Comment author: Gurkenglas 13 December 2015 12:47:15PM -1 points [-]

Here's how I predict your setup to work, and shame on you for chickening out:

http://sketchtoy.com/66313589

You start doing the experiment, you flip four coins, 15/16 of you memorize a sequence, 15*32 of you memorized pairwise probably different sequences. In the end, you have a probability of 15/16 to find yourself having memorized a sequence. If QI works and half of you who find a tails in a first four coins commit suicide, start-experiment-you only has a 15/17 chance to find themselves having found tails and failed to kill themselves.

Comment author: solipsist 13 December 2015 03:27:01PM 0 points [-]

What do you mean by "commit suicide" here? Memorize the results of 5 more coins?

Comment author: V_V 11 December 2015 02:54:42PM *  4 points [-]

Take a programing language with two characters. Assign each program a prior of 2^-length(program). If the program outputs some string, then P(string | program) = 1, else it equals 0.

This is exactly Solomonoff induction, assuming that the programming language is prefix-free.

I figure there must be some reason people don't do this already, or else there's a bunch of people doing it. I'd be real happy to find out about either.

Because it's uncomputable: there are infinitely many programs to consider, and there are programs that don't halt and for many of them, you can't prove that they don't halt.

If you set a maximum program length and a maximum execution time, then inference becomes computable, albeit combinatorially hard: maximum a posteriori inference can be easily reduced to MAX-SAT or ILP and is therefore NP-complete (optimization version), while posterior evaluation is #P-complete.

It's known that many NP-hard problems are practically solvable for real-world instances. In this case, there are indeed people (primarily at Microsoft, I think) who managed to make it work, but only for short program lengths in limited application domains: Survey paper.

Comment author: solipsist 12 December 2015 01:06:29AM *  3 points [-]

Spit balling hacks around this:

  • Weigh hypotheses based on how many steps it takes for them to be computed on a dovetailing of all Turing machines. This would probably put too much weight on programs that are large but fast to compute.

  • Weigh hypotheses on how much space it takes to compute them. So dovetail all turing machines of size up to n limited to n bits of space for at most 2^n steps. This has the nice property that the prior is, like the hypotheses, space limited (using about twice as much space as the hypothesis).

  • Find some quantum algorithm that uses n^k qubits and polynomial time to magically evaluate all programs of length of n in some semi-reasonable way. If such a beast exists (which I doubt), it has the nice property that it "considers" all reasonably sized hypotheses yet runs in polynomial space and time.

  • Given n bits of evidence about the universe, consider all programs of length up to k*log(n) run for at most n^k2 steps. This has the nice property that it runs in polynomial time and space.

Comment author: gwern 03 December 2015 02:37:54AM 19 points [-]

In November, I donated $3000 to Against Malaria Foundation and $500 to Give Directly. I also found the answer to a question I've been researching for ~3 years.

Comment author: solipsist 09 December 2015 04:10:13AM 1 point [-]

I also found the answer to a question I've been researching for ~3 years.

Boy, did you ever! Congratulations!

Comment author: Algernoq 07 December 2015 08:20:22AM 2 points [-]

I love this forum.

If I understand the experiment, your theory is that quantum weirdness makes it more likely to see four heads in a row because you resolved to flip many more coins if you don't.

Sounds fun. I'll flip four coins (actually use a string of 0's and 1's that's 4 bits long). If I don't get four heads, I'll generate a 10-digit sequence and memorize it. Let's explore this frontier!

I did it. It didn't work. My new favorite number is 1 1 0 0 0 0 0 0 0 1.

Reality hack failed.

Let's try again. If I don't get 4 heads, I'll memorize a 20-digit number.

It didn't work. My other new favorite number is 1 0 1 1 0 1 0 0 0 0 1 1 0 1 1 1 1 1 1 1.

I wonder if there's a better way to test this theory.

Comment author: solipsist 07 December 2015 03:30:04PM *  0 points [-]

I'm not sure if coin flips are quantumly random, or just hard enough to predict. Feels like coins would still work as well in a Newtonian universe. I tried to go with something that something that is clearly caused by quantum effects, like measuring if electron is either polarized up or down or down. Luckily, there's an app for that.

Comment author: Gurkenglas 06 December 2015 10:11:02AM *  5 points [-]

Corollaries: You expect to never try to exploit QI, because most of the anthropic weight ends up in the timelines where you didn't try to. If you are the sort of person who would try to exploit it regardless of this argument, you're likely never to come into the position to do so - for example, you, or the population of your Earth, might never think of it. If your Earth has thought of it, that is bayesian evidence QI doesn't work in the first place. (So is your being the sort of person that would exploit it.) Yay for newcomblike problems.

Comment author: solipsist 07 December 2015 05:49:07AM *  1 point [-]

I set up an experiment to test quantum anthropics.

Flip four quantum coins. If they all came up heads, stop. If any of them came up tails, flip 5 more coins and (using mnemonics) think really hard about the exact coin flip sequence. If I find myself in a universe where first four coins came up all heads, then with p < 0.0625, quantum weirdness kept me from finding myself in one of the universes the state of my consciousness split me 512-ways.

I got access to a quantum random number generator, resolved to do the experiment, called a friend and told them I was about to do the experiment, and... chickened out and didn't do the experiment.

I do not know how to interpret these results :-/

Comment author: solipsist 07 December 2015 04:30:32AM *  2 points [-]

Minor naming feedback. You switched from calling something "supervised learning" to "reinforcement learning". The first images that come to my mind when I hear "reinforcement learning" are TD-Gammon and reward signals. So, when I read "reinforcement learning", I first think of a computer getting smarter through iterative navel-gazing, then think of a computer trying to wirehead itself, then stumble to the meaning I think you intend. I am a lay reader.

Comment author: cousin_it 21 October 2015 12:56:00PM *  4 points [-]

Thanks to Turing completeness, there might be many possible worlds whose basic physics are much simpler than ours, but that can still support evolution and complex computations. Why aren't we in such a world? Some possible answers:

1) Luck

2) Our world has simple physics, but we haven't figured it out

3) Anthropic probabilities aren't weighted by simplicity

4) Evolution requires complex physics

5) Conscious observers require complex physics

Anything else? Any guesses which one is right?

Comment author: solipsist 05 December 2015 06:03:58PM *  2 points [-]

Other answers I've considered:

o) Simpler universes are more likely, but complicated universes vastly outnumber simple ones. It's rare to be at the mode, even though the mode is the most common place to be.

p) Beings in simple universes don't ask this question because their universe is simple. We are asking this question, therefore we are not in a simple universe.

2') You don't spend time pondering questions you can quickly answer. If you discover yourself thinking about a philosophy problem, you should expect to be on the stupider end of entities capable of thinking about that problem.

Comment author: passive_fist 02 December 2015 08:17:11PM 1 point [-]
Comment author: solipsist 02 December 2015 08:37:05PM 0 points [-]

Oh! So you're saying the spectrum of the acoustic noise at a given temperature will be the spectrum of black body radiation! Yes, I could definitely believe that. That is high-frequency indeed.

Comment author: Lumifer 02 December 2015 06:33:28PM *  5 points [-]

white noise is caused by air molecules moving randomly at high speed

This is wrong. What you hear is sound waves, that is, rarefaction/compression zones in the air, pressure differentials. They are a phenomenon at a different scale than molecules. In particular, the energy involved is different. "White noise" means the frequencies are uniformly distributed.

Essentially, an air molecule doesn't have enough energy to register at your hearing sensors, that is, to move your eardrum (or cochlear hairs).

Comment author: solipsist 02 December 2015 08:25:28PM 3 points [-]

Essentially, an air molecule doesn't have enough energy to register at your hearing sensors, that is, to move your eardrum (or cochlear hairs).

Though, now that I'm thinking about it, if the white noise generator I bought to help me sleep is really good at producing white noise with uniform power at high enough frequencies, an air molecule would have enough energy to move my eardrums. I would also be on fire.

And if my white noise generator is really really good at producing white noise with power uniform across all frequencies, the noise's mass-energy will cause my bedroom to collapse into a black hole and I will be unable to leave a 5 star review on Amazon.

Comment author: passive_fist 02 December 2015 06:32:30PM 4 points [-]

The peak frequency of thermal noise at room temperature is far higher than 5 GHz, it's actually closer to 30 THz. I'm not exactly sure about the biology here and whether Brownian motion of air molecules excites the hair cells in your cochlea. I'm guessing that it does, but even so, the range of frequencies you can hear (20-20,000 Hz) carries only a very, very tiny fraction of the thermal energy. Someone should do the calculations; my guess is that it's far below the detection threshold.

Another thing to keep in mind is that at equilibrium, you have thermal excitation everywhere. You might as well ask why you don't hear or see or smell the thermal excitation in your own brain.

Comment author: solipsist 02 December 2015 08:00:12PM 0 points [-]

Do you happen know a back-of-the-envelope way to get that 30 THz figure?

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