What if the Moon was closer?
Today in physics class, my teacher talked about the moon. He said that the moon is moving away from Earth each year by a certain distance. Can you tell me the actual annual movement of the moon away from Earth? Thanks Reply The average rate at which the moon recedes is 3.8 cm per year, about an inch and a half. See http://www.talkorigins.org/indexcc/CE/CE110.html This happens (and your teacher might have said so already) because of the tides in the oceans. The moon pulls the water into a wave which tries to remain pointing at the moon; the moon also pulls the entire Earth, leaving behind a second crest of the tide-wave on the opposite side of the Earth. The two crests try to line up with the Earth-Moon direction, but the rotation of the Earth under them causes them to collide with shorelines. Such collisions slow down the rotation of the Earth and give up energy, whose ultimate source of that energy is the rotation of the Earth and the motion of the Moon. However, by Newton’s 3rd law,
