True Number of Possible Different Universes?

[EquestriaGuy 1,074]

I have a very shaky, surface knowledge of topics like astrophysics, but I pay attention enough to understand a few things, and I think I'm pretty good at deducing facts from known variables. Having said this, I wanted to put forth what I think is the number for possible universes.

 

To get this number, which will be FUCKING HUGE (though nothing will probably ever match Graham's Number), I had to determine the size of the universe, and how long the universe will last from beginning to end.

 

Size of the universe= Currently, the largest known object is the Hercules Corona Borealis Great Wall. It's 10B light years across. It's so large, it's said to contradict the Cosmological Priciple, which states that at a sufficient enough scale, all matter is evenly distributed throughout the universe. Therefore, the lower bound for the size of the universe should be whatever makes the Great Wall once again compliant with the Cosmological Principle. This is probably a ghastly huge number.

 

Defining the beginning and end of the universe= It's said that heat death isn't actually the end of the universe. After very long timescales, a particle would inevitably come in contact with another, and through gravity attract others, until once again we have galaxies and an entire universe again, and eventually everything is exactly as it is now. I'm sitting here typing this, you're reading it later, everything is exactly as it was before. This is known as the Poincare Recurrence Time. Some models of inflation have the universe as being a googolplex meters across, and the Poincare recurrence time for a universe that large is 10^10^10^10^10^1.1 years. This number is laughably huge. Luckily, the Poincare recurrence for our observable universe is a mere 10^10^10^10^2.08 years. Don't hold your breath through that one either.

 

So, that brings us to our solution. Let's say you have two parallel universes of a size that brings the Great Wall in compliance with the CP, and those universes have a Poincare Time of 10^10^10^10^10^1.1 years. These universes from beginning to end were mirrors of each other, no differences at all EXCEPT for one Planck second, one Planck volume was different from the other universes equivalent. Maybe the quantum foam in that Planck volume was different somehow, whatever the case may be, this is literally the only difference between them. Now you have to calculate how many different combination of differences there can be for all the Planck volumes and all the Planck seconds in these universes as defined above.

 

This is what I think could be defined as the number of possible universes. Now correct me EVERYWHERE I'm wrong, so I can be laughed at for this wrong and silly idea.

[SFyr 1,982]

I'm not well versed in this, but if I understand Planck units right, aren't they the smallest measurable or significant units, where going further than that is simply so small it doesn't really matter to us in quantum mech.?

If so, I think you run into the issue that even Planck units aren't sufficient; it's the idea that when a particle moves, it doesn't "clip forward" in units of Planck length, it moves or drifts until its displacement is measurable. ...I think this would more or less mean that, for length or volume, we're working with a gradient that can be infinitely subdivided, to where you can get an infinite number of little differences within a single Planck length/volume at a given instant. 

[EquestriaGuy 1,074]

Awesome. Then I guess what we're looking for here are the maximum number of measurable differences in universes.

[cmarston1 5,962]

I thought the number of possible different universes was near limitless/infinite.

[I used to be a stranger 7,994]

There's a difference between possible universes and theoretically extant parallel universes through multiverse theory.

 

Possible universes are an exploratory tool used in logic and philosophy.

The Multiverse is a theoretical physics concept.

 

The crossover is in Cosmology, but the purpose there is to find something, like possible anomalies in spacetime, or the size of things.

 

There are infinitely many possible universes if the range of variables you permit is infinite, which makes your question seem to me more speculative than defined.

Edited December 20, 2015 by Blue

[EquestriaGuy 1,074]

aye, that's why I want to limit the range to measurable differences. If a planck volume is the smallest measurable space, and a planck time the shortest measurable time, then that establishes the groundwork for all the math to follow.

[Nsxile 27,637]

I imagine it would be infinite if those hypothetical universes existed.

[Lucky Bolt 35,109]

There is only one other universe I know of....

Equestria! 

[Stone Cold Steve Jobs 22,477]

The number of possible universes is infinite. 

To give you an idea of how poor we as people are at comprehending infinity, each of these universes can also be infinite in its own right.

There is a difference between very large numbers and the concept of infinity.

[Splashee 28,589]

There are multiple levels of infinity, at least in mathematics. So to try to figure out this very important question, if there are more than one universe, etc, etc. I mean we don't even see past our own noses, and our brains can't keep more than 3 active apps in our head at the same time...... Yea I made that last one up.

 

If the universe is a balloon, and the surface of the balloon is the space we see, then.... brain, please follow.... I think an error has occurred.