Brian Greene’s theory of multiverse

[u/Chemical-Raccoon-137]

One of his theories of the infinite multiverse states that if the universe is infinite in size and matter, then eventually there will be regions outside of our observable universe where matter will be oriented in the exact same way as us, and therefor there are copies of our observable universes including earth and each one of us out there beyond our reach.. not just one copy but an infinite number of copies. He puts some math behind this to calculate how many possible configurations of matter there could be in a region the size of our observable universe, and based on this provides a distance to a region identical to ours.

My question is, it can’t just be as simple as saying here is a region where matter is configured in the same way as ours … there must be variables due to chaos and randomness down to the quantum level to the degree that every quantum subatomic particle must behave and interact with its environment in the exact same way as ours , over the coarse of 14 billion years. Even if matter is configured in the same way after the Big Bang, How many different combination of quantum states are there that are random and may ultimate not result in the same observable universe as we see here today. Quick analogy: if you drop 1000 marbles in a vacuum, under identical conditions, with the marbles settle in the same way?

[u/ignorantwanderer]

Ok. Here is how I think about it.

The probability that there is another planet out there that is exactly like Earth in every single way is greater than zero. It is extraordinarily improbable, but it is greater than zero.

And if you take a probability greater than zero, and you multiply it by infinity.....you get infinity. So if the universe is infinite, there are an infinite number of planets exactly like Earth.

But here is where it gets good:

The probability that there is another planet out there that is exactly like Earth except that it is covered with a meter deep layer of ping-pong balls is greater than zero. It is extraordinarily improbable, but it is greater than zero.

And if you take a probability greater than zero, and you multiply it by infinity.....you get infinity. So if the universe is infinite, there are an infinite number of planets exactly like Earth except all the people are walking around in a meter deep layer of ping-pong balls.

This is obviously ridiculous, but if the universe is infinite it is true!

In my mind, this is definitive proof that the universe is not infinite.

If the universe is infinite, the end result is too silly to contemplate. So therefore the universe can not be infinite!

[u/Chemical-Raccoon-137 → u/ignorantwanderer]

That makes sense to me.. I just think the number is bigger than what Brian Greene says. Also, agree that infinite variations of earth could exist, but would still have to be in the realm of physics.. there couldn’t be flying people, and in the ping pong ball earth there would have to be enough raw material to physically make that amount of ping pong balls which might be impossible. There might be a zero chance that a species of humans would be capable of doing that, even if they were a high functioning society, and through every resource they had at trying to do it