It doesn't matter how smart you are, you still need to run experiments to do physics. Experiments take nontrivial amounts of time to both run and set up (you can't tunnel a new CERN in picoseconds, again no matter how smart you are). Similarly, the speed of light (= the speed limit of information) and thermodynamics place fundamental limits on computation; I don't think there's any reason at all to believe that intelligence is unbounded.
The only thing you could do in a "digital space" (a.k.a. on a computer) is a simulation. Simulations are extremely useful and help significantly with designing and choosing experiments, but they cannot _replace_ real experiments.
> Like, the time window from the discovery of fire to the discoveries of Quantum Mechanics but in a flash.
And my point is that there's no good reason to think this is possible and many to think it isn't.
> it's more of a fun sci-fi idea
It's being presented as extremely serious possibility by people who stand to gain a _lot_ of money if other people think it's serious... that's the point of the linked post. Unfortunately, these AI boosters make it very difficult to discuss these ideas, even in a fun sci-fi way, without aggravating the social harms those people are causing.
Doesn’t specify the 2020’s.
Either way, I do feel we are fast approaching something of significance as a species.