Why is it hard for a program to generate random numbers?

Question

My kids asked me this question and I couldn\'t really give a concise, understandable explanation.

So I\'m hoping someone on SO can.

Answer 1

Primarily because computers don't have any functions that behave in discrete, non-random ways. A computer is predictable, which allows us to program reliable software. If it wasn't predictable it would be easier to generate a random number (since our software could rely on this unpredictable method).

While it's possible to generate pseudo-random numbers, and numbers that are distributed randomly, you cannot generate truly random numbers without separate hardware. There is hardware that generates truly random numbers based on "quantum" interactions (at least according to the manufacturers). Online poker sites sometimes use these adapters for their generators.

Apparently there are even online services to provide random numbers - random.org for example.