I don't understand that quote. Any scientist would tell you that perpetual motion machines of the first or second kind are impossible, and they're probably right. In general I don't know many examples of impossibility results in math or physics that were later overturned. Anyone?
It's just a maxim, it doesn't apply in every case. I think the motivating example is Einstein's fervent denial of entanglement in quantum physics. In other words, he's saying the tendency of scientists as they get older is to be more resistant to new ideas.
Whether that's true or not in general, is debatable. But it wasn't intended as an ironclad law in the first place, just a tendency
> Where to start: We are forever barred from knowing the composition of stars - stated around 1850, I believe. The sun couldn't possibly have sustained combustion for more than 10 million years, hence no time for evolution og geology. Parent poster is referencing Arthur C. Clarke, not Niven, btw.
ifix: You're probably right about Arthur C. Clarke. I think it was an SF author, but I couldn't remember who.
