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Comment by iherbig | Hacker News Reader

IBM's response to Google called "On 'Quantum Supremacy'" has this to say:

"Because the original meaning of the term “quantum supremacy,” as proposed by John Preskill in 2012, was to describe the point where quantum computers can do things that classical computers can’t, this threshold has not been met."

In other words, "quantum supremacy" is not being used as just a buzzword.

So yeah, IBM is casting doubt on Google's claims of "quantum supremacy" because "supremacy" doesn't just mean "better than everything else."

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But it's still pretty fuzzy. If we agree that 10,000 years on a classical system is supremacy but 2.5 years isn't, where's the cutoff? 25 years? 250? An average human lifespan?

Edit: Thanks guys for pointing out where I misread the article, leaving mistake intact so the replies make sense.

2.5 days, as reported by IBM, is more clearly feasible.

But you’re right, it is a subjective judgement.

2.5 _days_, not years.

A still fuzzy and arbitrary but imo somewhat elegant cutoff would let feasibility be set by the market and technological development, in the sense of something not being worth throwing compute at _now_ because the timescale of work is slow enough that future classical efficiencies will progress (much) quicker.

For market forces to be meaningful, the calculation would need to provide value to someone. At the moment the desired output is simply "a distribution which is hard to simulate classically," so assessment in terms of market value would be very premature.

But that goes for any raw benchmarking, it’s busywork by design.

I'm pretty cynical about this specific experiment, but that's taking it to another level.

The ROI was terrible, but it wasn't mere busywork when Galileo was mucking around with balls and ramps.

Haha sorry should've been much clearer, I meant specifically computer power benchmarking.

You perform busywork, if for marketing purposes usually of the kind or at least set up in a way favorable to your product, and on the presumption that it will in some manner transfer to real work.

The more synthetic the less likely that is, but it's still indicative of something and I don't see what you mean is so different here.

The cutoff is on a complexity level. IBM claims it is linear complexity so that is easily solved in a classical computer, regardless of the time it takes. Google's claim is that it is exponential which means they achieved quantum supremacy or proven a quantum processor that can solve a problem a classical processor cannot.

Yes, but the interesting thing to me is how that cutoff between linear and exponential complexity comes down not to the processor but other computing resources.

Meaning when supremacy soon is demonstrated even accounting for storage, it should be able to be undone for a while yet by, say, appropriating everyone’s phones and fridge storage, Silicon Valley style.

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