Experiment This Weekend To Measure Speed Of Gravity
An anonymous reader writes: "Is gravity an instantaneous phenomenon, as we were taught in high school, or is its speed, like all other Einsteinian phenomena, bounded by the speed of light? A radical new experiment, proposed by Sergei Kopeikin, and involving the Very Long Baseline Array, is set to occur this weekend, and results should be known within about two weeks."
If it's instantaneous, then that would provide a means of faster-than-light communication. Of course, it's probably impractical, as the amount of mass we would have to move to be detectable at a significant distance would be prohibitive. ...unless you had some way to implement gravity shielding, and turn it on and off like smoke signals.
Fun to think about. Probably more practical for a science fiction story than reality.