Friday, April 26, 2013

Female Physicists Doctoral Experiences

I haven't had time to read this paper in its entirety, but that should not prevent me from highlighting it here. You should be able to download the paper for free.

Abstract: The underrepresentation of women in physics doctorate programs and in tenured academic positions indicates a need to evaluate what may influence their career choice and persistence. This qualitative paper examines eleven females in physics doctoral programs and professional science positions in order to provide a more thorough understanding of why and how women make career choices based on aspects both inside and outside of school and their subsequent interaction. Results indicate that female physicists experience conflict in achieving balance within their graduate school experiences and personal lives and that this then influences their view of their future careers and possible career choices. Female physicists report both early and long-term support outside of school by family, and later departmental support, as being essential to their persistence within the field. A greater focus on informal and out-of-school science activities for females, especially those that involve family members, early in life may help influence their entrance into a physics career later in life. Departmental support, through advisers, mentors, peers, and women’s support groups, with a focus on work-life balance can help females to complete graduate school and persist into an academic career.


Thursday, April 25, 2013

Secrets Of The Dark Universe: Simulating The Sky

I'll post the synopsis to this video, which you can also read on YouTube:

An astonishing 99.6% of our Universe is dark. Observations indicate that the Universe consists of 70% of a mysterious dark energy and 25% of a yet-unidentified dark matter component, and only 0.4% of the remaining ordinary matter is visible.

Understanding the physics of this dark sector is the foremost challenge in cosmology today. Sophisticated simulations of the evolution of the Universe play a crucial task in this endeavor.

This movie shows an intermediate stage in a large simulation of the distribution of matter in the Universe, the so-called cosmic web, accounting for the influence of dark energy. The simulation is evolving 1.1 trillion particles. The movie shows a snapshot of the Universe when it was 1.6 billion years old.

While this video may be obvious to people in the field, it would be nice if they had some narration to accompany each scene so that we know what we are looking at! After all, they went to all this trouble to make a visual representation of the simulation and posting it on YouTube for the public to see. Might as well put a little bit more effort in telling us what each of those different scenes are. Otherwise, all we see are cool images without learning anything much.

Of course, the physicist in me would like to know what kind of parameters were used, what are the assumptions, where was this/will this be published, etc. Y'know, the mundane stuff! :)


Wednesday, April 24, 2013

You Can Teach Yourself To Think Like A Scientist - Part 2

{You Can Teach Yourself To Think Like A Scientist - Part 1}

OK, I'm trying to pick up this series again, hopefully with less typos and grammatical errors (hey, you have to expect these things especially when many of my blog entry are written on the fly).

The idea behind this series is to emphasize the notion that many of the decisions on how we live and behave are due to how we arrive at certain ideas or knowledge. I truly believe that the more we realize that we need to use the same scientific methodology in arriving at decisions and actions that we do everyday, the better off we are.

It has been raining a lot in the Chicago area the past couple of weeks. I was in a friend's vehicle during one of a rainy period, driving to somewhere. He had his windshield wipers on, and driving rather slowly. I told him that he could speed it up a little so that we get there faster. He told me he is just abiding the law, and driving just below the speed limit that was posted. I told him if he was so concerned about abiding the law, why didn't he have his headlights on? He had no answer.

{Here, in Illinois, the law says that when you have your windshield wipers on, you must have your headlights on as well}

One of the things I see very often here is that people often justify their actions because they are following some more generalized principle. In the example I relayed above, my friend was living by the principle of "abiding the law". A consequence of living by this principle is "driving under the speed limit". But as we all know, there are OTHER CONSEQUENCES of the principle of "abiding the law". I mentioned one of them, "wipers on, lights on". Yet, my friend didn't do this, and chose to ignore it, without any explanation.

So now, we are left to speculate on why that is. Is he truly living by the principle of "abiding the law"? Or is he really living by the principle "abiding by the law that I find convenient and the one that I remember"? If he is doing the latter, then simply espousing the idea that he is living by the principle of "abiding the law" is highly inaccurate. If you live by a certain principle, then you must follow and do all that principle asks you to do. You cannot pick and choose. If you do, you are no longer living by that principle, but rather, living by a modified form of that principle. This, you must clarify or you are conveying the wrong information.

In physics, any general idea, principle, or theory has a body of outcomes and consequences. Special Relativity, for example, makes many different predictions. Each one of them must be tested and confirmed. If any of the predictions and consequences do not match experimental observations, then (i) either the theory is wrong or (ii) there's new physics beyond what that theory can predict. We simply cannot pick-and-choose. This means that if something doesn't work all the time, we must know clearly where that boundary is, and this must be made very clear so that people know that beyond this boundary, it no longer works.

To think like a scientist in this case is to make a clear analysis on what the general principle is that people are using to justify their actions or arguments. You need to sit back, and figure out if what someone is arguing is based on some central principle or belief. Let's apply it to a hot topic of the moment, the debate on gay marriages. It is a hot topic here in the US at the moment, and it is certainly is one in France right now.

One of the most common argument against gays, and against gay marriages, that I've heard is that it is "not natural". Some of these people tried to "intellectualize" the argument against it by taking out the religious aspect of it, and using Mother Nature as the argument. So let's apply our analysis that I stated above. What is the overriding principle involved here? Of course, it is the principle of living "naturally", obeying what is natural, or opposing what is "not natural". Let's look at this critically.

First of all, what actually is meant by "natural"? Is it what would happen if left on its own without human intervention? Is it what can be found in nature without any artificial means or intrusions? Let us adopt both.

If these people are living by the principle of upholding what is "natural", then:

1. Does that mean that everything that is natural is OK and can be practiced by human beings? This includes animals eating and devouring their youngs that they know won't survive, and having multiple sexual partners, which is prevalent in the animal world.

2. If they are opposed to everything that is not natural, then they should also question other unnatural human behavior, such as clothings, shaving, circumcision (now what could be more unnatural than cutting off a piece of one's body?), etc.

Yet, these people who opposed gay marriages on the grounds that it is "not natural" (the principle involved here) do not oppose other unnatural aspects of human life. So are they like my friend who drove very slow, but chose to ignore turning on his headlights? Are they arguing against something "not natural", but with caveats? Are they closer to living the principle of "I oppose things that are unnatural, but only limited to my own personal dislike of certain behavior". Or maybe "I oppose things that are unnatural that are dictated by my religious beliefs. Other unnatural things are fine."

Either one of those will be significantly more accurate than simply stating that one is opposed to something because it is "not natural". The reason why this must be made explicitly clear is that knowing what principle is involved provides a very well-defined boundary condition and playing field. You clearly know that this really isn't JUST about something being unnatural. There are other factors involved. The analogy to physics is that this isn't just a simple trajectory motion. Other external factors such as wind resistance is involved. So the discussion (or arguments) can be framed within such boundary conditions. That other person is arguing against something based on a number of factors, not just because it is "not natural", the same way my friend was driving slow not just because he's obeying the law.

And interestingly enough, I find that some of the people I talked to, often do not realize this aspect themselves. In other words, those who opposed gay marriages by using the argument that it is "not natural", often truly believe that that is all the reason for such opposition. Like my friend, when I asked them whether they also oppose circumcision and wearing of clothing, and shaving, they looked at me funny. It often never occurred to them that there are other unnatural human behavior, and yet, these never bothered them. What is happening here is that they never examined ALL the consequences and outcomes of adopting such a principle. They never carefully thought through what other unnatural behaviors and practices are out there. Just because wearing clothes is normal, it doesn't mean it is natural. Just because one is familiar with something doesn't make it "natural", based on our definition above. Just like my driving friend who never considered the fact that living by the principle of abiding the law means that one has to abide by ALL the laws, these people also never made such consideration of living their lives without anything "not natural".

In physics, knowing what the general principle is is extremely important. It is the origin and the source of many other things, and we understand the limits, the boundaries and what can and cannot be done based on that overriding principle. A lot of  arguments that I've seen among the public and in politics are often arguments of the consequences of such-and-such a principle. Some politicians want to cut spending because they live by the principle of "small government" or some other things. Yet, if you examine carefully, the principle that they live by are not well-defined, and more often than not, they adopt it inconsistently, applying it here, while ignoring it there - cut spending and budgets for science funding, social programs, etc, while continue to increase military spending (drive under the speed limit, but ignore to turn on the headlights).

My personal diagnosis on all of this is that, many people FIRST adopt the CONSEQUENCE (i.e. oppose gay marriage, oppose funding social programs, don't want to drive fast), and THEN went back and find some general principle to justify their position (not natural, want to cut spending, want to follow the law). Now, there's nothing wrong with that. It is done in science too. In physics, we tackled problems such as the Blackbody radiation, which then eventually led to a more general principle of quantum mechanics. Only later on, do we realize that the blackbody radiation is a consequence of QM. But once QM has been formalized, we adopt ALL of QM as we learn more and more about it. We continue to test it, and explore the boundary of its applicability.

Unfortunately, this is not true in the cases of human decision that I've stated above. There was never any self-diagnose of one's adoption of some overriding principle. Those who adopt the opposition to things that are "not natural", never examined if they are opposing ALL of things that are not natural, because they are not! My friend never examined if he truly is living by the principle of abiding the law, because he wasn't.

So the central principle of this entry is the examination and the consequences of a central principle. Isn't that neat? :)


Tuesday, April 23, 2013

APS April Meeting Plenary Session Videos

In case you didn't attent this year's APS April meeting, the plenary session videos are online.


Sunday, April 21, 2013

"Do You Read Science Fiction Books?"

I wrote a while back on one of the most frequent question that I get asked once people find out that I'm a physicist. "Do You Watch "The Big Bang Theory"?" is one of them. The one other most common question: do you read science fiction books? They think that since I deal with a lot of science, then reading science fiction would be almost second nature.

Simple answer: I don't!

First of all, I seldom read fiction books. I seldom read books anymore, actually. I just can't have any long-term relationship with a book of any kind. I do so much reading in a day, the last thing I want to do when I wind down is read some more. So putting in a lot of time to read and finish a novel is not my idea of a good time.

Secondly, while I know of many scientists who enjoy reading science fiction novels, and many find them "stimulating", I don't. This is because I often find it a bit annoying that that some parts of logic, reality, and even some aspects of physics is "bastardized" to such extent. I suppose it is my problem that I simply can't let go of reality when I try to read such novels. While I do enjoy watching sci-fi movies, I find them to be more of an entertainment for a couple of hours, view them more for the story than for the accuracy. The exception being some of the more awful sci-fi movies that simply makes no sense and force you to suspend logic and reality way too many times.

Lastly, many of the sci-fi novels tend to use the more "sexy" aspects of physics, but they miss many more fascination parts that do not get wide press coverage. This is where I find stuff in physics a lot more imaginative and a lot more fascinating than even some of the most outlandish imagination in sci-fi. The concept of "phase coherence" is a conerstone in quantum mechanics. But has it been used and depicted in sci-fi novels? Or what about the fact that in 1D conductors, the many-body effect of spin-charge separation would cause a "particle"'s spin and charge to move separately?

These are details that those who are not in physics would not have understood, and thus, unable to exploit. Yet, to me, they are extremely fascinating. If I were a sci-fi writer, I could make one heck of a story using those principles alone.

As imaginative as sci-fi stories are, I find actual physics to be significantly more fascinating. So kids, that is why I don't really read science fiction books.


Friday, April 19, 2013

Self-Assembling Nanoparticles

This is a video showing nanoparticles self-assembling into a larger structure.

This brings me to a related topic on evolution. One of the arguments that I often hear from those who oppose the concept of evolution is the idea that the probability of life occurring out of this random mess is extremely small that it should have never happened. Thus, the idea out of evolution that we call came about due to this random formation of life in the beginning, and then slowly evolve over time, can't be correct.

The few so-called estimates on the probability calculation that I have seen never ever mentioned, or take into account, something that many of us in condensed matter are aware of, which is this very fact that there are phenomenon of self-assembly of atoms and molecules. We know this happens. Each time we have ice crystals, or see naturally-formed quartz, etc., those are naturally-occurring self-assembly. What are the odds of those things being formed simply via random arrangements or capture of atoms? The fact that they do form, and form pretty frequently, means that the phase-space for that happening isn't that small, and actually is quite high.

So I can't help wondering if that such self-assembly, especially when there is a change that causes a form of phase transition, might play a role in the formation of life or single-celled form of life. And because of that, the chances of it happening isn't as small as it is made up to be.


Let's Measure the Diameter of the Sun

Hey, Forstbite Theater is back! In this video, they show a demo on how to measure the diameter of the sun.


Thursday, April 18, 2013

Parallel Universes: Many Worlds

Here is Minute Physics take on the 'ever popular' Many Worlds/Parallel Universes picture of quantum mechanics. While this view may make it easier to digest certain conceptual issues of QM, it also creates a whole slew of other issues that I find hard to swallow. As is the case, you might solve one, while creating other set of messes.

As an experimentalist, until there is an ability to test one versus the other, I'll stick to the "Shut up and calculate" view. It is less stressful! :)


Wednesday, April 17, 2013

Peter Higgs: In His Own Words

Here's a fascinating interview with the man of the moment, Peter Higgs.

1. He got into theoretical physics because he was "incompetent" as an experimentalist:

That sort of set the scene for me and when I chose to go to university, which was Kings College London, I continued to show all sorts of symptoms of incompetence in the lab while I was a student there. So very early on, I was heading towards the theoretical end of physics as the only kind of thing I was competent in.

2. He thinks that the field that has been named after him should have been called the Goldstone field instead:

It shouldn't be a Higgs field. If it's anybody's it should be Goldstone field, I think. When Nambu wrote his short paper in 1960, Jeffrey Goldstone of Cambridge University, who was visiting Cern, heard about it. He then wrote a paper which was conceptually similar to what Nambu had done, but a simpler model.

3. He doesn't like the name "god particle". In fact, I know of no physicist who does!

That name was a kind of joke, and not a very good one. An author, Leon Lederman, wanted to call it 'that goddamn particle' because it was clear it was going to be a tough job finding it experimentally. His editor wouldn't have that, and he said 'okay, call it the God particle', and the editor accepted it. I don't think he should've have done, because it's so misleading.

4. He thinks, as I concur, that the LHC should have sold itself in a broader term, rather than being popularized as a machine to look for the Higgs. As I've said many times, no one and no institution would fund something THIS expensive just to do ONE thing.

I was a bit unhappy about the way it was being sold. Not because I didn't think they should go after the Higgs Boson, of course, but I thought they should have educated people more about the breadth of the programme of the machine, and not concentrated on this so much. It seemed to me they were taking a risk that when they found the thing, then a lot of people would say 'oh well, that's it, isn't it? Why do we still want this machine?

5. His reaction to the announcement at CERN that the Higgs might have been found:

I didn't accept it was me that they were cheering. I regarded it as cheers for the home team, as at a football match, and the home team were the two experiments, Atlas and CMS, with 1,500 members each. That's what it was really about. Maybe they were cheering me too but that was a minor issue.
Don't miss an earlier spotlight on Peter Higgs that has a bit more in-depth coverage of the history leading up to the formulation of the Higgs field.


Tuesday, April 16, 2013

Possible Detection of WIMPs?

A preprint that was just released from the CDMS collaboration indicates a strong possibility of detection (finally!) of WIMPs. which is a candidate for dark matter.

You can also read a press coverage of this here.


Monday, April 15, 2013

Fair-Sampling Loophole Closed

Another Bell-type experiment out of the Zeilinger's group, and this time they have effectively closed the fair-sammpling loophole in this experiment.

This kind of tight monitoring is important as it closes an important loophole. In previous experiments on photons, there has always been the possibility that although the measured photons do violate the laws of classical physics, such non-classical behaviour would not have been observed if all photons involved in the experiment could have been measured. In the new experiment, this loophole is now closed. "Perhaps the greatest weakness of photons as a platform for quantum experiments is their vulnerability to loss – but we have just demonstrated that this weakness need not be prohibitive," explains Marissa Giustina, lead author of the paper.

I will not be surprised if we will soon see in one experiment where ALL the loopholes are closed simultaneously.


Sunday, April 14, 2013


Another video out of JLab, and this time it is on lasers.

However, this video only describes the different types of lasers, and says nothing about the principles behind it. It didn't even describes what a free-electron laser is, even though the person in the video works with FEL. Too bad!


Thursday, April 11, 2013

Fund Me, Maybe

OK, so I may be late getting to the party, since this video obviously has gone viral without my knowledge of its existence till recently (thanks to Lavabug at Physics Forums). Still, if you haven't seen it, it is hysterical.

From the description, the video footage was captured during the 221st meeting of the American Astronomical Society in Long Beach, CA.

With the US Science budget in the dumps during this budget sequestration, maybe all of us need to make such a video!


Wednesday, April 10, 2013

Recent Physics PhDs - Skills Used and Satisfaction With Employment

The AIP has released its latest statistics on recent PhDs. This one is from the graduating class of 2009 and 2010, meaning that these people graduated and entered the job market at the height of the economic meltdown. This survey asked about the skills used in their jobs, and the level of satisfaction in those jobs.

The non-surprising aspect here is the set of skills needed between postdocs and those in the private sectors:

Differences by type of position can be readily inferred from the previous figures. Postdocs were far more likely than PhDs in the private sector to regularly do basic research and utilize advanced physics principles regularly in their work. A large proportion of PhDs in the private sector were regularly involved in design and development, applied research, and quality control.

These differences reflect inherent differences in these types of employment; postdocs are temporary positions with research agendas largely motivated by scientific exploration, while jobs in the private sector typically involve producing a tangible product for a customer or providing a service to a client.
A lot of data also on the job satisfaction, and whether they had sufficient mentoring from their advisors.


Review of "Nuclear Forces: The Making of the Physicist Hans Bethe"

Here's another name that is a giant among physicists, yet it isn't a household name for the general public. This is a book review of of a recent biography of Hans Bethe published in this month's issue of Physics Today.

Of course, my admiration for Bethe can be summed up in this paragraph of the review:

Among the most pervasive features of Bethe’s emerging style was his fundamental criterion that theory must be grounded in real-world observation—a view he shared with other young physicists in his circle, including Edward Teller, Rudolf Peierls, Nevill Mott, Enrico Fermi, and later Richard Feynman. Bethe’s physics would not be aimed at formulating radically new ideas, but rather at critically analyzing and extending theories and formulating models that could test their validity.

This is probably a good book to read about Bethe. I plan on getting it, but if you have read it, I'd like to hear your views on it.


Sunday, April 07, 2013

The Man Who Put His Head In A Particle Accelerator And Survived

OK, it is highly recommended that one doesn't try this. But it is still an amusing story.

Of course, if this were to happen today, in the US, there's a good chance that several major safety violations would have occurred and this facility would have been shut down.


Friday, April 05, 2013

What Is An Electron?

OK, I am normally a fan of videos produced out of JLab (check the series of educational and hiliarious FrostBite theater videos). Unfortunately, this is a rather surprisingly weak production coming out of this lab, explaining what an electron is:

OK, a "tauon"? Is this really the common name that is used in place of the tau? The Standard Model chart that we distribute to people, and also the particle data book, both call this a "tau". I know we are arguing about something as trivial as the name here, but really, if there's no reason to call the same thing with different names, then we shouldn't!

But the bigger problem is this. He said "electrons are so small, we haven't been able to measure it.."!!! This is extremely misleading and possibly erroneous. We HAVE been able to measure it! That's how we know it has a charge, a spin, etc.. etc. What we haven't been able to measure, and what I think he meant, was that we haven't been able to measure its SIZE!

This is important because I can easily see getting someone coming into a physics forum, showing me this video and quoting this particular line as "evidence" that we haven't been able to measure an electron! Again, it is extremely crucial that, when we communicate to the public who has a weak understanding of science/physics, we pay extra attention to not only what we say, but how we say it. There are plenty of times where what we mean is not what they understood! This video contained way too many things stated almost in glib, and that's too bad considering the opportunity they had to inform and educate. It was as if this was done as an after thought.


Thursday, April 04, 2013

Planned Apple Building Costs Several Times More Than NSLS II

I some time shake my head at some of the twisted priorities we often have, and how little we value science, which is the seed for many of the future economic growth.

I was reading a report on the future headquarters for Apple that have been dubbed as the Apple "Spaceship". Maybe it looks like a spaceship to the general public (or reporters), but to me, it looks like a synchrotron center! :) But what caught my eye was the current projection of the cost to be at $5 billion. Now mind you, this is an OFFICE COMPLEX, costing $5 billion!

Since it looked like a synchrotron light source, I decided to look up ballpark costs of a synchrotron source being built right now, and I know of one - the NSLS II that has just been constructed at Brookhaven. I suppose I could scout around more carefully at what it cost to build this, but I found an early estimate for it, and it costs around $1 billion. Now, this is not just the building, but also includes all the "content", which is the accelerator complex, the storage ring, etc.. etc. Anyone who has deal in purchasing scientific equipment can attest that these components are not cheap, especially when they are custom made.

Now, obviously, I haven't compared the floor space and size of these two buildings, but c'mon! An office complex costing almost 5 times the cost of a complex, complicated, and an extremely important scientific facility? What do they have? Solid gold toilets? Or maybe they are secretly housing a particle collider in there to challenge the LHC! Coming to your nearest Apple Stores: the iCollider!

For $5 billion, we can do a lot of things in science that will produce immeasurable benefits and advancements. But until society realizes the value and how they have benefited from such investments, and until people who have rather short attention space realizes just how far in advance they have to invest into science to reap its benefits, this upside-down skewered priorities will never correct itself.


Wednesday, April 03, 2013

The True Science of Parallel Universes

For this one, MinutePhysics tackles the different models of "parallel universes". It took them more than a minute to do this, though... close to 5 minutes! :)

It boils down to 5 minutes of describing something that "has no experimental support" certificate! :)

Remember, kids. Physics is science, not philosophy! :)


AMS Confirms Excess Positrons

Hope you guys were following the announcement today.

In any case, APS has released the paper on the latest result from AMS, reporting and confirming earlier reports on the excess positrons measurement. You can get acess to the PRL paper for free from the link. What does this all mean?

There has been no shortage of speculation about what might cause the positron “excess” above 10GeV. One idea is that relatively nearby cosmic bodies, such as pulsars, act as accelerators and colliders that produce antimatter, much like our terrestrial Large Hadron Collider. But a more exciting possibility is that the positrons come from the annihilation of dark matter particles, which may populate the Milky Way and its halo. Dark matter is, after all, a dominant form of the matter-energy budget of the Universe, but we don’t know its particle nature or how it interacts with itself and with normal matter (other than through gravitational interactions). It is no overstatement to say that identifying the dark matter is one of the greatest problems in modern science.
A lot of work remains to be done, but unlike the search for Supersymmetric particles, there are experimental indications that are consistent with Dark Matter models.


Tuesday, April 02, 2013

Recent Results From The AMS Experiment

I don't know if the buzz surrounding this announcement will amount to anything, but there is certainly a buzz.

Samuel Ting will present the latest result from the Alpha Magnetic Spectrometer instrument that's orbiting earth. If you recall, the AMS went up with the Space Shuttle on one of its last missions. This could have some implications on the search for Dark Matter.

I probably won't have a chance to view the life feed. If you are planning on it, or if you have the chance to actually attend this event, I'd appreciate a brief report.


Lifting Lemon

This is a simple experiment, and variations of this have been done in many classroom demonstrations, I'm sure. But it still becomes a topic of discussion as to why it happens, as demonstrated by the discussion on this video's YouTube page.

This link provides an explanation for this effect.