More on whether useful quantum computing is “imminent”

scottaaronson.blog

125 points by A_D_E_P_T 20 hours ago


yoan9224 - 12 minutes ago

Aaronson's take is characteristically grounded. The Willow chip announcement was impressive technically but the media coverage predictably overshot into "RSA is dead" territory when the actual achievement was improving error correction rates. The relevant timeline question is: when do quantum computers solve problems faster than classical computers for commercially useful tasks (not just contrived benchmarks)?

The error correction milestone matters because it's the gate to scaling. Previous quantum systems had error rates that increased faster than you could add qubits, making large-scale quantum computing impossible. If Willow actually demonstrates below-threshold error rates at scale (I'd want independent verification), that unblocks the path to 1000+ logical qubit systems. But we're still probably 5-7 years from "useful quantum advantage" on problems like drug discovery or materials simulation.

The economic argument is underrated. Even if quantum computers achieve theoretical advantage, they need to beat rapidly improving classical algorithms running on cheaper hardware. Every year we delay, classical GPUs get faster and quantum algorithms get optimized for near-term noisy hardware. The crossover point might be narrower than people expect.

What I find fascinating is the potential for hybrid classical-quantum algorithms where quantum computers handle specific subroutines (like sampling from complex distributions or solving linear algebra problems) while classical computers do pre/post-processing. That's probably the first commercial application - not replacing classical computers entirely but augmenting them for specific bottlenecks. Imagine a drug discovery pipeline where the 3D protein folding simulation runs on quantum hardware but everything else is classical.

prof-dr-ir - 19 hours ago

I am confused, since even factoring 21 is apparently so difficult that it "isn’t yet a good benchmark for tracking the progress of quantum computers." [0]

So the "useful quantum computing" that is "imminent" is not the kind of quantum computing that involves the factorization of nearly prime numbers?

[0] https://algassert.com/post/2500

tromp - 19 hours ago

I realize this is a minority opinion, and goes against all theories of how quantum computing works, but I just cannot believe that nature will allow us to reliably compute with amplitudes as small as 2^-256. I still suspect something will break down as we approach and move below the planck scale.

Aardwolf - 19 hours ago

Once quantum computers are possible, is there actually anything else, any other real world applications, besides breaking crypto and number theory problems that they can do, and do much better than regular computers?

bahmboo - 19 hours ago

I particularly like the end of the post where he compares the history of nuclear fission to the progress on quantum computing. Traditional encryption might already be broken but we have not been told.

jasonmarks_ - 18 hours ago

Zero money take: quantum computing looks like a bunch of refrigerator companies.

The fact that error correction seems to be struggling implies unaccounted for noise that is not heat. Who knows maybe gravitational waves heck your setup no matter what you do!

Antibabelic - 4 hours ago

Is it possible that practical quantum computing is actually impossible and we only think it is because of our incomplete understanding of physics?

noname120 - 5 hours ago

I can’t believe how the very first line of the article is a grotesque strawman. Tbh I expected better from Scott Aaronson.

sallveburrpi - 5 hours ago

So summary is that useful quantum computing is definitely not imminent (as in probably happening in the next 10-20 years) - or am I misreading ?

ursAxZA - 4 hours ago

Which one ends up being more accurate — quantum-computing forecasts or fashion-magazine trend predictions?

ktallett - 19 hours ago

As someone that works in quantum computing research both academic and private, no it isn't imminent in my understanding of the word, but it will happen. We are still at that point whereby we are comparable to 60's general computing development. Many different platforms and we have sort of decided on the best next step but we have many issues still to solve. A lot of the key issues have solutions, the problem is more getting everyone to focus in the right direction, which also will mean when funding starts to focus in the right direction. There are snake oil sellers right now and life will be imminently easier when they are removed.

osn9363739 - 7 hours ago

This is the worst quantum computing will ever be.

cubefox - 7 hours ago

This sounds slightly alarming:

> I’m going to close this post with a warning. When Frisch and Peierls wrote their now-famous memo in March 1940, estimating the mass of Uranium-235 that would be needed for a fission bomb, they didn’t publish it in a journal, but communicated the result through military channels only. As recently as February 1939, Frisch and Meitner had published in Nature their theoretical explanation of recent experiments, showing that the uranium nucleus could fission when bombarded by neutrons. But by 1940, Frisch and Peierls realized that the time for open publication of these matters had passed.

> Similarly, at some point, the people doing detailed estimates of how many physical qubits and gates it’ll take to break actually deployed cryptosystems using Shor’s algorithm are going to stop publishing those estimates, if for no other reason than the risk of giving too much information to adversaries. Indeed, for all we know, that point may have been passed already. This is the clearest warning that I can offer in public right now about the urgency of migrating to post-quantum cryptosystems, a process that I’m grateful is already underway.

Does anyone know how much underway it is? Do we need to worry that the switch away from RSA won't be broadly deployed before quantum decryption becomes available?

nacozarina - 17 hours ago

another late signal will be a funding spike

once someone makes a widget that extracts an RSA payload, their govt will seize, spend & scale

they will try to keep it quiet but they will start a spending spree that will be visible from space

Traubenfuchs - 17 hours ago

Cloud providers will love it when we will need to buy more compute and memory for post quantum TSL.

willmadden - 18 hours ago

We'll know when all of the old Bitcoin P2PK addresses and transacted from addresses are swept.

eightysixfour - 19 hours ago

Did anyone else read the last two paragraphs as “I AM NOT ALLOWED TO TELL YOU THINGS YOU SHOULD BE VERY CONCERNED ABOUT” in bright flashing warning lights or is it just me?

tgi42 - 18 hours ago

I worked in this field for years and helped build one of the recognizable companies. It has been disappointing to see, once again, promising science done in earnest be taken over by grifters. We knew many years ago that it was going to take FAR fewer qubits to crack encryption than pundits (and even experts) believed.

hellobluelings - 7 hours ago

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