<p>Which of the sciences have Simulations to make of systems. How do simulations help scientists?
And can a physics major get a PhD in Molecular simulation of Fluids? If yes how does it fit into physics' study of nature?</p>

<p>Statistics, computer science (and anything else where you can involve probability and programming, so, basically all of science)... it's all about computing things that would be either too complex or intractable mathematically, or too costly or impossible to run in real life or in real time.</p>