Monday, April 20, 2015

Cyclotron Radiation From One Electron

It is a freakingly cool experiment!

We now can see the cyclotron radiation from a single electron, folks!

The researchers plotted the detected radiation power as a function of time and frequency (Fig. 2). The bright, upward-angled streaks of radiation indicate the radiation emitted by a single electron. It is well known theoretically that a circling electron continuously emits radiation. As a result, it gradually loses energy and orbits at a rate that increases linearly in time. The detected radiation streaks have the same predicted linear dependence, which is what allowed the researchers to associate them with a single electron. 

Of course, we have seen such effects for many electrons in synchrotron rings all over the world, but to not only see it for one electron, but to also see how it loses energy as it orbits around is rather neat. It reinforces the fact that we can't really imagine electrons "orbiting" around a nucleus in an atom in the classical way, because if they do, we would detect such cyclotron radiation and that they will eventually crash into the nucleus.

But I also find it interesting that this has more to do with the effort in trying to determine the mass of a neutrino independent of the neutrino mass oscillation via measuring the electrons mass to high accuracy in beta decay.


Saturday, April 18, 2015

Complex Dark Matter

Don Lincoln has another video on Dark Matter, for those of you who can't enough of these things.


Thursday, April 16, 2015

Tevatron Data Reveals No Exotic, Non-Standard Model Higgs

She may be long gone, but the old gal still has something to say.

A new paper that combined the data from CDF and D0, the two old Tevatron detectors at Fermilab, has revealed that the Higgs that has been found is indeed consistent with the Standard Model Higgs. It strengthens the much-heralded discovery made at CERN a while back.

...... the two Tevatron-based experiments, CDF and D0, uncovered evidence in 2012 of a Higgs boson decaying into fermions, specifically, a pair of bottom quarks. The two collaborations have again combined their data to check for exoticness in this fermion decay channel. The Tevatron data show no signal consistent with a Higgs boson having spin zero and odd parity (a so-called pseudoscalar) or spin 2 and even parity (gravitonlike). The results are important for building the case that the Higgs boson seen in particle colliders is indeed the standard model Higgs.


More Quantum Physics In Your Daily Lives

I pointed to an article a while back about the stuff we use everyday that came into being because of our understanding of quantum mechanics (basically, all of our modern electronics). Now, Chad Orzel has done the same thing in his article on Forbes, telling you how you actually start your mornings by relying on the validity of QM.

The tiny scale of all the best demonstrations of quantum physics can lead people to think that this is all basically meaningless, arcane technical stuff that only nerds in white lab coats need to worry about. This is deeply wrong, partly because I don’t know any physicists who wear white lab coats, but more importantly because quantum phenomena are at the heart of many basic technologies that we use every day.

In fact, I can’t start my morning without quantum mechanics, in the form of my bedside alarm clock.

You may read the rest of his arguments in the article.

I will also add something that I've mentioned before. The presence of quantum effects may be more prominent than what most are aware of, if we go by the evidence for the existence of superconductivity. As stated by Carver Mead, it is the clearest demonstration of QM effects at the macro scale. Yet, a lot of people simply do not recognize it for what it is.


Wednesday, April 15, 2015

Use "i,j,k" notation instead of "arrow" representation for vectors in Intro Physics?

That is what the authors of this study have found to be more effective in analyzing students understanding and ability to comprehend vector problems. (The paper is available for free.)

First, we replicated a number of previous findings of student difficulties in the arrow format and discovered several additional difficulties, including the finding that different relative arrow orientations can prompt different solution paths and different kinds of mistakes, which suggests that students need to practice with a variety of relative orientations. Most importantly, we found that average performance in the ijk format was typically excellent and often much better than performance in the arrow format in either the generic or physics contexts.

My question is, is this the result of an inherent conceptional problem in the arrow representation, or simply a matter of correcting some of the ways we teach vectors to students?


Thursday, April 09, 2015

How Do Airplanes Fly?

I get asked this often, strangely enough. So it is nice to have a quick illustration via a video on how it works.


Where HEP Technology Becomes Commercial

This is a nice article to introduce you to all the benefits that the rest of world gets from the innovations that came about due to the experimental needs in high energy physics, nuclear physics, astrophysics, etc. The effort of HEPTech is clearly to make the technology transfer a conscious and systematic one, rather than just ad hoc or via accident.


Wednesday, April 01, 2015

CERN Confirms The Existence of The Force

I can't let April 1st go without at least one goofy post, can I? So here it is!


When Physics Demo Goes Wrong


Just found this news article on a physics demo for an AP physics class that didn't go as planned.

It apparently shows a physics teacher teaching a class a lesson by taking aim at a concrete block.

But he doesn’t quite hit the block correctly and ends up hitting a fellow teacher in a very sensitive area.

Now I'm all for doing demos in class, since not only can they be educational and fun, it also keeps the students from falling asleep. But I don't know if this is a bit on the more "daring" side. There's certainly plenty of chances for things to go wrong with demo such as this.

If anyone has any follow-up news on this, please let me know. The YouTube video implied that the teacher doing the demo lost his job, and there's confusion on the person holding up the blocks and got hit was another student or another teacher.


Sunday, March 29, 2015

Stephen Hawking and Brian Cox To Trademark Their Names

"Stephen Hawking" and "Brian Cox" will be trademark names very soon. So if you have plans to market t-shirts and other products with these people's names, watch out!

Maybe this will get rid of some of the tacky stuff that I've seen associated to them, especially Hawking. But then again, who knows, they may turn around and produce their own tacky merchandise.


A Tale Of Two Scientists

It is fascinating to read about the stuff behind the scene involving the negotiations between the United States and Iran regarding Iran's nuclear program. And in the middle of all this are two scientists/engineers out of MIT with nuclear science background.

At the Massachusetts Institute of Technology in the mid-1970s, Ernest J. Moniz was an up-and-coming nuclear scientist in search of tenure, and Ali Akbar Salehi, a brilliant Iranian graduate student, was finishing a dissertation on fast-neutron reactors.

The two did not know each other, but they followed similar paths once they left the campus: Mr. Moniz went on to become one of the nation’s most respected nuclear physicists and is now President Obama’s energy secretary. Mr. Salehi, who was part of the last wave of Iranians to conduct nuclear studies at America’s elite universities, returned to an Iran in revolution and rose to oversee the country’s nuclear program.

You may read more about it in the article. And I definitely agree with this sentiment:

Mr. Moniz, 70, understands his role well: He is providing not only technical expertise but also political cover for Mr. Kerry. If a so-called framework agreement is reached in the next few days, it will be Mr. Moniz who will have to vouch to a suspicious Congress, to Israel and to Arab allies that Iran would be incapable of assembling the raw material for a single nuclear weapon in less than a year.

“It wouldn’t mean much coming from Kerry,” said a member of the administration deeply involved in the strategy who spoke on the condition of anonymity. “The theory is that Ernie’s judgment on that matter is unassailable.”

At the heart of this is a scientific/technical issues. Now once presented, it is up to the politicians to decide, because beyond that, it is no longer a science/technical decision, but a political one. To have someone, a negotiator, who is not only knowledgeable in that area, but also who happens to be a world-renowned expert, is extremely beneficial.


Monday, March 23, 2015

This Tennis Act Disproves Physics?!

Since when?!

Why is it that when some "morons" see something that they can't comprehend, they always claim that it violates physics, or can't be explained by physics, as IF they understand physics well-enough to make such judgement? I mean, c'mon!

This is the case here where this writer claims that Novak Djokovic ability to stop the ball coming at him with his racket somehow defy physics and turning it all into "a lie". (

Look, I know this is written probably in jest, and probably without giving it a second thought, but such stupid comments of journalism should really be stopped and called out. There's nothing that can't be explained here by physics. If Djokovic had held the racket with a stiff arm, he would not have been able to stop the ball the way he did. In fact, it would have bounced off the racket. But look at how he stopped it. He moved his arm back to "absorb" the impact, basically allowing the strings to absorb the momentum of the ball. This is called "Impulse", where the force on the ball to change its momentum to zero is spread out over a longer period of time. Thus, the force needed to slow it down is small enough that it doesn't cause it to bounce off the strings.

In other words, what is observed can easily be explained by physics!

BTW, Martina Navratilova had done this same thing a few times while she was an active player. I've witness her doing this at least twice during matches. So it is not as if this is anything new. Not only that, although it is less spectacular and easier to do, badminton players do such a thing numerous times as well when they are trying to catch a shuttlecock.


Wednesday, March 18, 2015

CERN's ALPHA Experiment

See, I like this. I like to highlight things that most of the general public simply don't know much about, especially when another major facility throws a huge shadow over it.

This article mentions two important things about CERN: It is more than just the LHC, and it highlights another very important experiment, the ALPHA experiment.

ALPHA’s main aim is to study the internal structure of the antihydrogen atom, and see if there exist any discernible differences within it that set it apart from regular hydrogen. In 2010 ALPHA was the first experiment to trap 38 antihydrogen atoms (an antielectron orbiting an antiproton) for about one-fifth of a second and then the team perfected its apparatus and technique to trap a total of 309 antihydrogen atoms for 1000 s in 2011. Hangst hopes that with the new updated ALPHA 2 device (which includes lasers for spectroscopy), the researchers will soon see precisely what lies within an antihydrogen atom by studying its spectrum. They had a very short test run of a few weeks with ALPHA 2 late last year, and will begin their next set of experiment in earnest in the coming months.

They will be producing more amazing results in the future, because this is all uncharted territory. 


Friday, March 13, 2015

Crowdfunding Physics?

I read this article on Symmetry yesterday and started to think of the idea of going directly to the public for funding. It is an intriguing idea, especially since federal funding of the physical science in the US has been declining for the past decade or more. This is especially true for high energy physics, which is the focus of this article.

I look at how much research grants that I had gotten, and they seem to average between $150k to $250k per year, and each of these grants ran for a period of 3 years. The money typically paid for part of my salary, a postdoc, a graduate student, M&S (materials and supplies), and the relevant overheads. In some cases, it is for the purchase of capital equipment.

But this is not a "sexy" area of study that most of the public are enamored with. It is not a search for exotic, godlike particles, or searching for the elusive dark matter/dark energy, or anything remotely front-page news. This is a "workhorse" area of study, where our advances allow other areas to be able to achieve progress in their areas. We do a lot of the behind-the-scene dirty work that seldom get appreciated, but yet, are vital components to progress.

Crowdfunding for something that isn't sexy? Might be improbable.


Thursday, March 12, 2015

The Detectors at the LHC

Don Lincoln has a video on the 4 detectors at the LHC.

As you watch this, don't miss the fact that these are "... technological marvels..." in themselves, and that high energy physics had to invent and make their own detectors and detection processes to advance the field. Detector and instrumentation physics have always been an integral part of experimental high energy physics, and one often sees students in this field that are actually working on detector physics.

As a consequence, high energy physics drives innovations and new applications that eventually leaks into the rest of the world. This is a point that is often missed by those outside of the field.