Hacker News Reader

Comment by shroedingaway | Hacker News Reader

No that's the funniest aspect of the Google result. They barely have any control over what their gates do.

Gil makes this point, but doesn't call it out: they're claiming supremacy by turning the challenge around. "You can't classically simulate our device (which largely does it's own thing because of issues)."

A kid shoots an arrow at a target. The arrow hits the haybale, but not the target. Suddenly the kid yells "I bet you can't hit my arrow!" and claims Archer Supremacy because nobody even cares to try. Are you impressed? I'm not.

View on HN

Scott Aaronson's description of the result made it out to be more subtle. If I understood it properly, it might be more like the kid shooting 20 arrows, which all form a particular pattern around a point that the kid can't choose or control at all. Now a regular archer can readily choose a particular point, in a way that the kid can't, but can't produce the sort of pattern that the kid does with nearly as much accuracy and nearly as little effort.

Or to make a less specific analogy, there is something about the kid's archery that regular archers can't replicate with their archery skills, but it's not really something that anyone would traditionally have described as "skilled archery". Then Aaronson and Kalai disagree about whether or not this unusual feat that's not very easy to relate conceptually to the ability to hit targets is a sign that the kid is plausibly going to be able to achieve traditional archery skill in the future.

Is that fair?

> Or to make a less specific analogy, there is something about the kid's archery that regular archers can't replicate with their archery skills, but it's not really something that anyone would traditionally have described as "skilled archery".

Yes, I'd call that a fair description.

> They barely have any control over what their gates do.

I don't understand this, could you explain?

My understanding is that the gates are perfectly normal quantum gates, which they use to connect qubits in a programmable way. Due to the probabilistic nature of quantum computing, running this circuit generates samples from a random distribution.

I attended a Google talk where they acknowledged difficulty in controlling their device. That was given as the motivation for running problems that consist of "random gates".

My understanding from reading Scott Aaronson's FAQ is that the "random" in "random gates" just means that they pick a random circuit to evaluate. But this circuit is known, just like a program can pick a random number and then print it out.

The fact that quantum computing behaves "randomly" by nature further complicates the discussion :)

So in this metaphor, the "Extended Church-Turing Hypothesis" is the belief that there is no haybale?

Reply on news.ycombinator.com