[gjm11]

It says:

> the chip itself didn't just spit out 5 and 3. Instead, it came up with an answer to the "order-finding routine"

O noes! The quantum computer only did the "order-finding" part of Shor's algorithm! ... But wait. Here's the Wikipedia page for Shor's algorithm:

> Shor's algorithm consists of two parts: 1. A reduction, which can be done on a classical computer, of the factoring problem to the problem of order-finding. 2. A quantum algorithm to solve the order-finding problem.

So, the article GP cited says that a quantum computer did the part of factoring the number 15 that actually uses a quantum computer. Nothing wrong with that.

The article's link to the actual paper is broken, which makes it harder to tell whether as you say they cheated somehow, but here's another article about factoring 15 with a quantum computer https://science.sciencemag.org/content/351/6277/1068 which so far as I can see claims to have actually done the whole of (the relevant part of) Shor's algorithm on actual QC hardware.

[scottlocklin]

Even assuming I humor you and refuse to notice they left out the gates to the wrong answer, and assuming I humor the authors in agreeing that this is a scalable form of the Shor algorithm (I deny both of these for the record) .... congratulations: by 2016 someone was able to factor the number 15. I guess quantum supremacy is right around the corner!

[DebtDeflation]

>to notice they left out the gates to the wrong answer

Can you explain this a little more? I've seen similar references to this elsewhere. If it means what I think it means, it's kind of a really big deal. But it may mean something else.

[scottlocklin]

http://www.theory.caltech.edu/~preskill/pubs/preskill-1996-n...

[gjm11]

That doesn't explain in what sense this entirely different paper from 20 years later allegedly "left out the gates to the wrong answer".

The paper I linked to says, e.g., the following:

> Subsequent multipliers can similarly be replaced with maps by considering only possible outputs of the previous multiplications. However, using such maps will become intractable, [...] Thus, controlled full modular multipliers should be implemented.

So in at least one case they are explicitly not taking a particular shortcut because it doesn't scale to factorizing larger numbers. If you say they are taking other shortcuts that don't scale by "leaving out the gates to the wrong answer", then I think you owe us an actual explanation of what shortcuts they are taking and how you know you're taking them, rather than just a link to a paper from 1996 that says how to take some shortcuts.

[scottlocklin]

Frankly I don't owe you or the muppets attempting to participate in this thread by zombie-walking "MUH PRESS RELEASES" a damn thing: if you want to believe in pixie dust, you're free to do so. None of the "quantum computing results" factoring the number 15 have done the actual Shor algorithm -they've all used the shortcut described in this paper. Someone below posted another paper pointing out the same thing, as well as some discussion on a forum .... pointing out the same thing.

It's not my fault you believe in press releases without understanding what they mean.

[gjm11]

I haven't said a thing about press releases.

The paper I linked to (1) doesn't cite Preskill et al and (2) explicitly claims not to be taking shortcuts that don't generalize to numbers other than 15; as well as the bit I quoted earlier, they say "for a demonstration of Shor’s algorithm in a scalable manner, special care must be taken to not oversimplify the implementation—for instance, by employing knowledge about the solution before the actual experimental application" and cite an article in Nature decrying cheaty oversimplifications of Shor's algorithm.

I don't see anything in their description of what they do that seems to me to match your talk of "deleting the gates that lead to the wrong answer".

(The Kitaev paper they cite also doesn't cite Preskill et al, unsurprisingly since it predates that, and also doesn't contain anything that looks to me like cheaty shortcut-taking.)

It is, of course, possible that that paper does take cheaty shortcuts and I've missed them. It is, of course, possible that its authors are flatly lying about what they're doing, and trying to hide the evidence by not citing important prior papers that told them how to do it. If so, perhaps you could show us where.

Otherwise, I for one will be concluding from the surfeit of bluster and absence of actual information in your comments so far that you're just assuming that every alleged "factoring of 15" is indulging in the dishonesty you think they are, and that you aren't interested in actually checking.

(You don't, indeed, owe anyone anything. It's just that if you want to be taken seriously, that's more likely if you offer something other than sneering and bluster.)

[core-questions]

God, you've got a bone to pick, don't you? I see you every time there's a HN thread about quantum computing. Scott Aaronsen posting under a sock account?

[scottlocklin]

Unlike you, I post under my name. Aaronson doesn't know what he's talking about half the time.

Some people laugh at the chicanery of scumbags who claim fully autonomous vehicles are right around the corner. I laugh at the frauds and mountebanks of "quantum information theory" and the muppets who believe everything they say. De Gustibus.

[core-questions]

I changed my mind, you called someone a bugman in another thread, so while you're wrong about the current state of QC you're alright in my books