Links for June 2016

The “modern” pentathalon is bizarre:

The modern pentathlon is an Olympic sport that comprises five very different events: fencing, 200 m freestyle swimming, show jumping, and a final combined event of pistol shooting, and a 3200 m cross-country run. The sport has been a core sport of the Olympic Games since 1912 despite dispute…

The addition of modern to the name distinguished it from the original pentathlon of the ancient Olympic Games, which consisted of the stadion foot race, wrestling, long jump, javelin, and discus. As the events of the ancient pentathlon were modeled after the skills of the ideal soldier of that time, Coubertin created the contest to simulate the experience of a 19th-century cavalry soldier behind enemy lines: he must ride an unfamiliar horse, fight enemies with pistol and sword, swim, and run to return to his own soldiers.

Everyone should know Moore’s here-is-one-hand argument:

In his 1925 essay A Defence of Common Sense, Moore argues against idealism and skepticism toward the external world on the grounds that skeptics could not give reasons to accept their metaphysical premises that were more plausible to him than the reasons he had to accept the common sense claims about our knowledge of the world that skeptics and idealists must deny. In other words, he is more willing to believe that he has a hand than to believe the premises of what he deems “a strange argument in a university classroom.” “I do not think it is rational to be as certain of any one of these … propositions”….

Another form of refutation simply points out that not everyone shares Moore’s intuition. If a person finds the skeptical possibility sp more intuitively likely than the knowledge claim q, then for that person Moore’s own defense of intuition provides a basis for their skepticism. Moore, however, defends his argument on the grounds that skeptical arguments seem invariably to require an appeal to “philosophical intuitions”. He feels we have considerably less reason to accept such intuitions than we have to accept the claims that they mean to refute.

Primordial black holes should be distributed like dark matter halos, whereas astrophysical black holes should be concentrated in galactic discs. Also, the typical eccentricity of the astrophysical black hole binaries should be different. With some luck, the primordial black hole dark matter scenario may be vindicated or robustly excluded in the near future.

Consider now two players playing the game called bilateral monopoly. They have a dollar to divide between them, provided they can agree how to divide it….the players are free to talk with each other as much as they want.

But while they can talk freely, there is a sense in which they cannot communicate at all. It is in my interest to persuade you that I will only be satisfied with a large fraction of the dollar; if I am really unwilling to accept anything less than ninety cents, you are better off agreeing to accept ten cents than holding out for more and getting nothing. Since it is in the interest of each of us to persuade the other of his resolve, all statements to that effect can be ignored; they would be made whether true or not. What each player has to do is to guess what the other’s real demand is, what the fraction of the dollar is without which he will refuse to agree. That cannot be communicated, simply because it pays each player to lie about it….the players must coordinate their demands (so that they add up to a dollar) without communication. It seems likely that they will do so by agreeing to split the dollar fifty-fifty.

Although it’s generally understood that strong incentives to lie mean people are less able to trust each other, Friedman’s simple insight is that this mean it is useful to analyze some human interactions as if humans are unable to communicate. Friedman then goes on to argue that property rights are the Schelling point of games concerning who gets to use what property.

The best critique of this line of reasoning is probably just the general failure of game theory at predicting real-life interactions. Still, I think this idea is more fundamental than the formalism used to describe it here.

Using a sample of all academics that pass through top 50 economics and finance departments between 1996 and 2014, we study whether the granting of tenure leads faculty to pursue riskier ideas. We use the extreme tails of ex-post citations as our measure of risk and find that both the number of publications and the portion that are “home runs” peak at tenure and fall steadily for a decade thereafter. Similar patterns holds for elite (top 10) institutions, for faculty with longer tenure cycles, and for promotion to Full Professorship. We find the opposite pattern among poorly-cited publications: their numbers steadily rise after tenure. The decline in both the quantity and quality of publications points to tenure incentivizing less effort in publishing rather than more risk-taking.

Suits Drive Cabin Diameter…EVA Suits are Physically Larger Than IVA Suits…If crew has to remove suits, it gets worse! Must remove suits after about 12 hours. Maximum Absorbency Garment (MAG) is rated for ~8 hours, but work is ongoing to extend limit….

The basic way [E-Ink] works is that they have dark pigment particles and white pigment particles, and they respond oppositely to applied voltage. So to switch, you just apply voltage: one set of pigments rises to the surface and the other sinks.

The challenge with color is that it becomes multidimensional, so using a one-dimensional controller (voltage) isn’t straightforward anymore. You could do separate pixels for separate colors using color filters, but this drastically reduces total reflectance (presumably by about 2/3), so everything just looks dark.

It looks like they use four pigment primaries (white-cyan-magenta-yellow), two of which are negatively charged and two that are positively charged. They were very vague about their exact method, but it’s some combination of using race conditions (i.e. cyan will rise faster than magenta) and some other weird techniques to achieve all color configurations. Still not sure how it works, but I guess that’s the way they want it.

Relatedly is this guy’s incredibly laborious attempt to mimic e-ink properties with an LCD display:

The final feature I added was what I call “shy mode”. When shy mode is enabled, the picture frame uses a discrete camera and a simple face detection system to determine whether anyone is currently looking at it. If someone is, then the frame won’t change what it’s displaying, since that would be a total giveaway.

For instance, I knew Mathematica kept a copy of all input and output expressions, even plots. But did you know that by default it keeps everything for an arbitrarily long session and, if it runs out of memory, simply crashes mysteriously? Change $HistoryLength to fix this.

By the way, the Apollo Moon lander had single-use aluminum honeycomb crushable shock absorbers too.
https://www.youtube.com/watch?v=LDpGCfZAraU

While existing U.S. reactors don’t have a standard design, the country of France already fully standardizes the design of all of its nuclear power plants. The standardization allowed France to become a world leader in nuclear power (75% of the country’s electricity comes from nuclear) and achieve one of the lowest electricity prices in Europe of 17 cents per kilowatt-hour when converted with purchasing power parities to U.S. dollars. Compare that to neighboring Germany’s 37 cents per kilowatt-hour or Poland’s 34 cents per kilowatt-hour. (All data from the International Energy Agency).