Relativity · Explainer
The time a clock actually measures.
Proper time begins with one clock, two events, and the path that connects them.
Branches of physics
Relativity & Gravitation
Space, time, motion, and the geometry of gravity.
Relativity · Research brief
A new search for galaxies that bend light.
Euclid’s Space Warps project brings citizen scientists into the search for strong gravitational lenses.