/sci/ - Science and Mathematics

>>1687

But if the donut-shaped universe theory has any merit, wouldn't it eventually collide and contract? I'm probably wrong, but just wondering.

>>1683

>The universe expands

Correct

>then contracts

That's an idea, yes.

>Is it possible that the universe we live in was created before?

You know what they say about monkeys and typewriters.

>If so, could we have lived our lives and died, to come back again?

By this I assume you mean in the universe that is created the same way as the one we previously lived in. And if we assume the idea is true, then yes.

But keep in mind that the cyclic models are ideas. We don't have any evidence that suggest that they will happen, so they're fun to walk around and think about, but currently they're not worth much more than that.

>>2975

asd

>>1683

wow i made this thread months ago

and its alive what the fuck

seriously this board is dead

>>2975

I dont know what they say about monkeys and typewriters?

>>3003

> 02/15/15

… that and their /ogen/ is why I don't want to fully discard halfchan.

>>3006

They say that with infinite time, anything can happen. Even the same universe being created twice.

https://en.wikipedia.org/wiki/Infinite_monkey_theorem

>>3333

Wrong! Wrong! Wrong!

The infinite set of even natural numbers contains no odd numbers. Just because something is infinite does not mean it is all-encompassing. In fact, under many set-theoretic models it is completely and totally impossible to create a set of all sets (and also impossible to create a theorem machine that can prove all possible true theorems.)

>>3356

TL;DR The universe cannot be abstracted to a natural number, and if anything short of two absolutely equivalent Universes are not the same to you, you might be right. But how do you know that this does not work in discrete steps?

I was just explaining what they say about monkeys and typewriters.

I understand that "because something is infinite does not mean it is all-encompassing" and I know about the Entscheidungsproblem (also about Popper's theory of science in so far that any scientific statement needs to be falsifiable, if that matters). But we are talking about possible universes, more precisely about the possibility that one universe created matches another universe created before.

Let's assume you are thinking of one even natural number, no matter the size. Almost always I will guess the wrong number. But if we assume that I had infinite time, i.e. an infinite amount of guesses, then I must guess the right number eventually.

Natural number = An universe

Number you are thinking of = First Universe

Wrong guess = Universe is different from First Universe

Right guess = Universe is the same as First Universe.

I am not a physician but I do know that the energy states of small particles (at least of electrons) are always discrete, not continuos. From that might or might not follow that universes exist in discrete states as well. Discrete would mean that between two states are only countable many other states, just like in the set of natural numbers.

Those are all just speculative thoughts I came up with just now, I cannot make that claim as I am obviously arguing way beyond my scientific knowledge.

>>3363

>Let's assume you are thinking of one even natural number, no matter the size. Almost always I will guess the wrong number. But if we assume that I had infinite time, i.e. an infinite amount of guesses, then I must guess the right number eventually

The only reason it seems obvious you can do that with the natural numbers is because of their particular structure, which suggest an optimal strategy. With the rational numbers it's less obvious that such a strategy exists. (One does, but you have to be a bit clever about it.) With other countably infinite sets, there might not be a strategy that you can find.

>>3405

Sorry for the trifagging, forgot to take it off after posting in the other thread.

>>3405

The very definition of countably infinite means that there exists such a strategy, though.

A better way to refute >>3363 would be to argue that there are an uncountably infinite number of base states of the universe. We can do this by noting that one of the factors that distinguishes the base states is the configuration of the particles that make up the states. There are other factors, such as the numbers of these particles and their energy states, but as mentioned before such factors are countably infinite. Let's say, for sake of argument, that we have at least three particles in our base state, and that two of the particles are at distinct posititions from each other. There are an uncountably infinite number of locations where the final particle could go.

>>3414

>a strategy that you can find.

I never said that a strategy didn't exist.

However, it may be the case the strategy(or, rather, a bijection to the natural numbers) is not computable.

>>3415

…and without that strategy, you can't be sure you're not missing a whole bunch of possibilities.

>>3002

fghjkl;'