Saturday, October 31, 2015

Leo Kadanoff

This past week marked the passing of a giant in the field of physics - Leo Kadanoff. The public won't know  him, but those of us in physics, especially in Condensed Matter and Statistical Physics, will have heard of him and his numerous contributions to these field of studies.

“Leo was a prodigious scientist,” said his longtime UChicago colleague Sidney Nagel, the Stein-Freiler Distinguished Service Professor in Physics. “His work on statistical mechanics is one of the great achievements of 20th-century theoretical physics. It laid the conceptual and mathematical foundations for some of the most insightful and effective tools on which our modern understanding of nature is based.”

Kadanoff’s work has applications throughout physics, ranging from condensed matter (liquids and solids) to elementary particles, Nagel said, with the reach of his work extending to mathematics and other sciences.

I mentioned about the review paper that he wrote phase transition and the mean-field theorem quite a while back. And of course, those of you who had subscribed to Physics Today for a long time would have read his rather critical review of Stephen Wolfram's book "A New Kind of Science", in which in the end he said "... I cannot support the view that any “new kind of science” is displayed in NKS. I see neither new kinds of calculations, nor new analytic theory, nor comparison with experiment...." That rather sealed the deal for me.

He will be sorely missed.


Tuesday, October 27, 2015

"I Want To Do High Energy Physics"

So you are a physicist in the US, and you're having a casual conversation with a bunch of new physics graduate students. When you ask them what they intend to major in (a very obvious question to ask in a situation like this), some of them say "I want to major in high energy physics".

What do you say in return? Do you just say "Well, good luck!" and leave it at that? Or do you feel a sense of responsibility to tell these students of the prospect that they will face here in the US for someone with that major?

This issue is nothing like the issue with students wanting to do "theoretical physics", because these students, presumably, a smart enough to know the area that they are going into. However, while they have a good idea of the nature of the subject matter, they have very little idea of the funding, job prospects, etc. of those people who graduated with that degree. And for HEP, the outlook is even bleaker than a lot of the other areas in physics for someone who wants to have a career in that field. The US funding for HEP has consistently been cut year after year, and especially more so after the Tevatron at Fermilab shut down. While many in the US collaborate on work done at the LHC, funding for the HEP division of DOE's Office of Science continues to shrink, and it doesn't look any better in the future.

So, knowing all this, what would you say to such students? Do you try to persuade them to change their minds and tell them that it is not to late to switch to a different field of physics? Do you lay out the reality of the situation? Do you tell them that if they still wish to continue, they need to be prepared for the possibility that they will not be able to pursue a career in such a field?

In my case, walking away and not say anything is not an option. I somehow feel some level of "paternal" responsibility towards these kids, and I can't just let them go into something blindly without at least giving them some dose of reality. Whether they listen to it or not is an entirely different matter, but at least I tried.


Thursday, October 22, 2015

Local Realism - Is It Dead Yet?

There have been several tests that have been conducted that pointed to the violation of local realism and consistent with quantum mechanics. I've indicated at least two recently (this, and this). Now come the most spectacular demonstration yet of such violation, and this one comes from what the authors claim to be an experiment free of the detection loophole and locality loophole.

The preprint appeared a while back on ArXiv, but the paper has finally been published in this week's issue of Nature (Oct. 21, 2015). So even if you don't have access to the Nature article, you should be able to read the preprint.


Wednesday, October 21, 2015

What Is A Multiverse?

Good question. This video might address that:

I must say that the majority of instances that I come across a discussion of Multiverse is online, in a forum where non-physicists are more apt to be impressed by it and to even consider it seriously. Maybe I don't hang around too many physicists who are working in this area, but the overwhelming majority of physicists that I encounter couldn't be bothered by this topic.

Now, it is not that they, and I, are dismissing it. Like Don Lincoln in the video, I think I'll pay more attention to it, and put time and effort to try and appreciate it ONLY when there are strong indications that such an idea might be right. This means that there are signs of observational/experimental agreement that distinguish  it from other theories. Until that happens, Multiverse is nothing more than one of the numerous ideas out there that cannot be tested and have no experimental verification.

That isn't harsh, is it?


Sunday, October 18, 2015

Come Out, Physicists. Come Out Where Ever You Are!

This post came about after I heard one of my colleagues introduced himself at a party. Someone asked him what he did for a living. His answer was "Oh, I'm a College Professor". Which is true. But he is a physics professor, and more often than not, he is also a physicist. But I found it rather fascinating that he would introduce himself as a college professor first. I suppose that is more understandable to most people than telling them you are a physicist.

So when you see the word "Occupation" on a form, what do you write? I suppose if you are a physicist working in a lab, and that's all you do (i.e. you're also not a college instructor), you may write "Physicist" in that section. Or do you write "Scientist" instead, to make it more descriptive?

I have described myself as a "Physicist" when someone asked for my occupation. Half of the time, people kinda knew what it was, although their impression  of it may be wrong ("Oh, you work with nuclear bombs?" or "Oh, you work with at that big particle lab?"). But the other half of the time, I get this blank, puzzled look and I get asked "Oh? What is that?" The last person who had that reaction  was a new dental hygienist at my dentist. I didn't feel like explaining  too much because she was about to work on my mouth.

So let's face the fact. There aren't a lot of us out there. The general public does not bump into a physicist very often. In fact, in my wide circle of friends who are not connected with work, I know of no other physicist. I had never, EVER, bump into another physicist in a social setting that is not related to work, or not related to a colleague from work. The probability of one physicist bumping into another physicist outside of work/conferences/mutual work friends is almost as low as detecting a neutrino.

To their credit, some of the people that I've bumped into, when told about my occupation, were  curious enough about some of the stuff they've read to ask me questions. I don't mind that at all. I am fully aware that most people have never met a "physicist", and the fact that they have read these things and curious enough to ask me about it was an opportunity not only to educate, but also to correct any misconception and misunderstanding that most people have about many things.

But what if you were minding your own business, and you accidentally eavesdropped on a conversation that was full of inaccurate or outright wrong information? What if, say, you were riding on a train, and the people behind you were talking about the LHC and all the doomsday brouhaha that it would do based on what they've read in the news? Do you just ignore it and let them continue on with their lives with such ignorance, or  do you put down the iPad you were reading, turn around, and tell them all the wrong information that they've learned?

Guess which one I did?

Someone once asked me, at a social gathering, if we all should be worried that Fermilab might explode like a nuclear bomb just like a nuclear reactor. This was when the Tevatron was still running. After I recovered from my shock at that question, I asked this person what made him think that such a scenario was even possible? He just shrugged and said that he thought all nuclear experiments were like that and had that possibility.

After I told him that (i) Fermilab is not a nuclear facility; (ii) it doesn't have a nuclear reactor; and (iii) the experiments cannot, in principal, explode like a nuclear bomb, I proceeded in explaining to him what the experiment was about and why, really, in terms of safety, it is rather benign, especially with how difficult it was to maintain the colliding proton-antiproton beam. But it got me to think that, if someone who is above-average in education like  him can have such an impression, how do others think and understand all these things?

And that is why, I believe that physicists need to come out of the closet and make themselves known to the average Joe and Josephine. There aren't that many of us when compared to other profession. The general public needs to bump into one of us on a personal level. Wear that "Kiss Me, I'm a Physicist" t-shirt with pride!

But please, comb your hair and leave behind that pocket protector.


Tuesday, October 13, 2015

Physics Demo As An Off-Broadway Show?

It is ambitious, but it is so crazy, it might just work.

"The Physics Show" has been put together as an off-Broadway theatrical presentation, with the hopes of not only informing people about simple concepts in physics, but also be entertaining enough that people will pay to see it like any ordinary Broadway or off-Broadway show.

The idea to turn the show into a play came after Maiullo did his demonstrations in a theater appreciation class taught by Krebs, he said.

Krebs, a Rutgers alumnus and founder of the George Street Playhouse, strives to make theater more accessible to people who are not familiar with it, he said. He has been involved with the business for nearly 50 years.

Krebs saw Maiullo doing a demonstration and thought to present it to his theater appreciation class as a theatrical piece instead of a science demonstration. Maiullo did his demonstrations for multiple semesters, and the two have been thinking about making it an off-Broadway show for years, Krebs said.

I think the most important aspect for this thing to be successful is if it can be entertaining enough. And that requires showmanship and a lot of bells and whistles. Whether it can be educational in return, that remains to be seen. After all, how many people actually understood the physics involved in "Copenhagen" after seeing the play? Still, this particular presentation has a bit of an advantage because the entire show involves explanation of the physics. So maybe it will be different.

This is not too far out there. Physics demo shows such as Wonders of Physics that originated out of the University of Wisconsin-Madison, have been quite a hit with its traveling show. So maybe people will pay to be entertained and informed at the same time. We shall see.


Monday, October 12, 2015

More On Neutrinos

People seem to want to learn more about neutrinos! With the latest Nobel prize being awarded to the discovery of neutrino mixing, it is a good time to have some general article on what we know about neutrinos. John Beacom has written a rather nice article here that should give you an idea of the physics of neutrinos and why it is an important study.

It just struck me as a rather interesting development. When SNO and Super-K were discovering all this, there was hardly any neutrino experiment in the US. Oh, there was plenty of US participation, but neutrino experiments were not big or a priority. This is understandable because, back then, the Tevatron was still going strong and LHC hasn't completely come into force yet. Now, how things have changed considerably. With the Tevatron gone and the center of high energy physics collider having shifted to CERN, the US is now trying to be a major player in neutrino studies, with MINOS, NOvA, and the proposed LBNE. In DOE/funding lingo, the US has abandoned the "Energy Frontier" and has gone into the "Intensity Frontier".

I believe there are still huge amount of amazing physics to be discovered from neutrinos. So it will be interesting how all these new generation of neutrino detectors will pan out.


Wednesday, October 07, 2015

2015 Nobel Prize Work Free To Read

As a follow-up from yesterday's announcement of the 2015 Nobel Prize for Physics, the APS has made available the publications that are directly related to award to the two recipients this year.

Evidence for Oscillation of Atmospheric Neutrinos

Measurement of the Rate of νe + d → p + p +e Interactions Produced by 8B Solar Neutrinos at the Sudbury Neutrino Observatory

Direct Evidence for Neutrino Flavor Transformation from Neutral-Current Interactions in the Sudbury Neutrino Observatory

Notice my earlier point, as you look at the authors list on each of these papers, that they were a huge amount of collaborators on these projects.


Tuesday, October 06, 2015

2015 Nobel Prize For Neutrino Oscillation Discovery

The 2015 Nobel prize in physics went to Art McDonald and Takaaki Kajita for the discovery of neutrino oscillation at SNO and SuperKamiokande, respectively.

Now, for those readers who are not familiar with all this, do not get the impression that these two were working all by themselves and then discover these. They did not. There were huge number of people who were working on these projects, and the papers they produced listed a large number of authors. However, these two were either the leading scientist or the most prominent/significant figure representing each group. This is not unusual for an experimental discovery, especially in elementary particle physics, where the most prominent figure is singled out for the award.

When I read this, I must admit that I was a bit surprised. Not surprised that they are awarding it for the discovery of neutrino oscillation - it IS a major discovery. I was surprised because I somehow thought that this discovery had already been awarded the Nobel prize already! I mean, it was such a significant moment, and it is now already accepted that neutrino oscillation is a fact, that I somehow assumed the  Nobel prize had already been awarded for this discovery years ago. Obviously, I hallucinated that one.

Maybe the Nobel committee were debating all this time on who should deserve to receive the prize, considering the huge number of people involved, with several prominent physicists deserving it on each group.

In any case, the prize for this discovery was long overdue.


Monday, October 05, 2015

Physical Review Letters Tightening Its Standards

If you have submitted a manuscript to Phys. Rev. Lett (PRL) lately, or have been asked to referee a paper for the journal, you would have noticed an additional emphasis on the nature of the material that PRL considers to be "publishable":

To be publishable in PRL a paper must do at least one of the following: Substantially advance a particular field; open a significant new area of research; solve a critical outstanding problem and therefore pave the way for notable progress in an existing field; be of singular appeal to all physicists.

While this guideline isn't new (I kinda assumed that this is the standard that PRL had been adhering to all along), it is rather interesting that this is now clearly and explicitly emphasized. And, I must add, enforced, because I think I am an unfortunate recipient of the enforcement of this policy when one of our submission was rejected by the PRL editors.

Now, of course I'm biased since I was a coauthor, but before this, the manuscript would have been strong enough to have made it to the referees. After all, the original theory was published in PRL, and an experimental paper that partially tried to show a proof-of-principal demonstration also made it into PRL. Our paper showed not only a demonstration of a very critical aspect of the theory, but also where it deviated from our measurement. So we thought it was important enough, and certainly, important enough to make  it to the PRL referees.

But nooooooo.....

The rejection from the editors basically said that the content was not up to standard or not suitable. I know they are busy and inundated with tons of these stuff, but these are the times where you wish they could be specific and tell you exactly what they mean and what they were referring to rather than just some standard response. But of course, all of us listed on the paper were surprised that it didn't even make it past the editors. Usually, unless your manuscript is badly written, is clearly out of whack, or it can be seen that it is of a rather obscure topic, it will make it to the referees. But with their new policy, and also trying to lighten the burden on the referees, the editors have become a more significant gatekeepers.

So essentially, PRL is slowly becoming Nature and Science. :)

Now, don't get me wrong. It is not a criticism. I'm all for raising the standards, and the submission rate to PRL is  huge. Keeping things they way they were is simply not sustainable and they will run out of referees who would be willing to perform the review. Still, I wish the editor would briefly provide a reason why, because I'm sure we could easily provide a counter argument; or maybe that is why no reason was provided.

In any case, rather than continuing on to purse this with PRL, we sent it to another publication.

Ironically, a couple of weeks after the PRL rejection, I was contacted by PRL to referee a paper! :)


Friday, October 02, 2015

25% Of Physics Nobel Laureates Are Immigrants

The people at Physics World have done an interesting but not surprising study on the number of Physics Nobel laureates who are/were immigrants. They found that this number is more than 1/4 of all Physics Nobel winners.

They discussed what they used as a criteria of an "immigrant", and the chart they showed certainly is very clear that there is a huge influx of these  talents into the US.

Still, it would be nice to see how many of these immigrants did their Nobel Prize winning work before they migrated. And I definitely want to see this statistics for the next 10-20 years, especially now that they US is severely cutting budgets into basic physics research, the effects of which will not be felt immediately.

In any case, it is that time of the year again where we all make our predictions or  guesses on who will win this prize this year. I am still pinning hopes that a woman will win this, considering that we have been having very strong candidates for several years.