The universe is comparable to the surface of an expanding baloon?

Question

If this is so than if I set off in one direction than I would theoretically return to my stating point, correct? I have heard that space is actually expanding faster than light so this would never be able to happen as I wouldn't even be able to keep up with space if I was traveling at a significant portion of the speed of light so heres another scenario.

Lets say there are several alien civilizations called A, B, C, D, and E that all started broadcasting signals at the same time and are equally space apart along a straight line galaxy cluster spanning the entire universe from left to right from our perpective. Alien civilization B knows that civilizations A and C exist because they are close enough to have received both A and C's signals. C knows about B and D. D knows about C and E. Could E then know about A and D?

Answer 1

Yes, assuming they are equally spaced along a section of the sphere.

Actually it's thought to be a hypersphere, although that's purely speculative. Think of it this way: A one dimension construct (aka a line) curved and wrapped around two dimensional space becomes a circle. A two dimensional construct (aka a plane) wrapped around three dimensional space become a sphere. A three dimensional construct wrapped around a four dimensional space becomes a hypersphere.

Having said that, we can disregard the fourth spatial dimension for the sake of hypothesis and simply call the universe a sphere. Using our own planet as an analogy, pretty much all the early civilizations knew of the ones close to their own, but the Japanese probably didn't know anything about the Celts in Britain because they were so far apart.

Since then, however, the Americas and Pacific Islands were eventually discovered and colonised. Nowadays flights from one continent to another in either direction are an ordinary affair.

Answer 2

You have the idea wrong, it's not the same exact.  You're assuming the universe is this giant ball of thing.  What they're comparing to the expanding balloon is the Universe expanding, not getting more matter, just stretching out.

No, you wouldn't be able to do that, as for your question, since the universe is expanding at a faster rate then light then neither signal would reach any points, since the universe would be expanding to quickly.  The signals aren't fast enough to keep up with the stretching distance.

ASSUMING THAT'S WHAT YOU MEANT BY YOUR QUESTION.  IT WAS A LITTLE DIFFICULT TO UNDERSTAND.

Answer 3

no, if you set off in one direction without turning around, you will never get back to the starting point. And A wouldn't know about E at all they are the farthest apart duh

Answer 4

I don't personally believe that theory but if it was true then no, e wouldn't know about a because their signals don't travel at the speed of light

Answer 5

It is expanding faster than light, but that has nothing to do with light not being able to go anywhere in the universe. If it were we couldn't ever see stars or galaxies or quasars. As for the actual question, the universe doesn't have physical "boundaries". There's no brick wall at the edge. I don't know exactly what shape it is, but since it doesn't have a physical edge i don't think it could be a sphere as in the case of the earth. E would know about D but it would take longer for the signals from A to reach it. A better representation is to put dots on a cut rubber band (so its flat and not a loop anymore) and stretch the rubber band. Still, you might want to look more into this. It's quite interesting.