1. You can't look for information if you don't know it exists.
2. Most standardized tests aren't used in the expectation that the testee's knowledge will matter in the future. Instead, the idea is that people who score higher will be generally more competent at whatever it is you want them to do.
You absolutely can. I don't know if there are stats on the number of people who have circumnavigated the globe in an amphibious vehicle, but I can Google it.
I don't know whether the thickness of an electrical cable influences the electromagnetic field it creates, but I can Google it.
You can even Google generic stuff like "do charged particles in the atmosphere exert any force on objects at ground level" and get a survey of the forces.
That only holds true if you assume people are making very specific queries in an unfamiliar domain. It's entirely possible to start with very general queries in an unfamiliar domain and hone in on a specific piece.
It's common in software engineering. I don't understand how databases optimize queries, but I can start with a broad query like "what factors does Postgres use to optimize queries" and slowly hone in on whatever is making my query weird/bad.
I fail to see how information retention maps to skill in this case. I guess it could be a vague indicator of the amount of practice done, but some folks memorize so easily, it makes this system incredibly easy to game.
It doesn't really matter if you understand why it works; the facts are what they are.