Why does only one side of the Moon face the Earth?

Synchronous rotation does not last very long. To maintain this pattern requires some power. The center of gravity of the moon may not be in the middle of the moon.

Since the rotation cycle of the moon is the same as the time it takes for the moon to circle the earth, one side of the moon is always facing the earth. This is called Tidal Lock. This demo at Wikipedia shows how it works well.

Yes, in this configuration there is the power to support the earth and the moon, it is the gravity between the earth and the moon.

We know that the tide on the earth is caused by the traction of the moon. Instead, the earth drags the moon under the influence of gravity and creates bulges on both sides of the moon. When the moon does not rotate and rotates in the same period, the bulge no longer faces the earth directly and does not go near the earth. The gravity on the two protrusions becomes nonuniform, creating the torque to rotate the same side of the moon back to the earth. The "lock" phase is the most stable geometry of the earth and moon systems. Just like a ball rolling in a valley, even if the ball begins with a mountain, the ball is dragged to the bottom of the valley by gravity.

It is not unusual for this tide to be trapped in the solar system. For example, Pluto and its month card are trapped in a very close orbit.

The sea on the side of the moon facing the moon will be pulled toward the moon more than the center of the earth. This created a climax. On the other side of the earth another climax occurred because the center of the earth was pulled toward the moon instead of the distant sea. As a result, the planet is basically pulled apart from the ocean (a negative force that effectively separates the ocean from the sea). But there is no big difference between the gravity effect of the moon on one side of your body and the other on your side. Even the big lake, the tide is very small. For example, in the Great Lakes, the amount of tsunami does not exceed 2 inches, according to the National Oceanic and Atmospheric Administration (NOAA). "These small changes are covered by fluctuations in the water level caused by changes in wind and barometric pressure, so the Great Lakes are basically regarded as tideless."

We know that the tide on the earth is caused by the traction of the moon. Instead, the earth drags the moon under the influence of gravity and creates bulges on both sides of the moon. When the moon does not rotate and rotates in the same period, the bulge no longer faces the earth directly and does not go near the earth. The gravity on the two protrusions becomes nonuniform, creating the torque to rotate the same side of the moon back to the earth. The "lock" phase is the most stable geometry of the earth and moon systems. Just like a ball rolling in a valley, even if the ball begins with a mountain, the ball is dragged to the bottom of the valley by gravity.

The full moon is the phases of the moon when the whole moon is illuminating the earth. This phase occurs when the earth is between the moon and the sun. About a week later, the moon entered the quarter of the lunar month. At this point, half of the moon can be illuminated from the ground, so the moon looks like a semicircle. When the moon moves between the earth and the sun, the side facing the earth is completely dark. This is called the New Moon Phase, and we usually do not see the moon at this point. Sometimes, you can hardly understand the outline of the new moon in the sky. This is because a part of the sun reflects off the Earth and hits the moon. Before and after the quarter moon phase are uplift and new moon phase. During the expanse of the lunar moon, the moon was illuminated more than half, but it was not full. At the new moon stage, the moon is considered to have less than half the brightness, having only one sliver or crescent shape.