# What is E=mc²

**E-mc² is the most well-known equation in modern physics , which represents the link between the transfiguration of the mass of something into energy and vice versa . The equation e=mc² was discovered by Albert Einstein in 1905 and is part of the Theory or Principle of Special Relativity .**

**As for the meanings of the equation e=mc², we have:**

**E = amount of energy.**

**M = total mass.**

**C² = speed of light (300 thousand km/s) squared.**

**Therefore, e=mc2 means that, in a given system (which can be an atom, a living being or a galaxy, for example), the amount of energy is equal to its mass multiplied by the speed of light squared.**

**According to the theory of relativity, the speed of light is the only constant in the universe. Due to their meanings, mass, time, space and energy are relative elements, while the speed of light in a vacuum is always the same, without interference from the reference adopted to measure it.**

**Among Einstein’s great discoveries for science, brought with the Theory of Relativity and the equation e=mc², is the notion that mass and energy are different forms of the same thing. The meanings of both are similar, as matter can transform into energy and energy into matter.**

**The e-mc² equation is of enormous importance for science, especially for physics, since such a formula makes it possible to determine the amount of energy in an object, even if it is at rest and is neither heated nor radiated.**

**What is E=mc²**

**In addition to its general meanings for contemporary science, Einstein’s theory of special relativity made possible the development of technological innovations such as atomic bombs and particle accelerators.**

**Although one cannot directly link the meanings of Einstein’s discoveries to the creation of nuclear weapons, his conclusions helped the understanding of nuclear reactions, that is, how a small amount of mass can be transformed into a gigantic amount of energy.**

**The meanings of Einstein’s theory were also indispensable for the development of modern imaging tests, such as tomography.**

**E=mc² book**

**The book E-mc², by David Bodanis, talks about the importance of the equation, which constitutes one of the greatest scientific discoveries in history. The author proposes to report the “biography” of E=mc².**

**E=mc² exercises**

**It is possible to find exercises on the internet about notions of modern physics, including the application of the equation e=mc².**

**E=mc² units**

**The SI units for the equation E=mc² are: energy in Joules, mass in kg, and constant (speed of light) in meters per second (m/s).**

**E=mc² tattoo**

**Among lovers of physics and science in general, the tattoo of the equation E=mc² is quite popular.**