Randomness

Randomness is the theoretical idea used to describe events that occur without specific cause, pattern, or purpose. The existence or non-existence of randomness in the universe is a subject of philosophical and scientific dispute, and is as yet unfalsifiable.

Views on randomness

 * Determinism: There are no random events in nature;
 * Naturalistic determinism: All events are determined by physical bodies and natural laws;
 * Theistic determinism: All events are determined by the will of God;
 * Semideterminism: Some events are determined by the will of God, others by the independent will of living beings, others by natural law, and still others by randomness.
 * Nihilism: All events in nature are random, causeless, and meaningless;

Does randomness exist?
The key to solving this issue is learning to differentiate between what is truly random and what is simply unpredictable. An event may be non-random but unpredictable, because unpredictability may simply be a result of our inability to predict the outcome due to the limitations of our knowledge, rather than the impossibility of predicting the outcome, due to a total lack of any identifiable cause.

For instance:
 * When flipping a coin there is an equal probability of getting ether heads or tails, and the outcome of any one flip is unpredictable. However, the outcome is not random.  It is determined by a number of different factors, including the mass of the coin, the angle, direction and velocity with which the coin is flipped, the wind resistance and gravity it encounters during its flight, and how long it is permitted to fly before it is caught.  If we knew all of those facts before we flipped the coin, then we could predict the outcome of every flip.  Everything about the flip is determined by measurable, quantifiable facts.  However, because we don't know all the variables, we cannot predict the outcome.  A coin-flip is unpredictable, but it is not random.

Other examples include throwing dice, shuffling cards, "coincidental" events, traffic patterns, and voting patterns. Additionally, computers are incapable of creating truly random numbers, and instead create only "pseudorandom" numbers which run a reading of the system clock (a "seed") through a complicated algorithm to create numbers that are unpredictable, although not truly random, because the outcome is determined by the seed provided by the system clock.

In all these cases, the outcome is unpredictable because we cannot see, understand, or calculate the outcome; but the event is not random, because the outcome is determined by definite causes, and only one outcome is possible, given all the circumstances.

While the above cases are clearly unpredictable but not random, there are many other cases that are not so clear. Would weather patterns, animal behavior, cancer, and the motion of subatomic particles all be fully predictable if we had the tools to observe their causes? Or is there an element of true randomness in these events which makes it impossible to determine the outcome?

The simple answer is: "We don't know." It is extremely difficult to prove a negative, because the mere fact that you don't know what the cause of something is doesn't mean there is no cause; it may mean you simply haven't discovered it yet. Essentially, we can never know for certain whether anything is truly random or not until we fully understand everything about the causes in the universe, and see that one event is totally uncaused. That seems unlikely to happen anytime in the near future.

Video
This classic choral number illustrates the principle of randomness, as most people understand it, better than any words could.

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