So I was sitting around, thinking of nothing in general, when the idea struck me that to me gravity seems instantaneous. Realizing this is rather unlikely (many people at one time would have regarded light as instantaneous as well), I googled speed of gravity. Well, it seems the only experiments conducted as yet have been flawed, and this puzzles me. You see, it occurs to me that if the speed of gravity is different from light, then we have in our hands an entirely new way of communicating, among other things. If this is significantly faster than light, then the possibilities in my mind are endless (and I shall not list them all here.. lol). So I propose two experiments, one to determine the speed of gravity here on earth, and one to determine its speed in a vacuum, if different (but somehow, I doubt it is... common sense just tells me otherwise): 1. We place an electromagnet on one side of the earth. On the opposite side we place a detector. We pulse the magnet. Given the diameter of earth (about 7900 miles) and the speed of light (about 186,000 miles/second in a vacuum), there should be a .0425 second delay if the speed of gravity is the same as that of light (in a vacuum). This is a very detectable delay by modern electronics. In fact, a shorter distance should easily suffice; say, Caltech to MIT or something. This would decrease the necessary strength of the magnet considerably. 2. Same thing, but from a satellite to something placed on the moon, or another satellite, etc, provided they are in a high-enough orbit to be effectively in a vacuum, and far enough apart for the delay to be detectable. Now. Surely I am not the only one with this thought, so why hasn't this happened. Can we not detect changes that minute in the gravitational field? Can we not create a magnet powerful enough? It wouldn't need to be pulsed long enough to start drawing in cars, buildings, lab techs with too high a blood-iron count, etc., so there shouldn't be a "public danger" argument... Why can't this be done??