How many people can live in space?

[alexsok]

I was wondering. We have about 6.5 billion people on Earth and the potential for expansion is fluctuating between the optimistic estimates of 1.3 trillion towards 2030 (if the fertility rates stay the same which is unlikely) to the pessimistic 9 billion and downhill starting from 2020. So, assuming a theoretical scenario where the space is infinite (hasn't it been proven already?) and there is an infinite number of life-supporting planets out there, does it mean that there can indeed exist an infinite number of people at any one time?

What if there are, according to some interpretations of QM, an infinite number of parallel universes? Would infinity appy to these universes as well or is it possible that each universe would contain it's own infinity?

Or maybe infinity can never really exist outside of mathematics because for it to exist the birth/death process would have to stop completely since it is finite by it's very nature (someone is always being born or dies).

I think i've been thinking too long about infinity for the last couple of days after someone showed me an article where it is proven that infinity is indeed a number and should be treated as such:
http://www.johnath.com/~david/etc/infinity.html

 

[K.I.L.E.R]

10 people can live in space.

 

[The_Wolf_Who_Cried_Boy]

10 people can live in space.

Would two dwarves count as one?

 

[Graham]

Logic like that is interesting.

Assuming the universe is infinite, then the chances of something not being true approach zero, so therefore everything is true in some place in the universe. So taking the next logical step, there is a planet out there where their version of beyond3d forums is populated by sexually charged promiscuous females, typically each with an eye patch and a handle bar moustache.

Therefore it does well prove that humans can live and space.

The bigger question is how do you feed 1 trillion people in a space station.

 

[Dersaidin]

With Space bars.

Its lame on so many levels.

 

[Npl]

The bigger question is how do you feed 1 trillion people in a space station.

Cannibalism will save the human race.

 

[DemoCoder]

Logic like that is interesting.

Assuming the universe is infinite, then the chances of something not being true approach zero, so therefore everything is true in some place in the universe.

No, this is the traditional naive, and incorrect hand-waving "folk" wisdom about infinity, which unfortunately is wrong. There are differently sized infinities, and an infinite amount of space or matter doesn't guarantee anything, anymore than the infinitely long transcendental number 10100100010000100000... will eventually contain any given sequence you desire. In fact, it will never contain '2', nor '11', etc.

Or as another example, if I had an infinitely sized computer (infinite RAM), the number of possible programs runnable by this computer (an infinite number) still is vanishingly small compared to the total number of programs, just like the rationals can't be mapped to the reals. If you were to write down every possible program in an infinite list, I could show you programs that exist, which should run, but are not on your list.

 

[Nesh]

How many people will live in space in case earth does not welcome human life anymore?

Simple.

Count the RICH PEOPLE

 

[Graham]

Cannibalism will save the human race.

It's people!!!



I won't touch the infinite counter arguement because if the universe is infinite (which it both is and isn't) then you are both correct and completly wrong, just like I am.

 

[Frank]

You don't need habitable planets, you can build structures in space. A cubic kilometer of room can easily support a few million people.

 

[MuFu]

Well, I can't live in space. Cross me off the list.

 

[K.I.L.E.R]

Trust MuFu to come up with a hilarious response.

Well, I can't live in space. Cross me off the list.

In how many dimensions?

You don't need habitable planets, you can build structures in space. A cubic kilometer of room can easily support a few million people.

 

[alexsok]

There are differently sized infinities

Are you referring to the transfinite sets in mathematics? AFAICS (naively maybe), if the space is infinite then in a theoretically immaculate scenario there could potentially be an infinite number of planets with an infinite number of people (obviously, i'm talking about physical infinity).

Now, how do we feed them is not an issue here... Moreover, I seem to recall Nick Bostrom (who is a renowned transhumanist) saying that if we manage to come up with a way to upload our brains into other mediums (such as computer simulations, etc), then it would be possible on Earth alone to support up to 10^37 uploads (people) and no, there would be no more biological restrictions so no one would have to be concerned about feeding himself or his neighbor

This lives a lot of room for imagination if we go beyond the limits of our Earth to the infinite expanses of the cosmos.

 

[Frank]

In how many dimensions?

It depends on the (auxilary) space you need for everything and how much room everyone gets, but if you make the "floors" 2.5 meters high, that's equal to a floor space of 400 square kilometers. If you use half of that for living space and say that the average family consists of 2.4 people, that gives each family 480 square meters of living space for one million inhabitants. That's not bad, isn't it?

 

[pcchen]

Are you referring to the transfinite sets in mathematics? AFAICS (naively maybe), if the space is infinite then in a theoretically immaculate scenario there could potentially be an infinite number of planets with an infinite number of people (obviously, i'm talking about physical infinity).

No, he's talking about the "everything is true in some place in the universe" thing, which is not true even if the universe is infinite.

 

[alexsok]

No, he's talking about the "everything is true in some place in the universe" thing, which is not true even if the universe is infinite

Does that mean that an infinitely large universe with a capacity to contain an infinite number of events could not run an infinite number of programs at the same time? Makes sense.
But what if there are an infinite number of computers placed all over the universe all running an infinite amount of programs? Obviously, one computer couldn't do it at the same time, but an infinite number might be up to the task.

 

[Frank]

Btw, the only consideration in most of these things is the amount of power (energy) you have available. If you have almost unlimited power, almost everything is possible. You can use the brute force approach if there is no clever way to do something.

And you need a huge, automated manufacturing base, of course. But we could do that.

 

[DemoCoder]

The number of possible truths greatly outstrips the number of reachable truths.

Like I said, if you write down an infinite list of every program you plan to run in the universe on your infinite number of machines (remember, I am allowing you an INFINITE list) I can always construct a program that's not on your list via diagonalization argument.

Simply put, an infinite universe does not violate Godel, Church-Turing, Chaitin, and other limits to metamathematics and computation.

An infinite number of events certainly doesn't guarantee that everything that could happen, would happen.

 

[alexsok]

AFAIK, diagonalization argument is a proof that there are infinite sets which cannot be put into one-to-one correspondence with the infinite set of natural numbers... but i don't understand a whole lot about it so I would appreciate it if you could elaborate a bit on why it is so.

 

[London Geezer]

The bigger question is how do you feed 1 trillion people in a space station.

Oh please, who does food anymore?? By 2030 we'll all be size 0's. You don't need food to live. Just lots of water and drugs.