May 2012 by Dale Bryant
Folks, this is a lot easier than you think it is and we're going to demonstrate that together right now before you even get to dessert...
The algebraic equation "E=mc2" is an expression from the first part of Albert Einstein's relativity theory, "The Special Theory of Relativity" which he published in 1905 (his "General Theory of Relativity" was published in 1915) - and here's what he was talking about:
Although neither matter (mass)
nor energy can be created or destroyed, one can be converted into the other. Think of this as how matter is 'relative' to energy and vice-versa. Einstein showed that matter was, in fact, a form of stored up energy. Einstein's intent was to show that matter and energy are just different states of the same thing, in the same way that ice, water and steam are different states of the same thing. However, the conversion of matter to energy is accomplished through a violent nuclear chain reaction, or, reaction which takes place in the nucleus of an atom and involves tremendous amounts of heat transfer. Now let's take, for instance, an atom of zinc in a penny - one atom setting off a reaction in its nearest neighboring atom and so on and so on, but all of the atoms in the penny converting almost simultaneously. Gamma radiation, or, gamma rays (radiation with a shorter wavelength and even more energetic than x-rays, well above the ultra-violet end of the electromagnetic spectrum) was the first energy to be converted to matter in the lab some time ago, further validating Einsteinian relativity.
Please pardon any unit substitutions I may use throughout; I use them for familiarity purposes only. The basic premise and magnitude remains unchanged. "E" stands for energy in the form of ergs or joules units. Now ergs and joules aren't units too familiar to many of us, so, though not entirely accurate - but accurate enough for our purposes here - we're going to substitute watts instead. We can all imagine what the energy output from a 100-watt light bulb looks like so we'll save that for later. Now let's take the arithmetical operator "=" to mean "is equal to" so that we can ultimately turn this vague equation into a clear sentence in everyday English. Next is the letter "m" ("m" and "c" are traditionally used lower case). "m" stands for mass measured in grams. One penny is equal to about three grams. In the equation, "m" represents 1 gram, so multiply that by the next letter "c" which stands for the speed of light measured in centimeters per second. One centimeter is about equal to half an inch, and so, is easy to imagine and makes "c" in the equation memorable for this unit of length. Now comes the numeral "2", meaning "squared" or, "c" times itself, or "c x c".
O.K., you had to figure this was coming - a point where things were going to get a bit messy and, unfortunately, that's going to be in the value of "c" which is 30 billion centimeters. Neither one of us really wants to know that 30 billion centimeters squared is 900 billion billion centimeters, nor is there really a more palatable way to put it even if we had used miles instead of centimeters. But this obscurity and vastness is where all the excitement comes in! Here is the whole thing in a nutshell...
If you could use the total energy "E" (in watts) contained in one-third of one penny "m" (the mass of one-third of one penny) by detonating the penny using mass-energy conversion in the parking lot at the Cape Cod Mall, "c" (the speed of light) times "2" (times the speed of light again) it would immediately transform the town of Barnstable and its villages into chunks and bits and pieces!
That's where the watts come back into the picture and that's a lot of watts of raw energy. Can you imagine how many 100W light bulbs it would take to create a light equivalent to that kind of energy? In other words, the output, in watts of the explosion is exactly equal to the mass of one-third of one penny times the speed of light squared. The first, and to date most dramatic proof of the conversion of mass to energy came in two basketball-sized masses weighing eight pounds each, of the highly unstable metals Plutonium-239 and Uranium-236 (both isotopes or by-products of the elements proper) used as catalysts for the atomic bombs that destroyed each of the cities of Hiroshima and Nagasaki - and, sadly, their citizens - in Japan in 1945. Though Einstein showed how an atomic nucleus could be harvested for its energy, he was a pacifist who abhorred violence; it was society that felt it necessary to use the equation's more vicious implications against itself.
Our above equation, "E=mc2", for the conversion of mass to energy and vice-versa is only one aspect of the Theory of Relativity and I chose it as a starting point for its dramatic potential. Other aspects of Relativity include the impossibility of travel faster than the speed of light; length contraction; time-dilation (the slowing down of time as speed/velocity increase); gravitational lenses; infinite mass and quite a bit more...
E=mc2"; use it - don't abuse it!