Cosmic rays are particles from outer space that travel across the universe. They can be made by the sun, by other stars exploding, and even black holes. They move extremely fast, nearly the speed of ...
The Doomsday Clock is a metaphor that represents how close humanity is to self-destruction, due to nuclear weapons and climate change. The clock hands are set by the Bulletin of the Atomic Scientists, ...
The Hubble constant is one of the most important numbers in cosmology because it tells us how fast the universe is expanding, which can be used to determine the age of the universe and its history. It ...
The Earth formed over 4.6 billion years ago out of a mixture of dust and gas around the young sun. It grew larger thanks to countless collisions between dust particles, asteroids, and other growing ...
In 2016, a University of Chicago scholar stumbled across an extraordinary piece of writing that had been lost for nearly two centuries—one of the few firsthand book-length accounts of slavery, and ...