FORTRAN and C are equally as fast. But everyone knows programs spend most of their time in a small amount of code. You write in an easy to write language like Python, then a faster language like LUAJIT for the critical parts found from running the code. For example here is a quicksort in Python:For numerical calculations (as in a lot of scientific/physics programs), FORTRAN is reputed to be the fastest.
if len(arr) <= 1:
return qsort([x for x in arr[1:] if x < arr]) + \
[arr] + \
qsort([x for x in arr[1:] if x >= arr])
Dead simple. But you may need it faster. I have written a quick-sort in assembler so I would hack that rather than use Lua or C - but that's just because I am lucky in having the code. It's not hard in Lua though - and if that isn't fast enough use assembler - but as I said I was lucky enough to have one in assembler anyway so would go for that.
In general you could go to C for the ultra critical bits, but I tend to go for assembler - JuaJIT is mostly as fast as C. And yes you still need a minimum knowledge of C - its excellent for gluing languages together, plus I don't write assembler direct but rather as assembler statements in C.
I learned FORTRAN 35 years ago and avoided it as much as possible since then - never did like it.