Yes we all know C squared gives a new number in Einstein's equation. But squaring the speed of light even theoretically is theoretically impossible.

*sort by* **best** latest

E = mc2 Explained

"E = mc2. It's the world's most famous equation, but what does it really mean? "Energy equals mass times the speed of light squared." On the most basic level, the equation says that energy and mass (matter) are interchangeable; they are different forms of the same thing. Under the right conditions, energy can become mass, and vice versa. We humans don't see them that way—how can a beam of light and a walnut, say, be different forms of the same thing?—but Nature does."

"So why would you have to multiply the mass of that walnut by the speed of light to determine how much energy is bound up inside it? The reason is that whenever you convert part of a walnut or any other piece of matter to pure energy, the resulting energy is by definition moving at the speed of light. Pure energy is electromagnetic radiation—whether light or X-rays or whatever—and electromagnetic radiation travels at a constant speed of 300,000 km/sec (186,000 miles/sec)."

"Why, then, do you have to square the speed of light? It has to do with the nature of energy. When something is moving four times as fast as something else, it doesn't have four times the energy but rather 16 times the energy—in other words, that figure is squared. So the speed of light squared is the conversion factor that decides just how much energy lies within a walnut or any other chunk of matter. And because the speed of light squared is a huge number—90,000,000,000 (km/sec)2—the amount of energy bound up into even the smallest mass is truly mind-boggling."

Source = http://www.pbs.org/wgbh/nova/einstein/lrk-hand-emc...

Yes of course we know all that.

The question is how can you square "the universal constant " even in theory. It seems the only thing faster than light is Einsteins formula.

"Zillions" of times faster.

- See all 5 comments

In classical mechanics there is an equation for kinetic energy Ek = 1/2mv^2

Compare that to E = mc^2

So you might as well ask how can a velocity v be squared and why?

If a 1kg ball travels at 1m/s it has kinetic energy x. If the same ball travels at 2m/s is its kinetic energy twice that of x? No, its four times that of x. And as you approach the speed of light, the energy required to accelerate just a tiny amount is enormous. That is why you square the velocity.

The inverse square law is the same but in the opposite direction.

In Einsteins equation you use m and not 1/2m because its the total energy conversion of m. Everything else stays the same.

How can you square C without violating the laws of physics. Because it is only C as one term of a mathematical expression. Once C^2 is evaluated it is no longer the speed of light or the speed of anything... it is simply the speed of light squared... that is, it's a number, another term in an expression to be evaluated. The speed of light is still the speed of light.

I.e. we are not saying multiply the mass by the speed of lights illegitimate brother C^2. It's not his brother. It's just a value.

Yes you are almost entirely right: except for the irony of squaring C. It is proundly ironic. Of all the things to square he chose the universal constant. The holy grail of (it seems) the entire realm of physics! Does the irony strike you as odd?

- See all 2 comments