1 upvotes, 3 direct replies (showing 3)
View submission: Ask Anything Wednesday - Engineering, Mathematics, Computer Science
[removed]
Comment by Indemnity4 at 27/06/2024 at 09:00 UTC
2 upvotes, 0 direct replies
Big in the world of chemistry and simulations (basically the NP problem suggested by Tonexus).
It takes a buttload of time to actually make new chemicals and most of the time it doesn't work for reasons we don't know. Imagine someone dumping a truck of random ingredients into your house and you have to make a new cake. Eventually we learn basic rules of this works with that, but there are still new recipes that exist and we don't know what we don't know.
So we turn to computer simulations. It's okay to simulate maybe 10-20 atoms. We can get a good guess that this starting material will react with that thing and we get that other product.
Each time we add an extra atom the computation run time goes up exponentially. We still cannot simulate the really interesting molecules without extraordinary amounts of computing time. It takes extraordinary amounts of computational time to simulate nanoseconds of a reaction when really we want minutes or hours. Instead of just 2 molecules interacting with each other, we want a crazy amount like maybe 4.
Quantum computing lets us simulate each additional atom at a cost of polynomials, not exponential. That is phenomenally attractive to new drug design, new materials, new catalysts, atmospheric chemistry.
Comment by Tonexus at 26/06/2024 at 20:39 UTC
1 upvotes, 0 direct replies
Assuming we reach a point when errorless quantum computers are roughly comparable in speed to classical computers, Grover's algorithm will give a quadratic speedup over the best known algorithm for NP problems (brute force/exhaustive search). For instance, if it takes 100 hours to solve a particular instance of an NP problem by classical brute force, it might take roughly 10 hours on a quantum computer using Grover's algorithm.
There are some other information-theoretic applications, but they're related to cryptography and are a bit difficult to explain succinctly.
Comment by chilidoggo at 26/06/2024 at 22:21 UTC
1 upvotes, 0 direct replies
If you went back in time to the original computer developers and asked them, they would have been very excited about doing complex mathematical calculations, or the applications in code breaking (Turing's Enigma machine was exactly that). That's where we're at with quantum computing. If you asked them about video games, they maybe could have conceptualized it, but it would be the furthest thing from their minds.