Monday, May 13, 2013

This Explains Everything (a review)

This Explains Everything, edited by John Brockman, is a compilation of short answers to a question posed to the Reality Club, originally New York City intellectuals and now online at the Edge Foundation.  According to its website, the Foundation tries “to arrive at the edge of the world’s knowledge, seek out the most complex and sophisticated minds, put them in a room together, and have them ask each other the questions they are asking themselves.”

The question 148 people answered was this: What is your favorite deep, elegant, or beautiful
explanation?  I liked it enough to go back through a second time and extract tidbits and gems, so this has become more of a book report for myself than a book review, I’m afraid.

There were, as you can imagine, all sorts of answers.  Why the sky is blue (not as simple as I had remembered), the origin of money, Bayesian probability, empiricism, organic electricity, the importance of individuals, germ theory, sexual selection.  Why Greeks painted red figures on black pots, The scientific method. How languages change. A haiku poem.  Some were sweet and obvious.  One just wrote “keep it simple.
I found amongst them a lot of nice little take-aways: To learn how something works, first figure out how it got that way.  Information is the resolution of uncertainty. To have a good idea, stop having a bad one.   The brain's job is not to store or process information, it's to drive and control the actions of its large appendage, the body.  When it's clear that change is needed, it is often expensive, difficult, and time consuming; and when change is easy, the need for it is difficult to foresee.   Intervention in any complicated system usually causes unintended effects.   Epigenetics may be the “missing link” in the nature/nurture debate.  We can't perceive our environment accurately, or process it rationally.  Sometimes limiting one’s own choices can be a good idea.  Our skill at metarepresentations, like “Mary thinks John thinks it’s going to rain,” may be what distinguishes us as human.
Evolution figured in strongly, as I expected.  Gender ratio was used to explain the Evolutionarily Stable Strategy (S. Abbas Raza).  Samuel Arbesman explained how natural camouflage occurs; if you mix specific chemicals they result in unique patterns depending on the size and shape of the canvas.  The same mix that makes spots on the cheetah body will form stripes on his tail.  Make a giraffe the size and shape of a cow and the spots change to Heifer. 
Dawkins explained how sight in animals saves bandwidth by mainly detecting edges of moving objects with “strangeness neurons.”  The brain assumes everything else has remained the same.  David Eagleman called the brain an “inelegant device” with enough redundancy to solve the problem many different ways.
Jennifer Jacquet explained why tit for tat is a simple solution to the iterative Prisoner’s Dilemma, and Robert Sapolsky showed how simple algorithms applied in quantity, as with ants, can lead to “swarm intelligence” of groups.

The ratio between the second and fourth finger length shows how much testosterone one received in the womb, which directly affects one’s personality and interests.
Memes got support, of sorts, from Clay Shirky.   Dan Dennett argued that when someone derides an evolutionary explanation as a “just so” story they usually have a political motive.   They aren't presenting evidence that the story is false, he said -- plenty end up true.  It only means perhaps the hypothesis hasn’t been adequately tested.   And they are incredulous.
I liked these two a lot:  “Natural selection is the only known counterweight to the tendency of physical systems to lose rather than grow functional organization – the only natural physical process that pushes populations of organisms uphill (sometimes) into higher degrees of functional order” (John Tooby).   And Peter Atkins added that evolution is a device, like a water turbine, which harnesses entropy, and “thus, dispersal results in a local structure, even though, overall, the world has sunk a little more into disorder."  Regardless of how it may seem, everything is always getting worse!
Alison Gopniks explained that puberty comes much earlier now than in our evolutionary past, probably because of better nutrition.  What's more, common sense kicks in later than before, due to a more protective environment today: “It’s truer to say that our experience of controlling our impulses makes the prefrontal cortex develop than it is to say that prefrontal development makes us better at controlling our impulses.”  Result: a long period in adolescence where the engines are revved but neither steering nor brakes are ready.  Hence violence, accidents, teen pregnancy, drug abuse, etc.
Another nice if simple one, by Brian Eno – yes, that Brian Eno.  He pointed out the nature of intuition.  “[It] is not a quasi-mystical voice from outside ourselves speaking through us but a sort of quick-and-dirty processing of our prior experience.”
Barry Smith was one of several who focused on metaphor.  We’re full of “cross-modal correspondences," such that happy is high, sad is low, music is sharp or flat, lemons are fast and mangos are slow … and this is useful in communication and quite likely influences our aesthetic sense.
People who make more money feel more pressed for time.  Hence, someone suggested, by volunteering ones time, time itself is worth less, and so you feel you have more of it!   And that was Elizabeth Dunn; I think I once read something similar by Douglas Adams, in praise of misery.
I loved this one: Recursive abstraction by Douglas Rushkoff: “Land becomes territory; territory then becomes property that is owned.  Property itself can be represented by a deed, and the deed can be mortgaged.  The mortgage is itself an investment that can be bet against with a derivative, which can be secured with a credit default swap.”  There’s value, the representations of value, and eventually a disconnection from what has value.  The tragedy comes at the moment when we forget what the abstractions represent, and then we become vulnerable to fantasy, illusion, and abuse.  “Because once we’re living in a world of created symbols and simulations, whoever has control of the map has control of our reality.”  
Recipes worldwide are based on 300 ingredients, according to Albert-Laszlo Barabasi, and the ingredients vary in several dimensions (sweet, sour, bitter, etc.). By categorizing ingredients and studying recipes researchers found that meals in the West are mostly coordinated (creamy with creamy, etc.) while easterners combine polar opposites.
Videos consist of sequential frames, so how do we perceive motion?  First, an object must move not too fast and not too far between frames.  Then, there is a persistence of vision itself which fills the short gap between them. Finally, movement creates a blur in each frame, which indicates what is moving, in what direction, and how fast.  Pixar makes animations that look so real by adding the little blur. 
Time Perspective Theory was pretty interesting: some people are oriented toward the past, present, or future and each of these has negative or positive spin.  So there are six “time zones” to choose from.  For example, past-oriented folks may be driven by regret, failure, abuse, or trauma – or by gratitude, success, or nostalgia.  Apparently past-negative is related to anxiety, depression, and anger “with correlations as robust as .75,” and others are correlated with particular afflictions too. 
One extraordinary claim was that a normal brain shows activity about a third of a second before the person is aware of the sensation or phenomenon. I've heard this before.  And Gerald Smallberg  said we simply erase confusing bits from our stream of consciousness to make our experiences more understandable -- it’s these gaps that are exploited by card sharks, hustlers, and magicians.  Eric Topol reported that researchers in Berkeley have used a brain image to reconstruct the youtube video the person was watching at the time. I looked it up on youtube and wow.  It’s uncanny.
A handful came across to me as misguided, mistaken, or wrong.  The process of natural selection was completely misrepresented, like here: “Nature, unlike risk engineers, prepares for what has not happened before, assuming worst harm is possible.  If humans fight the last war, nature fights the next war.”   Someone else argued the opposite, also wrong: The Generalized Peter Principle: “in evolution, systems tend to develop up to the limit of their adaptive competence.”  Someone made an argument on raw incredulity that consciousness can’t have evolved. One claimed that the Inverse Power Law is ubiquitous in natural systems, so that the thousandth largest stone on a beach is a thousandth the size of the largest one, and so on , and the same for everything else.  It is “inevitable as entropy or the law of gravity.”  I know some bell curves which would disagree. And here’s another: someone actually claimed déjà vu experiences happen every six months, like clockwork.  Every year, “Not one.  Not three. Two.”  And there was a blank slate claim that people discover who they are by observing their own behavior, and therefore personalities can be shaped by manipulating experiences.  Someone liked the Gaia Hypothesis.
But anything having to do with deep physics, I could not judge.  There were many, and they just went right over my head.  Higgs Boson.  Holographic pigeonhole, infinite universes, spiners. Fermi levels at a junction … words, just words. 
Now that I've given it some thought, I'll add a favorite of my own, an explanation I got from a course by Mohamed Noor, biology professor at Duke.  It explains why my lovely dog went deaf. 
Purebreds are known for hundreds of problems: everything from Arcalasia in the Finnish Spitz to
von Willebrand's Disease in Setters and Whippets.  Deafness, it turns out, is common in the following:  Australian Cattle Dog, Australian Terrier, Border Collie, Boston Terrier, Brussels Griffon, Bull Terrier, Cavalier King Charles Spaniel, Dalmatian, English Cocker Spaniel, English Setter, Finnish Spitz, Italian Greyhound, Manchester Terrier, Parson Russell Terrier, Smooth Fox Terrier, Staffordshire Bull Terrier, Whippet, and Wire Fox Terrier.
It's inbreeding, of course.  Inbreeding is necessary, to some extent, to create the unique features of a breed.  But it can be too radical, especially when breeders cut corners.  The deeper explanation of inbreeding follows: 

Fact One: Problem genes are recessive
Mutations can be dominant or recessive, but most bad genes are recessive.  Why?  Because if they are dominant they have nowhere to hide.  Consider genes X and x at a particular location  If the dominant X carries deafness, dogs with either XX or Xx will be deaf.  Natural selection will gradually remove every X from the gene pool.  But if recessive x is the carrier, only xx dogs will be deaf, Xx will hear well and x remains in the gene pool.  Maybe rare, but persistent. 

Fact Two: Inbreeding removes heterozygotes
Inbreeding makes the double-recessive combination more common.  Imagine two clones (except for gender) having a baby.  At different places on the chromosome mom's XX comes against dad's XX, her Xx comes against his Xx, and xx comes against xx.  In the case of double dominant XX or double recessive xx  the result will be the same -- XX, or xx -- because there is nothing else to choose from.  But when Xx comes across Xx, you get 1/4 XX, 1/4 xx, and just one half Xx.  In the next generation there are more XX's and xx's and half as many Xx's.  Remember, the Xx's are healthy dogs.  But with each iteration 25% of these x alleles are delegated to double-recessive xx which may mean deafness, hip dysplasia, or another malady. 
That may not be beautiful, but it's a favorite, it's deep, and it's elegant and three out of four isn't bad.