1905Reputable sourceWell documented
Einstein's Special Relativity
On the timeline · around 1905 ·
What happened
In his 'miracle year' of 1905, Einstein published the special theory of relativity, showing that the speed of light is the same for all observers and that space and time are not absolute but relative to the observer's motion. From it came the most famous equation in science, E = mc², linking mass and energy.
Why it matters
Special relativity overturned the Newtonian ideas of absolute space and time that had reigned for centuries, and its equation E = mc² revealed the enormous energy locked inside matter — later unleashed in nuclear power and weapons.