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?
Factoring will be okay for tracking progress later; it's just a bad benchmark now. Factoring benchmarks have little visibility into fault tolerance spinning up, which is the important progress right now. Factoring becoming a reasonable benchmark is strongly related to quantum computing becoming useful.
Basically qc are so far from ever doing a useful computation we need other benchmarks to measure progress. We need to be thinking in timelines of our lifetime not 5 years
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.
So you have one of the scientists at the forefront of quantum computing theory telling you that he has no idea if quantum computing is already in a much more advanced state that he himself knows about?
If results in quantum computing would start to "go dark", unpublished in scientific literature and only communicated to the government/ military, shouldn't he be one of the first to know or at least notice?
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.
Eh, quantum computing could very well be the next nuclear fusion where every couple of years forever each solved problem brings us to "We're 5 years away!"
Yet, for sure we should keep funding both quantum computing and nuclear fusion research.
What makes it more akin to 60’s general computing development than 60’s fusion power development (that is still ongoing!)? The former is incremental, the latter requires major technological breakthroughs before reaching any sort of usefulness. Quantum computing feels more like there are roadblocks that can’t be ironed out without several technological revolutions.
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?
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.
In some ways i think that is the most exciting possibility. If attempts at making quantum computers let us find exactly where the current theories break down and probe how that happens, it will probably be one of the most important physics discoveries of the century.
The magnitude of an "amplitude" is basis dependent. A basis is a human invention, an arbitrary choice made by the human to describe nature. The choice of basis is not fundamental. So just choose a basis in which there are no vanishingly small amplitudes and your worry is addressed.
The amplitudes aren't small in the 512-dimensional subspace where 256-qubit calculations take place.
2^256 states are comfortably distinct in that many dimensions with amplitude ~1. Their distinctness is entirely direction.
The obvious parallels to vector embeddings and high-dimensional tensor properties have some groups working out how to combine them in "quantum AI", and because that doesn't require the same precision (like trained neurel nets still work usefully after heavy quantization and noise), quantum AI might arrive before regular quantum computation, and might be feasible even if the latter is not.
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?
I believe the primary most practical use would be compression. Devices could have quantum decoder chips that give us massive compression gains which could also massively expand storage capacity. Even modest chips far before the realization of the scale necessary for cryptography breaking could give compression gains on the order of 100 to 1000x. IMO that's the real game changer. The theoretical modeling and cryptography breaking that you see papers being published on is much further out. The real work that isn't being publicized because of the importance of trade secrets is on storage / compression.
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.
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!
> 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?
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.
Vanderbilt University [0] is about to open a "quantum research graduate studies" campus, somewhere near Chattanooga, Tennessee.
I have a degree in chemistry from that institution, and don't have a clue what this means beyond the $1,000,000,000 economic impact this facility is supposed to make upon our fair city, over the next decade.
31 comments
[ 3.7 ms ] story [ 55.4 ms ] threadSo 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
If results in quantum computing would start to "go dark", unpublished in scientific literature and only communicated to the government/ military, shouldn't he be one of the first to know or at least notice?
Yet, for sure we should keep funding both quantum computing and nuclear fusion research.
More realistically it breaking down would hopefully give us a new physics frontier.
2^256 states are comfortably distinct in that many dimensions with amplitude ~1. Their distinctness is entirely direction.
The obvious parallels to vector embeddings and high-dimensional tensor properties have some groups working out how to combine them in "quantum AI", and because that doesn't require the same precision (like trained neurel nets still work usefully after heavy quantization and noise), quantum AI might arrive before regular quantum computation, and might be feasible even if the latter is not.
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!
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
> 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?
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.
I have a degree in chemistry from that institution, and don't have a clue what this means beyond the $1,000,000,000 economic impact this facility is supposed to make upon our fair city, over the next decade.
[•] <https://quantumzeitgeist.com/vanderbilt-university-quantum-q...>
[0] In partnership with our government-subsidized "commercial quantum-ready" fiber network, EPB