Readings: Avalanches, Pay TV, Exercise, Robots, & Greeting Cards


Being caught in a small slab avalanche while skiing is like sliding across a steep room as someone pulls the carpet out, and then said carpet fractures and accelerates with you on bits of it, all going very fast in a direction you weren’t planning on going. (Being caught in a large slab avalanche is like having the surface of the earth pulled out from under you, then fracture into blocks, then accelerate to 60 mi/h with many trees and rocks over cliffs & through more trees and rocks, before burying you and then freezing solid.)

Neither is recommended. My perspective, which is that of sociologist Diane Vaughan, is to be aware of base rates (how statistically likely bad outcomes are), and never expand the risk envelope, no matter how many times you get good outcomes. Vaughan called the tendency to do the opposite — to respond to lucky non-failures by expanding the launch conditions — as “normalization of deviance”. She used an ethnographic study of the launch of the space shuttle Challenger to show how it happens, with “successes” causing steady and inexorable expansions of launch conditions, until there was a catastrophica failure.

Until your own risk-taking catches up with you, it is easy to convince yourself of two things: one, that you’re smart enough to operate near the risk frontier while knowing you’re there; and two, that you could remedy things if the worst happens.

Both of these are bad ideas. First, the only way to control backcountry risk is to know, as best you can, what they are, and then back way, way off. This is one of the reasons why small groups are safer than large ones: there is less risk-taking pressure. Second, having even a small slab fracture under you is instant mayhem, like being a small dish when a drunk, after-dinner magician pull out the tablecloth. People who think they can predictably ski off a small slab fracture watch too many YouTube avalanche videos.

Happily, however, you don’t need many experiences — ideally: none — with slab avalanches before you decide to never put yourself in that position again. Both of my small avalanche experiences were years ago, which, in terms of risk, is a very good thing. In any case where outcomes tend to be binary and too often terminal, taking a Kelly criterion approach to risk — let alone expanding the risk window — can be a very bad idea indeed.


  • Eccentric exercise has long been the gold standard when treating Achilles tendinopathy, so it’s surprising to see that pressure massage delivered similar results in a recent study. Granted, a small study size, but it does speak, at the very least, to our continuing profound ignorance about tendon disorders.
  • Surgeon promotes fraudulent research that kills people; his employer, a leading hospital, defends him and attacks whistleblowers. Business as usual.



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