Gravity, light, no rainbow......part of the Unified Pynchon Theory

[Monte Davis]

The Newtonian view of gravity was more or less contemporaneous with "light
has a finite speed" but 150 years before any developed field theory existed
to pull together all kinds of jiggling around with magnets and charges. So
it treated gravity as "existing in place" and didn't have anything to say
either way about questions such as "If the Sun ceased to exist -- or were
jiggled back and forth -- would the Earth's motion change at once, or would
it take time to 'get the news'..?"

>From the late 19th century on, and certainly after Einstein, the conviction
grew that it was the latter -- that  changes in a gravitational field must
propagate at the speed of light. Trouble is, the intrinsic strength of
gravity is almost 40 orders of magnitude less than that of electromagnetism.
So its waves are corespondingly harder to detect; at present we can hope to
detect them only from giga-events such as black holes forming or coalescing.
The waves also take a unique form: instead of changes in some flow of energy
"going past" a point, like a light or sound meter, you'd detect
gravitational waves by the alternate lengthening and "widthening" of a
reference object, or (in the most sensitive current work) the alternate
lengthening of two precisely known light paths at right angles to each
other.

There's been no 100% agreed-upon and unambiguous detection yet, but
physicists would be very very surprised if there *weren't* such
gravitational waves or if they *didn't* travel at light speed.