He did this through his famous paper on mass-energy equivalence, which introduced the equation E=mc². This equation demonstrates that energy (E) and mass (m) are interchangeable, with the speed of light (c) acting as a conversion factor.
While Einstein's work didn't directly address nuclear power as we understand it today, it laid the theoretical foundation for the understanding that tremendous amounts of energy could be released from the very small amount of mass contained within an atom. This concept would later be used to develop nuclear weapons and nuclear power.
