Sunday, August 20, 2017

RIP Vern Ehlers

The first physicist ever elected to the US Congress has passed away. Vern Ehlers, a moderate Republican from Michigan, passed away at the age of 83.

Vern Ehlers, 83, a research physicist and moderate Republican who represented a western Michigan congressional district for 17 years, died late Tuesday at a Grand Rapids nursing facility, Melissa Morrison, funeral director at Zaagman Memorial Chapel, said Wednesday.

I reported on here when he decided to retire back in 2010. And of course, when he was serving Congress along with 2 other elected officials who were physicist, I cited a NY Times article that clearly demonstrated how desperate we are to have someone with science background serving as politicians.

Unfortunately, right now, the US Congress has only ONE representative who is a trained physicist (Bill Foster). It somehow reflects on the lack of rationality that is going on in Washington DC right now.

Zz.

Solar Eclipse, Anyone?

It's a day before we here in Chicago will get to see a partial solar eclipse. I know of people who are already in downstate Illinois at Carbondale to view the total eclipse (they will get another total eclipse in 2024, I think).

So, any of you will be look up, hopefully with proper eye wear, to view the eclipse tomorrow? I actually will be teaching a class during the main part of the eclipse, but I may just let the students out for a few minutes just to join the crowd on campus who will be doing stuff for the eclipse. Too bad I won't be teaching optics, or this will be an excellent tie-in with the subject matter.

Zz.

Tuesday, August 08, 2017

Hyperfine Splitting of Anti-Hydrogen Is Just Like Ordinary Hydrogen

More evidence that the antimatter world is practically identical to our regular matter world. The ALPHA collaboration at CERN has reported the first ever measurement of the anti-hydrogen hyperfine spectrum, and it is consistent to that measured for hydrogen.

Now, they have used microwaves to flip the spin of the positron. This resulted not only in the first precise determination of the antihydrogen hyperfine splitting, but also the first antimatter transition line shape, a plot of the spin flip probability versus the microwave frequency.

“The data reveal clear and distinct signatures of two allowed transitions, from which we obtain a direct, magnetic-field-independent measurement of the hyperfine splitting,” the researchers said.

“From a set of trials involving 194 detected atoms, we determine a splitting of 1,420.4 ± 0.5 MHz, consistent with expectations for atomic hydrogen at the level of four parts in 10,000.”

I am expecting a lot more studies on these anti-hydrogen, especially now that they have a very reliable way of sustaining these things.

The paper is an open access on Nature, so you should be able to read the entire thing for free.

Zz.

Thursday, August 03, 2017

First Observation of Neutrinos Bouncing Off Atomic Nucleus

An amazing feat out of Oak Ridge.

And it’s really difficult to detect these gentle interactions. Collar’s group bombarded their detector with trillions of neutrinos per second, but over 15 months, they only caught a neutrino bumping against an atomic nucleus 134 times. To block stray particles, they put 20 feet of steel and a hundred feet of concrete and gravel between the detector and the neutrino source. The odds that the signal was random noise is less than 1 in 3.5 million—surpassing particle physicists’ usual gold standard for announcing a discovery. For the first time, they saw a neutrino nudge an entire atomic nucleus.

Currently, the entire paper is available from the Science website.

Zz.

Wednesday, August 02, 2017

RHIC Sees Another First

The quark-gluon plasma created at Brookhaven's Relativistic Heavy Ion Collider (RHIC) continues to produce a rich body of information. They have now announced that the quark-gluon plasma has produced the most rapidly-spinning fluid ever produced.

Collisions with heavy ions—typically gold or lead—put lots of protons and neutrons in a small volume with lots of energy. Under these conditions, the neat boundaries of those particles break down. For a brief instant, quarks and gluons mingle freely, creating a quark-gluon plasma. This state of matter has not been seen since an instant after the Big Bang, and it has plenty of unusual properties. "It has all sorts of superlatives," Ohio State physicist Mike Lisa told Ars. "It is the most easily flowing fluid in nature. It's highly explosive, much more than a supernova. It's hotter than any fluid that's known in nature."
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We can now add another superlative to the quark-gluon plasma's list of "mosts:" it can be the most rapidly spinning fluid we know of. Much of the study of the material has focused on the results of two heavy ions smacking each other head-on, since that puts the most energy into the resulting debris, and these collisions spit the most particles out. But in many collisions, the two ions don't hit each other head-on—they strike a more glancing blow.

It is a fascinating article, and you may read the significance of this study, especially in relation to how it informs us on certain aspect of QCD symmetry.

But if you know me, I never fail to try to point something out that is more general in nature, and something that the general public should take note of. I like this statement in the article very much, and I'd like to highlight it here:

But a logical "should" doesn't always equal a "does," so it's important to confirm that the resulting material is actually spinning. And that's a rather large technical challenge when you're talking about a glob of material roughly the same size as an atomic nucleus.

This is what truly distinguish science with other aspects of our lives. There are many instances, especially in politics, social policies, etc., where certain assertions are made and appear to be "obvious" or "logical", and yet, these are simply statements made without any valid evidence to support it. I can think of many ("Illegal immigrants taking away jobs", or "gay marriages undermines traditional marriages", etc...etc). Yet, no matter how "logical" these may appear to be, they are simply statements that are devoid of evidence to support them. Still, whenever they are uttered, many in the public accept them as FACTS or valid, without seeking or requiring evidence to support them. One may believe that "A should cause B", but DOES IT REALLY?

Luckily, this is NOT how it is done in science. No matter how obvious it is, or how verified something is, there are always new boundaries to push and a retesting of the ideas, even ones that are known to be true under certain conditions. And a set of experimental evidence is the ONLY standard that will settle and verify any assertion and statements.

This is why everyone should learn science, not just for the material, but to understand the methodology and technique. It is too bad they don't require politicians to have such skills.

Zz.

Is QM About To Revolutionize Biochemistry?

It is an intriguing thought, and if these authors are correct, a bunch of chemical reactions, even at higher temperatures, may be explained via quantum indistinguishibility.

The worlds of chemistry and indistinguishable physics have long been thought of as entirely separate. Indistinguishability generally occurs at low temperatures while chemistry requires relatively high temperatures where objects tend to lose their quantum properties. As a result, chemists have long felt confident in ignoring the effects of quantum indistinguishability.

Today, Matthew Fisher and Leo Radzihovsky at the University of California, Santa Barbara, say that this confidence is misplaced. They show for the first time that quantum indistinguishability must play a significant role in some chemical processes even at ordinary temperatures. And they say this influence leads to an entirely new chemical phenomenon, such as isotope separation and could also explain a previously mysterious phenomenon such as the enhanced chemical activity of reactive oxygen species. 

They have uploaded their paper on arXiv.

Of course, this is still preliminary, but it provides the motivation to really explore this aspect that had not been seriously considered before. And with this latest addition, it is just another example on where physics, especially QM, are being further explored in biology and chemistry.

Zz.

Sunday, July 30, 2017

Is Radiation Dangerous?

Believe it or not, there are still people out there who get scared witless and going out of their minds with their phobia about "radiation". I get questions related to this often enough that whenever I find info like this one, I want to post it here.

Don Lincoln decides to tackle this issue regarding "radiation". If you have little knowledge and idea about this, this is the video to watch.



Zz.

Quantum Tunneling Time

Chad Orzel has highlighted a couple of papers (one still a preprint) on the issue of quantum tunneling time or speed. I missed these, just like him, but unlike him, I didn't have as glamorous of an excuse - I was busy finishing up teaching a summer physics class.

I'll let you read have the pleasure of reading his article, because he also gave a quick background on the quantum tunneling phenomenon, if you're not familiar with it. But as background information, I did quantum tunneling spectroscopy measurement for my PhD research and dissertation. So I'm familiar with this, but not in the sense of the detailed question on tunneling time. We simply used the phenomenon to measure the properties of the material of interest, even though in the end, I ended up looking into the detailed description of the tunneling matrix elements, which are often simplified or ignored.

Still, the issue of tunneling time has always been something in the back of my mind, and the question on whether this thing happens "very fast" or "instantaneously" (just like quantum entanglement) has always popped up now and then. It is good to see new studies on this, even though the combined conclusion out of these two results is still uncertain.

Zz.

1. N. Camus et al., Phys. Rev. Lett. 119, 023201 (2017).
2. https://arxiv.org/abs/1707.05445


Tuesday, July 11, 2017

The Higgs - Five Years In

In case you've been asleep the past 5 years or so and what to catch up on our lovable Higgs, here is a quick, condensed version of the saga so far.

Where were you on 4 July 2012, the day the Higgs boson discovery was announced? Many people will be able to answer without referring to their diary. Perhaps you were among the few who had managed to secure a seat in CERN’s main auditorium, or who joined colleagues in universities and laboratories around the world to watch the webcast.

This story promises to have lots of sequels, just like the movies released so far this year.

Zz.

The Universe's First Atoms Verify Big Bang Theory

The Big Bang theory makes many predictions and consequences, all of them are being thoroughly tested (unlike Intelligent Design or Creationism). These predictions and consequences are quantitative in nature, i.e. the theory predicts actual numbers.

Many of these "numbers" have been verified by experiments and observations, and they are continually being measured to higher precision. This latest one comes about from the prediction of the amount of certain gases during the early evolution of our universe.

But more data has just come in! Two new measurements, in a paper just coming out now by Signe Riemer-Sørensen and Espen Sem Jenssen, of different gas clouds lines up with a different quasar have given us our best determination of deuterium's abundance right after the Big Bang: 0.00255%. This is to be compared with the theoretical prediction from the Big Bang: 0.00246%, with an uncertainty of ±0.00006%. To within the errors, the agreement is spectacular. In fact, if you sum up all the data from deuterium measurements taken in this fashion, the agreement is indisputable.

The more they test it, the more convincing it becomes.

Zz.

Wednesday, June 14, 2017

The Physics of Texting And Driving

First of all, let me be clear on this. I hate, HATE, HATE drivers who play with their mobile devices while they drive. I don't care if it is texting (stupid!) or just talking on their phones. These drivers are often driving erratically, unpredictably, and often do not use turn signals, etc. They are distracted drivers, and their stupid acts put my life and my safety in jeopardy. My nasty thought on this is that I wish Darwin would eliminate them out of the gene pool.

There! I feel better now. Coming back to the more sedate and sensible topic related to physics, Rhett Allain has a nice, short article on why physics will rationally explain to you why texting and driving is not safe, and why texting and driving ANNOYS OTHER PEOPLE!

OK, so my calmness didn't last very long.

The physics is quite elementary that even any high-school physics students can understand. And now, I am going back to my happy place.

Zz.

Saturday, June 10, 2017

What Non-Scientists Can Learn From Physics

Chad Orzel has a follow-up to his earlier article on what every physics undergrad should know. This time, he tackles on what he thinks non-scientists can learn from physics.

You may read the linked article to get everything, but I have a different track in mind. Sticking to students rather than just a generic non-scientist, I'd rather focus on the value of a physics education for both scientists and non-scientists alike. After all, many non-physicists and non-scientists are "forced" to take physics classes at various levels in their undergraduate education. How can we motivate these students of the importance of these classes, and what can they learn and acquire from these classes that will be useful to them not only in their education, but also in their careers and life?

I of course tell them the relevance of physics in whatever area that they major in. But even non-scientists, such as an arts major, can acquire important skills from a physics class. With that in mind, I'd like to refer to the NACE website. They often have a poll of potential employers and what they look for in new graduates that they are considering to hire. In particular, they were asked on what type of skills they tend to look for in a candidate.

The result can be found here.

I have extracted the info in this picture:

I often show this to my students because I highlight all the skills that we will employ and honed in a physics class. I tell them that these are what they can acquire out of the class, and to be conscious of them when we either tackled a physics concept and problem, or when they are working on an experiment. In fact, often times, I often try to get them to think on how they would approach a problem in trying to solve it, with the intention of emphasizing analytical skills.

I think as physics teachers and instructors, we often neglect to show the students the non-physics benefits of a physics class. A student, whether he/she is a physics, engineering, other science, or STEM major, can ALWAYS again an advantage if he/she has those skills that I highlighted above. This is why I've often emphasize that the skills that can be acquired from a physics class often transcends the narrow boundary of a physics topic, and can often be valuable in many other areas. These skills are not subject-specific.

I often notice the irrational and puzzling argument on TV, especially from the world of politics, and I often wonder how many people could benefit from a clear, analytical ability to be able to analyze and decipher an issue or an argument. So heck yes, non-scientists can learn A LOT from physics, and from a physics class.

Zz.

Friday, June 09, 2017

Host Interrupts Female Physicst Too Much, Audience Member Intervened

Hey, good for her!

The moderator of this panel interrupted physicist Veronika Hubeny of UC-Davis so much that audience member Marilee Talkington (appropriate name) got so frustrated that she intervened.

While watching a panel titled “Pondering the Imponderable: The Biggest Questions of Cosmology,” Marilee Talkington noticed that the moderator wasn’t giving physicist Veronika Hubeny, a professor at UC Davis and the only female on the panel, her fair share of speaking time.

So when the moderator, New Yorker contributor Jim Holt, finally asked Hubeny a question about her research in string theory and quantum gravity, then immediately began speaking over her to explain it himself, Talkington was furious.

Fed up with the continuous mansplaining, Talkington interrupted Holt by yelling loudly, “Let her speak, please!” The crowd applauded the request. 

You can read the rest of the story here.

Certainly, while it is awfully annoying, based on what Dr. Hubeny described, she didn't think it was a blatant sexism. Rather, she thought that the host was just overly enthusiastic. But you may judge that for yourself if the host didn't give the only female member of the panel a chance to speak.



But yeah, good for Ms. Talkington for intervening.

Zz.

Friday, June 02, 2017

50 Years Of Fermilab

Don Lincoln takes you on a historical tour of Fermilab as it celebrates its 50th Anniversary this year.



Zz.

Thursday, June 01, 2017

Planning For A Future Circular Collider

The future of the next circular collider to follow up the LHC is currently on the table. The Future Circular Collider (FCC) is envisioned to be 80-100 km in circumference (as compared to 27 km for the LHC) and reaching energy as high as 100 TeV (as compared to 13 TeV for the LHC).

Now you may think that this is way too early to think about such a thing, especially when the LHC is still in its prime and probably will be operating for a very long time. But planning and building one of these things take decades. As stated at the end of the article, the LHC itself took about 30 years from its planning stage all the way to its first operation. So you can't simply decide to get one of these built and hope to have it ready in a couple of years. It is the ultimate in long-term planning. No instant gratification here.

In the meantime, the next big project in high-energy physics collider is a linear collider, some form of the International Linear Collider that has been tossed around for many years. China and Japan look to still be the most likely place where this will be built. I do not foresee the US being a leading candidate during the next 4 years for any of these big, international facilities requiring multinational effort.

Zz.