I recently read on this forum a wonderful and easy to understand explanation of why we cannot travel faster than light.
Can someone please explain equally as simply the concept of folding space. If there is such a thing.

There are simular topics reguarding this in the Cosmology forum That you may be interested in.

I presume you're familiar with Einstein's General Theory of Relativity. In his theory, space-time itself has it's own geometry. It is such that you can imagine space-time as a flat grid with the properties akin to a cloth stretched over a drum. When an object of considerable mass, such as a star or planet, exists in space-time it creates an indent in the cloth - also known as a gravity well. This bending in space-time by mass is what we perceive as gravity. Gravity is a warping of space-time.

Geometrically, space-time is not flat though. It curves. One can conceive "the cloth of space-time" curving in on itself to create a fold. For example, the idea of wormholes is based upon the idea of "punching a hole" through the fold.

I hope this is what you were looking for.

About the only place you are going to see space folded is in science fiction. Dune is a good example. I do not expect man to ever achieve the technological means to actually produce this effect. It may be plausible to modify space time in another manner although it would not provide a means of travel. It might very well end the neccessity of travel.

I think Jabberwockey explained it as simply as possible, it's very difficult to imagine this sort of folded cloth or folded spacetime effect because it's a 4 dimentional effect. Picturing it is like trying to watch a 3D movie with one eye open. Just imagine spacetime as a stretched rubber skin like on a drum. It's usually flat. Now, lets say we place a heavy stone on it. (the stone resembles a star) now the rubber skin curves in towards the stone. If you roll a smaller ball like a marble (the marble resembles a planet of second star) it will spiral around the stone. Normally the scale is different because if you try this the marble will usually orbit the stone once or twice and hit it but in space the marble would be hundreds of times further and would take much much longer to fall into the stone. imagine the star as a very heavy soccer ball, the marble (if it were earth) would be the size of a kernel of popcorn and would be orbiting several meters away, also there is no friction to slow the marble in space, on the rubber skin, the rubber slows the marble down. There now we've defined spacetime. Now imagine this rubber skin, still stretched, was folded a few times. That is what folded spacetime is. Simple as that.
I hope this answers your question.

For the longest time it was so hard for me to actually picture how an object warps the space around it as described in the General theory of Relativity. The "rubber sheet" analogy is a good starting point. It leaves out one very important detail though ( I finally got this after reading a section in Brian Greene's book "The Elegant Universe", I know you are supposed to underline a book title, but I can't figure out how to on this form.) When you place a marble on a rubber sheet, the force that pulls the marble down, causing the warping effect, is gravity. This is not the case when the sun is "placed" on the "rubber sheet" of space-time. There is no gravity to "pull" the sun down when it is "placed" on space-time. The warping effect is due completely to the nature of the interaction between mass and the fabric of space. Mass warps space, thats all there is to it. I also want to note that I did not come up with this analogy, I stole it from Greene's book. This explanation was the apiphany that changed the whole way I viewed Einstein's theory of General Relativity.

P.S. Also the is an excellent illustration in the book on page 72 that depicts how space-time is warped by mass. It is the best picture I have seen that demonstrates how space is warped. I hope this helped someone out there like it helped me.

The Flatland analogy is good. Picture a 2-D civilization living on a sheet of paper. If you fold the paper down the middle, the people can quickly get from one side to the other without going through middle. Same principle with 3-D space-time folding.

PenguinEmperor,

I just had a thought about the rubber sheet analogy. lets say that two-space folded together as in your example. It would seem that the only way an inhabitant could cross the folded gap would either be (1) to enter three space, or (2) if the two sheets intersected and cohabited the same region of two space. Do you see what I mean? Even if the sheets were very, very close, they would still seem infinitely apart to a flatlander. Your thoughts?

Not infinite I don't think. They would just have to take the long way around to get to the other side - actually travelling along the fold.

brisk1: I'm pretty the space would actually overlap, so they wouldn't have to travel down through the fold.

Hi,
Nightout here!

Yes!
I know what you mean, with "PAPER"

There will be mean's off' that in the near future.
I think it will cost a "BOMB"

Good Luck...

There is another good book that talks about this topic its called "Hyper Space" by Michio Kaku. It is wonderful book about time warps, folding space, string theory, 10th dimension disccusion. A very good book and easy to read.

 To be able to 'fold' the universe for such travel is very improbable. Any such force would be too destructive to the universe itself. Gravity can pull and bend matter but that does not help exploration.

It would be impossible for a human body to pass through such a force unharmed.