Monday, August 31, 2015

The History of Antiprotons

Antiprotons, the one-half of the particle used in the collision at the departed Tevatron at Fermilab, have had a long and distinguished history in the development of elementary particle physics. This CERN Courier article traces its history and all the important milestones in our knowledge due to the discovery of this particle.

Over the decades, antiprotons have become a standard tool for studies in particle physics; the word "antimatter" has entered into mainstream language; and antihydrogen is fast becoming a laboratory for investigations in fundamental physics. At CERN, the Antiproton Decelerator (AD) is now an important facility for studies in fundamental physics at low energies, which complement the investigations at the LHC’s high-energy frontier. This article looks back at some of the highlights in the studies of the antiworld at CERN, and takes a glimpse at what lies in store at the AD. 


Wednesday, August 26, 2015

She's Still Radioactive!

She, as in Marie Curie.

This article examines what has happened to the personal effects of Marie Curie, the "Mother of Modern Physics".

Still, after more than 100 years, much of Curie's personal effects including her clothes, furniture, cookbooks, and laboratory notes remain contaminated by radiation, the Christian Science Monitor reports.

Regarded as national and scientific treasures, Curie's laboratory notebooks are stored in lead-lined boxes at France's national library in Paris.

While the library allows visitors to view Curie's manuscripts, all guests are expected to sign a liability waiver and wear protective gear as the items are contaminated with radium 226, which has a half-life of about 1,600 years, according to Christian Science Monitor.

What they didn't report, and this is where the devil-is-in-the-details part is missing, is what level of radioactivity is given off by these objects. You just don't want to sign something and not know the level you will be exposed to (which, btw, if you work in the US or at a US National Lab, a RWP (radiation work permit) must be posted at the door detailing the type of radiation and the level of radiation at a certain distance).

I suspect that this level is just slightly above background, and that's why they are isolated, but not large enough for concern. Still, the nit-picker in me would like to know such details!


Friday, August 21, 2015

Quantum Teleportation Versus Star Trek's "Transporter".

Chad Orzel has an article on Forbes explaining a bit more on what quantum teleportation is, and how it is different than those transporters in Star Trek. You might think that this is rather well-known since this has been covered many times, even on this blog. But the ignorance of what quantum teleportation is still pops up frequently, and I see people on public forums still think that we can transport objects from one location to another because "quantum teleportation" has been verified.

So, if you are still cloudy on this topic, you might want to read that article.


Wednesday, August 19, 2015

The Apparent Pentaquark Discovery - More Explanation

Recall the report on the apparent observation of a pentaquark made by LHCb a few weeks back. Fermilab's Don Lincoln had a video that explains a bit of what a quark is, what a pentaquark is, and how physics will proceed in verifying this.


The Physics Of Air Conditioners

Ah, the convenience of having air conditioning. How many of us have thanked the technology that gave so much comfort during the hot, muggy day.

This CNET article covers the basic physics of air conditioners. Any undergraduate student who had taken intro Physics course should know the basic physics of this device when studying thermodynamics and the Carnot cycle. This is essentially a heat pump, where heat is transferred from a cooler reservoir to a warmer reservoir.

But, if you have forgotten about this, or if you are not aware of the physics behind that thing that gives you such comfort, then you might want to read it.


Monday, August 17, 2015

Stnky Superconductor Breaks Record

No, I wasn't being deragoratory by calling it "stinky".

It turns out that hydrogen sulfide, the same compound that smells like rotten eggs, becomes a superconductor when solidified under pressure. And not only that, but it has recently be shown that it becomes a superconductor at a record highest transition temperature of 203.5 K.

Still, there are two points here that may make this not as "exciting" as one wold hope for. Earlier theoretical studies have predicted this to occur, and this material is expected to be a conventional superconductor mediated by phonons.

But the other issue, as in the practical aspect of this, may be even less enticing. This is because this material becomes a superconductor only under very high pressures.

The result may revive visions of superconductors that work at room temperature and magnetically levitated trains. But there's a catch: Hydrogen sulfide works its magic only when squeezed to more than 100 million times atmospheric pressure, roughly one-third as high as the pressure in Earth’s core. This condition makes it impractical for most applications. “Where does it go from here?” asks Igor Mazin, a theorist at the U.S. Naval Research Laboratory in Washington, D.C. “Probably nowhere.” Even so, the discovery is already altering the course of research in superconductivity.

So, while I think this is an exciting discovery, I'm not sure how much it will add to the physics and to applications..... yet.


Friday, August 14, 2015

Record Number of Authors In Physics Paper - Follow Up

Remember just barely a couple of months ago, I mentioned about the brouhaha regarding the record number of authors in a combined CMS/ATLAS paper out of the LHC/CERN? In a Physics Today article, there's a bit more on this, especially on the possibly "light-hearted" nature of the Wall Street Journal article that first mentioned this.

As I've mentioned in the earlier entry, I don't quite know why this is such a freaking big deal. The experiments are getting to be more and more difficult, it requires a more complex instrument, and thus, require a lot more people. The fact that this paper actually combined the results from two HUGE collaboration should, as expected, results in a lengthy authors list. What is the big issue here?

Unfortunately, it gives the wrong impression to the rest of the public. The fact that areas such as condensed matter physics, which produces way, WAY more papers than high energy physics and usually tend to have a significantly small number of authors, somehow has been ignored (Phys. Rev. B, for example, which publishes papers in condensed matter/material  science, is produced TWICE a month, and each edition contains TWO volumes!). And yet, the exception here has been used as a rule for the entire field of physics! Where is the logic in that?

And for the record, I had published a paper in PRL, on an experimental work, no less, and the paper only had THREE authors. Count em'!


Thursday, August 13, 2015

The US's Silly Metric Phobia

There are certain things that make me just shake my head in disbelief. This is one such example.

I was reading this CNN article on why the United States is still one of the remaining 3 nations who have not adopted the SI units for everyday lives. The other two being Liberia and Myanmar (what does it say about the company you keep?). If there is such a thing about irrational beliefs and excuses, this would be front and center. In fact, I would even call them very stupid reasons.

The rest of the world calls Americans pennywise and pound foolish for still using a system that on its face makes little sense. And Americans, in turn, shun the metric system as a foreign creation. Never mind that Americans use the thermometer invented by Daniel Gabriel Fahrenheit, a foreigner of Dutch-German-Polish extract.

I want to know who are these airheads who are shunning something just because it is a "foreign creation". They say this, of course, while using devices made in China, and without realizing that "lbs, feet, inches, etc..." are British units of measure, the same people that the Americans chased out for their independence.

But I also want to talk to author Tom Wolfe (is he still alive?) and am curious if he still thinks this way:

In 1981, The New York Times reporter attended an anti-metric party at which Wolfe, in his customary white linen, judged a "Most Beautiful Foot" contest. 

''I hear that the meter is based on a rod somewhere outside of Paris,'' Wolfe said, according to the Times story. ''To use that as a basis for measurement is completely arbitrary and intellectual. I should say I have tremendous admiration for the French, but a matter of this importance should not be left to them. I like the idea of the foot - as a measurement in relation to the human body.'' 

This is utterly silly and irrational for two reasons:

1. He liked the idea that it is a measurement in relation to part of a body? Why? This is purely a personal preference, like having a favorite color. It is an example  of a ".. measurement that is completely arbitrary". There's no rational  reason to choose something JUST because it had a body-part connection. This is stupid!

2. Now that the "meter"  is now defined based on a physical constant and no longer that stick in Paris, is this sitting better now with him?

When the Nazi was in power, there was a concerted effort to discredit Einstein's theory of relativity (both  Special and General). In fact, there was even an effort to label it as "Jewish theory". So the argument was not based on any form of merit, but rather simply because of who same up with it. I'm surprised people  are not seeing similar parallel with the arguments above. How could these people, whom I presumed are intelligent people, made that kind of arguments and reasoning with a straight face?

Maybe this is another important factor of science education, since we tend to use SI units in science classes.


Wednesday, August 12, 2015

Is There A Fundamental Difference In The Teaching of Physics and Chemistry/Biology?

I read in utter fascination of this opinion piece by Micheal McCracken. As you read this, pay attention not only to the fact that there appears to be a difference between how he perceived physics is taught at the undergraduate level, but also how the differences between the pedagogy of physics and chemistry/biology translates itself into how science is perceived by the public.

Abstract: During recent collaboration with colleagues to revise our institution's general-education curriculum, I encountered many perceptions of what we mean by the Natural Sciences. I was surprised to find that perceptions of scientific pedagogy varied significantly among the scientific disciplines, especially concerning issues of philosophy of science and epistemology, manifested in the approaches to teaching theoretical concepts and their development. These realizations suggest that Physics occupies a singular role in college curricula, introducing students, even at the introductory level, to the acquisition of knowledge by theoretical means and the assessment of theory based on experimental evidence.

His idea that fulfilling a student's requirement on learning Natural Science without taking physics and either chemistry or biology will be a serious deprivation on how science is done.

I tend to agree.


Monday, August 10, 2015

Neutrino Week, In Summary

I mentioned the "Lost In Translation" problem of the Fermilab press release on the NOvA result. Jon Butterworth has a better article that describes clearly the NOvA result, and also includes the detection by IceCube of the highest energy neutrino ever recorded.

But I hate to say that I was more fascinated by his footnote:

¹Fermilab is in the Chicago suburb of Batavia. The neighbouring suburb is Geneva, Illinois. The means that the current and previous high-energy record-holding machines were built next to a Geneva. Rumours that part of China is to be renamed have just started.

Geneva, China?

Still, I wouldn't be surprise if China does go ahead on its own and build its own collider.


Sunday, August 09, 2015

NOvA Neutrinos - A Slight Lost In Translation

OK, this post is making two different points, and try not to miss both of them, because one of them reinforces my stand that what you say may not exactly be what they understood.

This press release out of Fermilab announced the observation of neutrino oscillation by the NOvA detectors. This is crucial for NOvA to show that they can detect what has already been shown to exist, because it is their mission to study this more carefully and to make specific measurements on this phenomenon.

That's my first point, and that's the main news. Now comes the second point. Another "news"  article took that Fermilab press release, and reported it. But read how it has been presented in the beginning.

Scientists have witnessed their first evidence of oscillating neutrinos, taking a huge step forward in particle physics. The new findings confirm that the extraordinary detector built for the project not only functions as planned but is also making great progress toward its goal of a major leap in our understanding of these particles.

Now this is important, because it comes in at the very beginning of the news article and it sets the tone for the entire report. But read it carefully. If you don't know any better, reading the first sentence will give you the impression that this is the first ever sighting of oscillating neutrinos
Since they got this from Fermilab's press release, did the press release itself made the same mistake? Let's take a look. The Fermilab's press release wrote this:

Scientists on the NOvA experiment saw their first evidence of oscillating neutrinos, confirming that the extraordinary detector built for the project not only functions as planned but is also making great progress toward its goal of a major leap in our understanding of these ghostly particles.

Notice the subtle but important difference. Fermilab's press release indicated that this is the first observation of neutrino oscilation by NOvA scientists! Of course, those of us in the know are aware that this statement is indicating that the new NOvA detector has detected what it SHOULD detect, and this is a major milestone in the commissioning of any new instrument, i.e. it should detect what have already been detected to make sure everything is working as it should. It doesn't mean that this neutrino oscillation is the first detection anywhere!

But this is what frequently happens. I don't know the quality of news reporting on "Science World Report", but that is irrelevant because this time of "mistranslation" happens regularly when non-experts tries to interpret or understand scientific reporting. It is why what you write needs to be looked at in several different angles and from background of people who are ignorant of not  only the subject matter, but also the progress in that area. A person reading the news report will think that this is the first ever evidence of neutrino oscillation, when that is clearly false.

The Fermilab news release should look at this type  of misreporting, and see if they need to make their press releases even more "simplified" so that people aren't mislead into thinking the same way as the news report. We must always be vigilant of the fact that what we wrote and what we meant may not be exactly what they understand.


What Has Nuclear Physics Given Us?

I suppose I don't need to preach to the choir, but this is a nice, easy-to-read article if you ever encounter another person who is ignorant about how we have benefited from the study of nuclear physics.

A century is a long time in science, and things move quickly. It wasn’t long ago that we all had particle accelerators in our homes – the cathode ray tubes in our televisions. These have been superseded by LCD, LED and plasma displays, which are founded on our development of quantum technologies.

Perhaps the most prevalent application of particle accelerators today is in hospitals in the form of radiotherapy machines for the treatment of cancer.

In addition, Nuclear physics is the key to more or less all diagnostic imaging such as such X-ray, PET, CT, MRI, NMR, SPECT and other techniques that allow us to look inside the body without resorting to the knife.

If you’ve ever benefitted from one of these, thanks are due to many people, not least the nuclear physics pioneers who just wondered “what is this stuff?” and “what if…?”.

Certainly many aspects of nuclear physics overlaps with high-energy/particle physics, especially in the development of particle accelerators. But it is still worth noting that what started off as an area of study that had no obvious practical application has produced many indispensable necessities that are a part of our lives. This needs to be repeated many times for people  who simply do not see the value of basic, fundamental research.


Wednesday, August 05, 2015

Do Students Know What They Know?

This is a rather interesting research on an effect that I was never aware of till now - the Dunning-Kruger effect. This is the effect where "... low-performing students tend to overestimate their abilities, while high-performing students estimate their abilities more accurately... "

The authors in this study compared their results from a physics course and a chemistry course, and came up with roughly the same effect.

Abstract: We have conducted an investigation into how well students in introductory science classes (both physics and chemistry) are able to predict which questions they will or will not be able to answer correctly on an upcoming assessment. An examination of the data at the level of students’ overall scores reveals results consistent with the Dunning-Kruger effect, in which low-performing students tend to overestimate their abilities, while high-performing students estimate their abilities more accurately. Similar results have been widely reported in the science education literature. Breaking results out by students’ responses to individual questions, however, reveals that students of all ability levels have difficulty distinguishing questions which they are able to answer correctly from those that they are not able to answer correctly. These results have implications for the future study and reporting of students’ metacognitive abilities.

(You should be able to get the paper for free)


Monday, August 03, 2015

DES Sky Survey

I mentioned a while ago of the Dark Energy Survey project that is trying to map our universe and possibly produce a clearer picture of the dark energy phenomenon. This week we have one of the first mapping of our universe from DES, from just 3% of the DES data.

The DES dark matter map is not the first of its kind. Several pioneering analyses have come before it, most notably the Canada-France-Hawaii Telescope Lensing Survey, which used 4 times the number of distant galaxies that DES used to map an area of similar size but at higher resolution. The two teams have reached the same conclusions, though: The luminous matter that we can see is housed within the dark matter structures that we cannot see, and this dark matter forms a cosmic web of filaments, knots, and voids. As it continues collecting and analyzing data, DES will be able to map how these dark matter structures evolve over time.

There's a lot more to be discovered here as more of the data are analyzed.