"Mike Williams" wrote in message
...
Wasn't it Chris.B who wrote:
Wouldn't multiple dimensions require some rather strict
cross-dimensional physical placement? The leakage from even a small
black hole popping up on the dining table is apt to spoil ones
appetite. Surely any cross-dimensional gravitational effects should be
detectable?

It depends how close the next universe is. If the nearest brane that
contains matter happens to be the equivalent of a few tens of thousand
light years away, then the gravity that leaks into our universe would be
smeared out as if it were coming from diffuse invisible sources the size
of a galaxy.

What if the "other" branes containing matter/energy are exactly colocated
with our universe, but "folded up" to sub-Planck lengths and hence
undetectable. Matter/energy "here" corresponds exactly with matter/energy
"there" and what we perceive and measure as our physical reality is in a way
just the tip of the iceberg. The "distance" then is not physical...

Too much wine and not enough maths perhaps.....