[andy_card]

The friction from the tides of the moon and sun, the atmosphere, and the internal magma should add up to more than a millisecond every hundred years as is now observed.

I think you've underestimated it. As I understand it, the earth's rotation is slowing approximately .005 seconds per year, which would add up to half a second per century. That still doesn't present a problem, even extrapolating back 4.6 billion years. I'm not at all sure what you're trying to argue.

[#3Fan]

I think you've underestimated it. As I understand it, the earth's rotation is slowing approximately .005 seconds per year, which would add up to half a second per century. That still doesn't present a problem, even extrapolating back 4.6 billion years. I'm not at all sure what you're trying to argue.

[sigh] You are making a common mistake of thinking that since we're adding a leap second every ten months that the earth's rotation is slowing by a second every ten months. The earth has slowed by about 2 milliseconds in the last 179 years. When you consider the tidal frictions generating heat in wind, magma, and the oceans, it should be slowing more. It's x amount of milliseconds per day per century!