[cthalupa]

You keep repeating this, but as best as I can tell, it hasn't been factually accurate in a decade, unless you really want to quibble over the fact that they finished the calculation on a general purpose computer.

https://www.schneier.com/blog/archives/2009/09/quantum_compu...

>Instead, it came up with an answer to the "order-finding routine," the "computationally hard" part of Shor's algorithm that requires a quantum calculation to solve the problem in a reasonable amount of time.

They weren't the first team to do this, either, they just miniaturized parts of the hardware.

[scottlocklin]

The result you cite doesn't even say what you think it says; in fact it directly says they didn't factor a damn thing.

If I'm wrong and IBM's latest "quantum computer" can actually do the Shor algorithm on the number 15 using 4608 gate operations, I will publically eat one of my shoes like Werner Herzog. Assuming I can get someone else to take the other side of the bet, of course.

[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.

[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