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 input;
   Else;
     return function(input - 1);
   EndIf;

P             E


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.

Silly