Is there true randomness in the Universe ?

[Ambhi]

Randomness can be looked at different levels. e.g. One can ask you to say a number randomly from 1-100 or you could have a computer generated random number. I am not talking about those directly. I am referring to true randomness at the particle level.

To help you understand better:

Let's say the Universe is in a particular state S1 at a particular time T1. The state represents the state of each and every unit of the space and every subatomic particle of matter, energy, antimatter etc at the lowest level of granularity. The state also represents each subatomic particle at a particular point in space with a particular mass, speed, velocity, direction (some theories suggest you cannot 'measure' them all at once but I don't think they deny the attributes of mass, speed, velocity, direction having a deterministic value for every subatomic particle).

Let's consider time T2 which is 1 second after T1 and S2 the state of the Universe at T2. Is there only one possibility of what S2 can be or is there randomness in the Universe that makes S2 to be just one of multiple possible state at T2 ?

If it is confusing let me simplify my question.

Let's say we have two Universes 1 and 2 (hypothetically) in the same state S1 at T1. They don't influence one another.

Can these two Universes be in entirely different states at T2 for example can Universe 1 be in a state S2-1 and Universe 2 be in a slightly different state S2-2 at T2 ?

Assuming every subatomic particle has the same mass, velocity, position, direction in space in both Universes at T2 how could they possibly reach two different states at T2 ? Unless there is true randomness somewhere in the scheme of things.

You may refer to uncertainty principle et all and explain your understanding of randomness.

Coming back to the other 'trivial' randomness of guessing numbers or computer generated random numbers:

Guessing numbers: I think if the same person in both Universes that are in the same state are asked to guess a number between 1 to 100 at the same time their answer will be exactly same because the state of their neurons and their mind will be exactly same.

Computer generated: The computers will also generate the same random numbers in both Universes at the same time as most computers anyway use time as one of the criteria to calculate a random number.

If big bang does happen and the Universe keeps contracting and expanding like a Yo Yo. Will each instance be entirely different or the exact sequence of events will happen across the Universe through the life of the Universe during each iteration ?

What do you all think ?

[2centsWala]

If big bang does happen and the Universe keeps contracting and expanding like a Yo Yo. Will each instance be entirely different or the exact sequence of events will happen across the Universe through the life of the Universe during each iteration ?

What do you all think ?

Deeply upset over my lack of comprehending and visualizing what's written by the OP, I banged my head in frustration against the wall. For the next five seconds, I saw stars floating randomly in front of my eyes So yes, for now, I think that randomness exists in the universe.

Hopefully my head clears after a while and I am able to think clearly. :)

[gotskiz]

Deeply upset over my lack of comprehending and visualizing what's written by the OP, I banged my head in frustration against the wall. For the next five seconds, I saw stars floating randomly in front of my eyes So yes, for now, I think that randomness exists in the universe.

Hopefully my head clears after a while and I am able to think clearly. :)

How do you know the stars were floating randomly? We need a large sample to conclude this - please repeat the exercise 10 more times :p

[Ambhi]

Deeply upset over my lack of comprehending and visualizing what's written by the OP, I banged my head in frustration against the wall. For the next five seconds, I saw stars floating randomly in front of my eyes So yes, for now, I think that randomness exists in the universe.

Hopefully my head clears after a while and I am able to think clearly. :)

Let me rephrase it. If the Universe were to reset back 20 years with atoms and all in same state they were 20 years back would home prices still be this high in the Bay Area ? :)

[Hyderabadi]

You must be randomly bored, the particles in your body are all in a different state of boredom. Please choose a numb3r between 1-100. If you chose 3 then it was not random :)

[RainGarden]

If the Universe is reset 20 years back with atoms in the same state, will the same sequence of events happen in the same order? Will raise in home prices be caused by the same sequence of events or completely different set of events will still cause the same end effect.

[realgoogler]

Other way to ask is "Is the universe deterministic ?"
My thought says there may be no absolute randomness and we will never be able to establish that there is absolute randomness because we could wind up doubting observer limitations.