By "physical sciences" it sounds like you mean something like chemistry or physics. And I agree, Aspies would do well there. They are all about rules and structure, and there is one answer. F = (G * m1 * m2) / r^2 forever and ever and always. You can write legislation to make pi = 22/7 or 3, but you can't change the fundamental workings of the Universe.
You'd be surprised. At an undergrad level, sure, but when you hit grad school you learn that what you were taught in undergrad is not necessarily true.
Take F = (G*m1*m2)/r^2, the Newtonian gravitational law. I spent a full year in a master's level relativity course learning that this law is actually *not* generally true; it's only true in certain, special circumstances. However, you need to learn tensor calculus before you can even approach Einstein's General Theory.
One of the courses I took as an undergrad was completely invalid within a few years of graduating. Basically, I took a course on solar system astronomy. The next year, solar systems outside of our own were discovered, and we found out that most of the theories of solar system formation we had were totally wrong. If I taught that course now, the material would be completely different.
A student who insisted that what they learned in undergrad *had* to be true, even when presented with evidence to the contrary, wouldn't make it past the course work, let alone the qualifier, and would be completely incompetent at original research. They'd probably be fine applying current, well accepted theories to practical applications, but that's not what's involved in the PhD.