Links for April 2015

  • The recently completed Effective Altruism Handbook is a collection of key articles which cover a lot of the movement’s basic arguments. It’s available here as a PDF. There are also two new EA books coming out by Peter Singer and Will MacAskill (with annoyingly similar titles…). And here is the Huffington Post’s take on all the noise at Harvard.
  • Authorea authors write on the problems with peer review associated with hyperspecialization:

    [T]he average number of authors per paper has been steadily increasing in the last few decades, while the number of referees per paper has not.


  • Relatedly, the new Leiden Manifesto argues against giving bibliometrics (h-index, etc.) a leading role in the hiring and funding processes. Although I agree with much of it, they take a wishy-washy stance that dilutes its effectiveness. I once compared the objectivity of citation metrics to a vote by spectators about who ran the fasted 100 yard dash, and my opinion has only gotten more pessimistic since then.
  • Some good modern discussion of the theory of a Land Value Tax by Bryan Caplan, Jeff Kaufman, and Noah Smith. Some of their disagreement is semantic (i.e., compared to which platonic ideal are we calling something a “friction”, versus an inherent problem?), but it’s still illuminating.
  • Now you can get your raw genetic data for SNPs for free, so long as you allow your data to be used anonymously for research.
  • Here is a toy models for Gompertz’s law of human mortality, that the human mortality rate grows roughly exponentially, across many times, places, and cultures. However, it’s more complicated than that:

    The Gompertz–Makeham law states that the human death rate is the sum of an age-independent component (the Makeham term, named after William Makeham and an age-dependent component (the Gompertz function, named after Benjamin Gompertz), which increases exponentially with age. In a protected environment where external causes of death are rare (laboratory conditions, low mortality countries, etc.), the age-independent mortality component is often negligible. In this case the formula simplifies to a Gompertz law of mortality [an exponential increase in death rates with age]…The Gompertz–Makeham law of mortality describes the age dynamics of human mortality rather accurately in the age window from about 30 to 80 years of age. At more advanced ages, some studies have found that death rates increase more slowly – a phenomenon known as the late-life mortality deceleration – but other studies disagree….The decline in the human mortality rate before the 1950s was mostly due to a decrease in the age-independent (Makeham) mortality component, while the age-dependent (Gompertz) mortality component was surprisingly stable. Since the 1950s, a new mortality trend has started in the form of an unexpected decline in mortality rates at advanced ages and “de-rectangularization” of the survival curve.

  • TedX talk by Ben Todd from 80,000 Hours: “To find work you love, don’t follow your passion”.
  • The Nasal Cycle:

    The nasal cycle is the often unnoticeable alternating partial congestion and decongestion of the nasal cavities in humans and other animals. It is a physiological congestion of the nasal concha due to selective activation of one half of the autonomic nervous system by the hypothalamus. It should not be confused with pathological nasal congestion.

    (h/t Gwern.) Apparently, the period of the cycle varies a lot from person to person, but is rather consistent for any individual.

  • More rhinology: Virtual noses to reduce “simulator sickness” in virtual reality.
  • Visually arresting comparison of old and new cars in highway crash tests:
  • Sabine Hossenfelder discusses the possibility of using DNA as a directional dark matter detector.
  • The oldest evidence of life has been overturned:

    New analysis of world-famous 3.46-billion-year-old rocks…shows that structures once thought to be Earth’s oldest microfossils do not compare with younger fossil candidates but have, instead, the character of peculiarly shaped minerals.

  • Math proofs without words. (H/t Giuseppe Ottaviano.)
  • Wired piece, mostly fluff, on Zhao Bowen of BGI and their attempt to pin down the genetic component of intelligence. Steve Hsu is a scientific advisor to BGI, and covers them more thoroughly from his blog.
  • Neat tear-down piece on the Tesla Model S internal network. Yet another cool article that could never exist without the internet.
  • The world needs this list expanded: The best textbook on every subject. What I really want is a “franchise expansion” (a la StackExchange) of the phenomenal to cover textbooks.
  • The US Navy has developed cannon-launched swarming drones. Scary-looking stuff:
  • I had characterized Meyers-Briggs as feel-good pseudoscience in the past, but that wasn’t totally justified. Meyers-Briggs is reasonably well correlated with the Big Five personality traits:

    McCrae and Costa present correlations between the MBTI scales and the Big Five personality construct, which aims to organize the complete set of basic personality domains. The five personality characteristics are extraversion, openness, agreeableness, conscientiousness, and emotional stability (or neuroticism)….

    These data suggest that the four MBTI scales are subsumed within the Big Five personality traits, but that the MBTI lacks a measure for emotional stability dimension of the Big Five (though the TDI, discussed above, has addressed that dimension). Emotional stability (or neuroticism) is a core domain predictive of depression and anxiety disorders. These correlations refer to the second letter shown, i.e. the table shows that I and P have negative correlation to extraversion and conscientiousness respectively, while F and N have positive correlation to agreeableness and openness respectively.

    These findings led McCrae and Costa, the formulators of the Five Factor Model (a Big Five theory), to conclude, “correlational analyses showed that the four MBTI indices did measure aspects of four of the five major dimensions of normal personality. The five-factor model provides an alternative basis for interpreting MBTI findings within a broader, more commonly shared conceptual framework.” However, “there was no support for the view that the MBTI measures truly dichotomous preferences or qualitatively distinct types, instead, the instrument measures four relatively independent dimensions.”

    (H/t nostrademons.) Meyers-Briggs is still sometimes peddled by crooks, and it still appeals to whatever it is that draws people to astrology, but like most folk wisdom it has a degree of truth to it.

  • GoPro footage from space walk at the ISS:
  • Neat natural lighting experiment in Chinese school to prevent myopia. I like the building, but it would probably be easier to do this with special lights. Also, this:

    Atropine, a drug used for decades to dilate the pupils, appears to slow the progression of myopia once it has started, according to several randomized, controlled trials. But used daily at the typical concentration of 1%, there are side effects, most notably sensitivity to light, as well as difficulty focusing on up-close images.

  • TeX for Gmail appears to be robust now, and I highly recommend it. I haven’t gathered enough personal experience to be confident that the embedded pictures appear consistently for all email users, but gmail-to-gmail messages are perfect. My only complaint is that once you convert to a picture you lose the raw TeX. I would have thought they could have added it to the picture’s description and allowed you to recover it. Edit 2016-7-8: Happy to say this has all been fixed. Non-gmail users see clean messages, and the conversion from an image back to TeX is fast, allowing for easy mistake correction. Awesome.
  • Relatedly, see this Chrome plugin that renders Wikipedia math in the much prettier MathJax.
  • Asteroids, ranked by mining value, ease of access, etc. The numbers are probably completely made-up, but who cares? Worth noting that the mass of all asteroids is roughly equal to the mass of the Earth’s crust down to 2 kmMoon mass: 7×1022 kg. Total asteroid mass: 3×1021 kg. Earth mass: 6×1024 kg. Density Earth’s crust: 2.7 g/cm3. Earth area: 5.1×108 km2. Mass Earth’s crust to 2km depth: 2.8×1021.a  , while the deepest mines are about 4km. However, the compositions of the asteroids are vastly different than the Earth’s crust, in part because much of the heaviest metals sunk to the core of the Earth while it was forming.
  • SpaceX to attempt ground landing of Falcon 9 1st stage after this near-miss at sea:

    “I can’t help but feel bad for that one poor little RCS thruster doing its level best to keep the first stage upright, but ultimately running out of fuel.” – HN Comments. See also the video from the deck.
  • Ikea introduces wireless charging furniture. Personally, I’d rather have my electronics decoupled from my furniture for replacement reasons, especially until the Qi standard (used by Ikea) win, loses, or merges with the PowerMatRezence alliance (used by Starbucks).
  • I’ll probably keep sending you to the latest link posts from Slate Star Codex but you should really be checking them out on your own. They obviously inspired me to do it.
  • Impact certificates are one of the best recent ideas to come out of Effective Altruism. It’s a grand experiment that I think will ultimately fail, but it’s hands down the best stab at how EAs will handle all the weird distortions to normal incentive structures from pursuing global non-excludable public goods. The key question is: what actually motivates EAs (in the effective, Hansonian sense of the word), and how to we interface that with a market system?
  • Spaced-based lasers to eliminate debris in low Earth orbit. Hopefully.
  • Before it flew to space, the space shuttle orbiter was released from the top of a 747 to test the orbiter’s flight characteristics:

    (Here’s the landing video.)
  • Nautilus has an excellent summary of the Japanese space agency’s Hayabusa 2 probe, an ambitious asteroid sample return mission:

    The small carry-on impactor (SCI) is a flat, 2.5-kilogram (5.5-pound) copper disk that floats in the weak gravity of the asteroid. After it’s dispatched from the spacecraft, an onboard timer will set off an attached, 4.5-kilogram (10-pound) explosive charge, distorting the disk into a bullet that rams into the asteroid’s surface at two kilometers per second (4,500 miles per hour), creating a hole around 10 meters (33 feet) in diameter. The delay before the explosion gives Hayabusa2 time to duck behind the asteroid out of harm’s way from the explosive debris. Since no one wants to miss the fun of an explosion, Hayabusa2 will dispatch a detachable camera to watch the proceedings.

  • The Levytator: an escalator that can follows curves:

    I can’t find evidence that it’s had much success since that 2010 conceptual video, though.

  • New Horizon takes its first color image of Pluto.
  • How trains stay on tracks (hint: it’s not the flange): [PDF].
  • In the time before genetic engineering, there was Gamma Gardening: breeding plants exposed to large doses of gamma radiation in search of valuable new mutations. (H/t Dinosaur Comic via Will Riedel.)
  • It turns out you can design glasses that improve color discrimination for many types of color blindness by filtering some of the spectrum. But might this all be made moot by a one-time injection that cures the condition?
  • Striking images of nanoinjectors for gene therapy:

    This is going to hurt

    See the bigger and alternate versions.


(↵ returns to text)

  1. Moon mass: 7×1022 kg. Total asteroid mass: 3×1021 kg. Earth mass: 6×1024 kg. Density Earth’s crust: 2.7 g/cm3. Earth area: 5.1×108 km2. Mass Earth’s crust to 2km depth: 2.8×1021.
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