Well, first, it would be so far beyond anything we can comprehend as intelligence that even asking that question is considered silly. An ant isn't asking us how we measure the acidity of the atmosphere. It would simply do it via some mechanism we can't implement or understand ourselves.

But, again with the caveats above: if we assume an AI that is infinitely more intelligent than us and capable of recursive self-improvement to where it's compute was made more powerful by factorial orders of magnitude, it could simply brute force (with a bit of derivation) everything it would need from the data currently available.

It could iteratively create trillions (or more) of simulations until it finds a model that matches all known observations.

> Well, first, it would be so far beyond anything we can comprehend as intelligence that even asking that question is considered silly.

This does not answer the question. The question is "how does it become this intelligent without being able to interact with the physical world in many varied and complex ways?". The answer cannot be "first, it is superintelligent". How does it reach superintelligence? How does recursive self-improvement yield superintelligence without the ability to richly interact with reality?

> it could simply brute force (with a bit of derivation) everything it would need from the data currently available. It could iteratively create trillions (or more) of simulations until it finds a model that matches all known observations.

This assumes that the digital encoding of all recorded observations is enough information for a system to create a perfect simulation of reality. I am quite certain that claim is not made on solid ground, it is highly speculative. I think it is extremely unlikely, given the very small number of things we've recorded relative to the space of possibilities, and the very many things we don't know because we don't have enough data.