The Hubble constant, explained
One of the most important numbers in cosmology, the Hubble constant tells us how fast the universe is expanding, which in turn tells us the age of the universe and its history.
The solar wind, explained
First proposed in the 1950s by UChicago physicist Eugene Parker, the solar wind is a flow of particles that comes off the sun at about one million miles an hour.
The Doomsday Clock, explained
The Doomsday Clock is a symbol that represents how close humanity is to self-destruction. The clock hands are set annually by the Bulletin of the Atomic Scientists, a group formed by Manhattan Project scientists at UChicago after World War II.