Are we not speaking of theoretical science here?
Not really. A nice amateur telescope set-up, these days, is enough to show that the universe is expanding. The various surveys that are measuring the microwave universe really do measure something from way out there - repeatably. The theoretical-sounding calculations of how much hydrogen, helium, lithium, and beryllium came from The Bang are supported very well indeed by observation in the lab and in space both. The "material kind of science" that clocks speeding cars and lets us generate electricity from uranium fissioning....