IT IS ONE of the biggest mysteries in cosmology—and getting bigger all the time. Ever since Edwin Hubble, an American astronomer, published observations of distant galaxies in 1929, scientists have ...

Because the Earth is doing the work of increasing the Moon's momentum, the Earth's rotation slows down in turn, as its momentum goes to the Moon. To put it another way, as the Moon's orbital momentum ...

Would you guess that the Earth is spinning at 1,000 mph around its axis and at the same time hurtling through space on its ...

People have been telling stories about renewable energy since the nineteen-seventies, when the first all-solar-powered house opened on the campus of the University of Delaware, drawing a hundred ...

The Moon appears unchanging in the night sky, but its movement hides a slow transformation. For decades, scientists have observed that our satellite is gradually moving away from Earth, year after ...