What does the "bulk" look like?

[Polish3d]

Short synopsis from Wikipedia:

"The central idea is that the visible, four-dimensional universe is restricted to a brane inside a higher-dimensional space, called the "bulk". The additional dimensions may be taken to be compact, in which case the observed universe contains the extra dimensions, and then no reference to the bulk is appropriate in this context. In the bulk model, other branes may be moving through this bulk. Interactions with the bulk, and possibly with other branes, can influence our brane and thus introduce effects not seen in more standard cosmological models."


So... what might the "bulk" be like? Are they envisioning little self-contained universes moving around a much larger space? With the extra-dimensional aspect can it even be described in four dimensional terms?

If so, what might it be like?

 

[lyssword]

alternator-sized. You can buy it online, like 10lbs :laugh:

One of the things I heard is that the extra dimension might be like a pipe. You look at it and see only the surface and how tall it is. But since it's curved, stuff might be sticking to inside walls of the pipe or on top of the pipe's surface. Then imagine even more complex shapes

 

[m1ldslide1]

Originally posted by: lyssword
alternator-sized. You can buy it online, like 10lbs :laugh:

One of the things I heard is that the extra dimension might be like a pipe. You look at it and see only the surface and how tall it is. But since it's curved, stuff might be sticking to inside walls of the pipe or on top of the pipe's surface. Then imagine even more complex shapes

Yeah, I thought of bulk beef first and foremost also.

For some reason I'd been picturing the 'bulk' as a sort of fabric, kind of like a hanging shower curtain that is swaying and flowing next to infinite other shower curtains in all directions. Probably just because that's one of the graphics from the Nova string-theory special.

Carl Sagan also talked about extra dimensions to some degree in Cosmos. He couldn't fully describe them, as that would be kind of a paradox (at least to my mind), but he did talk about how you can strain your mind to try to get the idea.

 

[DivideBYZero]

Beaten to it.

 

[Born2bwire]

Originally posted by: DivideBYZero
Beaten to it.

I came in here just for that reason too.

 

[bwanaaa]

the bulk..i love it. what if our universe is just the manifestation of a wave through space. other universes are just similar waves that precede and follow. but unlike light waves which spherically spreads out from the point source, (and all of which are visible in 3d space), these waves a "4 dimensional" . they impress an organized array upon all the matter and energy in space. the waves may infact be spreading through the bulk just as light waves spread through 3 space. but because everything we sense is "riding the wave" our frame of reference does not allow detection of other waves. other universes may therefore be right next to us, co mingled in time and space-a simpler analogy might be like threads in fabric- but since we live in a thread (like the residents of the book 'flatland'), we cannot detect the other threads (except perhaps indirectly)