Cosmos

The next time you are enjoying the sun’s warm rays, think of the tremendous voyage those photons have taken to get to you. Traveling, by definition, at the speed of light they left their point of origin about eight minutes previously in a furious...

Why is the expansion of the universe speeding up, instead of being slowed by the gravitational attraction of galaxies and dark matter? What is the history of the Milky Way galaxy and of the chemical elements in its stars? Why are the planetary...