Special vs. General Relativity: What's the Difference?
Both are Einstein's theories of relativity, but they cover different situations. Special relativity (1905) deals with objects moving at constant high speeds with no gravity; general relativity (1915) extends it to include gravity and acceleration, describing gravity as the curving of spacetime.
See the difference, explained visually.
Watch a 2-minute animated lesson comparing special relativity and general relativity.
At a glance
| Special Relativity | General Relativity | |
|---|---|---|
| Year | 1905 | 1915 |
| Covers | Constant-speed motion, no gravity | Gravity and acceleration |
| Key idea | Light's speed is constant for everyone | Mass curves spacetime |
| Famous results | E = mc², time dilation | Black holes, gravitational lensing |
| Relationship | The special case | The general theory (includes special) |
Which should you use?
Special Relativity
Special relativity applies when gravity is negligible and things move at steady high speeds — like particles in an accelerator.
General Relativity
General relativity is needed wherever gravity matters — near stars and black holes, or for precise GPS timing.
Frequently asked questions
- Why is one 'special' and the other 'general'?
- 'Special' relativity handles a special case — no gravity, constant speeds. 'General' relativity is the more general theory that also covers gravity and acceleration.
- Which came first?
- Special relativity (1905) came first; Einstein spent another decade extending it into general relativity (1915) by incorporating gravity.
- Do I need general relativity in everyday life?
- Indirectly — GPS satellites must correct for general (and special) relativistic effects to pinpoint your location accurately.