Why is it hard for a program to generate random nu

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

Because computers are deterministic machines.

Answer 2

Computers can only execute algorithmic computations, and a truly random number isn't an algorithmic thing. You can get algorithms that produce numbers that behave like random numbers; such algorithms are called 'Pseudo-Random number generators'.

At various times in the past, people have made random number generators from analog-digital converters connected to sources of electronic noise, but this tends to be fairly specialised kit.

Answer 3

Computers just don't have suitable hardware. Ordinary computer's hardware is meant to be deterministic. With suitable hardware like mentioned here random numbers are not a problem at all.

Answer 4

As surprising as it may seem, it is difficult to get a computer to do something by chance. A computer follows its instructions blindly and is therefore completely predictable. (A computer that doesn't follow its instructions in this manner is broken.) There are two main approaches to generating random numbers using a computer: Pseudo-Random Number Generators (PRNGs) and True Random Number Generators (TRNGs).

Answer 5

Generating random numbers on a computer is like playing "Eenie meenie miney moe" when choosing who's It first in a game of tag. On the surface it does look random, but when you get into the details, it's completely deterministic. It's hard to make eenie meenie miney moe into a scheme that a person really can't predict the outcome of.

Also there's some difficulties with getting the distribution nice and even.

Answer 6

Its not hard, here's a couple for free: 12, 1400, 397.6