Quick answer here, but perhaps further discussion should move to
Science, lest we be declared OT.  THIS topic is nothing if not
"technical", but not quite what is expected.

 PR> So what keeps the
 PR> first 2-D universe from detecting all those masses from neighbors.
 PS> Well, how would you distinguish the gravitons from "here" from
 PS> gravitons from  "there"? They would come from the same
place and thus it
 PS> looks like they all were generating by mass in the first 2
 PS> D universe.

Exactly.

 PS> Also, it would depend a lot on how well gravitons travel
 PS> between universes. Maybe they lose a lot of energy so that

The "transdimensional" gravitons are supposed to explain how the
gravitational force is so much numerically weaker than the
EM/Strong/Weak forces.

 PS> gravitons from rather light objects (say, a planet) don't
 PS> make it. That would mean that galaxies and clusters would
 PS> be in the same spots in parallel universes, but stars and
 PS> planets don't have to be.

Think about it.  That would mean the gravitational force we experience
on the Earth is greater than in the stellar environment?  Not true.
The equation for the moon around the earth uses the same "g" as the
earth around the sun.  When it comes to galaxies, that would be exactly
the wrong direction--we have to hypothesize "missing mass" to explain
the Doppler shifts.  Got a tagline for you.  ;-)

 PR> Summed, you've got as much gravity as if the gravitons never left it
 PR> in the first place.
 PS> Yep. No way to find out which is really happening. Unless

My point is, I could quickly think of a number of fairly obvious serious
questions with the theory which were not addressed with this TV show, so
I felt it wasn't well done.  I hope the book addresses them.

... Please insert another quarter and try again.
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