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Comment by dekhn | Hacker News Reader

the best thing about watching the entire quantum computing debacle is every time somebody says their QC does something faster than a classical computer, somebody tunes the classical computer to beat the QC. Combined with the fact that chip infrastructure is already paid for and there is a large market to enable economy of scale, coupled with the lack of true problems where exponentially better problem solving is critical to business or military success, means we're going to see a series of QC claims that really just prop up classical computers for some time.

(I used to work in supercomputing and chemistry and await the day we have useful QCs doing simulation better than what we can do on supercomputers)

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With all of the sensationalization, I am now convinced that many of the people in quantum computing itself are grifters, and that funding agencies keep paying them to put pressure on classical computing (despite knowing that QC is a big grift).

Already, optimization problems have seen classical "ising" chips get great results (as good as the quantum annealing chips), proving that optimization doesn't actually need tunneling or superposition.

Now, the number theorists just need to come up with a classical analog for a QFT or another similar transform, and we will see them obviate QC here. Arguably, RSA being obsolete has already done this.

In simulation, supercomputers are also making huge advances in power.

In my experience in QC, I've yet to see many grifters. In fact, many of the people in quantum computing are quite open about the fact that we aren't that close to "useful" quantum computing, that the number of practical problems that quantum computers will beat classical computers with could be quite small, and are actively worried about over-hyping. People selling today's QCs as a solver for generic optimization problems are indeed grifting, but that is not most of the community.

Despite all these problems, myself and much of the community still think QC is worth attempting --- for my part, the applications to quantum physics is the main motivation, and one in which it's relatively certain that QC will not "become obsolete". (It's also still perfectly valid to _research_ how to make QC useful in various types of classical problems, including optimization, and it's plausible that progress _could_ be made that would open up more widespread uses of QC. The line, for me, is when people misrepresent the likelihood of success of that research.)

When people are hyping something that is probably still 20 years out, i think its safe to say they are trying to sell you something.

Quantum computers will be a real (albeit not earth shattering) advance, but we are still far off.

Still rather people pump money here than crypto bs.

Getting research funded is part of the process by which things that are 20 years off actually get developed. People seem to think it's just fated that we will have fusion on X date etc as though it's independent of how much effort is put into it. This kind of research is expensive on an individual scale, but very much a drop in the bucket at the scale of the US national budget.

Quantum computing has been 10 years away for the last 30 years.

I don't think that is true, i imagine most people thought it was much more than 10 years away 30 years ago. I think 30 years ago people still weren't sure if it was physically possible at all.

In the mean time real progress has been made. If we continue at this rate (big if) we will eventually have quantum computers. Just not tomorrow.

I think it’ll be like AI: perpetually 50 years away until some big discovery is made and everyone stops laughing.

For AI it was the “attention is all you need” paper. I’ve been told that for QC it might be error correction that scales but I’m not knowledgeable enough to know if that’s true.

I expect that nuclear fusion will follow the same trajectory of being 50 years away until it’s suddenly 0 years away.

The reality for all these is that steady progress is constantly being made but isn’t visible outside experts in the field. Then it reaches a critical mass and you have the “chatgpt moment.”

> QC it might be error correction that scales but I’m not knowledgeable enough to know if that’s true

"Error correction that scales" is basically what the definition of a working quantum computer. That is less the breakthrough needed so much as what the breakthrough would lead to.

Comparing to AI doesn't look so good for QC. The research that led up to the attention paper has a consistent trend of producing lots of useful applications for its 60-year history. You may not remember this, but in 2012 there was a computer vision "watershed moment" around the CNN architecture. Before that, there was the DARPA autonomous driving challenge and related research in robotics. Going back further, there have been many other big breakthroughs in ML/AI with immediate application, down to the perceptrons of the 60's and hidden markov models of the 70's. In other words, the field that eventually became AI was pretty much immediately useful.

The relative lack of useful intermediate results raises major red flags for me, but it doesn't seem that physicists are all that bothered by it. Indeed, the high energy theorists have been at it for longer with a lot less to show for their work: At least we have a few toy quantum computers, while there is still nothing testable about string theory.

Honestly, I hate to say this, but I think it's going to take a major war for QC to have its watershed moment (a "Manhattan project"), and I think the odds are that it will actually work if it comes to that. However, the window is kind of closing on the usefulness of the technology as post-quantum encryption starts to get legs, and I don't really want another World War 2...

I’m curious, what “real progress” did QC make since the 90s?

While they said 30 years ago, so since 1993?

On the theoretical side shor's algorithm was invented 29 years ago, which is what started the hype in the first place. 30 years ago is 1 year before anyone really cared.

Late 90s early 2000s you start to see progress on quantum error correction, which is key progress neccessary to make this all work theoretically

Starting Mid-2000s you start to see toy realization proof of concepts (devices with a few qubits). Thdy aren't very useful but realizing a physical device is the first step to doing anything at all. These keep getting better and better.

Early 2020s you start to see devices that can perform computation, that well not particularly useful, are complex enough that they would require a super computer to do clasically. This in my opinion is quantum computer's "hello world" moment in my opinion. Writing a hello world program is still very far off from say writing the linux kernel, but its the step where things get real.

Like most things in science, most of this is not zOMG breakthrough, but small gains compounding over time to create real progress.

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