Is the age of quantum computing upon us? What are the implications?

how is it different from normal computers ?

>>7843280
>Is the age of quantum computing upon us?

No

>What are the implications?

For the average person, probably not that much. Once they actually work (and can do prime factorisation) then RSA will become obsolete.

>>7843282
It supposedly uses quantum mechanics to be much more powerful. They said it solves certain problems 100 million times faster than a regular supercomputer.

>>7843289
>Once they actually work (and can do prime factorisation) then RSA will become obsolete.

That doesn't really matter. Even though we don't have qc's people are already working at post quantum encryptions. The average person still won't notice a thing.

>>7843291
> They said it solves certain problems 100 million times faster than a regular supercomputer.
So it's only got a faster calculator ? And thats supposed to revolutionize some shit ? And what certain problems are they ?

>>7843298
>a computer? so just a fast abacus? how's that supposed to revolutionize shit?

>>7843298
It excels at optimization-type problems.

It also runs Crysis 3 at full specs.

>>7843298
It's not about speed but about possibility and the amount of data it can handle.

Your GPS is for example still not really optimal. But a QC could calcualte ALL the possible routes real-time and can help you avoid traffic jams for example.

Weather predicitng is still pretty terrible. QC can handle all the data at once and accurately predict weather. This is not only to help you from getting wet. It can also save lives by accuretly and in time predicting bad weather to warn people against those threats such as tornadoes and cyclones.

It can categorize billions of planet's and stars taken by the telescopes.

It can learn from its mistakes, and better correct it's code. Ie. It's good at machine learning. So expect some good AI to help you find the best porn you are looking for.

Etc.

Plus it's only a matter of time before it becomes self-aware and declares war on humanity.

>>7843312
>It can categorize ...
>It can learn...
>It's good at...

Last time I checked, "it" is still vaporware.

>>7843306
Faster abacus only supplied a faster abacus. A series of better computers over a few centuries revolutionized computers.

>>7843307
Wat does it do exactly ? Aside fomr running crysis 3 at max. which is admirable

>>7843312
Is it like multithreading calculations ? We can already do that. Even my shitty laptop can run 8 threads at once.

>>7843323
Google & Lockheed Martin both bought it. They think it works.

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>>7843280

No not by many years. Since it's not here then there are no implications, any suggestions are mere science fiction.

D-Wave is a nice attempt. Cute. But still a long way to go before true quantum computing is achieved.

>>7843312
Would 10^8 faster make such a great difference for NP problems? The precision ofc increases, but if we double the number of points, that we are able to brute force right now, even with QC the time of computation is insane.

Same with primes. We can just compute way larger RSA keys and be safe again despite sensationalists. All that would do is increase prices in IT security industry.

>>7843323
This is of course what it can do... If we get it working properly bro. And I of course mean real QC none of that D wave shit

>>7843336
Honestly I don't completely understand how they work but it's not linear like a normal PC. I there are for example 100^100 combinations of one thing a normal PC would check them one by one really fast, but a QC can check them all at once and instantly give you the answer. It has something to do with superposition if qubits and silly QM. I'll let a real physicists pitch in

>>7843341
Qubits. They can be 1, 0, or both simultaneously.

>>7843330
They have a fucking enormous experimental budget and they live on keeping all bases covered. The D-wave is a quantum annealing computer though so it's very much harder to work with than a classic programmable computer with a qbit register would be.

>>7843348
I got that far myself, but how does that enable it to make millions of calculations all at once, instead of a normal procedural way in a PC?

>>7843348
That makes no sense. Please explain further.

>>7843359
https://en.wikipedia.org/wiki/Quantum_algorithm

>>7843291
Compared to regular computer simulating quantum calculations

>>7843341
>>7843362
Not him but here's the explanation a rather technical QC seminar gave to us listeners:

A QC can make a probabilistic computation, giving a higher signal for a certain value(through what manners of mechanism I have not the slightest fucking clue).

By repeating it a few times you can be more certain that the answer is the output with the highest signal strength, which can then be verified by a normal computation.

Here's some details on one of the classic QC algorithms: https://en.wikipedia.org/wiki/Shor%27s_algorithm

>>7843373
Man I don't know dick about maths. It's the mehcanism I'm wondering. Standard computers work by 0&1 and there is no higher signal or anything of the kind. Plus how the hell does it give the correct answer with the highest signal for the computer to figure out ? If it can assign signals to specific values, then it must have already done the calculation, which takes equal amount of time as the standard computers.

It doesn't explain how it is able to make calculations faster.

It works through woo.

>>7843397
Pretty sure this is the only correct answer

>>7843397
Lad

>>7843384
>It doesn't explain how it is able to make calculations faster.
Depends what you mean by "calculation".

Do you mean individual CPU instructions, or do you mean higher-level algorithms?

A quantum computer is actually quite a bit slower than a traditional one when it comes to individual CPU instructions. But it can solve some problems much faster than traditional CPU's because there are very efficient quantum algorithms for them. Basically, each instruction takes 10x as long on the QPU, but the quantum algorithm takes 1/100 as many instructions as the standard algorithm.

>>7843427
>>7843384
Its like P vs NP. Quantum computer can give a "likely" right answer for NP problems. They repeat the quantum calculation, and get the higher signal thing right? Well with NP problems, finding the right answer is slow, but checking the right answer is fast. So qbit finds the maybe right answer and reg PC checks the answer quickly.
Qbits are entangled, so they can hold a lot more conventional information, I can't remember exactly how it works, but a few qbits, like a thousand of something, could hold more conventional data than all of the atoms of the universe representing a single 1 or 0.

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https://youtu.be/JhHMJCUmq28

>>7843282
From what I can gather, it uses qubits instead of bits.

Meaning that instead of 1s and 0s, it uses things that are sometimes 1 and sometimes 0. Basically bits in a quantum state.

Meaning that many calculations can be done at once. Also meaning that decrypting keys and cracking passwords takes literally minutes.

>>7843312
NO IT CANT

>>7843514
Meaning that many calculations can be done at once. Also meaning that decrypting keys and cracking passwords takes literally minutes.

There are no working quantum computers that decrypt keys and crack passwords. Stop your bullshitting.

Quantum computers would open a whole new set of "Quantum algorithms", algorithms which are asymptotically much faster than classical algorithms but can only run on quantum computers. Many of these algorithms are usually NP-Hard or NP-Complete on classical machines, but can be restructured to run in polynomial time on a quantum computer.
https://en.wikipedia.org/wiki/Quantum_algorithm

Quantum computer architecture is completely different from classical computer architecture. Because of this, the models we use for generalizing theorems about computing have to be completely rebuilt from scratch in the case of Quantum computers. If they ever become mainstream, you can expect every field of computer science to explode as new quantum computer scientists start submitting research. I'm very excited for this, but we aren't there yet. The DWave is probably not a real Quantum computer, and there aren't any other candidates out there that have been built which can compete in computing power with current classical machines. It may very well be an impossible mission.

>>7843514
solve this equation with quantum computing please.
What is [(1 or 0) + (1 or 0) * (1 or 0)] / (1 or 0). If it was a standard computer that used either 1s or 0s, it would take a fraction of a second. I'd like to see how the quantum computer solves it "faster"

>>7843487
> Its like P vs NP. Quantum computer can give a "likely" right answer for NP problems.

You're talking about probabilistic algorithms. You don't need a QC for those.

> They repeat the quantum calculation, and get the higher signal thing right?

WTF are you talking about?

> Qbits are entangled, so they can hold a lot more conventional information

I don't think you know what entanglement means.

> like a thousand of something, could hold more conventional data than all of the atoms of the universe representing a single 1 or 0

Keep on bullshitting yourself.

>>7843581
>solve this equation with quantum computing please.
>solve this equation
>equation

Go back to school.

>>7843588
solve the problem X = [(1 or 0)*(3 or 71)X] / (5 or 2)
what is X ?

>>7843575
>Many of these algorithms are usually NP-Hard or NP-Complete on classical machines

Algorithms cannot be NP-Hard or NP-Complete. Please google harder.

Holy shit you're all high schoolers and undergrads.

None of you even know what the ising model is, I bet, despite talking about this thing.

>>7843595
Explain what you mean by (a or b).

>>7843607
Explain what you mean by mean

>>7843607
The qubits are in a state of superposition so the value can either be b or a. You need to figure out which one it is, then do the calculation much faster than a normal computer.

>>7843620
I don't think you understand what "superposition" means.

>>7843626
I think you're desperately trying to come up with an explaination for your bullshit and you're avoiding questions.
Explain with examples of how qubits are supposed to work, otherwise stop shitposting about things that you have no idea about.

>>7843632
Alright dumbass: A qubit is just a quantum mechanical system whose state space is a 2-dimensional Hilbert space and where the basis kets (aka vectors) are normally denoted by |0> or |1>.

The state of an arbitrary qubit can thus be written as a|0> + b|1>, where a and b are so-called probably amplitudes (complex numbers whose squares represent probabilities).

Saying that a qubit is in "superposition" just means that neither a nor b are 0. When you measure this qubit, you will measure the |0> state with probability a^2 and |1> with probability b^2.

Of course, this is the Schrödinger picture that I'm describing. You can also represent qubits ala Heisenberg using so-called observables (i.e. Hermitian operators).

Shall I continue?

>>7843280
yes. but not because of your picture. real quantum computers will actually be here in 5-10 years.

read scott aaronson's blog.

>>7843675
No, because you're not talking in terms of hardware, you're talking in terms of autism. Describe the hardware and how it differs from the standard computers. Describe the way the electrons travel on circuits if it came to that.

For all the people in this thread that have no idea how quantum computing works:
1.) It will give you the right answer, not some distribution of possible answers. If I ask Shor's algorithm to factor a number, I will get the prime factors of the number I fed into Shor's algorithm, not the right answer and occasionally the wrong answer according to some probability distribution.
2.) Quantum computing uses superposition as a sort of massive parallelism. This is why the first step of the majority of quantum computing algorithms are Hadamard gates: it throws everything into a superposition state allowing all possible combinations to be tested simultaneously.
3.) The only reason you wouldn't get the same answer all the time to a non-random algorithm is because of computational error, which is what a lot of people spend a lot of time trying to fix with quantum error correction. Computational error is also not unique to quantum computing, it is just harder to implement corrections successfully than it is in classical computers.

Forgive my ignorance on the subject, but it seems to me that perhaps a real quantum computer is like a practical fusion reactor. It is fun to talk about, but doesn't really exist at this time.

>>7843685
There are several possible quantum bits. The last time I was heavily involved in quantum computing specific research, Josephson junction based superconducting qubits were the big thing. Now, it looks like we are getting into more exotic forms, like braiding Mjorana fermions on semiconductor nanowires embedded in a superconductor (see the Kitaev chain fora toy model). This one is more popular since the quantum information is encoded in the topology of the braids, which makes it less sensitive to environmental noise and closer to the threshold where systematic errors are at the level where current quantum error correction protocols can be successfully employed.

>>7843693
They have built quantum computers. The biggest one to date was built by Intel and was able to factor 15 using Shor's algorithm.

>>7843685
What's the point of discussing "hardware" when you don't even understand the basics. There are many ways to build QC "hardware" and all require advanced knowledge in experimental physics that is way beyond the comprehension of anyone in this board including myself.

>>7843696
>semiconductor nanowires
That should probably be ferromagnetic nanowires, thinking on it a little.

>>7843696
TQFT!

>>7843704
Yes.

>>7843696
Explain to me how the qubit is different from a bit when storing memory. As far as I understand QC entirely relies on the superpositioning of 1s and 0s wheres a PC is set for either 1 or 0. But You can't control the qubit value, you can only measure it and find out what it is. Which doesn't help anyone.

>>7843696
The last time I was heavily involved in quantum computing specific research

Experimental or theory?

>>7843700
I was aware are that, but I view that as a toy at this point.

>>7843693
>>7843700
they have built fusion reactors aswell

>>7843730
Even the explaining video says that QCs won't replace your PC because basically they're bullshit.

>>7843714
If I have a two level system, I can map it onto what is called the Bloch sphere, and where my state vector points on the surface of this sphere is analogous to the voltage state of a classical bit. By applying the right signals, I can move the systems state vector around on the Bloch sphere. So, in the case of the old Josephson junction qubits, I could apply a small AC signal and manipulate the energy state of the junction. Depending upon how long I applied the signal and at what frequency, I could make specific changes to the state vector.

In the more modern topological scheme, braiding acts to switch the ground state of the system between a handful of degenerate states. Since everything is happening in the ground state, it is more stable than the JJ scheme above since I don't have to worry about excitations tunnelling out of the potential and it is less sensitive to noise because topological rather than geometric features determine the ground state degeneracy and how it evolves upon braiding.

>>7843735
Yes, we have. But are they efficient and usable in a practical sense today?

>>7843726
Theory.

>>7843730
It is still a "real" quantum computer. It is not terribly useful, but it is actually doing a quantum computation. More useful quantum computers are probably not too far off given the current state of the field (and might already exist; who the hell knows what the NSA is up to in its labs)

>>7843784
Great. Wake me up when it can do something interesting.