"jughead" wrote in message
...
On Mar 11, 6:00 pm, Double-A posted this excerpt:

A planned gravitational wave space experiment, the European Space
Agency's Laser Interferometer Space Antenna (LISA) that will be
launched in about 10 years' time, will be sufficiently sensitive to be
able to reveal this radiation from RX J0806.3+1527 with a high degree
of confidence. Such an observational feat would open an entirely new
window on the universe."

Gravitational wave detection schemes are configured to detect
transversely-polarized/ quadrupole waves arriving from above. For
example see the LIGO system (pg. 6)-
http://zebu.uoregon.edu/~rayfrey/QNet/LIGO-2.pdf
Presumably VIRGO and LISA are likewise so configured. But if GWs are
not transversely polarized but rather are of *longitudinal*
polarization, these detectors will be deaf to the waves. The belief in
transverse polarization springs from the earliest days of general
relativity. It is rooted in the belief that space is a 'Void-Nothing'
and as such could not support longitudinal (compression-rarefaction)
waves. Therefore 'The Math' had to describe the premise of transverse
polarization and is modeled on the manner in which sound propagates in
solids, It has been "grandfathered" down to the present day, and
dictates the design of GW detectors

The kicker is - if space is *not* a Void-Nothing but a very real
medium that's compressible/expansible and amenable to density
gradients, GWs will be longitudinally polarized compression-
rarefaction waves exactly analogous to sound waves in air. The above
described detectors *might*, incidentally, be capable of hearing
longitudinal waves arriving laterally. In such a case, they would be a
scientific mega-boondoggle paling to insignifigance the HST primary
mirror fiasco.

$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$

I think LISA might detect them, because there is most
likely at least a small transverse component, and LISA
might be sensitive enough to detect it. Of course, the
kikker is that even if this happens, astronomers will
still be unaware of the much more intense longitudinal
component.

happy days and...
starry starry nights!

--
Indelibly yours,
Paine Ellsworth

P.S.: "Our intuitions about motion through space will usually
fail us if we try to apply them to the effects of space
expansion." Odysseus of alt.astronomy

P.P.S.: http://Astronomy.painellsworth.net
http://PoisonFalls.painellsworth.net
http://en.wikipedia.org/wiki/User:Paine_Ellsworth