Quantum computers!

How do you overclock a quantum computer?

Buy more cats.

(xpost to the article.)

oh, those deadpan scientists.

seriously, how long before we acausal and nonlinear computing, where it knows the question before you actually ask it?

or would that fall in the category of "tachyon comptuers", which sounds like something from Master of Orion?

That "issue" is completely resolved, for all intents and purposes. The Quantum Zeno Effect, upon which this experiment is based, is also well-established experimentally. Applying QZE to quantum computing and wowing the media with "wow, it works even when it's NOT ON" is the new stuff. The guy in charge of the project, Paul Kwiat, is a genius when it comes to designing these sorts of experiments.

You're right, this nicely summarizes ILX's interest in science vs ILX's interest in waxing poetic about "science".

A PHYSICIST WRITES [John Derbyshire]

Me: "Why would the on-off switch on a quantum computer have two positions? Shouldn't it just have one, labeled INDETERMINATE?"

He: "Only when you're not looking at it."

heh. see also the south dakota thread, with the one politico quoted as how "science" proves when conception is.

I am taking a class in quantum computing now - let the weirdness being.

bumping this with a basic tutorial, because it just seems wrong that we have a thread on quantum computers with nothing in it, even as all sorts of amazing stuff is apparently happening.

https://www.wired.co.uk/article/quantum-computing-explained

note: i have no idea wtf is going on

I thought this was really interesting:

https://www.quantamagazine.org/teenager-finds-classical-alternative-to-quantum-recommendation-algorithm-20180731/

Yeah results like that one, plus the generally conservative outlook of most academic experts in quantum computing, mean my baseline stance on the field is that it's a neat model that I sure as heck don't totally understand but I have no particular reason to think that practical quantum attacks on (say) RSA encryption are likely to exist in the foreseeable future or ever.

That said post-quantum cryptography is a standard crypto researchers are trying to meet, just in case.

In 2014, at age 14 and after skipping the fourth through sixth grades, Tang enrolled at UT Austin and majored in mathematics and computer science. In the spring of 2017 Tang took a class on quantum information taught by Scott Aaronson, a prominent researcher in quantum computing. Aaronson recognized Tang as an unusually talented student and offered himself as adviser on an independent research project. Aaronson gave Tang a handful of problems to choose from, including the recommendation problem. Tang chose it somewhat reluctantly.

“I was hesitant because it seemed like a hard problem when I looked at it, but it was the easiest of the problems he gave me,” Tang said.

...Tang set to work in the fall of 2017, intending for the recommendation problem to serve as a senior thesis. For several months Tang struggled to prove that a fast classical algorithm was impossible. As time went on, Tang started to think that maybe such an algorithm was possible after all.

“I started believing there is a fast classical algorithm, but I couldn’t really prove it to myself because Scott seemed to think there wasn’t one, and he was the authority,” Tang said.

ok tang, you're smart but you have much to learn about not being a dick

practical quantum attacks on (say) RSA encryption are likely to exist in the foreseeable future

"practical" is not a modifier that large nuclear-armed nations trade in IME

I'm using "practical" in what I understand to be the cryptologist's sense of "achievable using an extant amount of computing power" and I'm pretty sure the most qubits anybody's gotten to cohere in one spot long enough to look at is, like, 7?

close to 40 i thought

nope i’m wrong

I am under the impression we have gone from 1-2 qubits to 20 qubits in the span of about a decade.

according to that bad wired recap i posted, badly,

Whether it’s an arbitrary goal or not, Google was pipped to the supremacy post by IBM in November 2017, when the company announced it had built a 50-qubit quantum computer. Even that, however, was far from stable, as the system could only hold its quantum microstate for 90 microseconds, a record, but far from the times needed to make quantum computing practically viable. Just because IBM has built a 50-qubit system, however, doesn’t necessarily mean they’ve cracked supremacy and definitely doesn’t mean that they’ve created a quantum computer that is anywhere near ready for practical us

the fact that people have gone from "it's a theory" to "it's real but it's just not practical" in such a short span of time is exactly why people who have secrets encrypted with long-ass RSA keys are sweating and have already thrown out all their ECC algos

I wrote my A-Level physics coursework on qantum computing in 1996. As tombot says its being incredible to see this evolve to this level. It didn't seem like single qbits would be practical back then and to have achieved this level is remarkable.

I have been doing a lot of research on this lately and have concluded that the sheer amount of money being thrown at it has been extremely influential in taking it from academically interesting to "about to happen, all at once, for real" - like usable, universal quantum computing and quantum communications by 2026-ish

just in time for the collapse of civilisation, v cool

What will be the practical implications iyo?

Ive looked into it a few times but then I realize "superposition" is something I don't really understand.

each quantum computer is powered by a cat in a box which may or may not be dead

the cat is capable of performing multiple computations simultaneously, vastly increasing the power of the computer over conventional devices

however if you open the box, the quantum wave collapses and the computer becomes useless and you either have to bury a cat corpse or make peace with your furniture being used as a scratching post for the next decade or so

https://www.youtube.com/watch?v=as6hSAqJ_g4

But will anyone be able to afford quantum computers other than the NSA and a few national governments? I do not find this idea reassuring.

1) prices will go down. for reference, see every other invention ever.
2) I can't afford a server, yet I reap benefits (in my daily life) from their existence.

Once they solve the supercooling technology, a quantum computer can pretty much be built from off-the-shelf components.

I said get OFF the SHELF! Damn cat.

I don’t know who to believe but this is an amusing rant:

https://scottlocklin.wordpress.com/2019/01/15/quantum-computing-as-a-field-is-obvious-bullshit/

Will this be the next bullshit tech bubble after AI?

Microsoft has announced a quantum processing unit that can't do anything, and has not demonstrated that it has the quantum state they are claiming. But it comes in a shiny gold case.

https://en.wikipedia.org/wiki/Majorana_1
Fireship: Microsoft's new chip looks like science fiction...

i dont have time or attn to answer that just yet im still so busy debunking the benefits of the cloud and AI to senior mgmt tbh

good man

it's quantum, so it's both working and not working at the same time

Why Quantum Cryptanalysis is Bollocks

Thank you for that link. I really enjoyed that. I've been a quantum computing skeptic for years, but pretty much without base. It just feels like bullshit. Same as A.I. always has, and still does.

Awesome link

Calling it quantum computing is the goofiest aspect of it, but it's really just a faster chip or processor right? Chips and processors keep getting faster and faster, so I've got to assume it's not out of the realm of possibility that there should be some big leap in efficiency, given all these other leaps in efficiency over the last couple decades.

There was some article I read, don't remember where, maybe the Wall Street Journal? Anyway, it was about a huge quantum computer campus being developed in Chicago. Big money.

No Josh

If the original idea of quantum computing had been suggested by a physicist of far less stature than Feynman, would anyone have picked up on it? Or would it have been roundly dismissed as the product of an undisciplined imagination and far too impractical?

quantum laws state that you can know the name of the theorising physicist or you can accurately analyse the validity of their theory, but never both

wow, great link there.

anybody read the book quoted from at the end, Lost in Math: How Beauty Leads Physics Astray?

Sabine Hossenfelder is now a youtube crank. her book wasn't received well at the time either. avoid.

ahh great to know, thanks!

Like everyone in computer science, the hype (and subsequent investment) is obnoxious. The Microsoft press release is a great example of this obnoxiousness. But studying alternative computing models is good for both practical and humanity reasons, e.g., alternative computer models have made us better at math and (my former fields of) optical and photonic computing can solve very real practical issues.