Best of Rationality Quotes
Mitch Hedberg on the distinction between labels and the things to which they are applied:
I just bought a 2-bedroom house, but it's up to me, isn't it, how many bedrooms there are? Fuck you, real estate lady! This bedroom has a oven in it! This bedroom’s got a lot of people sitting around watching TV. This bedroom is A.K.A. a hallway.
If you do experiments and you're always right, then you aren't getting enough information out of those experiments. You want your experiment to be like the flip of a coin: You have no idea if it is going to come up heads or tails. You want to not know what the results are going to be.
-- Peter Norvig, in an interview about being wrong. When I saw this, I thought it sounded a lot like entropy pruning in decision trees, where you don't even bother asking questions that won't make you update your probability estimates significantly. Then I remembered that Norvig was the co-author of the AI textbook that I had learned about decision trees from. Interesting interview.
"I do not agree with what you say, but I will defend to the death your right to misattribute it to Voltaire."
-Voltaire
(The phrase was written by Evelyn Beatrice Hall as a summary of Voltaire's attitude toward free speech. Since then, people started attributing it to Voltaire himself, and the myth has spread far and wide, as nobody really checks to see if he actually said that. Hearing something somewhere is plenty of evidence for most people, most of the time, and the conviction gets more solid over time. Which brings me to my second rationality quote, from Winston Churchill: "A lie gets halfway around the world before the truth has a chance to get its pants on.")
He who refuses to do arithmetic is doomed to talk nonsense.
-John McCarthy, on mainstream environmentalism.
As someone who regularly gets into arguments about this, I can say that he's definitely right; you wouldn't believe the amount of nonsense that can be disposed of simply by looking up the relevant numbers and doing a minute's worth of easy arithmetic.
For example, I've heard some people recently claiming that a combination of solar photovoltaics, electrolysis to produce hydrogen, and these new Bloom box fuel cells are cheaper than nuclear fission. Look up the costs of solar farms; about $3 per peak watt. Their average power output is less; we can very optimistically assume that they run at 20% of capacity on average. Efficiency losses from electrolysis and fuel cells are about 50%. Putting it all together, this would cost about $30 per watt of average power delivered. Not including the cost of the fuel cells.
A little googling will show that the total cost of building two new AP1000 reactors in Georgia is about $14 billion, and they average at least 93% of their peak power, and transmission line losses bring their average power delivered to about 1000 MW each. So their cost is about $7 per watt of average power delivered, or about 23% the cost of solar.
There's a lot of extremely harmful bullshit out there, and defeating most of it doesn't take any advanced techniques; it just takes a willingness to look up some relevant numbers and do a bit of arithmetic.