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Google claims to have proved its supremacy with new quantum computer

telegraph.co.uk

71–80 of 237 posts

Re: Google claims to have proved its supremacy with new quantum computer

#71

Earlier quoted context omitted.

The difference between you breaking a stick and the computer modeling it is that you've measured nothing. You don't know, with any precision, the amount of force you used, the rate the stick broke at, how much mass remains in the two pieces and how much was lost to splintering, etc. In other words, assuming the computer model has sufficiently accurate data as an input, it can produce significantly more refined output…

> You don't know, with any precision, the amount of force you used, the rate the stick broke at, how much mass remains in the two pieces and how much was lost to splintering, etc. But I can measure those with a ruler and a scale. Both before and after the breakage. Takes a few seconds, and I'd need to do that before punching those numbers into the simulator anyway. And I can be precise with where I apply the force, e…

You're going to measure every point like this? https://www.researchgate.net/profile/Andrzej-Baier/publicati...

Likewise, you can crash a car in a lab and do a simulation of one. Both tell you "fascinating" things and are still done by engineers.

Re: Google claims to have proved its supremacy with new quantum computer

#72
post #19
post #7

Dumb question: Say I have a wooden stick and I break it in half in less than a second. Assume a computer would need several minutes to simulate everything that would've happened in the stick. I clearly got the output faster than a computer (and with more precision), so does this imply I'm doing anything particularly fascinating? I assume the same scenario is possible to concoct for a quantum computer. I assume it wou…

One would be the direction of entropy. Breaking the stick is not "particularly fascinating" because you're going in the direction of increasing entropy. However, _putting it back together_ is. In the simulation it takes no more effort to go one way or the other, while you probably cannot put the stick back together no matter how hard you tried. A quantum question that is "interesting" would also be similar to finding…

If I provide two model sticks to a physics simulation, it can work out how to put them back together with no more effort than it took to model the break?

Like I can model shooting a cannon ball out of a cannon and it will tell me where it lands. Or I can model a cannon ball sitting on the ground and it will tell me where the cannon was?

Re: Google claims to have proved its supremacy with new quantum computer

#73

Earlier quoted context omitted.

The difference between you breaking a stick and the computer modeling it is that you've measured nothing. You don't know, with any precision, the amount of force you used, the rate the stick broke at, how much mass remains in the two pieces and how much was lost to splintering, etc. In other words, assuming the computer model has sufficiently accurate data as an input, it can produce significantly more refined output…

> You don't know, with any precision, the amount of force you used, the rate the stick broke at, how much mass remains in the two pieces and how much was lost to splintering, etc. But I can measure those with a ruler and a scale. Both before and after the breakage. Takes a few seconds, and I'd need to do that before punching those numbers into the simulator anyway. And I can be precise with where I apply the force, e…

You really just answered this yourself:

> Assume a computer would need several minutes to simulate everything that would've happened in the stick. I clearly got the output faster than a computer (and with more precision), so does this imply I'm doing anything particularly fascinating?

You assert that you have output faster than a computer with more precision. However, you do not have any empirical data, just observable data; as stated by zdragnar:

> The difference between you breaking a stick and the computer modeling it is that you've measured nothing. You don't know, with any precision, the amount of force you used, the rate the stick broke at, how much mass remains in the two pieces and how much was lost to splintering, etc.

Then you further state that you can measure those with a ruler and a scale; however, this inherently takes time with significant uncertainty in your measurements and calculations. Whereas a computer will provide all of those numbers.

The other thing to consider is the method of simulation such as finite-element analysis (FEA) and the resolution you need. You can get segmented data all the way to down a specific volume of that stick, good luck with the hand calculations on that.

Re: Google claims to have proved its supremacy with new quantum computer

#74
post #66

Earlier quoted context omitted.

I wonder about that frequently. The universe 'executes' physics in, as far as I can tell, a realtime basis (at least within the local reference frame). What is that called as compared to computing a model of the same.

Of course for you it feels like realtime, because the physics of “you” are being executed on the same “system”. It’s funny to think that if we are living in a simulation, that the machine we’re running on might have horrible uptime, but we’d never know because our “time” only works when the machine is running!

Just like a tick rate in a game

Re: Google claims to have proved its supremacy with new quantum computer

#75
post #22

Earlier quoted context omitted.

I don't think it's that the concepts are contrived (although the test cases certainly are), it's just that our quantum computers are really early in their development and can't do the more complicated things yet. It's like if we had calculators that took an hour to do each arithmetic operation- the fact that people wouldn't use it doesn't mean arithmetic is contrived, just that it isn't as powerful as better alternat…

There's a fundamental question as to whether or not it's exponentially difficult to add additional qubits. If each marginal qubit is 5% more difficult to add as the previous one the task would be essentially impossible - and even if it wasn't impossible it would turn out to basically be cheating (in that you would be doing exponential work via either the quantum computing route or the conventional route).

Note: that there is good physical reasons why the cost of QC may grow exponentially with qbits. Refrigeration is exponentially inefficient as T=>0 and the gap of a quantum system which sets the temperature you must cool to shrinks as you couple new degrees of freedom. This dynamic has been the basic reason for the sub exponential progress in the area (despite exponential expenditure)

Re: Google claims to have proved its supremacy with new quantum computer

#76

Earlier quoted context omitted.

A potential hidden bonus: if quantum computing theories get enough attention, maybe people will start to consider using the quantum computing abilities of the human mind with conscious intentionality (since by the time we get computers to be able to do it, it may be too late)!

What are these capabilities of which you speak? Or have i missed the sarcasm

I’m guessing he’s referring to the Roger Penrose stuff — https://en.m.wikipedia.org/wiki/The_Emperor%27s_New_Mind , etc.

Re: Google claims to have proved its supremacy with new quantum computer

#77
post #7

Dumb question: Say I have a wooden stick and I break it in half in less than a second. Assume a computer would need several minutes to simulate everything that would've happened in the stick. I clearly got the output faster than a computer (and with more precision), so does this imply I'm doing anything particularly fascinating? I assume the same scenario is possible to concoct for a quantum computer. I assume it wou…

Oddly enough, I think this can be answered by headlines alone. Imagine you could do anything remotely interesting with a relative speedup of 47 years to 'instant', where we can say an instant is 1 millisecond. That'd mean in one day of calculation, you could do things that'd take a current era supercomputer more than 4 billion years to achieve. And so on upward from there. Yet we're focusing on this odd and relatively boring metric of 47 years?

That suggests that the implications intentionally provoked by the phrasing "Google’s quantum computer instantly makes calculations that take rivals 47 years" are obviously false, even if the statement itself is true in some extremely specific context. So in other words, when genuine quantum progress has been achieved - I don't think we'll need to debate it, as the results would speak for themselves.

Re: Google claims to have proved its supremacy with new quantum computer

#78
post #19
post #7

Dumb question: Say I have a wooden stick and I break it in half in less than a second. Assume a computer would need several minutes to simulate everything that would've happened in the stick. I clearly got the output faster than a computer (and with more precision), so does this imply I'm doing anything particularly fascinating? I assume the same scenario is possible to concoct for a quantum computer. I assume it wou…

One would be the direction of entropy. Breaking the stick is not "particularly fascinating" because you're going in the direction of increasing entropy. However, _putting it back together_ is. In the simulation it takes no more effort to go one way or the other, while you probably cannot put the stick back together no matter how hard you tried. A quantum question that is "interesting" would also be similar to finding…

Nice comment

Re: Google claims to have proved its supremacy with new quantum computer

#79

Earlier quoted context omitted.

> You don't know, with any precision, the amount of force you used, the rate the stick broke at, how much mass remains in the two pieces and how much was lost to splintering, etc. But I can measure those with a ruler and a scale. Both before and after the breakage. Takes a few seconds, and I'd need to do that before punching those numbers into the simulator anyway. And I can be precise with where I apply the force, e…

> I can literally measure those with a ruler and a scale You can’t measure a number of internal stress-strain conditions during the moment of failure. You can’t repeat the experiment with the same stick. The best way to get a fast intuition for why the simulation is superior is to take an entry-level CAD course with a focus on material design.

> The best way to get a fast intuition for why the simulation is superior is to take an entry-level CAD course with a focus on material design.

I'm sorry but you're completely missing the point of my question. The question was not "what can simulations do that experiments can't". My background in simulation is not zero, and I've never had that question. The question as something else entirely.

> You can’t measure a number of internal stress-strain conditions during the moment of failure

But what if that's not what I'm interested in simulating or measuring? What if all I care about is something easily measurable, like the length of each remaining piece? Isn't that precisely my point here? There are so many things quantum computers can't compute either - yet we seem to be judging them by what they're really good at. Just like with the wooden stick. So how do I tell if they're the same sort of scenario or not? What's the distinguishing criterion?

Re: Google claims to have proved its supremacy with new quantum computer

#80
post #19

Earlier quoted context omitted.

One would be the direction of entropy. Breaking the stick is not "particularly fascinating" because you're going in the direction of increasing entropy. However, _putting it back together_ is. In the simulation it takes no more effort to go one way or the other, while you probably cannot put the stick back together no matter how hard you tried. A quantum question that is "interesting" would also be similar to finding…

If I provide two model sticks to a physics simulation, it can work out how to put them back together with no more effort than it took to model the break? Like I can model shooting a cannon ball out of a cannon and it will tell me where it lands. Or I can model a cannon ball sitting on the ground and it will tell me where the cannon was?

A hypothetical perfect simulation should be able to do it both ways indeed!

However, the current consensus take of quantum uncertainty means _if_ such a simulator exists, it cannot be of our universe. Or, more likely, such a perfect simulator does not exist.

Of course all of this is about a hypothetical of a hypothetical at this point...

(This is the same problem as entropy (our current understanding of it). We know it is increasing one-way w.r.t. time, and we can imagine what it means to "reverse entropy" and that there's nothing really theoretically preventing that, but we can't build an actual machine to do that.)

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