Q:

Do random experiments actually exist?

I am studying probability and in most of the books that i have read they mention that for an experiment to be random-- (1)there should be more than 1 possible outcome--(2)even when the experiment is repeated under similar conditions the outcomes must not be predictable.The second point really confuses me...if we take a coin toss for example and we repeat the experiment under totally similar conditions   of gravity,air resistance,apply the same force,etc won't we be able to predict the exact outcome every time and as long as the conditions remain same my intuition tells me that i will get the same outcome every time....so do random experiments exist?and if they do what can be considered as a random experiment?

A:

There is a long standing question of whether true randomness actually exists.  Sometimes these discussions delve closer to theology than math or physics.  Computers have long been criticized for the low quality of their random number generators.
Radioactive decay, and quantum properties are considered to be random.  They are definitely unknowable.
Chaos theory says that many systems have a high degree of sensitivity to initial conditions.  And so, as we move away from these initial conditions, the future state of the system becomes increasingly difficult to predict.  This means that no matter how good our data is, we will never be able to generate good long-range weather forecasts.  It also suggests that coin flipping, dice rolling and bingo hoppers tend to be good random number generators.
So, while we probably can build a coin flipping machine that flips head every time, it is safe to say that a human who has not practiced his coin flipping will only flip heads 50% of the time.

