Schrödinger's lunch

While visiting the University of Vienna for a conference, I came across Erwin Schrödinger's old desk set up in the lunch room. Sitting down at the desk to eat my lunch I stumbled upon a new quantum "paradox". Schrodinger's lunch

The Minute Physics Interactive Periodic Table of Awesome

Interactive Periodic Table

Henry Reich and Jasper Palfree have created an amazing interactive version of the Periodic Table. As you change temperature, you can see the elements transition between different states of magnetism. You can also see at what temperatures an element changes state from solid to liquid to gas. There is even an option to display temperatures in Fahrenheit for the heathens among you. If that isn't awesome enough, Henry makes clever use of Youtube, HTML5, and the interactive periodic table to explain how to destroy a magnet. You can also click on any element to see a clip, courtesy of Periodic Videos, about it. This is a great educational tool. I can't wait to see what Henry and Jasper come up with next.

Connection Doesn’t Work the Way You Think It Works

Rebecca Brightly:

Traditionally, the lead is in charge of the entire structure of the dance. The lead must give the follow clear instructions. Traditionally, the follow has limited choices, and all choices must mesh with the lead’s instructions.

First, the traditional definition is literally inaccurate. Of course you can dance that way. But the best dancers do not. The best dance partnerships work as a team, both people contributing creative ideas on the fly, each responding to the other’s movements, adapting the direction of the dance based on their partner’s input.

This is a must-read article on the subject of connection in dance. One of the biggest breakthroughs in my own dancing came when I realized that the lead can initiate a movement that the follow then completes. How a follow chooses to move in response to the lead is where much of their creativity is expressed. This movement then influences how the lead subsequently moves, and the cycle continues.

lindy hop connection yin yang

The best dances I have occur when ideas flow back-and-forth seamlessly. The distinction between leading and following disappears, and the dance becomes about two people together weaving something beautiful out of the music and movement they share. Yin & Yang. Lead & Follow.

I Charleston the World

The idea is simple–"make videos of you doing Charleston in front of famous places around the world... and share." So far over two-dozen videos have been submitted. This one from Berlin is my favourite. Excellent dancing and production values. 

UPDATE This video from Nashville, released today, gives the Berlin one a run for its money. Great song choice.

Canon develops amazing low-light sensor

Canon has just announced a new 35 mm full-frame sensor that is incredibly sensitive to low-light levels. The sensor does this in part by using large pixels (19x19 microns^2), which is about 7.5 times larger than the pixel size of their other cameras. Right now the sensor is optimized for full-HD video. Here is the video Canon has released of some footage from a sensor prototype. Most impressive are the shots of the Milky Way, illuminating a person using an incense stick, and being able to shoot in moonlight as if it were daylight.

So just how sensitive is this camera? According to the specs, the camera can form a useable image at ~0.03 lux. Doing a quick back-of-the-envelope calculation, 0.03 lux corresponds to a sensitivity of about 40,000 photons hitting each pixel each second (for green light). If we shoot at 24 frames/second, this is about 2000 photons/frame/pixel–or about 0.5 femtowatts.

Any sensor will have noise associated with it. In order to get a useable image, you should have a decent signal to noise ratio. Let's say that 5% of the pixels have noise on them (corresponding to a fairly noisy image), that means each pixel experiences about 100 noise counts/second.

What is remarkable is that this takes place at room temperature. There are other sensors that have been developed for scientific applications that are much more sensitive than this Canon camera, but they must be cooled first. For example, a camera I have worked with in the past is the Andor iDus. This camera is sensitive down to the single-photon level when cooled to -80 C. This is achieved in part by using some clever electronics to reduce the readout noise and using larger pixels (26x26 microns^2). At -80 C, the camera experiences a negligible amount of dark counts/s (much less than 1). Increase this to 20 C (room temperature), and that number goes up to a couple of hundred noise counts/pixel (as best as I can tell from the specs).

This analysis should be taken with a grain of salt. The take home message is that at room temperature, the new Canon CMOS sensor performs on par with the best EMCCD cameras out there. This is seen in Canon's own tests (where they measure against a three-EMCCD). It would be interesting to see how well this new sensor performs when cooled.

I can't wait for this technology to eventually make its way into consumer-level technology.

Screen shots from the Canon Video

This scene is illuminated only by moonlight.
An incense stick is bright enough to illuminate a man's face.
A comparison between a three-EMCCD and the new Cannon sensor.

Grammar that!

Brilliant takedown of a grammar jerk in the comments at Ars Technica. User Kikjou writes: "Bacteria is plural of bacterium. Please use is correctly. The same goes for media and medium, which is not in this article but is often misused in scientific writing." To which Ars Centurion Okton responds:

In Latin maybe. And the phrase you are nitpicking is actually "from a bacteria". So if you were anything but pedantic, you would exclaim "that requires the ablative of source! In the singular." Following your logic, the article should read "...from a bacterio". But wait, Latin has no indefinite article, so whether it is "a bacterium" or "a bacterio", the noun phrase is redundant since indefiniteness is presupposed in simple noun forms. But "from bacterio" is neither grammatical English nor comprehensible Latin. And the ablative of source usually employs a preposition, so "from a bacteria" should read "ab bacterio" to be exact.

Problem is: This is not FRICKING Latin. This is a word of Latin origin that has entered into English. Therefore our rules apply. Because if you demand a Latin singular, I demand the proper Latin case, pronunciation, etc. We took the plural form for obvious reasons. Because of the physical size of bacteria, the word became a mass noun and functions as both plural and singular. Same reason for taking "data": it is collective. There are rarely "bacterias". And certainly no "datas". One sheep. Two sheep. Ten sheep. One form, all numbers. It is legal in English - accept it.

I can only assume you are one of those people who thinks the plural of "octopus" is "octopi" as well. Except there is no such word as "octopus" in Latin. The word is "polypus", "Octopus" is from the Greek ὀκτάπους, and the plural of that is ὀκτάποδες. And even if people knew "octopodes" was the true plural, they would say it wrong since the epsilon is not silent. Why? Because it is adapted for usage in the new language. It has no obligations to its old morphology and phonology.

By your inanity, if you ever say the word "cherry" for a single unit, I have every right to chastise you. That word never existed in French. "Cheris(e)" is the singular form that was introduced into English. How dare you impose English conventions of depluralization on it! You will say "Shair-eez" for one piece of fruit, you'll do it in a beret and you'll like it. You doctrinaire dope.

via Ed Yong

Nature acquires open access publisher Frontiers

Nature, the scientific publishing behemoth, has acquired the upstart open-access publisher Frontiers. It will be interesting to see how this will shake out; will Nature publications move towards a more open access model, or will Frontiers shift to a more traditional model?

Scientific publishing is big business. From the Economist article:

Outsell, a consultancy, estimates that open-access journals generated $172m in 2012, up 34% from 2011.

This is still a tiny fraction of the $6 billion or so generated by journal subscriptions. But the traditional subscription-based model is falling out of favour. Academics have long complained that publishers abuse their monopoly-like power. Perusing Tetrahedron, say, is a must for any self-respecting chemist. So they (or rather, their university libraries) grudginly cough up €18,570 ($24,267) for an annual subscription. More than 13,000 scientists are boycotting Elsevier, a big Dutch publisher of thousands of journals, including Tetrahedron, whose 37% margins on $2.1 billion in revenues make it the biggest offender in the eyes of many.

In comparison, $6 billion dollars a year is more revenue the music industry generates from iTunes1 ($5.6 billion), or iOS developers make from the App store2. Scientist must pay significant fees to publish their articles, and then institutions have to pay even larger fees to access the research. Now, with the internet, it is becoming possible to publish in journals or preprint servers that anyone can access. In physics things are already moving this way with the advent of the Arxiv, a free online repository that contains a mix of peer-reviewed and non-peer-reviewed work:

ArXiv is already hosted by Cornell University at a cost of around $830,000 a year. Tacking on an "epijournal", so that referreed papers would sit alongside the original preprints, for instance, should not add too much on top of that.

The idea makes perfect sense. Scientists already do most of the heavy lifting involved in publishing research: they write up and format papers, post them to online servers, sit on journals' editorial boards and review their colleagues' work. One reason for Elsevier's mouth-watering margins is that this work is typically done for no compensation.

With that much money at stake, it will take some time for things to change.

  1. The iTunes Value Structure 
  2. A more complete picture of the iTunes economy 

Marriage advice from Antartica: How to get along and avoid extreme cabin fever

Debora Shapiro and her husband Rolf

Deborah Shapiro writes about the 270 days she spend in isolation with her husband, Rolf Bjelke, in the Antarctic.

It never ceases to amaze us, but the most common question Rolf and I got after our winter-over, when we spent 15 months on the Antarctic Peninsula, nine of which were in total solitude, was: Why didn't you two kill each other?

We found the question odd and even comical at first, because the thought of killing each other had never crossed our minds.

We'd answer glibly that because we relied on each other for survival, murder would be counter-productive.

The personal skills needed to survive such extreme isolation:

Showing tangible signs of caring and of empathy ensures that cabin fever never takes hold. It's one of the personality traits Sir Ernest Shackleton looked for, when signing-on crew for his expeditions.

As Rolf, who has Shackleton as a role model, always says: "I can teach anyone how to sail, but I can never change a person's personality."

When Russian meteors attack

It appears a huge meteor has just struck somewhere over Russia. Phil Plait is posting frequent updates over twitter. What is amazing is how many cameras seem to have caught the entry, and subsequent breakup, of the meteor. In Russia most cars have dashboard cameras installed to collect evidence in case of accidents. There are some crazy videos of Russian driving on Youtube, but this is the most awe-inspiring dashcam footage I have seen yet. 

Also, check out this video shot after the meteor passed by. About 20 seconds in you can hear the awesome sonic boom caused by the meteor's entry

UPDATE: Phil Plait has posted a more in depth analysis of the meteor strike, including some impressive footage.

A levitating Eiffel Tower

Julien Bobroff, a French physicist who is heavily involved in science outreach, has been coming up with clever ways of exploring the boundary between art and science using superconductivity. Check out his outreach site for some clever videos, craft projects, and animations that deal with a range of quantum behaviour.

I particularly like his collaboration with designer François Azambourg to convey some of the surprising properties of superconductivity. These include levitating jewellery, a no-contact line of clothing, a superconductivity circus, and a delightful superconducting Rube Goldberg machine breakfast maker.

He has also produced this page, Quantum made simple, which has some stunning animations of quantum tunnelling, lasers, and the double slit.

The Myth of the Well-Rounded Scientist

Adam Ruben writes about the attitude in academia that a moment not spent in the lab is a moment wasted.

My outside interest during grad school—my “Batman job,” as a grad student from Case Western Reserve University called it last month—was stand-up comedy. (I quickly learned that audiences in downtown Baltimore aren’t fans of math puns. Like this one: “I was curious about the alcohol content of my mouthwash, but the label on the bottle didn’t say anything about it. I guess the proof was beyond the text of this Scope!” And that’s why I’m not famous.)

One day, my adviser called me into his office. The campus newspaper had just published a little profile of the stand-up-comedy-performing grad student, and my adviser happened to read it. Over the next 10 minutes, I learned that my hobby was an embarrassment to the department, that there was no way I could properly focus on biology, and that every negative lab result I ever produced was a direct result of telling jokes at night.

My "Batman job" is swing dancing. Many of the best things in my life are a direct result of my being involved in a dance community. I met my wife through dance, I have become a better teacher, and my communications skills have dramatically improved. I remember keeping my physics life and dance life separate at the beginning of grad school after being warned by some well-intentioned individuals that such "poppycock" hobbies would hurt my academic career. Then I realized that dance is a big part of who I am, and I did not want to work at a job where I could not be myself. If my hobbies and passions keep me from getting an academic position, then it isn't a place I want to work. Now my physics and dance lives bleed into one another, and this has led to a number of interesting opportunities for me. My "Batman job" has made me a better physicist.

I would wager there are far more scientists with "Batman jobs" than those without.

Avalanche at Tunnel Creek

A gripping tale of an avalanche that overwhelmed some of the best backcountry skiers in the world. There is a lot of interesting science in this article about how avalanches form that is expertly interwoven with the human drama that unfolds. This story took six months to write and it shows. One of the best usages of HTML5 I have seen. If you read one thing this week, this should be it.

The blackhole firewall paradox

Excellent overview by Jennifer Ouellette of a new paradox that is taking the physics world by fire. I first heard about this a month ago from Patrick Hayden. It looks like this could turn into one of the great thought experiments that tackles the difficulties merging quantum mechanics and general relativity.

Paradoxes in physics have a way of clarifying key issues. At the heart of this particular puzzle lies a conflict between three fundamental postulates beloved by many physicists. The first, based on the equivalence principle of general relativity, leads to the No Drama scenario: Because Alice is in free fall as she crosses the horizon, and there is no difference between free fall and inertial motion, she shouldn’t feel extreme effects of gravity. The second postulate is unitarity, the assumption, in keeping with a fundamental tenet of quantum mechanics, that information that falls into a black hole is not irretrievably lost. Lastly, there is what might be best described as “normality,” namely, that physics works as expected far away from a black hole even if it breaks down at some point within the black hole — either at the singularity or at the event horizon.

Together, these concepts make up what Bousso ruefully calls “the menu from hell.” To resolve the paradox, one of the three must be sacrificed, and nobody can agree on which one should get the ax.

Physicists don’t lightly abandon time-honored postulates. That’s why so many find the notion of a wall of fire downright noxious. “It is odious,” John Preskill of the California Institute of Technology declared earlier this month at an informal workshop organized by Stanford University’s Leonard Susskind. For two days, 50 or so physicists engaged in a spirited brainstorming session, tossing out all manner of crazy ideas to try to resolve the paradox, punctuated by the rapid-fire tap-tap-tap of equations being scrawled on a blackboard. But despite the collective angst, even the firewall’s fiercest detractors have yet to find a satisfactory solution to the conundrum.

Joe Polchinski, one of the authors who published the paper on the blackhole firewall paradox, has a more technical write up of the subject over on Cosmic Variance.

Earlier this year, with my students Ahmed Almheiri and Jamie Sully, we set out to sharpen the meaning of black hole complementarity, starting with some simple `bit models’ of black holes that had been developed by Samir Mathur and Steve Giddings. But we quickly found a problem. Susskind had nicely laid out a set of postulates, and we were finding that they could not all be true at once. The postulates are (a) Purity: the black hole information is carried out by the Hawking radiation, (b) Effective Field Theory (EFT): semiclassical gravity is valid outside the horizon, and (c) No Drama: an observer falling into the black hole sees no high energy particles at the horizon. EFT and No Drama are based on the fact that the spacetime curvature is small near and outside the horizon, so there is no way that strong quantum gravity effects should occur. Postulate (b) also has another implication, that the external observer interprets the information as being radiated from an effective membrane at (or microscopically close to) the horizon. This fits with earlier observations that the horizon has effective dynamical properties like viscosity and conductivity.

I love that one of the postulates is called "no drama."

Billionaires warn higher taxes could prevent them from buying politicians

The New Yorker at its satirical best:

The group, led by casino billionaire Sheldon Adelson, commissioned a new study showing that the cost of an average politician has soared exponentially over the past decade.

While the American family has seen increases in the cost of food, health care and education, Mr. Adelson says, “those costs don’t compare with the cost of buying a politician, which has gone through the roof.”

Beautiful LOTR statistics and graphs


With the release of The Hobbit in a few days, I found this beautiful–detailed–look at population statistics of Middle Earth timely. Emil Johanssen has created some fascinating interactive charts detailing population, age, genalogical trees, and the routes and distances various characters take in the books.