Google claims to have proved its supremacy with new quantum computer • Hacker News Board

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

#21

Post by swframe2 » Mon, Jul 03, 2023, 4:34 PM UTC

mikewarot wrote: post #2

The cited paper[1] references "random circuit sampling" which is defined in [2] which then gets so heavy into abstract math, and I give up. Can someone explain this in terms an EE or programmer can understand? [1] https://arxiv.org/abs/2304.11119 [2] https://arxiv.org/abs/2007.07872

(I don't have a background (or interest) in quantum computing) I've tried some of the "chat with pdf" websites for other topics. It seems like they could help you understand the paper. If you give it a try, could you report back here on how it worked for you.

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

#22

Post by tedivm » Mon, Jul 03, 2023, 4:35 PM UTC

marricks wrote: post #10

> He said: “This is a very nice demonstration of quantum advantage. While a great achievement academically, the algorithm used does not really have real world practical applications, though. > “We really must get to utility quantum computing – an era where quantum computers with many thousand qubits actually begin to deliver value to society in a way that classical computers never will be able to.” This seems to be t…

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 alternatives.

As the quote mentions, we'll need "many thousand qubits" to reach the point where society itself is getting new benefits out of things. These contrived cases help figure out how to scale the whole system.

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

#23

Post by rcme » Mon, Jul 03, 2023, 4:35 PM UTC

dataflow wrote: 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…

Did you really get the answer faster than a computer?or put another way, what question did you answer? How much force was applied to the stick before it broke? How fast was the stick moving 0.04s after breakage? How much sound was produced? There are thousands of questions you don’t have answers to when you simply break a stick.

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

#24

Post by wuubuu » Mon, Jul 03, 2023, 4:38 PM UTC

dataflow wrote: 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…

Not a dumb question!

There is a great video by the mathematician Richard Borcherds on this exact objection to current examples of quantum supremacy.

https://www.youtube.com/watch?v=sFhhQRxWTIM

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

#25

Post by dataflow » Mon, Jul 03, 2023, 4:38 PM UTC

fsh wrote: post #5

Google's and IBM's previous "quantum supremacy" demonstrations were quickly crushed by improved classical simulations. Let's see if it survives this time.

Would you have any links handy for those?

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

#26

Post by knorker » Mon, Jul 03, 2023, 4:38 PM UTC

esrauch wrote: post #15

knorker wrote: post #9

Earlier quoted context omitted.

My understanding is that quantum computers only have two real use cases, as of today: 1. Breaking crypto. 2. Simulating other quantum systems. For (1) it's basically all downsides. For (2) unless you're a particle phycisist you'll never need quantum computers. But that's now. Maybe there will be a killer app for it some day, changing everything. Or indeed, we could get it indirectly. Maybe simulating quantum systems…

If it is able to break crypto then surely that means it can do other "interesting" mathematical calculations that are currently extremely slow/hard though?

Possibly. This is way beyond my knowledge.

But I'm not aware of many other "search this finite part of the number line for this property", where "this finite part" is still too big for classical computers.

It almost sounds like quantum computers are tailor made for the types of problems we've been building cryptosystems on.

But maybe this is not all quantum computers will be able to do. I couldn't even explain exactly how they apply to simulations of quantum systems, but have only taken more knowledgeable people at their word.

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

#27

Post by zdragnar » Mon, Jul 03, 2023, 4:40 PM UTC

dataflow wrote: 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…

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 than a human can through trial.

In fields where human trial is exceptionally inefficient- molecular physics, chemical synthesis design, structural material design, etc- a sufficiently fast computer will allow for faster design iteration and perhaps even development of new processes and materials.

More concretely, if you wanted to design a new stick that breaks under exactly the conditions that you intend it to, then you can skip a lot of trial and error if your computer can accurately model the materials you are designing and testing.

Think construction, civil engineering, energetic chemistry, biological processes (medicine design) etc.

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

#28

Post by Aperocky » Mon, Jul 03, 2023, 4:40 PM UTC

rcme wrote: post #23

dataflow wrote: 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…

Did you really get the answer faster than a computer?or put another way, what question did you answer? How much force was applied to the stick before it broke? How fast was the stick moving 0.04s after breakage? How much sound was produced? There are thousands of questions you don’t have answers to when you simply break a stick.

I think that was his exact argument against quantum computing.

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

#29

Post by mistermann » Mon, Jul 03, 2023, 4:42 PM UTC

marricks wrote: post #10

> He said: “This is a very nice demonstration of quantum advantage. While a great achievement academically, the algorithm used does not really have real world practical applications, though. > “We really must get to utility quantum computing – an era where quantum computers with many thousand qubits actually begin to deliver value to society in a way that classical computers never will be able to.” This seems to be t…

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)!

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

#30

Post by avidphantasm » Mon, Jul 03, 2023, 4:43 PM UTC

dataflow wrote: 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…

Regardless of how good our classical or quantum computers get, simulating “complex” natural systems is ultimately limited by our ability to observe and measure the physical properties of the “components” (I put quotes here to acknowledge the difficulty/impossibility of delineating system components) of that system. I’m not sure quantum computers will help with that.