So Tom argued (I think) that by the time the gravitons arrived the stars etc would have moved on in their motion - unless gravitons travelled faster than light.
I've seen his argument on that vis-a-vis the Sun and how its apparent direction would change by the time gravitons got to a planet.
From what I understand of the "regular" graviton argument, gravitons create fields; they are not responsible for direct interactions, so Tom's main argument does not necessarily hold any water. That said, there would seem to be a speed limit on how fast a gravity field could follow an accelerating mass. If that proved not
to be the case (where would we find such an experimental setup, though?), then perhaps Tom's idea might have some merit.
I can understand why he might find his own idea compelling - it sets up two media, like space and air carrying light and sound - the sound is limited by the speed of the air. Finding that the medium of gravity has a much higher permissible speed than the medium of photons and particles would allow for some equivalent of a faster-than-light "jet" (in the metaphor, propeller planes are limited to the speed of air), probably replete with "light boom". Fun, but unlikely :)
Pity he went out on a limb with man made structures on Mars.
Yes, seriously. I've hardly ever seen anyone with so much of a fetish for Cydonia. It was like his own personal Elvis sighting. It really did detract from pretty much anything else he said, which is too bad, because he at the very least seemed to have a natural grasp of orbital mechanics and some of its interesting implications.