[dangkhoa (OP)]

If I decide to eat some fruit and just pick the first fruit that comes into my head...A banana !...Have I really chosen that at random or have i been influenced by my own fruity proclivities ?

What about if I grab a handful of rice and sprinkle them on a chess board from a metre up !...Has the rice dropped randomly or has it been influenced by height, air , climate, chess board and neighbouring rice ?..ie...does each grain of rice come to a stop exactly where it is supposed to ?

If a computer is told to pick a number at random...does it really ?...or does it have to perform a function/follow a rule........ that makes it appear to choose randomly ?


Does Randomness Truly exist Or Is There A Formula For Every Eventuality ?

whajafink ?

[jeffreyH]

Consider the Dirac delta function.
https://en.m.wikipedia.org/wiki/Dirac_delta_function
Along the horizontal axis it is zero everywhere except at the origin at x=0. That is definite. Not random. There is zero probability that the value is non-zero anywhere else. It is all about probability. Global systems are chaotic by nature. You just can't model them exactly. You can however find the probability of an event. This implies uncertainty. So chaos is indirectly linked to the uncertainty principle. One is a macroscopic concept while the other is microscopic ruled by quantum mechanics. This is where randomness rules.

[evan_au]

If a computer is told to pick a number at random...does it really ?...or does it have to perform a function/follow a rule........ that makes it appear to choose randomly ?

Most traditional computers used a "pseudo-random random number algorithm" to produce a number which appears random - but if you knew the algorithm's program and data, you could predict the next number by running the algorithm.
See: https://en.wikipedia.org/wiki/Pseudorandom_number_generator

UNIX systems have a function that "harvests" randomness from system events like people typing characters on keyboards, or the seek time of hard disks. This goes into a pool of randomness from which you can "withdraw" random numbers. This system tracks how much randomness has been added to the pool, and how much has been withdrawn, to ensure you don't try to overdraw the amount of randomness.

Modern PCs contain a chip which continually generates "genuine" random numbers using an electronic circuit which is affected by subtle temperature and electrical noise differences within the chip. This random number function is used to generate keys for encryption and decryption, which is also done by the same chip.
See: https://en.wikipedia.org/wiki/Trusted_Platform_Module

[chris]

Our own @evan_au did a wonderful job of explaining randomness on a podcast for us a little while back:

https://www.thenakedscientists.com/podcasts/special/what-random

[evan_au]

What about if I grab a handful of rice and sprinkle them on a chess board

At one time, it was thought that if you could measure the position and velocity of every atom with sufficient accuracy, you would be able to predict the future.

With developments in quantum theory in the 1900s, we now know that it is impossible for us to measure the position and velocity of subatomic particles with unlimited accuracy.
See: https://en.wikipedia.org/wiki/Uncertainty_principle

With developments in chaos theory in the 1900s, we now know that in many cases (eg the weather and planetary motions), any small errors in initial measurement will grow exponentially until they eventually overwhelm any useful prediction.
See: https://en.wikipedia.org/wiki/Lyapunov_exponent

[puppypower]

We live in a quantum universe, meaning only certain states are possible. For example, the electron of the hydrogen atom has five energy levels, each  defined by a specific quanta of energy. There are not an infinite number of energy levels and movement between energy levels requires a very specific amount of energy. There is a probability of 1.0 or 0.0. If we know the energy, we know how hydrogen will roll with probability of 1.0.

A practical problem appears when we try to scale this up to say one gram of hydrogen atoms, which is 6.02 x 10²³ hydrogen atoms. It gets very complicated to keep track of all the atoms, especially before the invention of modern computers. Approximation methods were developed, such as statistics, to average things so we can correlate to bulk observations.This random model assumes all states are possible, even though we know there are only a limited number of quantum states, each defined by a specific quanta of energy. The model has to depart from reality for simplification purposes.

What appears to have happened was, over the years the success of this approximation method, has led new generations of people to forget about the original purpose and need, causing the cart to be placed before the horse. Now we just assume randomness, even though we also teach a quantum universe.

In my observation, randomness better describes manmade things, while quanta works better with natural things. We explain randomness and statistics to students using examples such as dice, cards and political candidates, where humans assign subjective values that are not physically quantified, such as by energy.

For example, a six sided dice will have different subjective values placed on each side. The dice is designed to weigh the same on all sides. This is not natural. There is no energy quanta correlation to each side, like with the hydrogen atom. The hydrogen atom is a more like a loaded dice, as are most natural things, Human things are more subjective and don't load in a natural way. They tend to load in a subjective and arbitrary way, where randomness is related.

It may be useful to look at the history of statistical modeling. It was originally developed by bankers and investors to help predict profitable investments, all of which have human subjective influences. Unlike natural behavior which is more predictable, human behavior has subjective wild cards due to will power and choice.  There is still an investment angle to statistical predictions; money and fame.