On a similar note, there's a lot of work put into optimal matrix multiplication algorithm. We know the lower bound is N*2, the obvious upper bound is N*3, the best (complexity wise, not practical at all) current algorithm is N*2.37, but we don't know how fast can it really get. Is it possible to write N*2 algorithm? We don't know.
It comes from directly applying the definition of matrix multiplication on a square matrix.
Being worse on purpose is always possible, but it doesn't change that bound.
It's the "obvious" upper bound, not the "how did you even get here without noticing the obvious method" upper bound.
> Available computational power may catch up to the crossover point, so that a previously impractical algorithm becomes practical.
Are there examples of Galactic Algorithms that now aren't Galactic Algorithms?
edit: turns out some matmul algorithms are?