Natural Science Forum / Physics / General Physics / September 2007

[Shrugs] You cant try to tackle wormhole or warpdrive problems by
assuming flat spacetime, and some would say you can't even do
cosmology properly assuming flat spacetime.
Most of the interesting stuff to do with optics involves bending
lightbeams, or dealing with the particulate aspects of matter that
special relativity explicitly doesn't attempt to deal with. Gravity is
also an interesting thing, and that doesn't play nice with special
relativity either. Ditto gravitomagnetism.

And the quantum gravity guys are increasingly adopting acoustic
metrics to try to model things like trans-horizon radiation, which
work well in some archaic models, but are incompatible with modern
SR-based GR.
Quantum principles also intrude into larger-scale subjects like
sociology and economics, and you can think of the "market forces" idea
as being a precursor to QM, as a way of reducing the bulk reaction of
a complex chaotic (and largely undefined) system to a series of
applied potentials and reactions.

So there's all sorts of cool stuff that you can study scientifically
outside special relativity, by pretending that the special theory
doesn't exist. Not all that interesting stuff would normally be
classified as relativity theory. In fact, most of it wouldn't.
Gravity, quantum theory, system behaviour cosmology ... a lot of
people would say that those things are just "physics".

The original idea of the book was to try not to mention SR at all.
But as the book grew, I reckoned that I was probably going to be
expected to give the thing a cursory runthrough, just to be able to
say to physics people, yes, the theory exists, yes I understand it,
and no, its not neccessarily all that relevant to the more interesting
problems involving particles, warped spacetime, and attempts to
combine the two together, that I want to explore.

=Erk= (Eric Baird)

Cheers!
 If //I'd// posted that here, people would have told me off for
posting something that the ng charter says not to post.  <grin>
The idea was to do any SR-based debates regarding the book's contents
over on s.p.r, and the other physics debates here on s.p .

One of the questions asked in the book is whether we might be able to
extend the "curved-spacetime" paradigm all the way down to quantum
mechanics.
On the small scale, QM allows a moving particle to interact with
nearby light by the magic of quantum field theory, on much larger
scales, GR generates analogous interactions between matter and light
thanks to gravitomagnetism. On the medium scale, we know that
composite particulate objects drag light along, too (e.g. the water in
Fizeau's tubes), even though they're larger than quantum-scale, but
too small to normally be considered as having significant conventional
gravitational fields.

Since all these forms of dragging ought to affect lightbeams, they
ought to //all// be reconsiderable as problems in curved spacetime.

If they can, and if we can produce a single set of curvature-based
rules that works across all scales, then all these tedious ongoing
arguments about SR, which led to the subject being exiled to its own
newsgroup, become irrelevant. Even if one accepted the perfection of
SR as an abstract mathematical system, if real physics was built on
curvature there wouldn't be a "flat-spacetime domain" in real physics
for the SR equations and Minkowski metric to apply to. The Minkowski
metric could be reconsidered as a perfect, provably-correct answer to
an unphysical question.

Instead of having to put up with another thirty years of tedious
arguments about the pros and cons of SR, we could exile these debates
not just out of sci.physics, but out of physics altogether.

Some sci.physics people might like that idea. <g>

hmmm. Maybe I should start another thread here specifically on
spacetime curvature, and on how far people think the idea can be
taken, in which nobody is supposed to use the "R" word ... should be
possible ...

=Erk= (Eric Baird)