Dictionary

free

In the context of relativity theory, a particle (object, observer…) that is not acted upon by any force except gravity is said to be free or, a bit more specific, to be in free fall. Free test particles play an important role in understanding the structure of general relativity.

What is Einstein Online?

Einstein Online is a web portal with comprehensible information on Einstein's theories of relativity and their most exciting applications from the smallest particles to cosmology.

Einstein Online is provided by the

Max Planck Institute for Gravitational Physics
(Albert-Einstein-Institut)

About Einstein Online

Includes information on our authors and contributing Institutions, and a brief history of the website.

Glossary

More than 400 entries from "absolute zero" to "XMM Newton" - whenever you see this type of link on an Einstein Online page, it'll take you to an entry in our relativistic dictionary.

a b c d e f g h i j k l m n o p q r s t u v w x y z