h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

I've seen the subject of randomness come up in a number of the postings on free will, and would like to focus a discussion on this particular matter.

I would like to look at what is really random. I'm an undergrad studying computer science, and we are frequently reminded that random number generators are in actuality pseudo random. When given the same seed, they will always return the same string of "random" numbers.

It seems to me that many everyday examples we commonly accept as being random are really no different. For example, a deck of cards; if you shuffle them exactly the same way everytime, you will always get the same results. If the first card was an ace of spades the first time, it will be so again (assuming constants such as the firmness of the cards when shuffling). In this case, your manner of shuffling is the seed given to your (pseudo)randomizer algorithm.

I think that things like rolling dice or flipping a coin could be looked at the same way. If you were to hold a dice the exact same way, and roll it with the same amount of force, etc. you would always get the same number on top.

So, it is my thought that there doesn't exist anything that is truly random. It is instead a concept we use to make up for an incomplete understanding of all the inputs (ie. amount of force applied to the dice, etc.).

In my mind, this is no different from how we use the concept of free will to compensate for an incomplete understanding of what causes our actions.

Comments anyone?

> there doesn't exist anything that is truly random

Current physics disagrees. Radioactive decay is the classic example.

I must say, I'm not too familiar with radioactive decay. Could you be so kind as to elaborate? Thanks.

Brent

Suppose you have created an atom which has a nucleus in an unstable state. At some point in the future the nucleus will undergo radioactive decay. For example, emitting an alpha particle, which is a helium nucleus. The time between the unstable nucleus being created, and it decaying, appears random (poisson distribution). Last I checked, physicists believe that this time is truly random: there is no information with which one might predict the decay time more accurately.

This kind of randomness is indistinguishable from 'too complex to predict'. A random number generator does not (as The Brent said above) generate random numbers, nor does a lottery ball-mixer. What they generate is simply too complex to predict, and that is all that is required (assuming that the predictor in the first case has no access to the seed and generator program).

Random can mean no more than 'unpredictable'. Certain things are unpredictable in practice, but is anything unpredictable in principle? If we knew more about quantum effects, they would no longer appear random. To put that another way, the word 'random' can only apply to appearance, to interpretation.

This Entry proposes a strange, unnecessary, and surely mistaken view of the effect of quantum randomness on the problem of free will. It is not randomness that removes free will, nor is it (as some argue) randomness that guarantees free will.

Free will was challenged by the first atomists, and their followers Democritus, Epicurus and Lucretius, who argued for a deterministic world. Randomness had nothing to do with their argument. Their modern equivalent is Dan Dennett, who argues very convincingly in Freedom Evolves (2003) for a deterministic universe.

We are not completely free (nobody seriously supposes we could be). We are however freer than other less complex beings; free, that is, to respond to subtler stimuli. The fact that we respond to them in physically determined ways may seem a denial of freedom, but it's the best there could possibly be, and it is utterly unpredictable.

But randomness has nothing to do with it. Even if quantum effects really are random, they make no difference to our freedom or lack of it.