does space really go on forever?

Question

If space is Really infinite, than why do scientist say that everyday space gets bigger and bigger, isn't infinite, infinitie? theres nothing more than infinity.. i mean its freakin INFINITY for peeps sake.. so what does the term "space gets bigger every day" really mean?

so.....then... it doesn't go forever? scince it gets bigger?

Answer 1

My old calculus teacher was careful to not use infinity as if it were a number. Instead of "as x approaches infinity" in an equation, he'd say "as x increases without bounds." That said, other than at the beginning of Star Trek reruns, I've never heard that space is infinite. Never. Current theories hold that the universe is expanding from a big bang, and nothing travels faster than the speed of light. So if the universe is about 15 billion years old, it's size must be less than 15 billion light-years across. Big, but finite.

Answer 2

I'm not sure that anyone knows how big the universe actually is. And by "how big it actually is", I mean that if hypothetically you froze the universe as it is, and started travelling across it, trailing a tape measure, and stopping until either you reach and edge, come back to where you started, or keep going on forever. Of course, to *do* such a thing is impossible, but it gives meaning to the idea.

The part of the universe which we can *see* has a well known size, which is about 13.7 billion lightyears. But this size is just the distance that a light beam could travel in the age of the universe, so it says more about the age of the universe than it does about its size.

As to the size of the universe as defined in the first paragraph, it could be infinite/unbounded. Or it could be that the universe has no edges (think of a sphere, or the Earth: you start walking south and travel in a locally straight line and eventually you come back to where you started). Physicists tend to dislike the idea of the universe having edges as then there would be a priviledged position in the universe (on the edge of the universe, for instance) (that no such place exists is one of the key assumptions of cosmology and astronomy).

As to the statement that "space gets bigger every day", I assume you mean the expansion of the universe. The best analogy for this I've ever heard is the balloon analogy. If you take a balloon, and stuck little objects to its surface (little pieces of paper, etc), and then start blowing the balloon up, the objects will move farther apart from each other. It's not that any of the objects are moving per se (a very tiny person sitting on one of these objects may very well think they were sitting still while the other objects moved away from him), but that there is more and more balloon between each of the objects.

In astronomy we see distant galaxies moving away from us at speeds depending on how far away that galaxy is. A person in any given different galaxy would see *us* moving away from them instead of them moving away from us. And really, nothing is moving, but instead, just like with the balloon, there is more and more space between any two points in the universe as time passes.

By the by, as a note on infinity, not all infinities are created equal. There are an infinite number of positive integers (1, 2, 3, 4...), but there is an even larger infinity of real numbers (1.01, 3.14, 2.7, 9.467321, 47.5637, 14834.4627, etc) (see: http://en.wikipedia.org/wiki/Cantor%27s_diagonal_argument). Just in case you wanted to know, which you probably didn't. ;)

Answer 3

The scientist would mean that as we explore the cosmos more and more of it is being revealed. The gap between the known an unknown is slowly growing smaller and the "infinate" cosmos is comming closer and closer with ever trip to Mars or whatever. So our known universe is what is getting bigger and bigger everyday. Also as we explore more of the universe shows itself and poses more questions. And the many questions make the infinate questions grow more infinate.

Answer 4

The term "space" usually refers to the vacuum or the emptiness of the universe. That goes on forever.

When they say, "space gets bigger every day" they really mean that all the matter in the universe is spreading out away from its center.

Answer 5

There are theories about the origin of the universe that suggest that our universe is a bubble of four dimensional space-time/existence in a super universe of unknowable characteristics. Theoretically, there can be 20-something dimensions (currently twisted up into the fabric of matter), so our bubble may reside in this multi-dimensional existence. In that case, there would be some kind of existence outside our universe, but we could never detect it and certainly never visit.

Answer 6

the space is Infinite, there is no end!
and if u made it in ur mind, wut will be there after the planets or after the sun, jst a HUGE empty space with lots of stars, and lots of other galaxy's, our galaxy is jst 0.001% from the Space, or maybe smaller than that, and imagine that u travel in space, will u go to a place and hit a wall?? a wall that stars are drawn on it??
that cant be!

Answer 7

Good observation. I think different people use the term infinity in different fashions.

Answer 8

They say this because the big bang caused the universe to keep expanding. The pressure from this explosion is still continuing from the big bang. So, it's constantly expanding.

Answer 9

big bang boom... everything in the universe is traveling away from everything else at high speed so space itself is getting bigger every day

Answer 10

yes is goes on forever, yes it gets bigger, it expends, if it stops then what is beyond the stopping piont? MORE SPACE!!!!