Some students are supposed to prove all odd numbers are prime. The first student says "3 is prime, 5 is prime, and 7 is prime. So by induction, all odd numbers are prime."
The physics student doesn't like this so he says "3 is prime, 5 is prime, 7 is prime, 9 is experimental error. So all odd numbers are prime."
The computer scientist doesn't like how long that method takes so he writes a program to test numbers for them. He runs the program and reads the output "1 is prime, 1 is prime, 1 is prime."