Science now believes that space is curved.?

Question

If you travel in a straight line in space, you will meet yourself on the way back. If this is so and you could travel at the speed of light how do you get to another universe?

Answer 1

You don't. Space is curved in such a way that if you were able to travel faster than the speed of light in a straight line you would end up back where you started. The only problem is that it would take all the mass in the universe to provide the energy needed for such a trip so that there would be no universe to see when you got back. It is not possible to get to another universe since they are a seperate set of dimensions that our physical bodies can't even exist in.

Answer 2

Hmm, so many misconceptions in that question...

First: the space that makes up the universe is "flat" to a very high degree -- what little "curve" there is barely takes us away from flat. That "curve" doesn't mean a 3-dimensional curve, though -- it has to do with how the universe is expanding, and whether than expansion will continue forever or eventually gravity will get the better of expansion and it'll start contracting.

Second -- you can't travel at the speed of light.

Third -- there is no evidence that there are any other universes. Speculation, yes. Evidence, no.

Finally...we've known that space is "curved" since 1919, when Arthur Eddington confirmed Einstein's theory of relativity by measuring the positions of stars near the sun during a total solar eclips. Sure enough, as relativity predicted, the stars' positions appeared to change as the sun's mass bent space around it.

Answer 3

A good analogy for this curved thingy is:

If you were to get in a 'plane that was able to fly around the World without re-fuelling, and you were awake all the time, what you would see is land underneath you all the time - and it looks flat.
So, being the intelligent person you are, you've got to assume that at some stage in the flight, the land will run out and you fly into space.
But what's actually happening is your travelling (flying) in a straight line that is slightly curved - and you miraculously land in the airport you took off from despite travelling in an apparent straight line away from where you took off.

Same sort of thing in the Universe.

As to jumping from one Uni to the other is like asking the pilot to land on Mars. Awfully difficult, and needs lots of wee bags of salted nuts.

Answer 4

You two topics are probably unrelated.

It is possible that the 3-D universe is actually a sub-space of a higher-dimension space (mathematically speaking). An analogy would be to consider Earth's surface to be a 2-D object, inhabited by 2-D beings (e.g., flatlenders) who cannot perceive a third dimension.

As far as they are concerned, Earth's surface is boundless (no end point, no wall). Because Earth's surface has positive curvature, if a flatlander were to travel in a constant direction, he would eventually pass over his start point (after going all the way around the Earth). For us, 3-D beings, it would be clear that he did not go in a straght line, but actually turned around Earth's centre (halfway around Earth, he was actually pointing the opposite way from our point of view, but not from his).

Mind you, by the time he reaches his departure point, he does not meet himself because he had left earlier...

As for going at the speed of light:

It appears that our perception of the flow of time changes as speed increases (relative to another frame of reference). This is necessary for the speed of light to be perceived as the same in all frames of reference.

Lorentz's equation has this flow vary as the inverse of SQRT(1 - v^2) where v is the speed expressed as a fraction of the speed of light.

If it were possible to travel at the speed of light in relation to some frame of reference, then, if Lorentz time dilation is still true at such speed, the perceived elapsed time for any trip of finite distance from a point A to a point B will have to be 0. This means that from the traveller's perspective, the distance from A to B must be zero. Since this is true for any points A and B in the Universe, then that means the entire visible Universe has size zero.

It also means that the traveller, leaving from a point A at the speed of light, cannot tell the difference between his destination B and any other point C, since all points are a distance zero.

So, even if he meets himself, he wouldn't know.

Answer 5

I've read your question about 3 times, and it still doesn't make sense.

Yes, space and time is curved - but you wouldn't meet yourself, you'd just end up in the same place eventually. You cannot travel faster than light under any circumstances and we have no idea whether or not other universes exist or not.

Answer 6

Space is probably not curved as such.
Intense gravitational fields may distort it locally.
At the big bang a 2 cm diameter ball had a curved surface.
It was filled with the quanta produced by the first space-time pulse.
If you filled a big cube with ball bearing would you define the ball bearing as square?

Answer 7

No. In order to come back to your starting point the system has to be closed. Space is curved, but it is curved both up and down, yield a flat surface when viewed from an outside angle. Remember that everything is relative to your point of observation.

Answer 8

they mean space is the total space and I have heard this before, so it is like a big ball really, because of the curve. But the thing I want to know if space is a ball and curves what is space contained within.

Answer 9

You go sideways or upwards!!!

Actually, you should have said that we are traveling in a straight line from our point of view, since our paths would have to be curved in order for us to meet ourselves on the way back.

Answer 10

Latest theoretical physics says that the universes are actually membranes (and the Big Bang was a collision between two 'branes) so to get to another universe, you would have to reach the end of ours and cross the 'brane - because space isn't literally just curved, it has wormholes and loops and flat bits too.