Hacker News Reader

Comment by pera | Hacker News Reader

I feel a bit embarrassed for asking, but can someone explain in layman's terms why the Gaussian boson sampling experiment proves quantum supremacy?

I believe my main confusion is why is this experiment being called a computation: to me this seems to be simply the observation of some physical phenomena which happens to be very hard to calculate with a classical computer.

View on HN

I think here computation does not mean general programmability, rather just a single narrow problem. A classical computer running a predefined program would be hard to calculate on pen and paper, so there is silicon supremacy. Here finding the probability distribution of the outputs is hard classically, hence quantum supremacy.

https://en.wikipedia.org/wiki/Analog_computer

> An analog computer or analogue computer is a type of computer that uses the continuously changeable aspects of physical phenomena such as electrical, mechanical, or hydraulic quantities to model the problem being solved. In contrast, digital computers represent varying quantities symbolically and by discrete values of both time and amplitude.

Isn't a quantum computer digital? ("Quantum" and "continuously changeable" sound opposite to each other.)

Yes but I don't understand how this can be seen as modelling anything but the experiment one is performing: the way I interpret this proof of quantum supremacy is (and again I know this is incorrect but don't know why) almost like selecting any physical phenomena to which a simulation of it is computationally hard, and then say that the result of this experiment is the returned value of a "computation". I feel it's almost like claiming you are going to simulate fluid dynamics with an actual water tank, some dye, and a camera.

Reply on news.ycombinator.com