The concept that mass and energy are equivalent and can be converted into each other.
Special theory of relativity: A scientific theory that explains the fundamental principles of time and space.
Principle of Equivalence: Within special relativity, all fundamental forces (including gravitational forces) are treated as equivalent forces.
Kinetic energy: The energy that a body has due to its motion.
Work: The energy of motion transferred by force acting over a distance.
Conservation of energy: The principle that energy cannot be created or destroyed, only transformed from one form to another.
Rest mass: The mass of a body when it is stationary relative to an observer (also known as "invariant mass").
Energy-momentum four-vector: A mathematical concept that combines the energy and momentum of a particle.
Lorentz transformation: A mathematical tool used to describe the way measurements of space and time differ between observers moving relative to each other.
Mass-energy equivalence: The concept that mass and energy are interchangeable, and that the total energy of a body is equal to its rest mass plus its kinetic energy.
Radiative processes: The emission and absorption of electromagnetic radiation by particles.
Nuclear reactions: Processes that involve the conversion of one or more atomic nuclei into different nuclei, along with the release or absorption of energy.
Particle accelerators: Devices that use electric and/or magnetic fields to accelerate charged particles, often to very high energies.
Nuclear power: The use of nuclear reactions to generate electricity.
Cosmology: The study of the origins, evolution, and overall structure of the universe.
Black holes: Regions of spacetime where the gravitational field is so strong that nothing, not even light, can escape.