CERN Sets Date For First Attempt At 7 TeV Collisions in the LHC

Press release from CERN:

CERN sets date for first attempt at 7 TeV collisions in the LHC

Geneva, 23 March 2010. With beams routinely circulating in the Large Hadron Collider at 3.5 TeV, the highest energy yet achieved in a particle accelerator, CERN has set the date for the start of the LHC research programme. The first attempt for collisions at 7 TeV (3.5 TeV per beam) is scheduled for 30 March.

“With two beams at 3.5 TeV, we’re on the verge of launching the LHC physics programme,” explained CERN’s Director for Accelerators and Technology, Steve Myers. “But we’ve still got a lot of work to do before collisions. Just lining the beams up is a challenge in itself: it’s a bit like firing needles across the Atlantic and getting them to collide half way.”

Between now and 30 March, the LHC team will be working with 3.5 TeV beams to commission the beam control systems and the systems that protect the particle detectors from stray particles. All these systems must be fully commissioned before collisions can begin.

“The LHC is not a turnkey machine,” said CERN Director General Rolf Heuer. “The machine is working well, but we’re still very much in a commissioning phase and we have to recognize that the first attempt to collide is precisely that. It may take hours or even days to get collisions.”

The last time CERN switched on a major new research machine, the Large Electron Positron collider, LEP, in 1989 it took three days from the first attempt to collide beams to the first recorded collisions.

The current LHC run began on 20 November 2009, with the first circulating beam at 0.45 TeV. Milestones were quick to follow, with twin circulating beams established by 23 November and a world record beam energy of 1.18 TeV being set on 30 November. By the time the LHC switched off for 2009 on 16 December, another record had been set with collisions recorded at 2.36 TeV and significant quantities of data recorded. Over the 2009 part of the run, each of the LHC’s four major experiments, ALICE, ATLAS, CMS and LHCb recorded over a million particle collisions, which were distributed smoothly for analysis around the world on the LHC computing grid. The first physics papers were soon to follow. After a short technical stop, beams were again circulating on 28 February 2010, and the first acceleration to 3.5 TeV was on 19 March.

Once 7 TeV collisions have been established, the plan is to run continuously for a period of 18-24 months, with a short technical stop at the end of 2010. This will bring enough data across all the potential discovery areas to firmly establish the LHC as the world’s foremost facility for high-energy particle physics.

Crossing fingers!

Zz.

Evolution and Earth's Entropy

A nice short paper on evolution and the earth's entropy. Here, the author estimated the difference in entropy of the earth between day and night.

Abstract: Entropy decreases on the Earth due to day/night temperature differences. This decrease exceeds the decrease in entropy on the Earth related to evolution by many orders of magnitude. Claims by creationists that science is somehow inconsistent with regard to evolution are thus show to be baseless.

It also strengthen the earlier arguments on this topic that I highlighted already. The moral of the story is that, if one understands physics (in this case, the 2nd Law of Thermodynamics) only SUPERFICIALLY, one can make many silly mistakes with it! This is why I dislike what Deepak Chopra is doing.

Zz.

Chopra Versus Shermer at CalTech and on Nightline - Follow-up

If you didn't read the earlier entry on the debate between Deepak Chopra and Michael Shermer at CalTech, you might want to catch up first.

One of my argument against Chopra is that he's using merely a superficial understanding of QM and applying it to where it doesn't belong or hasn't been shown to be valid. In fact, in that earlier article, he even agreed to get a lesson in QM by a theorist in the audience. Unfortunately, even with his admission that he doesn't know QM, it doesn't stop him from continuing with his ignorant "use" of it.

It appears that he has blog a rebuttal to that debate. And sadly, it continues to propagate the same faulty understanding of QM. His usage of the HUP is, to put it mildly, is very pedestrian.

It would be consistent with common sense if these particles, and the subatomic particles that they can be broken down into, were solid and stable in spacetime. But they aren't. Thanks to two breakthrough ideas -- the Uncertainty Principle and the Observer Effect -- nothing in Nature can be seen as solid and fixed in spacetime. The Uncertainty Principle says, in its simplest terms, that you cannot know the position of a particle and its momentum at the same time. The observer effect says that particles are only a superposition of possibility waves until a non-material observer causes them to collapse from one state, a wave, into another, a particle.

Already I can see readers glazing over, but these are important points for the existence of God and also for our existence. All solid objects exist, in essence, as invisible waves that extend infinitely in all directions. When an observer enters the picture, the wave collapses into a point, and that point is a spacetime event -- or a particle -- that you can measure. So it turns out that looking at a virtual electron (waves) causes it to appear as an actual electron (particle).

This, of course, isn't correct, because the HUP doesn't say anything about the accuracy of one single measurement of the position and one single measurement of the momentum. This is a common misconception of the HUP.

But the amusement doesn't stop there. He then tried to argue that quantum effects can be extended to "large" scale.

On the side of materialism, Shermer and many others say no. Quantum behavior, or as Shermer calls it "Quantum weirdness," is confined to the microscopic world. It doesn't leak into the macroscopic world of rocks, trees, clouds -- and the moon. But there are three weaknesses in this argument:

1. Recent discoveries have produced quantum weirdness on the macroscopic level. See this article about "supersizing" quantum mechanics

2. Quantum physics is behind all kinds of technologies used in the big everyday world: transistors, superconductors, experiments with superfluids. There are even cutting-edge experiments with time travel and teleportation, very Star Trek, although so far the results are on the level of light beams, not Scottie and Captain Kirk.

3. Most crucial of all, if you don't allow quantum phenomenon to interact with the big world, you run into a huge problem with physics itself. Quantum physics is the basis of our macroscopic physical world, so there has to be an interaction, even if that interaction is not fully understood.

Let's tackle this one at a time, shall we?

1. Look at the amazing set of conditions that a system HAS TO BE PUT UNDER for the quantum effects to show up. It has to be cooled down to ridiculously low temperatures, it is completely isolated from the environment, etc.. etc. In other words, it is NOT EASY to observe quantum effects in progressively larger and larger systems! Why? Because thermal noises and interactions with the environment can easily destroy the coherence of the quantum effects! He cited the news reports of such a thing, but he did not understand the physics, nor the experiment, on how we were able to observe such a thing. It is another clear example of my claim that he and his minions only know QM superficially, but still have no qualms and "using" it without any fundamental understanding.

2. This is right, QM is the physics behind devices, etc. However, these devices rely macroscopic behavior of the system. We measure not "electrons" directly, but current, let's say, which is a macroscopic measurement. In fact, one can safely say that the physical quantities that we measure, such as position, momentum, energy, etc, are ALL classical properties, because they require the system to interact not only with a macroscopic device, but also because we measure a LARGE NUMBER of them. Those devices do not make use of ONE particle, but rather a huge number of them. Any student who has done any amount of basic QM in school can see that when we average out a large number of system, the system approaches the familiar classical behavior (ref: harmonic oscillator). So while the microscopic description of the behavior of the system is quantum mechanical, the physical behavior of the devices above is purely classical (you don't see your semiconductor in your computer appearing in several locations simultaneously, do you?)

3. If the interaction of QM with the macroscopic world is not fully understood, then why in heck is a Deepak Chopra already using it? The problem here is that we KNOW that the classical world is different than the quantum world. You NEVER see a soccer ball appearing in different locations simultaneously. You NEVER see the macroscopic effect of quantum entanglement. So we KNOW these two are different. How different they are, and how QM can merge into such differences is the question that continues to be studied. It means that anyone making use of QM into a realm where we still don't fully understand is making an utterly speculative proposition.

It is ironic that he's using QM to support his crackpottery without even giving one second of consideration that QM has plenty of experimental evidence, while he has none. Again, it comes back to what I was saying earlier, than lacking direct experimental evidence to support his view, he simply piggy-back onto a well-established physics and say, hey, if it works there, it should work here as well, and left it at that without providing any evidence. This is what happens when one understands QM superficially without any clear view of the basic formalism of QM. As I've mentioned earlier, when they only see the philosophical implication of it and see all these "strangeness" appearing out of nowhere, they seem to think that anything goes and things can be invented freely.

I sometime wish that they leave our physics alone and invent their own silly theory of the world to back up their claims.

Zz.

Lasing With Electrons

This is a good brief article on the history and development of the free-electron laser. I think you also get free access to the relevant historical papers being highlighted here. You also get an overview of what they're doing at the LCLS.

The thing that should be pointed out here is that, while they share the same name, i.e. "laser", the regular laser and these free-electron lasers are not under the same domain of study. Regular lasers might fall under atomic/molecular physics, or even solid state physics, whereas free-electron laser falls under accelerator physics because it deals with high energy electron beam and various accelerator structures.

Zz.

The Physics of Cooking

Anyone following this blog for any considerable period of time would know that I like to cook - or, let's say, that it is a hobby. I mentioned a long time ago how I learn how to bake bread when I was preparing for my oral comprehensive exam in graduate school.

Now, while I do apply a bit of physics in my cooking, such as knowing that a denser concoction will take more time to heat through than something looser, I certainly don't pay as much attention to it as this author. He's describing the various physics that is involved in cooking, such at the various types of heat transfer.

A stove's burner supplies energy to a pan via conduction - i.e. two surfaces in contact. But here I'm more interested in what's happening inside the pan.

The bottom of the pan is made hot. So liquid at the bottom gets hot enough that it begins to evaporate, forming small bubbles.

When the bubbles get large enough, they peel off the bottom of the pan. Being less dense than the liquid around them, the bubbles float to the surface.

Finally, and less noticeably, some liquid at the surface is cooler than its surroundings, so it in turn sinks. This process is what we call convection.

Yeah, but Hamburger Helper???!! :)

Zz.

National Lab Day

In case you haven't seen this yet, there's an ongoing effort to get students to learn about science by "doing" things. This includes everything from demonstrations, doing stuff in a lab, computer simulation, or visiting places. The project is called the National Lab Day here in the US.

While May 12, 2010 will be called the National Lab Day, the project has been going on for a while now this year. There are already teachers in schools seeking assistance for various aspects of their projects. If you are a teacher, this is the place to seek assistance with your various science education efforts. If you're a student and your science teacher hasn't seen this, show it to him/her. If you are a scientist/engineer, they need you to volunteer your time and/or expertise. Some of these may even be in your community.

It's a good way to get kids to not only be interested in science, but to have them learn from doing or observing something, rather than just reading books and listening in class.

Zz.

New Revolutions in Particle Physics - Part 10

The latest video on this series of lecture by Leonard Susskind is now online. I've updated the original blog entry that has all of these videos. You can find all 10 of them (so far) at one place.

Zz.

Patterns, Correlates, and Reduction of Homework Copying

Holy Cow! I had WAAAAY too much fun read this paper!

This paper examines the behavior of students in a physics class at MIT, especially how much homework copying was down, and the impact on the exam results[1]. It is very fascinating.

Abstract:Submissions to an online homework tutor were analyzed to determine whether they were copied. The fraction of copied submissions increased rapidly over the semester, as each weekly deadline approached and for problems later in each assignment. The majority of students, who copied less than 10% of their problems, worked steadily over the three days prior to the deadline, whereas repetitive copiers (those who copied >30% of their submitted problems) exerted little effort early. Importantly, copying homework problems that require an analytic answer correlates with a 2(σ) decline over the semester in relative score for similar problems on exams but does not significantly correlate with the amount of conceptual learning as measured by pretesting and post-testing. An anonymous survey containing questions used in many previous studies of self-reported academic dishonesty showed ∼1/3 less copying than actually was detected. The observed patterns of copying, free response questions on the survey, and interview data suggest that time pressure on students who do not start their homework in a timely fashion is the proximate cause of copying. Several measures of initial ability in math or physics correlated with copying weakly or not at all. Changes in course format and instructional practices that previous self-reported academic dishonesty surveys and/or the observed copying patterns suggested would reduce copying have been accompanied by more than a factor of 4 reduction of copying from ∼11% of all electronic problems to less than 3%. As expected (since repetitive copiers have approximately three times the chance of failing), this was accompanied by a reduction in the overall course failure rate. Survey results indicate that students copy almost twice as much written homework as online homework and show that students nationally admit to more academic dishonesty than MIT students.

The impact on the exam results is very interesting. Students who copied more than 30% of their homework shows poorer performance in the exams. This is not surprising for many of us who have taught such subjects. I'm sure many of us have had suspicions on why a question that is similar to the one that the students have done correctly in a homework assignment, still can't be answered correctly.

But what made me laughed out loud was this passage in the paper:

Briefly, we found that students commit about 50% more copying than they self-reported on the self-reported survey. We showed that actual copying from both 2003 and 2005 data correlated with demographic factors: being male and being a business major as found in previous self-reported dishonesty surveys. Since our freshmen had not declared a major when they took the survey, we showed that copying is a leading indicator of becoming a business major.

This is hysterical, if somewhat sad. I wonder if this is a root cause of our economic debacle? :)

Zz.

[1] D.J. Palazzo et al., Phys. Rev. ST Phys. Educ. Res. v.6, p.010104 (2010).

Micron Size Quantum Object

An amazing feat of accomplishment here in this experiment. A group at UC-Santa Barbara has made a quantum oscillator the size of a 0.0002 millimeter-square wafer[1]. You can read a review of this work at Wired Science.

The mechanical object used in the experiment, published March 17 in Nature and led by Cleland and fellow UCSB physicists John Martinis and Aaron O’Connell, is a 0.0002 millimeter-square wafer of quartzlike material bracketed by metal plates. The wafer is a piezoelectric resonator, expanding and contracting in response to electrical voltages at a precise, extremely high frequency. Cleland likened its expansion and contraction to the inflation and deflation of a balloon.

The quantum device is a qubit, a term that generically refers to a kind of quantum transistor being used for quantum computation, in this case made from an ultrathin aluminum-based superconductor. At extremely cold temperatures, it goes quantum: It exists in an oscillating waveform spanning an excited state, an unexcited state, or both simultaneously, all controlled by electrical currents.

So we are beginning to see larger and larger sizes of objects exhibiting clear quantum mechanical behavior. However, note that, even though by quantum standards, these are "large" objects, they are still minuscule by our everyday scale. Yet, look at all the trouble they have to go through to be able to make such a size behave quantum mechanically. The cooling process to get it into its lowest quantum state is not trivial. We have to do that so that we CAN detect clearly the quantum behavior. It is not that easy to detect such behavior for large objects, and think of how difficult it is to detect quantum behavior from an object the size of a ping pong ball!

The points in all of this is that, to see quantum behavior in macroscopic objects at the macroscopic scale, one has to put the system into a very spacial situation. It makes it extremely difficult to see quantum effects at such a scale. This is one important point that pseudoscientists and crackpots have overlooked when they bastardize quantum mechanics. People like Deepak Chopra and The Secret used QM to justify their beliefs, but they somehow missed the fact that at the macro scale, the quantum effects predominantly unobservable. We continue to make baby steps at constructing larger and larger system that can exhibit quantum behavior, but these systems are very difficult to construct and requires a lot of "hoops" to jump through. So to declare that some human behavior or human consciousness can be described via a principle that can be explained using quantum mechanics is totally unjustified and unverified. It has no empirical basis at all.

Zz.

[1] A. D. O’Connell et al., Nature advance online publication 17 March 2010 (exact reference will be posted when it is published).

Economics and Econophysics

In an earlier blog entry, I pointed to an essay that argues why economics will never be like physics, no matter how much it tries to assimilate concepts and mathematical models of physics. Now comes an article in the latest issue of Am. J. Phys. that argues that even in two areas of study that deals with the economy, even they are not like each other. Christophe Schinckus of the University of Quebec argues in an opinion piece on why the fields of econophysics is a rather completely separate field of study that economics[1].

Are econophysics and economics complementary fields or totally separated disciplines? In this paper I argue that econophysics is not a subfield of economics, and these two fields are separate disciplines.

There are two kinds of gaps between economics and econophysics. The methodological gap refers to a way of doing science. Although economists base their work on a priori methodology, econophycisists use a data-driven methodology. The other gap concerns the way they think about reality. Econophycisists and economists do not see the world in the same way.

In contrast to econophysics, economics is not an empirical discipline. Even if there are debates about the empirical dimension of economics, the empirical dimension in economics is exaggerated. According to econophysicists, complexity studies need an empirical basis. “The real empirical data are certainly at the core of this whole enterprise econophysics and the models are built around it, rather than some non-existent, ideal market as in economics.” This empirical dimension is frequently mentioned in econophysical research and is often presented as the main difference with economics.

Well, there ya go. If economics is not even similar to a field of study in physics that also deals with the same subject matter, then it is even further away from other fields of physics. There are some who don't even think it is a science.

Zz.

[1] C. Schinckus, Am. J. Phys. v.78, p.325 (2010).

Abusing Albert Einstein

I'm glad that there are writers like Tom Chivers of the UK's Telegraph. There need to be someone who points out the stupidity in things like what he's highlighting in this article. In it, he's pointing to the recent book on the supposed "scientific case" for ESP where the authors used Einstein's quotes and possibly his physics to justify ESP.

But when a genuine hero of science has his consoling words to a bereaved woman twisted to make it sound like he believes what in a family newspaper I can only describe as “claptrap”, I think we should object. Make up your own nonsense, Ms Hennacy Powell, and stop dancing on the grave of a great man.

As with Deepak Chopra, it is amazing how people who do not understand physics can somehow bastardize parts of it to justify a pseudoscience. For some odd reason, they can't generate their own validity, because the lack proper empirical evidence. So instead, they latch onto established physics as "justification" that what they believe is valid because physics says it's possible. This of course, is completely bogus. The Standard Model says that the Higgs should be there. Now even when the Standard Model has been successful so many times, we still just simply don't take its word for it, and we still want to be able to detect these Higgs bosons. That's why we have the LHC. We simply don't accept it via "induction". There must be convincing empirical evidence that the Higgs is there.

Now why these people who piggy-back onto various aspects of physics cannot see this, I have no idea. I suppose if you only cherry-pick various superficial ideas in physics, you miss all the important details. And they hope that the rest of the public will miss them as well. More often than not, the public does!

Zz.

A Search for the Mpemba Effect: When Hot Water Freezes Faster Than Cold Water

I've mentioned before that when I got into physics, I didn't have some grandiose idea about solving the problems of the universe. I got into physics because I was curious about some of the apparently simplest observations around me. This is why I continue to be fascinated by this Mpemba effect.

I reported this a while back regarding both the theoretical and experimental observation of this effect. It appears that this effect is still being studied and remains a curiosity for others as well. A preprint appeared today on ArXiv detailing a "search" for this effect.

Abstract: An explanation for why hot water will sometime freeze more rapidly than cold water is offered. Two specimens of water from the same source will often have different spontaneous freezing temperatures; that is, the temperature at which freezing begins. When both specimens supercool and the spontaneous freezing temperature of the hot water is higher than that of the cold water, then the hot water will usually freeze first, if all other conditions are equal and remain so during cooling. The probability that the hot water will freeze first if it has the higher spontaneous freezing temperature will be larger for a larger difference in spontaneous freezing temperature. Heating the water may lower, raise or not change the spontaneous freezing temperature. The keys to observing hot water freezing before cold water are supercooling the water and having a significant difference in the spontaneous freezing temperature of the two water specimens. We observed hot water freezing before cold water 28 times in 28 attempts under the conditions described here.

There ya go! This effect certainly has a lot of legs!

Zz.

Edit 12/20/2010: This article has been published in AJP. The exact reference is:
J.D. Brownridge Am. J. Phys. v.79, p.78 (2011).

The Physics of Fundamental Constants

I've always found papers that collect many of the different resources, information, and references into one coherent publication to be extremely useful. This is one such paper.

P.J. Mohr and D.B. Newell, "The physics of fundamental constants", Am. J. Phys. v.78, p.338 (2010).

Abstract: This Resource Letter provides a guide to the literature on the physics of fundamental constants and their values as determined within the International System of Units (SI). Journal articles, books, and websites that provide relevant information are surveyed. Literature on redefining the SI in terms of exact values of fundamental constants is also included.

The authors included discussions on the various major fundamental constants, how each one was determined, and a list of references! The latter is the one I appreciate the most, because it tells you how these things came about in greater detail. If you don't have the patience to follow the CODATA report, this is the next best thing.

Zz.

Chopra Versus Shermer at CalTech and on Nightline

Oh, what I would give to be in the audience for this one...

Nightline filmed a two and half hour debate between True/Slant blogger (Skeptic publisher) Michael Shermer and Huffpo blogger (best selling author) Deepak Chopra titled "Does God Have a Future?" at Cal Tech yesterday. An edited version will air on March 23rd with the entire conversation to be available online on the same date.

It is interesting that when a theorist offered to teach Chopra about quantum mechanics, he accepted. This is rather strange because it clearly indicated that he is admitting that he doesn't know much about QM, but he's been "using it" in promoting his quackery all this time! What's wrong with this picture?

This is what many of the pseudoscientists do, i.e. bastardize QM without understanding what it is. All they "understood" are those they got out of pop-science books or articles. If that is all what QM is, then we should be able to make constructive devices out of such books and articles only. Well try it if you can. There are people who can't tell the difference between learning physics, and learning ABOUT physics. There IS a distinct difference between the two...

Now we'll just have to wait for not only the Nightline show, but also the whole thing to appear online....

Zz.

Physics in China

This is a rather informative overview of the rise of Physics in China, especially during the past decade. How much and how fast China has progressed in very advanced research during that time is extremely impressive. Such progress isn't just due to the increase in funding for physics, but also a reflection of its biggest resource - the Chinese population.

With a population of 1.3 billion and an economy close to overtaking Japan’s as the second biggest in the world, China seems set to become a front-rank nation in physics. Although its expenditure on science remains lower than that of the US and the EU, both in absolute terms and per capita, it’s catching up quickly. According to a recent report from the US National Science Board, China has already surpassed the US in the number of researchers (see the story on page 30 of this issue). 2

Indeed, the prospects for physics in China could depend on how it makes use of its greatest resource, its people. And in that respect, the challenges that lie ahead for China are not so much in funding but in creating an intellectual climate in which imagination and ingenuity, not just hard work and skill, can develop and flourish.

Zz.

Borexino Detects Geoneutrinos

More detection of geoneutrinos that was probably first observed at KamLAND a few years ago. This time, it appears to be a cleaner signal detected at Borexino experiment at the Italy's Gran Sasso National Laboratory {link may be available for free only for a limited time}. The preprint of the paper can be found on ArXiv.

The experiment ran for two years ending December 2009 and the Borexino collaboration (about 80 researchers from six countries) says that it detected 9.9 geoneutrino events, with uncertainties of +4.1 and –3.4. Spokesman Gianpaolo Bellini of the University of Milan says that the result also appears to rule out a controversial hypothesis that a large part of Earth's heat is produced by a naturally occurring nuclear reactor fuelled by uranium in the planet's core.

It's interesting how the difficult task here is not detecting neutrinos, but rather to be able to distinguish which ones come from where. One probably has to use both the energy distribution, time dependence, and path reconstruction to be able to discriminate the geoneutrinos from the others.

Zz.

Brian Cox Deserts Labour Party

You have to be a really popular physicist when the possibility that you will vote for a different political party made the news. This is the case for Brian Cox, who has indicated that he will no longer support the current UK's Labour Party and will vote for Liberal Democrat instead.

He said that the Labour government’s investment in research and development was worse in real terms than it had been under Margaret Thatcher. In Cox’s view, the 2007 funding crisis that struck the Science and Technology Facilities Council, which supports research into physics and space technology, had been a “cock-up, the biggest screw-up in science policy in the past decade”.

Britain’s international reputation for science had been damaged, he said. Overall, Labour’s record on science funding was “not as good as it should have been”.

It's one of the more interesting scenario for the UK, where it seems to go the opposite way of the US, France, Germany, China, Japan, South Korea, etc. during this tight economic times. All of those countries significantly increased spending in the sciences during the past year with the hope that this is a future investment that will invigorate the economy in the long run.

Zz.

New Revolutions in Particle Physics - Part 9

Part 9 of this tour-de-force lecture series by Leonard Susskind is now available online. I've updated the original blog entry to include this video.

Zz.

Between Encouragement and a Dose of Reality

What do you do when someone very young, say a high school student, come up to you and eagerly tells you that he/she wants to be a string theorist? Or a particle physicist? Or a nuclear physicist? Etc... etc.. i.e. pick any "sexy" physics profession that you can think of right now. What do you do?

Do you continue to encourage that person, or do you try to do that carefully while injecting a dose of reality?

Here's what I've written elsewhere on this matter, and I'll copy it here verbatim, with added commentary afterward:

I cringe every time I read in here of kids still in high school, or barely starting college, who already either are focused on a particular career, or already made up their minds that on a particular, exact career that they want to do. Now don't get me wrong, there's nothing wrong with having an ambition and aiming to want to be something. However, one needs to step back a bit and figure out if the "choice" being made here was made based on having all the necessary information (i.e. a well-informed decision), or made entirely based on superficial perception.

There are two important issues here that should be addressed and considered.

(i) It is highly unlikely that an 18-year old knows extremely well what is involved in being, say, a theoretical astrophysicist. So how did someone like that arrived at the conclusion that that is what he/she wants to be? More often than not, this person saw some TV shows, or went to some facility, or read some news coverage, and over a period of time, "fell in love" with the idea of being a theoretical astrophysicist.

(ii) It is also very likely that this person hasn't yet been exposed to ALL (or at least, a lot) of the exciting aspects of other field of studies. It is one thing to have seen all the "merchandise" and then make an informed selection, it is another to have only seen one or two and decided that those are sufficient to make a choice.

While there is nothing wrong with having a goal, there is a lot of things wrong when such a decision causes one to have blinders on and not even consider looking at other possibility. It is one of the reason why I conducted a non-scientific career poll on the PhysicsForums. I wanted to see how many here who actually ended up in the VERY exact field that he/she envisioned when he/she was that young. If you simply look at the results, you'll see that only 15% of the poll participants ended up in the very exact career that they envisioned[*]! Significantly more of the participants end up doing roughly the same type of field of study, but not exactly the area of specialization that they had in mind.

What is the lesson in all of this? The lesson here is that, if you're just starting out in your academic life, there's a VERY good chance that you WILL NOT end up in the very exact specialization that you had in mind. That is a very important take-home message, and could be one of your first smack of reality. What this means is that you should NOT close the door on other subject areas just because you already have an ambition to be something. Just because you want to be a theoretical astrophysicist doesn't mean that you shouldn't at least look into solid state physics or read new discoveries coming out of atomic/molecular physics. There's a good chance that you will not be a theoretical astrophysicist, and you need to prepare yourself for such a possibility. It is why I've always tried to emphasize an undergraduate education that is as WIDE-RANGING as possible. Want to be a theorist? Well, take that extra lab class anyway! You'll never now that your ability to make that thin-film deposition might be the very skill that get you that job, or that graduate school admission. Idealism can only go so far before financial reality steps in and smack you on your face.

[*] I am still skeptical of this number, and so far, only one participants have given an explanation on his selection. I think this number might be even significantly lower than what we end up with. I am guessing that many didn't actually read the full options posted in the first message of the poll. Of all the physicists that I've chatted with, I don't ever remember even one of them telling me that they are doing what they had in mind exactly when they were 17/18 years of age.

The fine line that I would walk here is to not discourage someone that young so that he/she continues to nurture that interest in physics. But the reality is that, there is a strong possibility that he/she would NOT go into such fields. Physics is such a wide subject area, and the less glamorous ones are often the ones that (i) have a larger chance of employment (ii) has more funding (iii) wider and larger number of opportunities. In many of my contacts with high school students, I think when the opportunity arise, I try to convey this view that physics is more than just the LHC or string theory. It is also the iPod and the silicon chips and the laser and the MRI. I can only hope that somehow, those blinders would start falling and they could see a wider horizon.

Zz.

Cryogenic Electron Emission

Hum... this is certainly something I didn't know about.

We know of various mechanisms of electron emission from a surface, especially metallic surfaces. Field emission and photoemission are two common examples. However, it appears that there's an emission that has no present-day explanation ... yet. This emission occurs as the temperature of a photomultiplier is cooled down below 220K, and the emission rate rises as one cools further.

This, of course, is counter-intuitive. In many experiments, we perform our measurements at very low temperature to reduce the "noise" level in our experiments. Thermal noises and also other agitation causes our data to also be "noisy". The Fermi function is also less spread out above the Fermi energy, so less number of energetic electrons are available as one approaches very low temperatures. So one would expect that a photomultiplier, which is nothing more than a cathode with an applied field, and a mechanism to multiply the electron emitted, would be less noisy as well as one cools it down. Instead, what we see here is that below a certain temperature, the number of dark counts seems to increase.

This certainly is an interesting phenomenon, and it is of interest to those in the detector physics field.

Zz.

Neil deGrasse Tyson's Long Lost Sibling?

Some time I think I post arcane nonsense in this blog! This is going to be one such example! :) :)

I watched the Graham Norton Show several months ago when Michael Buble appeared. It actually was quite a funny show, and Michael Buble performed his hit single at that time "Haven't Met You Yet". It was an amazing performance (it certainly made me buy his CD). But what struck me as strange was that as I was watching that performance, the trumpet soloists looked like someone familiar. I thought that was strange because why would I find someone familiar who happened to be one of the musicians on the Graham Norton show!

It was only much later when it came to me on why that soloist looked familiar - he looked like the famous astrophysicist and the director of New York's Hayden Planetarium, Dr. Neil deGrasse Tyson!

Well, of course, it isn't him, unless he moonlights as a backup musician! :) Still, it resemblance is uncanny. You can judge this for yourself. Here is a video of that performance by Michael Buble on the Graham Norton Show:



Look at the trumpet soloist at time 2:25 and 2:33. Next, look at a picture/video of Neil deGrasse Tyson at this link. Now you tell me they don't look alike!

:)

Sometime, I have no idea why these things stick in my head.....

Zz.

Popular Science Magazine Online

I don't read Popular Science magazine. I never have. But maybe there are people who do. So this may be news that some people might like. It appears that Popular Science as put its entire 137-year archive online and available for FREE!

We've partnered with Google to offer our entire 137-year archive for free browsing. Each issue appears just as it did at its original time of publication, complete with period advertisements. It's an amazing resource that beautifully encapsulates our ongoing fascination with the future, and science and technology's incredible potential to improve our lives. We hope you enjoy it as much as we do.

I didn't realize they've been around for that long. But then again, I've never read it, so how would I know?

Zz.

The Particle Adventure

VoA is highlighting The Particle Adventure as the website of the week.

"Essentially, The Particle Adventure is an interactive tour of the world of quarks, neutrinos, antimatter, extra dimensions, dark matter, Higgs boson, as well as accelerators and particle detectors," explains Michael Barnett, a physicist at the Lawrence Berkeley Laboratory in California and one of the people behind The Particle Adventure.

This is a terrific site for people wanting to learn a bit more about elementary particles, and it is suitable for people at any level. I have included the link to the Particle Adventure webpage in this blog's links roster for as long as I've had this blog. So if you don't know about it till now, it's time to give it a try.

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New Revolutions In Particle Physics - Part 8

Part 8 of this Leonard Susskind lecture series is now available online. I've updated my original blog entry to include the video of this lecture.

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A Crackpot In Russia

Well, I'm sure there are more than just one crackpot in Russia. Still, Viktor Petrik is kinda special and seems to have been able to fool a lot of influential people in Russia and outside of it.

He has won some high-level support. United Russia, the ruling party, regularly gives him prominent roles in events on innovation, while officials including Boris Gryzlov, the speaker of Russia's parliament and No. 2 in the party, have publicly endorsed his products. The two men are listed as the authors of a patent granted in 2009 for a filter that Mr. Petrik says can turn radioactive waste into water that's safe to drink.

Not only that, but he's also "friendly" with a former US President:

Mr. Petrik says he has also met prominent people outside Russia and shows pictures to prove it. In December 2004, he visited former President George H.W. Bush in Texas and discussed his technology for cleaning groundwater. "When we met, Bush knew a lot about me already," he says, adding that he hopes to have another meeting with him in the next few months.

A spokeswoman for Mr. Bush said the meeting was "a very short courtesy call" and that they haven't been in touch since and have no plans for further meetings.

Does this surprise anyone?

His "resume" is also quite "stellar"!

Mr. Petrik says he learned hypnosis from his uncle. He got an undergraduate degree in psychology at Leningrad State University in 1976, according to university records.

He says he also studied physics but didn't get a degree. The university says it doesn't have detailed records of the courses he took.

He spent much of the 1980s in prison. Yevgeny Zubarev, a journalist who wrote frequently about Mr. Petrik in the 1990s, says he saw the criminal file and the central charge was smuggling antique furniture. Mr. Petrik acknowledges he was in prison but declined to comment on the charges.

I'm tempted to call him a modern-day Rasputin, but that's too easy. But again, the problem isn't with him. There will always be charlatans and con artists like this, no matter where and when. It is the people that someone are gullible enough to be fooled into buying such snake oil that are at fault. In many cases, the harm done is usually to the individuals who are silly enough to believe in such a thing. But when such jokers can influence people in power, then that's another matter and can affect the lives of many people. This then should be dealt with swiftly.

Zz.

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Exotic Antinucleus Detected At RHIC

More exciting stuff coming out of RHIC lately. This one is way up there. They have announce the discovery of heaviest known antinucleus and the first antinucleus containing an anti-strange quark.

The new antinucleus, discovered at RHIC's STAR detector (http://www.bnl.gov/rhic/STAR.asp), is a negatively charged state of antimatter containing an antiproton, an antineutron, and an anti-Lambda particle. It is also the first antinucleus containing an anti-strange quark. The results will be published online by Science Express on March 4, 2010.

Zz.

Argonne's High School Summer Internship

This is a report from last summer's Argonne high school summer internship program for high school students around the Chicago area. There are some very bright students here. One can only wish that every students with some interest in science is given such opportunity to participate in programs like this. I like the fact that this is almost like a "mystery" game, and that these students not only have to fulfill the mission (i.e. to identify the sample), but also learn at least one particular characterization tool. Did they know that the skill of knowing such tools can, in fact, be a valuable trait when they go out into the work force and seek jobs? I hope someone impressed that upon them during the program.



Well done!

Zz.

Comedy Central Channel - Best Science On TV?

I must admit, I, for one, do not get my "science" from Comedy Central, even if I inadvertently did appear on it for a split second during an episode of The Daily Show. However, it seems that many prominent scientists think that The Colbert Report and The Daily Show are the two most consistent shows (both on Comedy Central) to hear scientists talk about their work to the public.

Carroll says the Science Channel has devoted itself to wacky pyrotechnics-based shows rather than real science. The satirical weekly The Onion mocked that the "Science Channel Refuses To Dumb Down Science Any Further" and noted shows such as Punkin Chunkin, which examines gourd-lobbing technology.

"It is a very bad thing for the country that Comedy Central is the go-to place for hearing scientists talk about their recent work, but it's great for Comedy Central," Carroll says.

Says Tyson: "Any access that real science gets to mass media is a good thing. Colbert and Stewart are very smart people. And they know the value and meaning of science."

Hum... not sure what to make of this. I don't think anyone has done any kind of study to see how effective science communication is from these shows.

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A Vision For UK Researech

The United Kingdom's Council for Science and Technology (CST) has released its report about the future of UK's scientific endeavor. In it, the council made several recommendations, among which to focus on the researcher, not just the research. This includes training Ph.D candidates on skills, such as management, that can be used in the private sectors.

There certainly is a lot to read in here.

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Neutrons - The Unsung Structure Probe

This article is a belated tribute to the often-ignored neutron. Not many people know that neutrons provide some of the best and most important probe to study a whole slew of things. This article hopefully will provide and enlighten many on its importance.

But neutrons have some unsung properties that make them useful for investigating matter. Because they are neutral, they can penetrate deeper into a sample than electrons can. Because they have mass and spin, they have a magnetic moment and can probe magnetism. Because they interact with nuclei rather than electron orbitals, they are sensitive to light elements and can even distinguish between hydrogen and deuterium. And they're nondestructive. These features are inspiring researchers to use neutrons to analyze a variety of materials, from coal and complex fluids to cell membranes and membrane proteins and including magnetic materials.

The inelastic neutron scattering probe has, since the early days of high-Tc superconductors, provided most of the evidence for the magnetic resonance peak for the Cu-oxide plane. So just in material science alone, this has been an extremely important technique. The Spallation Neutron Source at Oak Ridge, when it comes online, will be one powerful facility to study a whole zoo of things.

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Bridging Science And The Cinematic Arts

Seems to me that Hollywood is trying to get its act together in bringing in at least competent advice in its science content. The National Science Foundation and the CalArts school have announced a partnership ".... to forge collaborations between researchers and entertainment scholars to produce cutting-edge materials that inspire and inform mass-media audiences about science and engineering concepts..."

Not sure what the effect of this will be in future movies.

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Light Gains AND Loses Momentum At The Same Time

Well, it is only appropriate since we're dealing with quantum optics some time! :)

Just when you thought that the issue has been resolved and one side won, the same problem comes back into center stage. And in the latest twist of the story, it turns out to be a dead tie - BOTH sides are correct. That is, assuming that the latest theoretical explanation present is itself correct.

The question is about the momentum of light going through a dense medium with an index of refraction n.

It is well known than when light enters a material medium it slows down in proportion to the refractive index, n, of that medium. Minkowski and Abraham wanted to know how light's momentum changes as a result. Abraham calculated that the momentum of a single photon within the light is also reduced by a factor n, a result which agrees with our experience of everyday objects – as their speed drops, so too does their momentum. Indeed, a number of powerful arguments have been put forward over the years in support of this position. Prominent among these has been a simple proof based on Newton's first law of motion and Einstein's equivalence of mass and energy, which considers what happens when a single photon travels through a transparent block and transfers some of its momentum to the block, given that the motion of the system's centre of mass-energy must remain constant.

Minkowski's formulation, on the other hand, seems more natural from the point of view of quantum mechanics. As light slows down inside a medium its wavelength also decreases, but quantum mechanics tell us that shorter wavelengths are associated with higher energies, and therefore higher momenta. In fact, Minkowski's approach suggests that the momentum of a single photon of light increases by a factor n as it passes through a medium. This result can also be supported by strong theoretical arguments, among them one that considers what happens when an atom moving at some speed through a medium absorbs a photon and experiences an electronic transition.

Lately, it is thought that the Minkowski's version was pulling ahead, especially with the latest set of results. But hold on to your horses.

According to Barnett, however, both formulations are correct. He says that the one put forward by Abraham corresponds to a body's "kinetic momentum" – its mass multiplied by its velocity. Minkowski's momentum, on the other hand, is a body's "canonical momentum" – Planck's constant divided by its de Broglie wavelength. "These two formulations reflect the fact that in different situations momentum does different things," he adds. "In free space they coincide, but not when inside a medium."

Hum... I think I need to think a little bit more about this one.

Zz.

Foreign-Born Scientists At Oak Ridge Lab

This is an enlightening article on some of the "obstacles" of being a foreign-born scientist working at a US National Laboratory, and especially at laboratory such as Oak Ridge National Lab that deals with classified stuff.

Despite the international flavor, ORNL is less welcoming to foreigners than universities and even some of the other national labs, such as Argonne in Illinois and Lawrence Berkeley in California, Pennycook said. That's because they don't have the same security concerns as Oak Ridge, he said.

Most Oak Ridge facilities are dedicated to open science. That includes a powerful stable of supercomputers, featuring the Cray XT5 "Jaguar" - currently the fastest machine in the world. But about a hundred yards from the computing center is another modern, three-story brick building that houses the lab's national security program, which includes classified projects for the military and intelligence agencies, and it's strictly off-limits to foreign nationals.

"We work pretty hard to keep things separate," said Mason, who became ORNL director in 2007, barely a year after becoming a U.S. citizen. "We don't want the open, international world to get into our national security space. We also need to make sure that the national security way of doing things doesn't impede our ability to be players in science in the world."

I'm guessing that the security concerns are similar at Los Alamos, Sandia, and Lawrence Livermore labs.

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New Revolutions in Particle Physics - Part 7

The surprisingly entertaining series of lectures by Leonard Susskind continues. Part 7 of this lecture series is now available online. I've updated the original blog page to include this latest part.

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Cosmic Rays, Climate, And The Origin Of Life

Wow. That's a really fully-loaded topic, isn't it? But that's the title of a very informative article in the March 2010 issue of Cern Courier.

This phenomenon has a possible relevance to the origin of life on Earth. The current favourite models for this origin are either on comets in outer space, as Fred Hoyle and Chandra Wickramasinghe suggested, or in the black smokers or alkaline vents that result from volcanic activity in the deep oceans. However, another possibility follows from the famous early experiments of Stanley Miller and Harold Urey, in which they passed a spark through a mixture of liquids (water, methane, ammonia, etc) – the “prebiotic soup". This resulted in the appearance of the basic building blocks of life, such as amino acids, RNA and monomers. One problem, however, was that the available spark energy, from lightning, was thought to be inadequate.

This is where the long-term variability of EAS rates may have relevance. We have shown that there should have been periods during which the EAS rate was higher by orders of magnitude than at present (Erlykin and Wolfendale 2001). Our theory is based on the statistical nature of supernova explosions, which are thought to be the originators of high-energy cosmic rays. Figure 3 shows how, from time to time, periods of high cosmic-ray intensity of tens of thousands of years will occur, as a nearby supernova explodes. This will lead to high lightning rates. One of these, occurring at around 4 Gy before the present (a not unlikely occurrence), could have led to the formation of the building blocks of life via the Miller-Urey mechanism. Life could then have evolved from such a start.

There ya go! You and could have been initiated by cosmic rays! :)

Zz.

The Tevatron in 2009

This Symmetry Breaking article gives a very good summary of a very good year at the old dame of experimental high energy physics - the Tevatron at Fermilab. This workhorse of a collider has had a banner year in 2009, producing a number of significant results and refinement, even if it did not find one of the Holy Grail of elementary particle physics - the Higgs boson.

The experiments have made good use of the torrent of data. In 2009, they published over 100 scientific papers and presented more than 150 new results at physics conferences all over the world. Major highlights include the discovery of the production of single top quarks in the first observation of this extremely rare process. The collaborations made the world’s most precise measurement of the top-quark and W-boson masses with a precision of less than one per cent and one per mille, respectively; and they observed and studied new particles containing b quarks. By combining their data, the CDF and DZero experiments also reached important new conclusions on the possible mass of the proposed Higgs particle, now excluding a mass range near that of twice the mass of the W boson (162-166 GeV/c2).

For people who are not familiar with high energy physics experiments, note one very important thing. The Tevatron isn't just a one-purpose experiment. In other words, even though one of the main reason for its operation is to search for the Higgs, it also provides results in many other important studies of elementary particle physics. No one, and certainly no govt. agency, would fun a multi-billion dollar facility JUST to look for one thing. That's insane and not something anyone can justify spending.

So the same can be said about the LHC. While it certainly would like to hunt for the Higgs, it has a rich set of physics that it can do. And that's just what is expected! No one would be surprise if the LHC produces a lot of unexpected results and observations. That, in itself, is why high energy physicists are excited, regardless of whether they find the Higgs or not.

Zz.

The Invariance of the Speed of Light

I don't normally highlight a preprint on ArXiv, especially if it is still waiting for acceptance for publication (I do make some exceptions, especially by well-known authors). However, this is way too much fun to ignore. Besides, I want to keep a record of it here so that I can find it easily next time some crackpot point to me one of the papers as "evidence".

Early on, I came across this preprint that proclaimed to have found a variation in the speed of light that depends on the motion of the light detector. As is the case with any of these things, I wanted to wait until it gets accepted before mentioning anything about it. After all, there are many of these things that popped up regularly and went nowhere. As far as I know, this has not been published yet.

Still, a rebuttal to this work appeared on ArXiv today. And it's a good one! Read the conclusion:

In conclusion, because of the error we point out above, the claim in [1] that the velocity of light as measured by a moving detector does not equal c is wrong. It is particularly striking that the so called ‘measured’ discrepancy of 200 m/s between the light speed as calculated in the two frames does not depend at all on the measured time of flight of the laser pulse. That is, using the procedure of [1] to find cO, any random number put in for the time of flight T would give a result that is v0 larger than cS. Since the claimed anomalous result does not depend on the recorded time of flight, this experiment has, in fact, measured nothing.

I love it! :)

I think that actually, the original paper might be a good exercise for an advanced level physics course to pick apart and figure out what went wrong.

Now that this criticism has appeared, I wonder what is the fate of the submitted manuscript. Would the author write a response? Would the editor and/or referee of the journal be aware of this criticism?

Zz.

Topological Insulator

Topological insulators seem to be the latest hot topic of study in condensed matter physics. This review, which presumably will soon appear in Rev. Mod. Phys., provides a comprehensive review of our understanding of this complex and rich system.

Abstract: Topological insulators are electronic materials that have a bulk band gap like an ordinary insulator, but have protected conducting states on their edge or surface. The 2D topological insulator is a quantum spin Hall insulator, which is a close cousin of the integer quantum Hall state. A 3D topological insulator supports novel spin polarized 2D Dirac fermions on its surface. In this Colloquium article we will review the theoretical foundation for these electronic states and describe recent experiments in which their signatures have been observed. We will describe transport experiments on HgCdTe quantum wells that demonstrate the existence of the edge states predicted for the quantum spin Hall insulator. We will then discuss experiments on Bi$_{1-x}$Sb$_x$, Bi$_2$Se$_3$, Bi$_2$Te$_3$ and Sb$_2$Te$_3$ that establish these materials as 3D topological insulators and directly probe the topology of their surface states. We will then describe exotic states that can occur at the surface of a 3D topological insulator due to an induced energy gap. A magnetic gap leads to a novel quantum Hall state that gives rise to a topological magnetoelectric effect. A superconducting energy gap leads to a state that supports Majorana fermions, and may provide a new venue for realizing proposals for topological quantum computation. We will close by discussing prospects for observing these exotic states, a well as other potential device applications of topological insulators.

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Edit: This review has now appeared on Rev. Mod. Phys. The exact reference is: M.Z. Hasan and C.L. Kane, Rev. Mod. Phys. v.82, p.3045 (2010).

UK Funding For Homeopathy Should Be Cut

I seldom make reference to another blog, but this is one of the few times I will, because it is such an excellently-written blog article.

This blog entry reports on the recent recommendation, in the UK, to cut public money from being spend on research on homeopathy. The recommendation is contained in the report titled "Evidence Check 2 - Homeopathy". It was produced by the House of Commons' Science and Technology Committee. I'm guessing it is a recommendation for the MPs over there to stop such funding.

As the blogger has said, for once, the politicians are getting it right, and getting the right advice. To fund something that, for such a long time still cannot clearly established its existence, is futile. It is not the sign of a valid phenomenon. Yet, people buy into it based entirely on anecdotal evidence.

Zz.

Phonon Lasers

Amazing advancement this week in the area of producing phonon lasers. Two new papers published by two different groups have made significant progress in producing such a thing.

Despite all the similarities between photons and phonons, no phonon lasers have been developed up until now. The difficulty, ironically, can be traced to the same fact that makes phonon lasers so desirable [4]—the comparatively short wavelength of sound, which causes spontaneous emission processes to dominate over stimulated emission unless one modifies the density of phonon states by employing high-quality acoustic resonators.

You also can get the actual papers for free from that link.

Zz.

More "Rate of Speed"

I did my rant about the erroneous use of the phrase "rate of speed", when the person using it simply means "speed". This is the latest use of it by the Orange Country Register:

An initial investigation indicates that the Cadillac SRX was traveling at a high rate of speed southbound in the carpool lane when the driver lost control, veered across all lanes and struck the sound wall along the on-ramp, said officer Denise Quesada of the CHP.

So look at the INTENTION of what the report is trying to say. It is trying to convey the message that the vehicle was traveling VERY FAST, i.e. "high speed". So instead of saying what it should say, i.e. high speed, it got cute by writing "rate of speed", which in this case, since the vehicle is moving linearly, means ACCELERATION!

They'll never learn!

But what was funny is that one of the comments listed with this story was someone pointing to my blog entry on this bad usage! :)

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Heinrich Rudolf Hertz

A rather concise biography of Hertz on Wired today.

Hertz devised an oscillator made of two polished brass knobs separated by a tiny gap. Each one was wired to an induction coil. With the juice on, sparks jumped the gap between the two knobs. Those sparks, Hertz hypothesized, would — if Maxwell was right — generate electromagnetic waves. It was the first designed transmitter.

For a receiver, he made a wire loop with tiny knobs on opposite sides of a small gap. He placed this device a few yards away. The two devices were not wired to each other, but sure enough, sparks in the transmitter produced sparks in the receiver.

Hertz had demonstrated that Maxwell’s waves exist. He went on to time them, demonstrating that their speed of transmission is, as Maxwell had also predicted, the speed of light.

It is on his shoulder, and the shoulders of so many others, that we stand today with our progress and knowledge. What we accept now as "obvious" were not so, and took the ingenuity of people like him to discover and innovate.

Zz.

Traveling at Warp Speed Would Kill You

... but not due to what you might think!

William Edelstein, a professor at Johns Hopkins University’s School of Medicine, has thought of another scenario on why those people on the Starship Enterprise would not have survived traveling through space at close to the speed of light. And it has nothing to do with the contortions of warped spacetime either. It is more basic and more well-known that that.

“I put in the Star Trek thing cause it would be dramatic,” he explains. The point of the paper was to really look at the impact of radiation at high speeds, he said. When you travel at high speeds in space “you are basically plowing through hydrogen,” he explained. “What actually happens as soon as they encounter the ship, the atoms split into protons and electrons and the protons mainly go through you and do damage.”

Edelstein said in an interview with the Star that the problem is when travelling in space at close to light speed hydrogen turns into “intense radiation” that kills humans and destroys electronic instrumentation. Even a ship’s hull of 10 centimetres in thickness would do nothing in terms of preventing damage.

In his presentation he said that a fatal dose of radiation for humans is six sieverts. And with his calculations a crew would receive a dose of more than 10,000 sieverts within a second.

So forget about the stuff that we barely know of. Just simple rudimentary high energy collisions that we already know of, and its radiation effects, which we also know of quite well, can already kill you.

Tough luck, space travelers!

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5 Minutes With Brian Cox

Here's a 5-minute interview with Brian Cox.

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New Revolutions in Particle Physics - Part 6

Part 6 of this lecture series by Leonard Susskind is now available. You may watch it, and the first 5 video of the lecture series, at my earlier blog entry.

There ARE some funny moments in these videos that made me chuckle a few times! :)

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Ernst Mach

Here's a short history lesson on Ernst Mach.

Mach’s name was not coined as a term until 13 years after his death in 1916. A Swiss engineer named the variable after Ernst Mach in a 1929 paper to honor the Austrian’s work on the understanding of supersonic flow.

Mach is perhaps most well-known in the aviation community, and in particular the aviation community that flies very fast jets. A Mach number is a dimensionless number that represents the speed of an object moving through a fluid (most commonly air), divided by the speed of sound in that fluid. Mach 1.0 represents the speed of sound in any given fluid.

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The Science of Liberty

That is the title of Timothy Ferris latest book, which I haven't read yet, so let's get that out of the way.

This is a news article on Ferris's book that makes quite a provocative claim: that science and democracy go hand in hand.

"I'm trying to draw attention," said Ferris, "to what I think has always been a fundamental connection between science and liberal democracy, that the reason we had an Enlightenment -- and the democratic revolution that everyone agrees followed from the Enlightenment -- was because of the discovery of science."

I also find it rather fascinating that, towards the end, he mentioned that his most ardent critic are the post-modern left. I can't believe this group of people are still making such noise after being thoroughly embarrassed by the Sokal hoax, and Sokal's continued revelation of what fraud these people are!

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Gravity’s Effect On Time Confirmed

Another aspect of GR's equivalent principle gets confirmed to a higher precision. This time, it is the "time dilation" due to gravity.

In the experiment each of the atoms was exposed to three laser pulses. The first pulse placed the atom into a superposition of two equally probable states — either leaving it alone to decelerate and then fall back down to Earth under gravity’s pull or giving it an extra kick so that it reached a greater height before descending. A second pulse was then applied at just the right moment so as to push the atom in the second state back faster toward Earth, causing the two superposition states to meet on the way down. At this point the third pulse measured the interference between these two states brought about by the atom’s existence as a wave, the idea being that any difference in gravitational redshift as experienced by the two states existing at difference heights above the Earth’s surface would be manifest as a change in the relative phase of the two states.

The virtue of this approach is the extremely high frequency of a caesium atom’s de Broglie wave — some 3x1025 Hz. Although during the 0.3 s of freefall the matter waves on the higher trajectory experienced an elapsed time of just 2x10-20 s more than did the waves on the lower trajectory, the enormous frequency of their oscillation, combined with the ability to measure amplitude differences of just one part in 1000, meant that the researchers were able to confirm gravitational redshift to a precision of 7x10-9.

But what's more interesting, at least to me, is the name of one of the author of this paper. Someone by the name of "Steven Chu"! :)

This is the 2nd paper that has been published by him after he has assumed his role at the Secretary of DOE. Still, unless I missed something, this must be the first time an active DOE Secretary published a paper in something as prestigious as Nature. The other one appeared in PRL, which is nothing to sneeze at either!

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100 Years of Quantum Weirdness

This is actually a rather sensible account of QM and the struggle to deal with the "weirdness" that comes with it. I do have a bit of a disagreement towards the end, though.

So how does culture absorb this fact?

The first wave of reaction appears to have been the New Age movement of the 1960s and 1970s. New Age enthusiasms embraced quantum physics as proof that consciousness was more important than matter and that the world was imbued with spiritual realities of great and grand potential. It seemed very exciting. Unfortunately it was wrong, missing the essential point that quantum mechanics doesn't really "say" anything. It raises questions. It does not answer them. The New Age movement with movies like the infuriating "What the Bleep Do We Know" just inserted its own pictures into a theory that does not allow them.

Good argument against the "What the Bleep..." movie. However, I disagree that QM doesn't really "say" anything, and that it just raised questions. The "description" that QM gives DOES say something. It tells you what to do, where to do, and how to do it. It may not tell you WHY it does it that way, but that's far from saying that it says nothing. Furthermore, the "why" statements are a bit disingenuous. This is because if one examines even classical physics, it also doesn't tell you why. Can someone explains why the classical field works? Why does an electron feels a tug on it when it is in an electrostatic field? Do the Maxwell equations tell you why instead of just how? Why pick on QM only when physics, and science, essentially tells you only the how at the most fundamental level?

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Using Leftover Valentine's Day Candy To Measure The Speed Of Light

Here's a creative thing to do with leftover candy from Valentine's Day - use it and your microwave to measure the speed of light! :)

Well, actually, you measure the wavelength of the microwave. Then, using the frequency, you get the speed.

Zz.

Hot Quark Soup Produced at RHIC

A rather neat simulation and explanation of what they are looking at at RHIC. Here's the brief explanation that came with the video:

The Relativistic Heavy Ion Collider (RHIC) is a 2.4-mile-circumference particle accelerator/collider that has been operating at Brookhaven Lab since 2000, delivering collisions of heavy ions, protons, and other particles to an international team of physicists investigating the basic structure and fundamental forces of matter. In 2005, RHIC physicists announced that the matter created in RHICs most energetic collisions behaves like a nearly perfect liquid in that it has extraordinarily low viscosity, or resistance to flow. Since then, the scientists have been taking a closer look at this remarkable form of matter, which last existed some 13 billion years ago, a mere fraction of a second after the Big Bang. Scientists have revelaed new findings, including the first measurement of temperature very early in the collision events, and their implications for the nature of this early-universe matter.

Edit: here's a news article on this from Reuters, and another from the NY Times.

The departure from normal physics manifested itself in the apparent ability of the briefly freed quarks to tell right from left. That breaks one of the fundamental laws of nature, known as parity, which requires that the laws of physics remain unchanged if we view nature in a mirror.

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High-Tc Superconductors Are Very Kinky - Update 8

Looks like the cuprate high-Tc superconductors are kinkier than we originally thought!

In the compilation that I've done so far, we first discovered the 70 meV "kink", or band dispersion renormalization. Later on, came another kink at a significantly higher energy scale, at ~350 meV. Now comes news of another kink. This time, due to improved resolution using laser-based ARPES, a lower energy kink has been observed at about 8 meV below the gap.

Two publications/preprints have reported on this. The first one[1] reports that this kink seen in optimally-doped Bi2212 is tied to the optical phonon mode. The second one[2] appears to be reporting the nature of this kink over a wide doping range, and showing that it becomes stronger in the underdoped range. I said "appears", because I couldn't see the PDF document of this preprint on ArXiv. It won't open for me.

So now there are THREE kinks in the band dispersion of these cuprates! Anyway, both of these have been added to my original blog entry.

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[1] J.D. Rameau et al. Phys. Rev. B v.80, p.184513 (2009) http://arxiv.org/abs/1002.1990
[2] http://arxiv.org/abs/1002.2630

Courtney Love Is Into Quantum Physics?

Say it isn't so!

I thought it was fascinating that actress Anne Hathaway likes reading about physics. The news that Courtney Love, the widow of former Nirvana frontman Kurt Cobain, is into quantum physics kinda scares me a little! :) Look at what she follows:

She also said Robert Graves was her favourite author, that she would take Mozart's music to a desert island and that the work of poet Rilke, along with watching quantum physics videos on YouTube, had affected her music.

Oh dear! She probably watched "What the Bleep do we know!"

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Assessing the State of US Science and Engineering

This is a short interview with the chairman of the board’s Science and Engineering Indicators committee Louis Lanzerotti about the latest report on the 2010 Science and Engineering Indicators. It is interesting that, whether it was abbreviated or not, his analysis of the public support for science doesn't go that deep.

What did you find out about the public perception of science?

The interesting thing is that the perception of science and of engineering remains really very high in the United States.… Those who think it’s a very positive element of our American life … the percentage of the population who believes that is very high. It’s of the order of 75 to 80 percent, versus those who think that it’s a detriment for society, which are 10 percent or less. There have been some blips in that trend up and down by a few percent over the years, but if one does a sliding mean through all that data, one finds that that trend is basically a constant. The American public has a very strong view of the importance of science and engineering for our country. I think a very important point is that scientists rank as high in public respect as do firefighters. They’re second only to firefighters.

Now compare that to the analysis done by Chris Mooney, which goes a lot deeper than that. I still don't see anything here to change my perception that the public's support for science is not based on an understanding of what it is that they are supporting, but based on a PERCEIVED importance of what science is doing.

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New Revolutions In Particle Physics - Part 5

Part 5 of the lecture series by Leonard Susskind has now appeared. I've updated all the video available from this lecture series in the relevant blog entry. So don't miss it if you haven't checked it out yet.

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New Delay at the LHC and More Questions for the Tevatron

Looks like the LHC will not run at 10 TeV as originally anticipated during this run. It will continue at 7 TeV through 2011, and then go on a year-long repair hiatus with the hope of ramping to its maximum design energy when it gets back in 2012.

Strangely enough, those working at the Tevatron aren't gung-ho on trying to push for the Tevatron to run on into 2012.

Curiously, though, Fermilab physicists did not immediately clamor to run their 27-year-old Tevatron collider for an extra year through 2012. That contrasts to last year, when in response to a delay to the LHC, Fermilab scientists pushed hard to run the Tevatron through 2011, a move the U.S. Department of Energy (DOE) supports (Science, 20 February 2009, p. 993). This time, Fermilab physicists say an extra year's worth of data might not be worth the expense. "It's not like we're rushing out and saying ‘We want to run in 2012!’" says Fermilab's Dmitri Denisov, co-spokesperson for the 510-member team working with the D0 particle detector. "But we want to keep the possibility open."

Even at 7 TeV, there's plenty of physics to be done at the LHC. Already there are indications that they are seeing a few unexpected things. So there's plenty to be done in the next couple of years at this energy scale.

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Martin Rees Tackles Space, Politics and Scientific Advice

Lord Martin Rees, President of the Royal Society and the UK's Astronomer Royal, tackles several issues on space, politics, and science advice in this video interview.



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Lise Meitner

This is a nice, short article on Lise Meitner and her contribution not only to physics, but to our world as well. She certainly and fully would have deserved the Nobel Prize, and I would think that if the Nobel committee looks back on some of the people they missed giving the award to, Meitner would be way on top.

Having read a few of her biographies and life story, I am not only amazed at her dedication and skill as a scientists, but also her resolve considering all the obstacles she faced as a woman working in this field at that time. She is one tough woman, and someone that I truly admire as a person.

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The Big Bang, Modern Cosmology and the Fate of the Universe: Impacts Upon Culture

This is the text of the lecture given by Lawrence Krauss at the UNESCO/IAU Meeting titled "The Role of Astronomy in Society and Culture" this past Jan. 2009. There are several issues brought up in this lecture that, by themselves, can be the subject of whole lectures themselves.

Suffice to say that this is quite an article to read.

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First Physicist in US Congress Retiring

Vern Ehlers, the first physicist to serve in the US Congress, is retiring at the end of his term. One of only 3 physicists currently serving in the US Congress, he has always been a strong supporter of science funding.

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Quantum Tunneling Composite

Chalk this up for another direct application of QM. This new technology that makes use of quantum tunneling could introduce a "third dimension" to your 2D touchscreen that is so prevalent in many smart phones (i.e. iPhone lookalike) and upcoming tablets like iPad.

The composite works by using spiky conducting nanoparticles, similar to tiny medieval maces, dispersed evenly in a polymer.

None of these spiky balls actually touch, but the closer they get to each other, the more likely they are to undergo a quantum physics phenomenon known as tunnelling.

Tunnelling is one of several effects in quantum mechanics that defies explanation in terms of the "classical" physics that preceded it.

Simply put, quantum mechanics says that there is a tiny probability that a particle shot at a wall will pass through it in an effect known as tunnelling.
QTC-enabled handset

Similarly, the material that surrounds the spiky balls acts like a wall to electric current. But as the balls draw closer together, when squashed or deformed by a finger's pressure, the probability of a charge tunnelling through increases.

When I first read this, my first reaction was "oh, they finally found an application for that!" Let me explain. I did my Ph.D research in tunneling spectroscopy, or more precisely, in point-contact tunneling spectroscopy. What I had was this sharp, pointy tip, and this tip was pushed onto the sample that we want to study. The native oxide barrier on the sample acts as an insulator, and thus, the potential barrier. So one sets up a tunnel junction consisting of the tip-oxide insulator-sample. One can measure the I-V curve if one so desires due to the tunneling current. The more one pushes the tip into the insulating layer, the larger the junction conductance, and consequently, the larger the tunnel current.

{Of course, there is a limit to how hard one can push the tip into the material. At some point, you'll either get an Ohmic contact, i.e. a short, or you break the sample.}

The same can be said about STM system, but here, the vacuum between the tip and the sample acts as the insulating barrier. How much one varies the distance between the tip and the sample surface dictates the conductance and the amount of tunneling current.

So in essence, this new device, the QTC, is the application of what many of us in condensed matter have already known and made use. I guess with the new nanoparticles, they finally managed to find an application for it.

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Science of the Winter Olympics

With the Vancouver Winter Olympics looming, NBC Learn has launch an educational website on the Science of the Winter Olympics. It has a collection of videos discussing the various physics (mechanics) aspects of the various sports in the Winter Olympics.

The site also has a bunch of other educational items and videos suitable at almost any level.

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The First Lasers

In light of the 50th anniversary of the laser (pun intended), the AIP has a wonderful historical account of the birth and development of the laser. This is an opportunity not only to read about how the laser came to be what it is today, but also be aware of all the important figures in its history, and not just those who got the Nobel prizes for it.

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Job Outlook for Theoretical High Energy Physicists Sucks

In case you missed Peter Woit's blog entry, or Erich Poppitz latest data, you might want to read a summary of it here.

I've always stressed the issue of "employability" when students asked me about majoring in various areas of physics. While this is not an issue when students first get into grad school, it will be a huge issue when they graduate and looking for jobs. This doesn't mean that one shouldn't go into areas such as theoretical high energy physics. It means that one needs to be aware of the challenges when doing such a thing and be prepared for not finding the job that one wants. There has to be a backup plan in anything, and more so when one is specializing in an area with very limited employability.

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Steven Chu Plays "Not My Job"

If you haven't listened to this, you ought to, because it is hysterical. Steven Chu plays "Not My Job" on NPR's "Wait, wait, don't tell me".

You also get to learn a little bit about Steven Chu, but more than anything, this is rather entertaining and utterly funny. Too bad he didn't do as well as George Smoot on "Are You Smarter Than a 5th Grader?" game show, but this is to be expected since the questions were "not his job"! :)

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Teaching and Understanding of Quantum Interpretations in Modern Physics Courses

We all know that teachers and instructors can have a profound influence in the way a student not only understands a subject, but also how he/she thinks about how to view something. This notion is further reinforced by this study on how students interpret the complexity of quantum mechanics. {Note that you can get full access to the paper}

Abstract: Just as expert physicists vary in their personal stances on interpretation in quantum mechanics, instructors vary on whether and how to teach interpretations of quantum phenomena in introductory modern physics courses. In this paper, we document variations in instructional approaches with respect to interpretation in two similar modern physics courses recently taught at the University of Colorado, and examine associated impacts on student perspectives regarding quantum physics. We find students are more likely to prefer realist interpretations of quantum-mechanical systems when instructors are less explicit in addressing student ontologies. We also observe contextual variations in student beliefs about quantum systems, indicating that instructors who choose to address questions of ontology in quantum mechanics should do so explicitly across a range of topics.

It appears that if the students were left to their own devices, i.e. the instructor made no explicit interpretation, they tended to adopt a realist view of QM.

I've yet to read this paper fully and more closely (hey, I have a lot of things to do this week! :)). But you're welcome to it. If you are, or have been, an instructor in a similar class, I would be very interested to hear what you have to say, and especially on your approach for such a class.

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AAAS 2010 Annual Meeting

Hey, is anyone reading this will be attending the upcoming AAAS Annual Meeting in San Diego? If you are, I would be so grateful if you could contact me. You may e-mail me, or if you don't have my e-mail address, please leave a comment to this blog with your contact info. Don't worry, this blog is moderated, and your comment will NOT appear in public (I PROMISE!), so your contact info will be kept private and will be deleted.

Thanks a bunch!

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Weinberg Says That Obama Gets Space Funding Right

In light of the new proposed 2011 budget and the Obama Administration decision to cut spending on the human spaceflight to the moon and Mars, Steven Weinberg wrote an opinion piece that praised this step.

The manned space flight program masquerades as science, but it actually crowds out real science at NASA, which is all done on unmanned missions. In 2004 President George W. Bush announced a new vision for the space agency: a return of astronauts to the moon followed by a manned expedition to Mars. A few days later NASA's office of Space Science announced major cutbacks in its important Beyond Einstein and Explorer programs of unmanned research in astronomy. The explanation was that they "do not clearly support the goals of the President's vision for space exploration."

Soon after Mr. Bush's announcement I predicted that sending astronauts to the moon and Mars would be so expensive that future administrations would abandon the plan. This prediction seems to have come true.

The cost-to-benefit ratio, at least in terms of science output, is just not there for human spaceflight, and even the ISS for that matter. Decisions to do this have been based predominantly on politics, and funding appropriate home constituents. When one argues that such cutbacks can hurt science, and then to hear very prominent scientists disagree with that assessment, it kinda throw that claim into question.

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Cycling Physics

If nothing else, this physics teacher is certainly very resourceful, and not to mention, probably in a very good physical shape as well!

On Thursday Davis will be trying a new kind of demonstration: he will spend the entire teaching day — 7 hours — pedaling his bicycle on rollers. The purpose is to give his students a visual lesson in work, power, energy, angular momentum, torque, and other topics.

Good luck to him, and hopefully, his students do learn a bit of physics from all this.

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High-Tc Superconductors Are Very Kinky - Update 7

A new preprint appearing on ArXiv today adds another argument for the phonon mode (or modes) as being responsible for the kink in the band dispersion of high-Tc superconductors observed from ARPES measurement. The work studied the heavily-overdoped (Bi,Pb)2Sr2CuO6 and used a very high resolution, laser-based ARPES technique.

Abstract: Super-high resolution laser-based angle-resolved photoemission spectroscopy measurements have been carried out on a heavily overdoped (Bi,Pb)2Sr2CuO6 (Tc> 5 K) superconductor. Taking advantage of the high-precision data on the subtle change of the quasi-particle dispersion at different temperatures, we develop a general procedure to determine the bare band dispersion and extract the bosonic spectral function quantitatively. Our results show unambiguously that the 70 meV nodal kink is due to the electron coupling with the multiple phonon modes, with a large mass enhancement factor Lamda= 0.42 even in the heavily over-doped regime.

I've updated my original blog entry on this topic to reflect this new preprint.

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The Story Behind RealD 3D Technology

A rather nice "historical" account of RealD's emergence in the movie industry. Certainly, if you've seen any 3D movies within the past few years, and certainly if you've seen "Avatar", you would have experienced the more pleasant way of viewing 3D movies than those nasty bi-colored glasses.

The history of RealD's Boulder brain trust stretches back to work at the University of Colorado in the 1980s.

In 1987, CU received a federal award to establish the Center for Optoelectronics Computing Systems, which initially had strong focuses in physics and liquid crystal technologies, said Kate Tallman, director of technology transfer for CU-Boulder.

The center spawned a number of inventions related to color display technology and color projection technology and would be the incubator for a spin-off launched by two of its CU scientists.

I think that it is extremely important to make sure the public realizes where the seed money came from and from what initial research effort. Too often, what we get today is never connected to the original work that spawned off so many direct applications, so much so that the public doesn't see their tax dollars at work when it was invested into science and technology.

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