Does anyone understand how it actually works? I'm reading about it online and I don't get how a Qubit is supposed to be better than a Bit, just because its smaller?
>>101547480>represent same numbers with less electrical travelthis multiplies your speed you fucking retard
>>101547480yes and it is a meme. why do you think they are experimenting with brain tissue now?
>>101547480>Does anyone understand how it actually works? No, because it doesn't. It's a scam to steal more of taxpayers' money and funnel it to trust fund kids.
>>101548183>source: my left testicle
>>101548132Who are they?
>>101547480I read a few chapters of a quantum computing textbook once.Your whole quantum computer can be in a superposition of multiple states. That means it can hold and process way way more information than a classical computer. With big caveats.If a classical computer has eight bits then it can be in 256 possible states. Maybe it's in the state 01101001 for example.A quantum computer can be in a superposition of multiple states. Like, it can be 25% 01101001 and 75% 10010110. Or some sophisticated combination of 256 different states. At that point you could say that it's already working with a hundred times more memory than the classical computer.If you add more qubits then that builds exponentially. With 64 qubits you already have 18446744073709551616 possible states to create a superposition out of.Now all of this isn't nearly as useful as I'm making it sound. You need some careful tricky business to create useful superpositions, you can't just write normal programs as though you have a bajillion bytes to work with.You also can't actually get your bajillion bytes worth of state out of the computer. When you output the final answer for that simple quantum state above you get 01101001 with a 25% probability and 10010110 with a 75% probability. You don't get to see the whole complex internal state, you only get to see eight bits of it and what you get exactly is a matter of random chance.A useful quantum program has to do some weird dance to build up a ton of states that do a ton of work at once and then make the uninteresting states cancel each other out so that the end result will be something interesting. And you may have to run the program multiple times to deal with the randomness.This can be very useful for some very specific problems but it isn't useful for most computing.Also there are big engineering challenges. Also I dumbed it down and made mistakes, there's something about complex numbers that I no longer understand.It's useful but overhyped.
my limited understanding of it is more possible states beyond binary = more information
>>101548242the illuminoughty
>>101548322an actually helpful answer.>>101547672unlike this faggot.
Think about taking your girlfriend out for lunch. You have no idea where to take her, and you can't really guess either. You can't ask her what she wants to eat, because she will shoot that back at you, asking what do YOU think she wants to eat. Now, we don't have too many choices here.>tell her she will never guess where you're taking her today>observe her guesses and how excited she is with each guess>pick the guess which she is most excitedYour gf is effectively functioning as a qubit at that moment. Her excitation level is analogous to the probability a qubit will collapse to a certain binary value.
>>101547480it's not better or worse, they are different. Quantum computers will not be an improvment in all areas and replace classical computers. It's just better in some problems like physical simulation, and some machine learning optimization algorithms etc.
I had a job on quantum computing for a few months. It's not that difficult to understand, desu. You just need linear algebra and tensor products for the math. The physics is way more elaborate, but depending on what you do you don't need to know about the physical implementation of your qubits, just like programmers never think of how RAM works. The problem is that deep (aka long) and wide (aka requiring many qubits) quantum circuits are very hard to physically implement coherently. All the applications of QC where there is exponential speedup over classical computing require quantum Fourier transforms, and those require deep circuits. You lose coherence along the way. There's no way we're actually getting exponential speedups in reality IMO. But polynomial ones, yes. QC is overhyped because of what it can theoretically achieve, but in practice it's hard to physically implement coherent qubits that last long enough, as well as quantum gates that work according to specification and are unitary and so on.I can explain if you have specific questions.Don't mind the ignorant idiots ITT.
sabine told me they are a meme
>>101547480It has a lot of numbers.
>>101548322>superpositionHow does it accomplish this? A bit is easy to understand: you can represent it as on or off, or high or low electrical signal. How is a qubit representing a superposition, physically speaking? How are quantum logic gates operating on qubits to change their superposition?
>>101549895You should probably ask the other guy who says he actually worked with this stuff. I didn't even do the exercises.My hopefully-close-enough understanding is that superposition happens everywhere all the time, just not in a controllable way. There are certain physical processes that have a random outcome. Until that outcome is observed/collapsed/integrated by interaction with the outside world it exists in a superposition. (Schrödinger's cat bla bla bla.) But since everything interacts with everything else all the time such superpositions normally last an incredibly short amount of time.So people do things with liquid helium supercooling and so on to isolate the circuits as much as possible and stop the superposition from collapsing ("decohering") for long enough to perform a computation.You then need some true-random process to get the ball rolling I guess?Also I remember now that this part is so simplified that it's wrong:>it can be 25% 01101001 and 75% 10010110The actual probabilities are complex numbers. You do take their absolute values to get real probabilities when you collapse the system, but until then they're doing something more complicated, with a probability theory extended universe to make sure that all these complex probabilities still add up to 1. You need to understand the math in order to explain quantum logic gates but I no longer understand it.
