Far side Quote by Leonard Susskind

““Let’s return to the question of the ocean tides. The cause of the twice-daily rising and falling of the seas is exactly the same as the cause of the 2,000-Mile Man’s discomfort: the non-uniformity of gravity. But in this case, it’s the Moon’s gravity, not the Earth’s. The Moon’s pull on the oceans is strongest on the side of the Earth facing the Moon and weakest on the far side. You might expect the Moon to create a single oceanic bulge on the closer side, but that’s wrong. For the same reason that the tall man’s head is pulled away from his feet, the water on both sides of the Earth—near and far—bulges away from it. One way to think about this is that on the near side, the Moon pulls the water away from the Earth, but on the far side, it pulls the Earth away from the water. The result is two bulges on opposite sides of the Earth, one facing toward the Moon and the other facing away. As the Earth turns one revolution under the bulges, each point experiences two high tides. The distorting forces caused by variations in the strength and direction of gravity are called tidal forces, whether they are due to the Moon, Earth, Sun, or any other astronomical mass. Can humans of normal size feel tidal forces—for example, when jumping from a diving board? No, we cannot, but only because we are so small that the Earth’s gravitational field hardly varies across the length of our bodies. Descent””

— Leonard Susskind