I came across this recently and thought it was pretty funny. The original was in C.
Q: Does this function halt or not halt?
P function B
D function PI 10u 0
D input 10u 0
If input = 0;
return function(input - 1);
A1: Mathematician - It only halts for non-negative inputs. Negative inputs will loop infinitely as x approaches minus infinity.
A2: Computer scientist - It always halts due to the eventual stack overflow on a real machine.
A3: Computer scientist - It always halts due to the eventual integer wrap around on a real machine.
A4: Physicist - It always halts because running it infinitely would require more energy than exists in the universe.