Equation Invasion

The world's most famous equation is probably **
Einstein's
E=mc2
**. Einstein made an astounding discovery about the relationship between **
energy
** and
**mass**
, and put it into this formula. What does it mean?

**E = ENERGY**

**Energy makes things happen, such as making objects move or get hotter.****Energy often changes from one form to another. It comes in many forms, such as heat and light.**

**Equal sign = THE BIG THING**

**The equal sign let's us compare and connect two things that are equivalent. For example, 1 dollar = 100 pennies.****E=mc**^{2}compares and connects mass and energy.**E=mc**^{2}explains how much energy is in any amount of matterâ€”the more mass something has, the more energy it has.**Since****c**^{2}is such a huge number, a little bit of mass contains a huge amount of energy.

**m = MASS**

**Mass is the amount of "stuff" an object has.****Mass isn't connected to size.****Same-sized things can have different masses. For example, a box of tissues is the same size as a brick. But they have different massesâ€”and different results if you drop one on your foot!**

**c ^{2} = SPEED OF LIGHT SQUARED**

**c = the speed of light = 670 million miles per hour = 670,000,000 mph.****In this equation, c is squared, which is 670 million mph x 670 million mph. That's a big, big number!****c in the equation comes from the latin word celeritas, which means "swiftness."**

Converting the tiny mass in a paper clip into energy could light millions of homes for a year!

Photos: Michael Shara: courtesy of Denis Finnin, AMNH; Illustrations: Equation Invasion: Tony Persiani; Everyday Einstein: Daryll Collins; Light the Way: Space cop: Daniel Guidera; Electromagnetic Spectrum : Eric Hamilton