Q. In your review of "Independence Day," referring to the gigantic alien space craft, you write: "an object that size in near-Earth orbit might be expected to cause tidal waves." Tidal waves, or tsunamis, are caused by sudden earth movement, not extraterrestrial objects. However, a craft one-fourth the mass of the moon, if at the same distance as the moon, would result in tides (not tidal waves) approximately 25% above normal--not fun but tolerable. If the mother ship were located one-half the distance of the moon, tidal influence of the ship would be equal to that of the moon. BUT, its orbital speed would be substantially faster, resulting in wild tides. The closer the object, the worse the effect. If the object were in close earth orbit, it wouldn't need "death rays" to destroy cities; since most major cities are seaports, they would be ravaged by wild tides. I suspect this is what you meant and it is a excellent point. (Richard George, San Jacinto, Ca.)

Continue reading →