The Mass of...
What does Einstein's famous equation really mean?
The "E" is for "energy". Like the number of calories in foods.
The "m" is for "mass". Related to weight.
The "c2" is the speed of light squared.
The speed of light, "c", is a constant of nature. It doesn't change, so you can think of it like a unit conversion factor.
Just like multiplying by 1.61... will convert miles into kilometers, multiplying by c2 will convert mass (kilograms) into energy (joules).
So... how much mass-energy is stored in, say, a raisin? Scroll down to the scale to find out!
(not to say that we could actually extract and use that energy)
Just one more thing: E = mc2 isn't the whole story. The MinutePhysics video at the bottom of the page explains what's missing.
Looks like your screen is cutting off some of the content. Try rotating your device or using a larger screen. (sorry, there's a LOT of stuff going on and we couldn't fit it inside smaller screen widths)