Friday, February 27, 2015

Much Ado About Dress Color

Have you been following this ridiculous debate about the color of this dress? People are going nuts all over different social media about what the color of this dress is based on the photo that has exploded all over the internet.

I'm calling it ridiculous because people are actually arguing with each other, disagreeing about what they see, and then found it rather odd that other people do not see the same thing as they do, as if this is highly unusual and unexpected. Does the fact that different people see colors differently not a well-known fact? Seriously?

I've already mentioned about the limition of the human eye, and why it is really not a very good light detector in many aspects. So already using your eyes to determine the color of this dress is already suspect. Not only that, but due to such uncertainty, one should be to stuborn about what one sees, as if what you are seeing must be the ONLY way to see it.

But how would science solve this? Easy. Devices such as a UV-VIS can easily be used to measure the spectrum of reflected light, and the intensity of those spectral peaks. It tells you unambiguously the wavelengths that are reflected off the source, and how much of it is reflected. So to solve this debate, cut pieces of the dress (corresponding to all the different colors on it), and stick it into one of these devices. Voila! You have killed the debate of the "color".

This is something that can be determined objectively, without any subjective opinion of "color", and without the use of a poor light detector such as one's eyes. So, if someone can tell me where I can get a piece of this fabric, I'll test it out!


Monday, February 23, 2015

Which Famous Physicist Should Be Depicted In The Movie Next?

Eddie Redmayne won the Oscar last night for his portrayal of Stephen Hawking in the movie "The Theory of Everything". So this got me into thinking of which famous physicist should be portrayed next in a movie biography. Hollywood won't choose someone who isn't eccentric, famous, or in the news. So that rules out a lot.

I would think that Richard Feynman would make a rather compelling biographical movie. He certainly was a very complex person, and definitely not boring. They could give the movie a title of "Sure You Must Be Joking", or "Six Easy Pieces", or "Shut Up And Calculate", although the latter may not be entirely attributed to Feynman.

Hollywood, I'm available for consultation!


Friday, February 20, 2015

Unfortunate Superfish

I hope this doesn't taint the name "Superfish".

In case you missed it, this week came the news that Lenovo, the Chinese computer company (to whom IBM sold their ThinkPad laptop series) had been installing on some of their computers a rather nasty tracking software called Superfish Visual Discovery.

I would have paid that much attention to stuff like this weren't it for two reasons: (i) I own a rather new Lenovo laptop and (ii) I am familiar with the name "Superfish" but under a different context.

Luckily, after doing a thorough check of my system, I found no sign of this intrusive software. As for the second reason, there is a rather popular software called "Superfish" out of Los Alamos National Lab that we use quite often. It is a Poisson EM solver often used to solve for EM fields in complex geometry/boundary conditions. I'm guessing that they gave it that name because "poisson" is French for "fish", and it really is a super software! :)

It is unfortunate that in the context of computer technology, the name Superfish is "poison".


Wednesday, February 18, 2015

2015 International Year of Light

We had the 2005 International Year of Physics, and 2009 International Year of Astronomy. Now in 2015, UNESCO has declared that this will be the International Year of Light.

In case you missed it, the APS has made available a series of significant articles and papers related to this topic. Check them out.

Personally, as someone who has performed work at a synchrotron light source, and done studies using photoemission phenomenon, I can truly appreciate "light" beyond just what we normally do everyday.


Wednesday, February 11, 2015

Revealing the Nature of Dark Matter

This is a lecture given by Physicist Dan Hooper on Dark Matter at Fermilab. I haven't bump into Dan since we were both at Illinois Science Council event a few years ago at a bar in the Wrigleyville area in Chicago.


Sunday, February 08, 2015

Val Fitch

We lost Nobel Laureate Charles Townes several days ago, and now another Nobel Laureate has passed away. Val Fitch died this past week at the age of 91. His work in CP-symmetry violation is still one of the most fundamental aspect of elementary particle physics that is still being investigated.


Friday, February 06, 2015

Transistor Made From Silicene

With all the focus and attention paid on graphene, it is easy to forget that there are more potential for silicene, graphene single-layer cousin, to be made into an electronic device.

This report highlights one such accomplishment of producing a proof-of-principle capability of using silicene to make an important device - a transistor.

“For logic applications, graphene is hopeless,” says Le Lay. By contrast, silicene can boast a band gap, because some of its atoms buckle upwards to form corrugated ridges, which puts some of its electrons in slightly different energy states. What is more, makers of electronic chips have been wary of ditching decades of silicon-manufacturing experience in favour of carbon, says Lok Lew Yan Voon, a theoretical physicist at the Citadel, the Military College of South Carolina in Charleston, who first named silicene and modelled its properties back in 2007.


Wednesday, February 04, 2015

No Gravitational Wave and Inflation from BICEP2 Results

If you had missed the news, then catch up with the latest admission that the results from BICEP2 that points to evidence for inflationary primordial universe has been discredited.

I actually will have more to say on this in a later post. For now, this is one of the clearest example of science at work, where the checks and balance come into play, and where no one will accept a result even if it is consistent with the prevailing "party line".


Wednesday, January 28, 2015

Charles Townes

As reported almost everywhere, we lost Nobel Laureate Charles Townes at the age of 99. Oh how we we all are standing on the shoulder of this giant in physics.


Wednesday, January 21, 2015

GUTs and TOEs

Another informative video, for the general public, from Don Lincoln and Fermilab.

Of course, if you had read my take on the so-called "Theory of Everything", you would know my stand on this when we consider emergent phenomena.


Tuesday, January 20, 2015

Macrorealism Violated By Cs Atoms

It is another example where the more they test QM, the more convincing it becomes.

This latest experiment is to test whether superposition truly exist via a very stringent test and applying the Leggett-Garg criteria.

In comparison with these earlier experiments, the atoms studied in the experiments by Robens et al.’s are the largest quantum objects with which the Leggett-Garg inequality has been tested using what is called a null measurement—a “noninvasive” measurement that allows the inequality to be confirmed in the most convincing way possible. In the researchers’ experiment, a cesium atom moves in one of two standing optical waves that have opposite electric-field polarizations, and the atom’s position is measured at various times. The two standing waves can be pictured as a tiny pair of overlapping one-dimensional egg-carton strips—one red, one blue (Fig. 1). The experiment consists of measuring correlation between the atom’s position at different times. Robens et al. first put the atom into a superposition of two internal hyperfine spin states; this corresponds to being in both cartons simultaneously. Next, the team slid the two optical waves past each other, which causes the atom to smear out over a distance of up to about 2 micrometers in a motion known as a quantum walk. Finally, the authors optically excited the atom, causing it to fluoresce and reveal its location at a single site. Knowing where the atom began allows them to calculate, on average, whether the atom moved left or right from its starting position. By repeating this experiment, they can obtain correlations between the atom’s position at different times, which are the inputs into the Leggett-Garg inequality.

You may read the result they got in the report. Also note that you also get free access to the actual paper.

But don't miss the importance of this work, as stated in this review.

Almost a century after the quantum revolution in science, it’s perhaps surprising that physicists are still trying to prove the existence of superpositions. The real motivation lies in the future of theoretical physics. Fledgling theories of macrorealism may well form the basis of the next generation “upgrade” to quantum theory by setting the scale of the quantum-classical boundary. Thanks to the results of this experiment, we can be sure that the boundary cannot lie below the scale at which the cesium atom has been shown to behave like a wave. How high is this scale? A theoretical measure of macroscopicity [8] (see 18 April 2013 Synopsis) gives the cesium atom a modest ranking of 6.8, above the only other object tested with null measurements [5], but far below where most suspect the boundary lies. (Schrödinger’s cat is a 57.) In fact, matter-wave interferometry experiments have already shown interference fringes with Buckminsterfullerene molecules [9], boasting a rating as high as 12. In my opinion, however, we can be surer of the demonstration of the quantumness of the cesium atom because of the authors’ exclusion of macrorealism via null result measurements. The next step is to try these experiments with atoms of larger mass, superposed over longer time scales and separated by greater distances. This will push the envelope of macroscopicity further and reveal yet more about the nature of the relationship between the quantum and the macroworld.