 # The Role of Probability in Science.

Today we are looking at the proper role of probability in science. And how this has been subverted by modern physics. Let us first look at what probability is.

Let us suppose that we want to roll a six on a six-sided playing die. We know that on average, we will roll a six about one time per six rolls of the die. That is, if we roll the die six times, we would expect to get a six about one time.

We could throw the die twenty times and get six zero times. But we would be surprised if this happens. We would consider this to be a very unlikely event.

### The more superstitious person might consider oneself cursed!

We say that the probability, or chance, of rolling a six is one in six. But what do we mean by this? What does the concept of “probability” describe?

There is much that can be said about calculating and determining probabilities in a huge range of imaginable contexts. Mathematics has much to say on this topic and we can use it to calculate/estimate all sorts of probabilities using very sophisticated methods.

But we will keep things simple and ask what the concept tells us about reality, using simple examples.

### Probability is a method of dealing with uncertainty.

It takes certain processes, such as rolling a die or predicting the weather. These kinds of processes are very difficult to predict. We have little ability to be certain what the outcome(s) of these processes might be.

For instance, consider rolling a die. Although it seems to be a very simple process, we cannot track all of the tiny motions of the die. We do not have any way of knowing exactly how it will dance through the air and then strike the table. Such simple looking things, but it is next to impossible to predict the outcome of throwing them!

Or consider the weather. This is an extremely complex thing to predict. Countless factors go into determining the weather on any particular day or even hour. So many that we currently have no reliable way to account for them all and we likely never will.

What do we do? If we cannot account for all of the relevant factors and make any certain predictions, then do we throw our hands in the air and give up? We could, but often that is not a good option.

So, what then are we to do? Should we accept that it is difficult to predict the outcome with any certainty? Or should we try to estimate the relative frequency of certain outcomes?

### Can we do this, can we estimate the relative frequency of certain outcomes? And how is this useful?

Here we want to estimate how often certain outcomes will happen relative to others. If the process occurs this many times, how often do we estimate we would get this result or this other result?

In other words: we want some way to determine how likely something is to happen. Is it very unlikely or quite likely to happen? Should we expect it to happen often or not very often? This is what probabilities will help us estimate.

This is all probability is, an estimate of the likelihood of a given event to occur. That is, how often a given even is expected to occur.

This helps us estimate whether we should expect something to happen in a given instance or whether we should expect it not to. As well as to estimate how often a given event might happen.

Since we cannot keep track of all the factors that determine the outcome of certain phenomena, probabilities help us deal with uncertainties. We might not be able to account for everything and predict the outcome with much certainty, but we can estimate what the results might be.

This can help us determine which results to expect and which not to expect and how often those results might happen.

### This the proper role of probability in the sciences: dealing with uncertainties typically caused by our inability to track complicated or unpredictable phenomenon.

Say we find it difficult to predict the movements of an electron. We do not understand how to predict precisely where it will be two seconds from now.

However, we do know certain things about electrons. We know enough to predict that it is likely it will be somewhere in this area here. It is not likely to be in these other areas. While we cannot be certain where it will be, we at least have some ability to predict its behaviour and we might be able to do something useful.

Or take the weather. It is very hard to be certain what the weather will do days from now. But we can understand meteorology well enough to be fairly certain that on some days it will most likely rain. Or that rain is unlikely. We might not be certain and we might be wrong, but we know enough to advise people that they should prepare for these outcomes, as they are quite likely. The weather is a very complicated thing. We need a lot of very, very complicated math to predict probabilities here. And we know how often it can be wrong ….

In all these cases we are dealing with uncertainty and allowing ourselves to have some understanding of what to expect when faced with uncertainty. We might not be certain, but we know enough to say something about what is happening.

### Now let us get into something more controversial.

In quantum mechanics, there is the concept of probability. But it is not treated as a method of dealing with uncertainty and making predictions about possible outcomes. There it is treated as … something else.

In quantum mechanics, the behaviour of particles is said to exist in some kind of indefinite limbo state until observed. Particles are neither here nor there but in a superposition of positions. They do not have any definite momentum and so forth. Such properties take singular, definite values only when they are observed.

One might expect that they take some definite value according to some causal mechanism. However, that is not the case, not according to quantum mechanics. Once a particle is observed, it is said that the “probability waveform” of the particle collapses and then each property takes on a definite value.

In other words, particles do not have any definite nature. They are treated as things with no definite nature. As something not fully real.

1. funandlearning says:
2. Steve Hathway says: