# Bulk Drive

1. Oct 18, 2007

### Toastus

Could the Bulk possibly be used as a hyperdrive?

2. Oct 18, 2007

### BenTheMan

You'd have to understand gravity a whole hell of a lot better than we currently understand it...

Also, in models with a bulk, the matter is sometimes localized to a brane, so it might be utterly impossible.

3. Oct 18, 2007

### FTL_Diesel

I think that it would depend on the topology of our brane as well, but higher-dimensional topology is not something I know.

Still, if you look at the evidence for the visible universe being flat, and thinking about the analogy of a flat 2D brane in a 3D bulk; it seems to me that travel through the bulk would add distance onto your path.

4. Oct 18, 2007

### robousy

5. Oct 19, 2007

### Toastus

I would think that there would be some way to get yourself off of a brane without ripping your strings off and closing them. If there was a hole in a brane, would you be able to go over it and float off, or would it be like a barrier, so you couldn't go in it?

I meant if it had properties of hyperspace in fiction, such as particles travelling much faster, or higher lightspeed (even though there is no light in the bulk).

I never saw that... I know next to nothing about anything said in that, but it looks like the warp drive. I guess. :)

Would the Bulk possibly have the properties of hyperspace? And, if so, how could we get to it?

6. Oct 19, 2007

### BenTheMan

In many cases, matter JUST DOESN'T propogate in the bulk---there's no way around it.
Take a five dimensional orbifold GUT, for example---there are some fields which are stuck to the brane in the sense that they have no wavefunction in the fifth dimension. If the fields are stuck to the brane, there is absolutely no description of them off of the brane.

In some string models, matter is localized on a brane. In Type II strings, for example, open strings (by definition) end on a brane. So, again, there is no way to really describe an open string that DOESN'T end on a brane. As far as I know, the branes are space-filling and cannot have holes in them.

This said, there may be ways to do it. For example, in some orbifold GUT's, one can put one generation of SM quarks and leptons in the bulk, and two families on the brane. In this case, one could concievably build a ship out of top quarks, bottom quarks, and tau leptons, which would live in the bulk. Note that this is pretty hard to comprehend, considering that they can make only one top quark a second at LHC, and to get enough top quarks to do something with (not to mention the fact that they decay in a fraction of a second), you'd need ~10^25 or so.

You should beware that this is PURE speculation. (I wish I could write PURE in bigger letters!)

I remembered this paper, I just didn't want to link to it because people are sometimes funny about having there names associated with their online identities. I obviously don't care (people only have to look at my myspace page that is linked in my profile), but I didn't want to out you online :)

The way I remember it, you locally change the cosmological constant to ride a space-time wave, of sorts. Right? This would be understanding gravity a whole hell of a lot better than we do now''.

7. Oct 20, 2007

### Toastus

If only quarks are able to go through the bulk, would it carry you with it, or would you be left on our brane?