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The new Gödel Prize winner tastes great and is less filling

blog.computationalcomplexity.org

51–54 of 54 posts

Re: The new Gödel Prize winner tastes great and is less filling

#51

Earlier quoted context omitted.

> If you have infinite time, then you can wait for it to take more than a few hundred iterations. To be clear, you're making this argument while also arguing "this wouldn't happen in the real world". [1] You can't have it both ways. > Also "constant time" wasn't even part of the original promise! We're not even asking for "constant time". We're literally only asking for "will finish in any bounded amount of time". Ev…

> You can't have it both ways. I addressed that in my next sentence! The whole point of making it two sentences was to split up the real world and not real world cases. Come on. > We're not even asking for "constant time". We're literally only asking for "will finish in any bounded amount of time". Even an exponential time bound would've been better than this! N is 1. Every bound is a constant bound. > if you sold so…

> I addressed that in my next sentence! The whole point of making it two sentences was to split up the real world and not real world cases. Come on.

Your next sentence was just obviously flat-out wrong though. Not just because who says that's the case (maybe I don't have that much time?) but because it's trivial to find P(H) that makes it false for any duration of time. "A few hundred iterations" literally doesn't guarantee anything unless you make unstated assumptions about the biases your device works for.

I don't get why we're going in circles here. It seems we've hashed everything out.

> N is 1. Every bound is a constant bound.

Kind of a meaningless statement when you don't even say what your N is. I can imagine lots of N where that's not the case. But whatever you want to call it, my point entirely stands.

> They would not be entitled to a penny back because it's impossible for them to hit the failure case.

No, it is very possible. All they need to be given is a coin whose bias they don't know beforehand, whose bias is unfortunate. Or a coin whose bias they do know to be much worse than whatever you imagined a few hundred tosses would be enough for.

Re: The new Gödel Prize winner tastes great and is less filling

#52

Earlier quoted context omitted.

> You can't have it both ways. I addressed that in my next sentence! The whole point of making it two sentences was to split up the real world and not real world cases. Come on. > We're not even asking for "constant time". We're literally only asking for "will finish in any bounded amount of time". Even an exponential time bound would've been better than this! N is 1. Every bound is a constant bound. > if you sold so…

> I addressed that in my next sentence! The whole point of making it two sentences was to split up the real world and not real world cases. Come on. Your next sentence was just obviously flat-out wrong though. Not just because who says that's the case (maybe I don't have that much time?) but because it's trivial to find P(H) that makes it false for any duration of time. "A few hundred iterations" literally doesn't gu…

> because it's trivial to find P(H) that makes it false

As I already said in the comments you read, it's proportional to the bias. A few hundred multiplied by the ratio between heads and tails or vice versa will never be reached.

> when you don't even say what your N is

Number of outputs?

Look, if you want to invoke concepts like exponential time then you tell me what N is. Exponential of what?

> All they need to be given is a coin whose bias they don't know beforehand

See first answer.

If someone expects the bias to not matter, even a one in a million coin, they're the one with the problem, not the algorithm.

If they accept the bias affects speed, things are fine.

Re: The new Gödel Prize winner tastes great and is less filling

#54

Earlier quoted context omitted.

You can relax the constraints to bound the cost. If I asked a someone gambling, does it matter if this coin is biased 0.0001%, they will probably say no. And just like that, the algorithm is now guaranteed to terminate. It's a bit unfair to talk about the case (100% T) because in that case you don't have a source of randomness anymore, we've dropped the assumption that you have a source of randomness, and as expected…

You have a source of randomness — you just got exceptionally unlucky. A truly random source can produce the same value indefinitely. My point is that you have stochastic termination, but not guaranteed termination. Those are different things.

A random source can produce the same value indefinitely, but it cannot produce the same value forever. It is impossible in the sense that the probability that it will happen is zero. That is, even the unbiased version of the algorithm will terminate with 100% probability.
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