Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Is There Anything Beyond Quantum Computing?

pbs.org

Post reply on HN
Print view View original

31–40 of 44 posts

Re: Is There Anything Beyond Quantum Computing?

#31

Post by Havoc »

Jtsummers wrote: post #12
Havoc wrote: post #8

Scott is making it really difficult for people to follow along. My initial reaction was "wtf am I looking at" followed shortly by "why wasn't the HN link pointed straight to the PBS article?". And clearly others agree given that the top comment at the moment is a PBS link. No doubt the guy is competent but this just smells like a poorly executed attempt to move traffic to the blog. I fully expect it to get ignored as…

If you're a writer and you have an article available on some 3rd party site, wouldn't you inform your blog readers of it? Besides, the poster of this link is not Scott Aaronson, so why accuse him of attempting "to move traffic to the blog"? EDIT: And a blog without advertisements at that.

>so why accuse him of attempting "to move traffic to the blog"?

Remember what I said...one of the first responses (3rd at worst) is someone posting the "proper" link to the actual article. That was there before I posted - someone else read the blog extracted the relevant info and concluded that the single link is the core content of the blog post. Then I put the same thing into words and go downvoted to hell. Oh well.

OP has since altered the link to point at the PBS article.

As I said before I don't doubt the technical ability or integrity of Mr Aaronson. I was commenting purely on the HN submission because I felt both the HN submission and blog were subpar & did an injustice towards the actual content (the PBS post). Downvote away...

Re: Is There Anything Beyond Quantum Computing?

#32

Post by abdullahkhalids »

rohansingh wrote: post #18
rhth54656 wrote: post #17

But the more you accelerate the spaceship, the more energy you need, with the energy diverging to infinity as your speed approaches that of light. At some point, your spaceship will become so energetic that it, too, will collapse into to a black hole. That is simply wrong. It is called relativity for a reason. An object might be traveling arbitrarily fast, but in its reference frame it is not moving. That pretty much…

An object can accelerate arbitrarily, but in any reference frame it will never be traveling faster than c . Of course, it won't collapse into a black hole, but the amount of energy needed to accelerate further will increase asymptotically.

Note the Scott has made a correction in the comments.

Re: Is There Anything Beyond Quantum Computing?

#33

Post by [deleted] »

trhway wrote: post #15

> If so, then much like in Zeno’s paradox, your computer would have completed infinitely many steps in a mere two seconds! The next target isn't infinitely many. The target is infinitely infinitely many. Like something along the lines of forking infinite number of parallel Universes - that is pretty much "many-verse" interpretation of the quantum superposition(and thus computing) - enhanced with forking of infinitely…

[deleted]

Re: Is There Anything Beyond Quantum Computing?

#34

Post by KVFinn »

rhth54656 wrote: post #17

But the more you accelerate the spaceship, the more energy you need, with the energy diverging to infinity as your speed approaches that of light. At some point, your spaceship will become so energetic that it, too, will collapse into to a black hole. That is simply wrong. It is called relativity for a reason. An object might be traveling arbitrarily fast, but in its reference frame it is not moving. That pretty much…

>Dear Readers: I apologize; there's one point in this article that's not quite right and ought to be clarified. Namely, when I said that a spaceship traveling exponentially close to the speed of light would collapse to a black hole: that's only true because, when the spaceship inevitably collided with some interstellar particle, the energy in the center-of-momentum rest frame would be exponential. A spaceship in a theoretical vacuum could get arbitrarily close to the speed of light without collapsing.

>However, it's important to understand that this doesn't change the computational situation in any important way. It's still true that, to accelerate exponentially close to the speed of light, you need an exponential amount of energy! And therefore, it will take you exponential time to accelerate to such a speed---unless your fuel tank (or whatever else is providing your energy) is exponentially concentrated, in which case it will exceed the Schwarzschild limit and indeed collapse to a black hole.

Re: Is There Anything Beyond Quantum Computing?

#35

Post by rhth54656 »

KVFinn wrote: post #34
rhth54656 wrote: post #17

But the more you accelerate the spaceship, the more energy you need, with the energy diverging to infinity as your speed approaches that of light. At some point, your spaceship will become so energetic that it, too, will collapse into to a black hole. That is simply wrong. It is called relativity for a reason. An object might be traveling arbitrarily fast, but in its reference frame it is not moving. That pretty much…

>Dear Readers: I apologize; there's one point in this article that's not quite right and ought to be clarified. Namely, when I said that a spaceship traveling exponentially close to the speed of light would collapse to a black hole: that's only true because, when the spaceship inevitably collided with some interstellar particle, the energy in the center-of-momentum rest frame would be exponential. A spaceship in a th…

That is only true if assumed that the rocket will not gather additional energy on the trip.

Also the premise that the energy has to be concentrated to a certain are for the rocket to work is wrong. You can have as much energy on as large area as you want without reaching the critical mass and collapsing into a black hole. The rocket can be of any size to work.

Even so, a black hole is the perfect source of energy. Converting mass into energy without loss via hawking radiation. And the mass is collected when moving trough interstellar medium. Such micro black hole( it has to be small to radiate fast enough ) would still weight a lot and moving it would be difficult, but not impossible.

Re: Is There Anything Beyond Quantum Computing?

#36

Post by 3rd3 »

klodolph wrote: post #13
z3phyr wrote: post #2

Neuromorphic Computing? http://en.wikipedia.org/wiki/Neuromorphic_engineering

That's just a different architecture for a classical, non-quantum computer. (Keep in mind that analog computers came first, so this is a call back to the first half of the 20th century, albeit on a much larger scale.)

One thing we don't know is whether the brain is maybe able to perform calculations on real numbers which could allow for different or even more powerful calculations compared to the Turing machine.

Re: Is There Anything Beyond Quantum Computing?

#37

Post by jerf »

3rd3 wrote: post #36
klodolph wrote: post #13

Earlier quoted context omitted.

That's just a different architecture for a classical, non-quantum computer. (Keep in mind that analog computers came first, so this is a call back to the first half of the 20th century, albeit on a much larger scale.)

One thing we don't know is whether the brain is maybe able to perform calculations on real numbers which could allow for different or even more powerful calculations compared to the Turing machine.

It is extremely unlikely due to noise. It's the same reason we use digital computers right now... for all the "waste" of converting voltages into 1 and 0 it pays back in spades in that we get reliable computing. You hit the noise floor of an analog system long before you're into any sort of revolutionary computation land. It's not much use if something can theoretically compute something amazing if it can't do any of receive that degree of input, maintain that degree of accuracy during the computation, or output it to that degree of accuracy.

Re: Is There Anything Beyond Quantum Computing?

#38

Post by klodolph »

3rd3 wrote: post #36
klodolph wrote: post #13

Earlier quoted context omitted.

That's just a different architecture for a classical, non-quantum computer. (Keep in mind that analog computers came first, so this is a call back to the first half of the 20th century, albeit on a much larger scale.)

One thing we don't know is whether the brain is maybe able to perform calculations on real numbers which could allow for different or even more powerful calculations compared to the Turing machine.

No.

The line of thinking is, "Well, if we had real numbers, we could compute uncomputable functions." No shit. Most real numbers are not computable. If you start with something not computable, you end up with something not computable.

The big problem is that there is no way you will get more than several digits of precision on anything. The next problem is that there's zero evidence that anything in the universe is capable of encoding an arbitrary real number, even within a given bound. The last problem is that making a "real-number" machine capable of solving a problem that a Turing machine can't basically requires knowing the answer ahead of time and encoding it into the real-number machine as a constant. Unclear how you'd do that.

Re: Is There Anything Beyond Quantum Computing?

#39

Post by 3rd3 »

klodolph wrote: post #38
3rd3 wrote: post #36

Earlier quoted context omitted.

One thing we don't know is whether the brain is maybe able to perform calculations on real numbers which could allow for different or even more powerful calculations compared to the Turing machine.

No. The line of thinking is, "Well, if we had real numbers, we could compute uncomputable functions." No shit. Most real numbers are not computable. If you start with something not computable, you end up with something not computable. The big problem is that there is no way you will get more than several digits of precision on anything. The next problem is that there's zero evidence that anything in the universe is c…

How I understood it, and please correct me if i am wrong, is that a machine than can caluclate numbers with infinite precision in constant time has certainly a time benefit, but not necessarily a broader class of computable functions compared to a Turing machine. I interpreted z3phyr’s reference to Wikipedia as a hint to that idea. But I agree that the most convincing arguments are against the existence of such a machine.

(By the way, writing "No.\n\n" can be received as a rude response. I felt a little bit uncomfortable reading it.)

Re: Is There Anything Beyond Quantum Computing?

#40

Post by saalweachter »

Hah.

So Roger Penrose, not content with the now-seemingly-attainable quantum computing, speculates there is an even more magical quantum gravity computing, which brains just happen to use, that makes them special, that Turing machines can't compute?

The man just really hates the idea of AI, doesn't he?

Post reply on HN