FYI:
The slowing of the Earth's rotation is due to the Moon. Through certain tidal effects that I will describe below, the Earth is transferring its rotational energy to the moon's revolving energy, causing the Earth to slow its rotation and causing the Moon to raise its orbit around the Earth.
The Earth is mostly covered with water, which is obviously a very easily moved substance. The moon's gravitational pull is stronger on the near side of the Earth than the far side (because gravitational force decreases at the square of the distance), so the water gets pulled harder on the near side. This, of course, causes tides. As the Earth rotates, the area that the moon pulls on strongest changes. The tide moves with the moon. But water has momentum and inertia, and cannot perfectly follow the moon. It lags behind a little, causing there to be more mass on one side of the area of the moon's peak pull than the other. Since mass creates gravity, there is more gravity on that side. This pulls on the moon a bit, accelerating it. This also pulls on the Earth, slowing its rotational speed.
Interesting, eh?