, the MAJORITY of physicists are not even in these two fields that have garnered a disproportional amount of publicity lately.

So it is rather nice to read this article on biological physics, a field where both biology and physics come together.

So let me lay my credentials on the table. I am a soft matter-cum-biological physicist and what excites me is the world around me, the soft squidgy stuff that turns up ubiquitously scattered around our houses in food, cosmetics, paint and ointments, in bulk plastics and novel materials for renewable energy devices; but also, pervasively, in the tissues of our own bodies and the rest of the animal kingdom. Yes, physics and biology can sometimes collide and when they do, it can produce something entirely new.

We need to expose both the public and students getting into physics to the wide variety of subject matter that are part of physics, not just to some esoteric ideas that do not have a clear application to their everyday lives.

Zz.

Yes Virginia, There Are No Superluminal Neutrinos

Not wanting to to beat a dead horse, even though we already have sufficient confirmation that the original OPERA result is faulty. Still, a new paper published in PRL this week kinda sealed the deal[1]. They measured the speed of muon neutrinos from CERN to their detector in Gran Sasso, which is practically the identical situation as OPERA. So what did they find? Here's the abstract:

Abstract: We report the measurement of the time of flight of ∼17  GeV ν_μ on the CNGS baseline (732 km) with the Large Volume Detector (LVD) at the Gran Sasso Laboratory. The CERN-SPS accelerator has been operated from May 10th to May 24th 2012, with a tightly bunched-beam structure to allow the velocity of neutrinos to be accurately measured on an event-by-event basis. LVD has detected 48 neutrino events, associated with the beam, with a high absolute time accuracy. These events allow us to establish the following limit on the difference between the neutrino speed and the light velocity: -3.8×10^-6<(v_ν-c)/c<3.1×10^-6 (at 99% C.L.). This value is an order of magnitude lower than previous direct measurements.

Yup. No superluminal neutrinos!

Zz.

[1] N. Yu et al., Phys. Rev. Lett. v.109, 070801(2012).

First Year Physics Graduate Students

The AIP has released the latest statistics on first year physics graduate students in the US. There are a few but not surprising data here.

Asians still make up the largest percentage of foreign students (Table 2) in terms of continent of origin, with China sending the largest number of students (39% of all foreign students). In fact, China has more first year physics students than students from Europe, Africa, Americas, Middle East, and Australia/New Zealand combined!

The other interesting observation here is that foreign students also tend to major in a more "practical" subject area, more so than American students. Table 4 shows that the percentage of foreign students intending to major in Condensed Matter, Biophysics, Material Science, and other Applied Physics tend to be higher than their American counterpart. The percentage of foreign students majoring in Astrophysics, for example, is significantly low (4%), whereas for American students, the percentage (13%) is roughly equivalent to the other two other most popular subject areas (15% and 12%).

One can spin such statistics in a number of ways. :)

Zz.

The Higgs, From The Tevatron With Love

So we had the preprint of the ATLAS and CMS paper on the possible discovery of the Higgs. Not to be left out in all of this, the grand old lady of high energy collider, the Tevatron, reaches out from the dead, and with her last gasp, reveals the guilty party and announces her own discovery of the Higgs. (Well, OK, so I've been watching too many Mystery shows on PBS).

Both the CDF and D0 detectors at the Tevatron combined their effort to publish this result in this week's PRL (you can get the paper free of charge from that link). To be sure, the evidence isn't as strong at that produced at the LHC a few weeks ago. But what is neat here is that they are looking at a different decay channels than both ATLAS and CMS. They could have easily thrown a wrench into the discovery if they had, in fact, come up with a result that is inconsistent with the LHC results. But they didn't.

In fact, experimentalists don’t directly detect the Higgs boson. Instead, they look at all the different sequences of particles—or “channels”—that the unstable Higgs boson decays into. ATLAS and CMS were able to detect the Higgs boson by looking for its decay into two photons and two Z bosons, and, albeit with somewhat weaker significance, two W bosons.

All of these channels involve the Higgs boson decaying into bosons, but if the Higgs particle explains the masses of quarks and leptons (the electron, muon, and tau), it should be possible to see it decay into these particles, which are fermions, too. (This is another way of saying that the leptons and quarks couple to the Higgs field.) Although CMS has analyzed their data to look for evidence that the new particle decays into fermions, namely into two tau leptons or two bottom quarks (b quarks), they haven’t observed a clear signal in this channel yet.
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The new paper [1] combines the results of the CDF and the D0 experiments in one particular search channel, namely, the one where the Higgs boson decays into two bottom quarks (b quarks). In the combined dataset, the groups see an excess over what is expected from the background-only hypothesis, but is this excess caused by the same particle observed in the LHC experiments, and if so, does that mean that this Higgs particle indeed decays into fermions?

In any case, with the LHC continuing to run, and the planned increase to 14 TeV, I suspect that we will be hearing quite a bit more on the Higgs search during the next couple of years. This completely mystery isn't solved yet.

Zz.

LHC Breaks Another Record?

Not satisfied with passing the Tevatron for the highest energy collider, the ALICE detector at the LHC may soon snatch another world record from Brookhaven's RHIC for creating the highest manmade temperature.

The results come from the ALICE heavy-ion experiment (at right) — a lesser-known sibling to ATLAS and CMS, which produced the data that led to the announcement in July that the Higgs boson had been discovered. ALICE physicists, presenting on Monday at Quark Matter 2012 in Washington DC, say they have achieved a quark gluon plasma 38% hotter than a record 4 trillion degree plasma achieved in 2010 by a similar experiment at Brookhaven National Laboratory in New York, which had been anointed the Guinness record holder.

This isn't that much of a surprise, though, since the LHC is significantly more powerful than RHIC. It's a terrific use of the facility (LHC) in that it isn't just a high energy physics facility, but also a nuclear physics facility. One wonders if the life of the Tevatron would have been extended even longer had someone the insight to incorporate nuclear physics experiments as part of the facility.

Zz.

Quantum Teleporation Achieving Record Distances

If you missed these stories from last week, this link will give you a brief summary of them. Distances of 97 km and 143 km seem to have been achieved for qubits teleporation.

In the August 9 issue of Nature, a Chinese group reports achieving quantum teleportation across Qinghai Lake in China, a distance of 97 kilometers. (Scientific American is part of Nature Publishing Group.) That distance surpasses the previous record, set by a group that included several of the same researchers, of 16 kilometers.

But a more recent study seems to have pushed the bar even higher. In a paper posted May 17 to the physics preprint Web site arXiv.org, just eight days after the Chinese group announced their achievement on the same Web site, a European and Canadian group claims to have teleported information from one of the Canary Islands to another, 143 kilometers away. That paper has not been peer-reviewed but comes from a very reputable research group.

The reference for the Chinese paper cited above is

J. Yin et al., Nature v.488, p.185 (2012).

Zz.

3D Map Of Galaxies And Black Holes

The Sloan Digital Sky Survey III has released a rather neat video of a flight through the universe that maps the various massive galaxies and black holes.

With such a map, scientists can retrace the history of the Universe over the last six billion years. With that history, they can get better estimates for how much of the Universe is made up of dark matter - matter that we can't directly see because it doesn't emit or absorb light - and dark energy, the even more mysterious force that drives the accelerating expansion of the Universe.

It's still neat to see one of these maps for whatever the reason.



Zz.

High Energy Physics Drives Innovation And Technology

I want to bring one ONE very specific example of how high energy physics is driving advancement in a certain technology that WILL have huge impact later on in many parts of our lives.

This report shows the drive for larger, faster, and more importantly, cheaper photodetectors. This was driven by the needs in particle physics detection, especially for the Cerenkov light detection from neutrinos. Current technology is based on photomultiplier tubes and is dominated by almost a single-source supplier - Hamamatsu. And you can imagine, these photomultipliers are prohibitively expensive, especially the ones with higher light detection efficiency. But these PMTs also have "round" cross-section, and in some cases, will have coverage that are not very high.

All of these factors affect the light detection from such high energy physics experiments, and thus, the demand for better detection from such experiments are driving the need for new, better, and cheaper detectors. It is the driver for new innovation and technology, which is what high energy physics does all the time! They often have to build and invent their own detectors each time they build bigger and better colliders!

And guess what? We will benefit from such innovations! The technology invented with the photodetector described in the article will have a myriad of benefits. There are already discussion on the applicability of this technology for PET scanners. In this case, being large, cheap, and fast are three characteristics that are highly desirable.

So if you want to follow the development of something in "real time" as an example on how a demand in high energy physics eventually translates to something that you and I benefit from, here's one that you can track as it happens. The folks at R&D 100 obviously are already aware of the enormous potential for this one.

Zz.

Discovery Of The Higgs Caused Some Mass To Disappear

I mentioned earlier of the lost bet that Stephen Hawking made on the non-existence of the Higgs. This NY Times article describe all the other lots bets that were made on this Higgs. The most hilarious one was the one made between Janet Conrad and Franck Wilczek. They bet on 10 chocolate Nobel coins that can only be bought at the Nobel Museum in Stockholm. The journey from there to the hands of Wilczek resembles a path that might have been designed by Rube Goldberg.

So shortly after the July 4 announcement, she sent Chad Finley, a friend and physicist at Stockholm University, to the museum, where he bought the chocolates for about $15. He could have then mailed them to the United States but was worried they would melt; instead he passed them to Szabolcs Marka, a Columbia physicist who was in Sweden at the time.

Dr. Marka took them back to New York and gave them to Matt Toups, a postdoctoral researcher with Dr. Conrad who was headed for Fermilab, in Illinois, where Dr. Conrad was working. The pair wrapped the chocolates in plastic foam so they wouldn’t melt during the bus ride to La Guardia Airport.

Dr. Conrad picked up the chocolates just before a power failure sent temperatures in the Fermilab offices rising toward the chocolate melting point, and took them home to Cambridge, Mass., leaving them with her sister while she went off to a physics conference in Virginia and then back to Fermilab. She wrote in an e-mail, “I have not seen them, since they are carefully enclosed in their Styrofoam, but I trust they are in excellent shape!”

Dr. Wilczek, who is in New Hampshire, has not seen the chocolates either, but he said they had been delivered to his office.

Hysterical!

So, did YOU win or lose a bet on the Higgs?

Zz.

The Physics Of Pole-Vaulting

Of course, with the London Olympics going on, there's a lot of articles examining the physics associated with various athletic events.

This one is rather interesting, because it shows you the WRONG way of analyzing the physics of pole vault, and that using such a result will produce a ridiculously fast speed that a pole vaulter will need to clear such heights. Often, this is how we do physics, and when we realize that there has to be something more beyond what we currently understand. When the result of a current idea doesn't match reality, we have to figure out what went wrong - whether we didn't account for everything that's involved, or that our description is inadequate. In this case, it is the former (not accounting for the flexing of the pole), while our description (Newton's laws) is still valid.

Zz.

Physicists Going Into Finance

This is an excellent article that explores one job path outside of Academia for physicists.

Today that balance has changed. According to AIP data, in 2010 the number of physics bachelor's degrees and Ph.D.s awarded in the United States set or equaled respective all-time highs. One year after finishing their Ph.D.s, 60% of physicists were in postdocs. Nearly half of all physicists work in industry, and only about 35% work in academia. This reflects two trends, Czujko says: a relative decline in the number of tenure-track academic jobs in most physics fields, and increasing opportunities in certain fields for math-savvy physicists.

If you are in the middle of pursuing your PhD, even if you have no interest in pursuing the financial field for a career, this article should be read so that you are aware of the job situation that you are going into. In all my advice to physicist students pursuing a career in physics, I've always stressed that need to have as wide of an experience as possible, and to be open to explore other areas. Most of our plans do not happen the way we intended, and you just never know what you will need when you jump into the job market.

Zz.

Pier Oddone To Retire As Fermilab Director

The buzz news for today is the announcement that Pier Oddone will retire next year as Fermilab Director. Here's the press release out of Fermilab.

I would say that his tenure as Lab Director saw one of the most, if not THE most challenging times for Fermilab. Severe budget cuts caused a lot of layoffs, and now with the demise of the Tevatron, the lab is looking to reestablish its identity and its big projects to continue surviving.

The new lab director will have a lot of challenges to face.

Zz.

Bringing High Energy Physics To Chinese High Schools?

There's something not quite right with this picture. I'll let you read the entire article and I'll let you know why after that.

This article reports on an outreach program by a Fermilab team, invited by a Kavli Institute, to introduce high energy physics to students and teachers in China.

Shaffer was in China July 13-28 as part of a team from FermiLab, who was invited by the Kavli Institute for Theoretical Physics China. This was the first ever such program offered for teachers and students in China.

During this program, over 60 students and teachers learned how to bring high energy physics into the high school using real particles and real data. The first week emphasized the particle colliders like the Large Hadron Collider (LHC) in Switzerland and included a tour through Bejing’s BEPCII collider. Using data from the LHC, students learned to identify and conduct research on particles physics.

So let me get this right. US/Fermilab staff, who no longer have any kind of particle collider in the nation, are trying to introduce this to people in a country that HAS a running collider.

Isn't this similar to a bankrupt person trying to teach a millionaire how to make money?

Zz.