Half-erased blackboards from quantum physics labs

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“Momentum,” displayed at the Wilmotte Gallery in London (Alejandro Guijarro)

Blackboards, the legend goes, were invented by a teacher. In the mid-19th century, James Pillans was headmaster of the Royal High School in Edinburgh, Scotland. Teaching geography, he found himself in need of a device that would allow him to share visual information with all his students, simultaneously — a more theatrical and efficient version of the slates students used to write their lessons at their desks. Pillans had chalk; he had tablets. Then he had an idea.

Today, in an age of dry-erase whiteboards and write-on wall paint — an age that has produced surfaces and markers that allow writings to be undone with the ruthless efficiency of a single swipe — blackboards have taken on the wistfulness of the outmoded technology. And the semi-erased chalkboard, in particular — its darkness swirled with the detritus of unknown decisions and revisions — compounds the nostalgia. Its spectral insights mingle in the bright dust of calcium carbonate.

Alejandro Guijarro sees that blurry beauty better than most. Over the last three years, the Spanish artist has visited some of the world’s most prestigious blackboards: the ones housed at the quantum mechanics labs of places like the University of Oxford, UC Berkeley, Stanford, CERN, Cambridge, and the Instituto de Física Corpuscular. At each place, he used a large-format camera to capture the markings left on the boards, just as he found them.

“The images in this series do not purport to be documents holding an objective truth,” Guijarro says of his work; “they function purely as suggestions. They are fragmented pieces of ideas, thoughts or explanations from which arises a level of randomness. They are an attempt to portray the space of a flat surface and of a given frame. They are arbitrary moments in the restless life of an object in constant motion.”
Some of Guijarro’s images are reproduced below. 
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Cartoon Laws of Physics

Wile E. Coyote running off a cliff

From TheFunnyPages.com:

Wile E. Coyote running off a cliff

Cartoon Law I

Any body suspended in space will remain in space until made aware of its situation.

Daffy Duck steps off a cliff, expecting further pastureland. He loiters in midair, soliloquizing flippantly, until he chances to look down. At this point, the familiar principle of 32 feet per second per second takes over.

Cartoon Law II

Any body in motion will tend to remain in motion until solid matter intervenes suddenly.

Whether shot from a cannon or in hot pursuit on foot, cartoon characters are so absolute in their momentum that only a telephone pole or an outsize boulder retards their forward motion absolutely. Sir Isaac Newton called this sudden termination of motion the stooge’s surcease.

Cartoon Law III

Any body passing through solid matter will leave a perforation conforming to its perimeter.

Also called the silhouette of passage, this phenomenon is the speciality of victims of directed-pressure explosions and of reckless cowards who are so eager to escape that they exit directly through the wall of a house, leaving a cookie-cutout-perfect hole. The threat of skunks or matrimony often catalyzes this reaction.

Cartoon Law IV

The time required for an object to fall twenty stories is greater than or equal to the time it takes for whoever knocked it off the ledge to spiral down twenty flights to attempt to capture it unbroken.

Such an object is inevitably priceless, the attempt to capture it inevitably unsuccessful.

Cartoon Law V

All principles of gravity are negated by fear.

Psychic forces are sufficient in most bodies for a shock to propel them directly away from the earth’s surface. A spooky noise or an adversary’s signature sound will induce motion upward, usually to the cradle of a chandelier, a treetop, or the crest of a flagpole. The feet of a character who is running or the wheels of a speeding auto need never touch the ground, especially when in flight.

Cartoon Law VI

As speed increases, objects can be in several places at once.

This is particularly true of tooth-and-claw fights, in which a character’s head may be glimpsed emerging from the cloud of altercation at several places simultaneously. This effect is common as well among bodies that are spinning or being throttled.

A wacky character has the option of self-replication only at manic high speeds and may ricochet off walls to achieve the velocity required.

Cartoon Law VII

Certain bodies can pass through solid walls painted to resemble tunnel entrances; others cannot.

This trompe l’oeil inconsistency has baffled generations, but at least it is known that whoever paints an entrance on a wall’s surface to trick an opponent will be unable to pursue him into this theoretical space.

The painter is flattened against the wall when he attempts to follow into the painting. This is ultimately a problem of art, not of science.

Cartoon Law VIII

Any violent rearrangement of feline matter is impermanent.

Cartoon cats possess even more deaths than the traditional nine lives might comfortably afford. They can be decimated, spliced, splayed, accordion-pleated, spindled, or disassembled, but they cannot be destroyed. After a few moments of blinking self pity, they reinflate, elongate, snap back, or solidify.

Corollary:

A cat will assume the shape of its container.

Cartoon Law IX

Everything falls faster than an anvil.

Cartoon Law X

For every vengeance there is an equal and opposite revengeance.

This is the one law of animated cartoon motion that also applies to the physical world at large. For that reason, we need the relief of watching it happen to a duck instead.

Cartoon Law Amendment A

A sharp object will always propel a character upward.

When poked (usually in the buttocks) with a sharp object (usually a pin), a character will defy gravity by shooting straight up, with great velocity.

Cartoon Law Amendment B

The laws of object permanence are nullified for “cool” characters.

Characters who are intended to be “cool” can make previously nonexistent objects appear from behind their backs at will. For instance, the Road Runner can materialize signs to express himself without speaking.

Cartoon Law Amendment C

Explosive weapons cannot cause fatal injuries.

They merely turn characters temporarily black and smokey.

Cartoon Law Amendment D

Gravity is transmitted by slow-moving waves of large wavelengths.

Their operation can be wittnessed by observing the behavior of a canine suspended over a large vertical drop. Its feet will begin to fall first, causing its legs to stretch. As the wave reaches its torso, that part will begin to fall, causing the neck to strech. As the head begins to fall, tension is released and the canine will resume its regular proportions until such time as it strikes the ground.

Cartoon Law Amendment E

Dynamite is spontaneously generated in “C-spaces” (spaces in which cartoon laws hold).

The process is analogous to steady-state theories of the universe which postulated that the tensions involved in maintaining a space would cause the creation of hydrogen from nothing. Dynamite quanta are quite large (stick sized) and unstable (lit). Such quanta are attracted to psychic forces generated by feelings of distress in “cool” characters (see Amendment B, which may be a special case of this law), who are able to use said quanta to their advantage. One may imagine C-spaces where all matter and energy result from primal masses of dynamite exploding. A big bang indeed.

Quantum Invisibility Cloak Hides Objects from Reality

Quantum reality cloak graph

By The Physics arXiv Blog from MITTechnologyReview.com:

Physicists have worked out how to cloak a region of space from the quantum world, thereby shielding it from reality itself.

Invisibility cloaks are all the rage these days. Over the last few years, this blog has followed various attempts to develop invisibility cloaks for earthquakes, acoustics and for various parts of the electromagnetic spectrum. In the last few days, we’ve seen the emergence of a new generation of cloaks that can hide large, everyday objects across the entire optical spectrum.

Today, Jeng Yi Lee and Ray-Kuang Lee at the National Tsing-Hua University in Taiwan take the idea of cloaking to its ultimate limit. These guys have worked out how to build quantum invisibility cloaks. These are cloaks that shield objects from the quantum properties of the world outside. That’s not so much an invisibility cloak as a reality cloak.

The idea is simple in essence. Ordinary invisibility cloaks work by steering light around a region of space to make it look as if it weren’t there. The mathematical approach that describes this is called transformation optics. It starts with Maxwell’s equation which govern the behaviour of light as it passes through space.

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Barns Are Painted Red Because of the Physics of Dying Stars

Red barn

From SmithsonianMag.com:
Red barn
Image: Loring Loding

Have you ever noticed that almost every barn you have ever seen is red? There’s a reason for that, and it has to do with the chemistry of dying stars. Seriously.

Yonatan Zunger is a Google employee who decided to explain this phenomenon on Google+ recently. The simple answer to why barns are painted red is because red paint is cheap. The cheapest paint there is, in fact. But the reason it’s so cheap? Well, that’s the interesting part.

Red ochre—Fe2O3—is a simple compound of iron and oxygen that absorbs yellow, green and blue light and appears red. It’s what makes red paint red. It’s really cheap because it’s really plentiful. And it’s really plentiful because of nuclear fusion in dying stars. Zunger explains:

The only thing holding the star up was the energy of the fusion reactions, so as power levels go down, the star starts to shrink. And as it shrinks, the pressure goes up, and the temperature goes up, until suddenly it hits a temperature where a new reaction can get started. These new reactions give it a big burst of energy, but start to form heavier elements still, and so the cycle gradually repeats, with the star reacting further and further up the periodic table, producing more and more heavy elements as it goes. Until it hits 56. At that point, the reactions simply stop producing energy at all; the star shuts down and collapses without stopping.

As soon as the star hits the 56 nucleon (total number of protons and neutrons in the nucleus) cutoff, it falls apart. It doesn’t make anything heavier than 56. What does this have to do with red paint? Because the star stops at 56, it winds up making a ton of things with 56 neucleons. It makes more 56 nucleon containing things than anything else (aside from the super light stuff in the star that is too light to fuse).

The element that has 56 protons and neutrons in its nucleus in its stable state? Iron. The stuff that makes red paint.

And that, Zunger explains, is how the death of a star determines what color barns are painted.

Physics, Entropy and Web Design

Chessboard

ChessboardA long, interesting article by Anthony Wing Kosner from Forbes.com. Excerpts are below.

[Full article]

We have been taught to think of entropy as a bad thing. “Things fall apart; the centre cannot hold;/Mere anarchy is loosed upon the world,” wrote William Butler Yeats in the aftermath of World War I, in words that still ring true today. Yet Yeats was both a Romantic poet and a Modern one, and he followed up this couplet with a more counterintuitive one, “The best lack all conviction, while the worst /Are full of passionate intensity.”

These lines have always been a kind of zen koan for me. Lack of conviction would seem to lead to “mere anarchy,” but so often we find that it is fervent, fixed beliefs that lead us astray. Throughout history, poets, philosophers and heretics of all kinds have tried to express the kind of openness of mind that leads to reliably good outcomes. In the 70s Fritjof Capra’s The Tao of Physics introduced a generation to the intersection of science and Eastern thought. Now, we can add a computational physicist to that crowd.

My recent story on the Famo.us platform talked about how it will enable every data object on the web to be addressable in terms of physics properties. The ability to apply causal entropic forces to these objects will allow them to become emergently intelligent as well. For people who make websites and mobile apps, this means beginning to think about the content of software and the users of software somewhat interchangeably as physical entities subject to entropic forces.

To relate this to the immediate concerns of people who make websites and apps, consider Wissman-Gross’ primary example (a) above. The little diagram shows what happens over time in an open system where the horizontal and vertical movements of a single particle are entropically maximized—the particle “gravitates” towards the center of the space. In physics terms, “the central position maximized the diversity of causal paths accessible by Brownian motion within the box.” But in everyday internet terms that we all understand, a large button, centrally placed, will receive the most clicks. The hand and the eye will naturally (and intelligently) gravitate there in pursuit of the full, informational possibilities of the page.

Without the priority of entropic movement, the “maximum likelihood position” of a particle diffusing in a bounded box would be its initial state! That would be like a website user coming to a page, looking in the upper left corner and staying there! The active intelligence of interaction is governed by these forces of entropy. The most effective apps use default states to “force” certain kinds of actions. There is still an enduring social mystery about how you get people to your app or site, but once they are there, you can use the forces of entropy to guide their intelligent exploration towards the goal you want them to reach—even if they do not arrive with that goal in mind.

Physicists at CERN caught ‘colliding’ household objects

Inspectors examining a recent malfunction at the Large Hadron Collider found that senior scientists had been “inserting various household objects into the collider,” causing helium leakage and misalignment of several of the magnets. The Large Hadron Collider, or LHC, cost over 4.1 billion dollars to build, runs a length of 27 kilometers below Geneva and has been used to search for evidence of the Higgs particle and the associated Higgs field. These noble goals bear little relationship to the activities engaged in by Yukihide Matsuzi, a Japanese theoretical physicist, and his colleague, Klara Eschelbach, a mathematician interested in models of supersymmetry.

“Apparently they were just chucking stuff in there to see what would happen,” said a distraught David Branston, project leader overseeing CMS and Atlas projects. “Just when we might be seeing evidence of two different Higgs particles, these clowns almost destroy the collider!” The scientists in question admitted they had already collided several watches, a fountain pen, a bunch of keys and a can of coke. “It is very irresponsible of us, but our project has been delayed by 18 months. We’ve been here doing checks and simulations for more than four years now. I guess we just couldn’t help ourselves when we realized the machine was operational but not colliding proton beams. If we found a new particle by colliding coke-cans we were going to call it a colon…” Eschelbach said in a feeble attempt to lighten the situation. “Maybe we should have stuck with our original plan of making high-energy popcorn instead…”

Branston says he’s “just glad we could stop them before it got any worse.” “Just look at the stuff they had lined up!” the project leader said. Among the objects soon to be reduced to subatomic particles were a desk chair, a Microsoft Zune and two rather nervous looking mice. The damage to the LHC will extend the two-year break by several months.

Sadly, this story appears not to be true.