"But what I certainly wouldn't do is attempt to write a physics simulation in python"
Depends on whether performance is a hard requirement or not - I've written engineering simulations of parts of power stations (including one nuclear plant) in Lisp and they weren't particularly fast but nobody bothered because they weren't used interactively.
Eventually I did write Lisp to generate C++ code for the same models when we did want better performance and it worked really well - but I only did that as an optional step when someone needed the extra performance.
Depends on whether performance is a hard requirement or not - I've written engineering simulations of parts of power stations (including one nuclear plant) in Lisp and they weren't particularly fast but nobody bothered because they weren't used interactively.
Eventually I did write Lisp to generate C++ code for the same models when we did want better performance and it worked really well - but I only did that as an optional step when someone needed the extra performance.