Concept
Gravity
The force that shapes the universe.
Described by Newton as a force between masses, and by Einstein as curvature of spacetime. Holds you to Earth, planets to the Sun, and stars in galaxies.
See also
Dark Energy
The mysterious force accelerating the universe.
Redshift & Hubble's Law
The fingerprint of an expanding universe.
Baryon Acoustic Oscillations
A standard ruler frozen into the early universe.
Reionization Epoch
When the first stars and galaxies relit the universe.
Cosmic Dark Ages
The long pre-starlight era of the universe.
Big Freeze
A possible cold, dark final fate of the universe.