Application of true randomness

1. Sep 19, 2007

Xori

My understanding is that today's computers aren't able to simulate true randomness, only complex functions that appear random but can be predicted if someone knows how they work.

Is there any way to incorporate the "true" randomness of QM into technology to achieve true unpredictable randomness?

2. Sep 19, 2007

cesiumfrog

It would be better if you first googled "quantum random number generator" (and at least read, for example, the wikipedia hit), and then afterward asked any further questions you might have here.

Last edited: Sep 19, 2007
3. Sep 19, 2007

Xori

I guess that phrase is what I was looking for. Googling "random" was kind of fuitile :( Thanks

4. Sep 19, 2007

ganstaman

I must say that the skill I gained most at college was learning what to type in the google search box. That has helped me more than anything I learned (especially since a lot of what I learned was from what I searched on google...).

Then there's also blackle.com and cantfindongoogle.com. Endless hours of searching enjoyment.

As for the topic, I'd like to explain a bit about computer randomness. The basic idea is that the computer takes some seed (some sequence of 1s and 0s) and performs some operation on it. The output is the pseudo-random sequence of 1s and 0s (easily converted to a pseudo-random number or numbers or words, etc). It's not techniquely random because the operation is a deterministic process -- give it the same seed again, and it will output the same pseudo-random sequence again. Even if the source for the seed is or seems random, the operation treats it the same as a non-random seed.

However, it is practically random. That is, given the sequence up to a certain point, there's no way to predict the next number in the sequence without knowledge of the seed and operation. If the output is long enough, it's around 50/50 1s and 0s. Each number seems independent of all the others.

There are also variations on this theme, but they're not really important for discussing how random a deterministic algorithm could be. I admit that I don't yet know how a quantum random generator would work (I have to use google after this post...), but if it used the quantum randomness alone, then it would be random. If it only used the quantum randomness to generate a seed, then we'd be just as pseudo-random as we are now.