Yeah, that's what science says. I don't think they know any more than anyone else. They look in telescopes, take measurements, etc. of the now, then presume what happened billions of years ago. A cosmic Ms. Cleo.
That's where we disagree. The same scientific principles have been applied to the understanding of the universe as to the understanding of semiconductor technology -- by people just as smart. The computer you're using is a testament (and I don't use that word lightly) to how powerful these principles are. You might consider that perhaps our current scientific understanding of the universe is also of high quality.