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Is there any project or collaboration under the label of "Quantum Computing" out there that is not turn out as utter bullshit and charlatanerie?
Despite the hype, nobody seems to have even the most basic concept of how this could be turned into something that works.
>pic: the latest bullshit PR-stunt
dude a big black box
we now live in 2016 and not 1716.
>>8019146
I can't wrap my head around how they're going to make an inconsistent observation do what they want.
>>8019146
Imagine simulated annealing except testing every possible combination at once. It's not bullshit, you just don't understand it.
>>8019159
Even if it's inconsistent, it will still give an answer that's nearly globally optimal, but not quite globally optimal.
>>8019159
I'd say: You simply can't.
You might as well just guess the "result" of your programm and claim that your "probabilistic method" of guessing is much faster than conventional computers.
At least that's what comes to my simplistic mind when I read all the hyped crap that has been written.
>>8019163
>not bullshit
Please, go ahead and find just one successful experiment of a working "qubit"!
>>8019146
>nobody seems to have even the most basic concept of how this could be turned into something that works
Well shit. I thought people were trying hard enough. I guess I put too much faith in human ingenuity AGAIN.
>>8019188
Looks like the latest iteration of a perpetuum mobile.
I am quite sure that there are some natural laws that prevent such computing power from coming for free.
>>8019146
>nobody seems to have even the most basic concept of how this could be turned into something that works.
There are several viable candidates for qubits being worked on as we speak, I'd say that counts as at least a basic concept.
The field is still relatively young, think about how long it took for classical computers to actually get going. It wasn't just a few years after Turing, these things take time.
>>8019159
>I can't wrap my head around how they're going to make an inconsistent observation do what they want.
>>8019174
>I'd say: You simply can't.
Quantum algorithms are specifically designed to have the desired result be the most likely, have a read about them.
Say there's an unordered list of objects with a "special" item that we want to know the location of. A classical computer could do no better than checking each item from the start, the average number of checks to find the desired item being about half the length of the list. That is to say, the time taken to find this object is proportional to the length of the list.
There's a quantum algorithm called Grover's Quantum Search which does some quantum jiggery pokery that I can't quickly explain in this post meaning that each "check" it does amplifies the probability of getting the right answer. The number of times it has to do this for the right answer to be highly likely is only proportional to the square root of the length of the list. Sure you'd need to run it a few times to make sure you had the right answer but for large lists this would still be quicker.
>>8019233
Things being used as qubits include:
>Superconducting circuits (0 and 1 are clockwise and counter clockwise currents)
>Superconducting charge islands (0 and 1 are absence and presence of charge)
>Semiconducting charge islands (similar to before)
>Ions or Atoms with two states well separated from any other states (0 and 1 are the lower and higher states)
>Photons (0 and 1 are polarisation directions)
I read a paper from 2007 where they demonstrated a working CNOT gate using the first kind of qubit I mentioned.
http://www.nature.com/nature/journal/v447/n7146/pdf/nature05896.pdf
Stability of these systems has only improved in the past 9 years.
>>8019146
If I recall correctly the NSA has urged contractors to stop using certain encryption that would be vulnerable to quantum computers? That suggests that someone out there has one, or is close to having one. I'd also wager that someone is more likely an intelligence agency than any of the companies currently marketing on "WE HAS A QUANTUM COMPUTER!!!!"
>>8019247
I read the Wikipedia article on Shor's algorithm (which, as far as I can tell, is rather rigorous), and it seems like the biggest obstacle to reducing noise in quantum computing is finding more suitable particles.
>>8019260
Yeah, finding systems with longer decoherence times is always good. Current decoherence times for superconducting systems are about 60 micro seconds, which is actually pretty good because you can fit quite a lot gate operations in that time. Still though, more would be ideal.
There was also an article I read somewhere about these things called Rydberg Atoms being a pretty good system as well.
>>8019263
Here's my thought:
What if, by the time you run the calculation multiple times and correct errors, quantum computing takes exactly the same amount of time as regular computing to acheive the same precision?
That's not an argument against research by any means, but that's my hunch as a layman.
>>8019265
Quoting your comment in full because you deleted it:
>Every physical thing has quantised properties.
>Just calling it "quantum" does make it an actual qubit.
>Same goes for just cooling things down.
>And a working CNOT? - Such thing has never been built.
All the things I mentioned are able to enter superposition between their two states and can be operated on to achieve quantum gate effects, if that's not a qubit then I don't know what is.
>And a working CNOT? - Such thing has never been built.
I literally posted a paper where they reported exactly that. It's not just some bullshit pdf I found on some pseudoscience website, it was accepted and published in Nature, basically one of the most respected scientific journals in the world.
>>8019269
>What if, by the time you run the calculation multiple times and correct errors, quantum computing takes exactly the same amount of time as regular computing to acheive the same precision?
>That's not an argument against research by any means, but that's my hunch as a layman.
Running it multiple times isn't an issue for cases where QC is faster. Simply, say I need to run my Grover search algorithm 10 times before I'm sure of the answer. For long lists, 10√n is still smaller than n so it will be faster.
Error correction I don't know as much about so I can't offer nice explanations but some of the methods I've read about seem like they'd only result in an extent of the computation such that it's still faster.
>>8019269
quantum computing is instantaneous and resolves problems before they are complete inputs. like the human mind it anticipates and indexes problems and solutions in real time, correlates them to the ongoing string, and assumes the most energetic option before the user may even consciously consider them. quantum computing is more than input/output, it is a conversation between two entities of sentience
>>8019183
you fucking dumbass. They exist, they're just big and clunky, and connecting them is hard.
Look up ion traps, or any of the other multitude of working qubit models.
https://www.youtube.com/watch?v=1PcseLsYZ9Y
>>8019300
I don't think you don't know what you're talking about.
Quantum computing is by no means instantaneous, look up any quantum algorithm, they all have steps involved and they often have to be iterated over and over to make the right answer likely to be found.
>it is a conversation between two entities of sentience
Aren't you that guy from Spirit Science?
>>8019304
No, that's not me. On paper, you are correct, algorithms and matrices and what have you take a lot of time and effort. What you forget and what our quantum science fails to properly explain to the everyman is the nature of quantum particles. They are not bound by any concept of time. This is profusely difficult to explain. Ask me a question and I'll do my best to answer.
>>8019327
(cont.) I've said too much. My superiors are hijacking this device, i'll be back later
>>8019339
When you get back, please prove the correspondence of anti-de Sitter and conformal field theory.
Everyone here just needs to step back for a fucking moment and not be so fucking judgemental.
You don't need to know the science behind it. It just works!
>>8019257
It's a risk assessment thing.
>medium-high chance of quantum computer being usable in the coming years
>having encryption broken is a huge no-no
May as well ask people to switch now before it's an issue, because if it's an issue then it's really bad
>>8019146
John Martinis's group seems to be doing a less hyped effort to build a quantum computer. I think they're focusing on high quality qubits with decoherence being the operant buzzword. I know nothing of quantum computing so take this for what is worth.
>http://web.physics.ucsb.edu/~martinisgroup/
(page of the group)
>>8019146
It wont work because Einstein was right. There are hidden variables.
>>8019146
Everithing about this is very esoteric.
I'm smarter than NASA and Google, and I say this doesn't work.
Those idiots are just wasting money, as usual.
![Jacket[1].gif](https://i.imgur.com/qBK4lgq.gif "Jacket[1].gif")
>>8019865
>>8019146
This seems worth a read:
>http://www.scottaaronson.com/democritus/lec14.html
[...]So, on to the Eleven Objections:
Works on paper, not in practice.
Violates Extended Church-Turing Thesis.
Not enough "real physics."
Small amplitudes are unphysical.
Exponentially large states are unphysical.
Quantum computers are just souped-up analog computers.
Quantum computers aren't like anything we've ever seen before.
Quantum mechanics is just an approximation to some deeper theory.
Decoherence will always be worse than the fault-tolerance threshold.
We don't need fault-tolerance for classical computers.
Errors aren't independent.
What I did is to write out every skeptical argument against the possibility of quantum computing that I could think of. We'll just go through them, and make commentary along the way. Let me just start by saying that my point of view has always been rather simple: it's entirely conceivable that quantum computing is impossible for some fundamental reason. If so, then that's by far the most exciting thing that could happen for us. That would be much more interesting than if quantum computing were possible, because it changes our understanding of physics. To have a quantum computer capable of factoring 10000-digit integers is the relatively boring outcome -- the outcome that we'd expect based on the theories we already have.[...]
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>>8019870
Yeah, it is not like whole fields research tunred out to be pipe dreams, ever before.
If something sounds too good to be true it is usually the wises course to stay sceptical.
>>8019407
Explain the violation of Bell's inequalities then
>>8019915
Dunno
https://youtu.be/nmC0ygr08tE
In this thread: people who have no idea what they're talk about trying to sound cool.
Wait.
On this board: People who...
