Einstein’s mass-energy relation
Quick Summary
Albert Einstein's famous equation, E = mc², reveals that mass and energy are fundamentally the same and can be converted into each other. This means that even a stationary object possesses "rest energy" equal to its mass (m) multiplied by the speed of light (c) squared.12
When energy is released from an object, its rest mass decreases. This principle is evident in everyday chemical reactions but is far more pronounced in nuclear reactions, such as the fusion of hydrogen into helium in stars like our Sun. The equation is a cornerstone of special relativity and is crucial for understanding subatomic particles.21
Ask Britannica AI about this topic
Britannica doesn't have a full article on this topic, so we've curated a list of our relevant coverage.
