This isn't true. When you drive your car, E = mc² is at work. As the engine burns gasoline to produce energy in the form of motion, it does so by converting some of the gasoline's mass into energy, in accord with Einstein's formula. When you use your MP3 player, E = mc² is at work. As the player drains the battery to produce energy in the form of sound waves, it does so by converting some of the battery's mass into energy, as dictated by Einstein's formula.I don't believe this is true.
Those are examples of energy changing form - from chemical to kinetic and from stored electrical to sound energy.
The energies are in addition to the rest state energy of e=mc^2 no matter to energy conversion required. If he wanted an every day example he could have used glowing dials in a tritium watch or a Geiger counter finding background radiation in a concrete building.
On the other hand, the guy is a professor of physics so maybe I am missing something.
The exhaust gases have a very slightly smaller mass than the incoming air and fuel did (chemical). The car gains a very tiny amount of mass as it speeds up (kinetic). Because of that gargantuan c2 factor (speed of light squared) the mass lost or gained is far below the threshold of the ability of ordinary equipment to detect.
The "stored" energy manifests itself in the unrealized (potential) state as a tiny increase in the mass of the object in which it resides, compared to the masses of the constituent atoms making up the material. Combustion releases the "stored" chemical energy in the form of heat. If you compare the masses of all the combustion by-products to the original mass of the chemicals before combustion, some mass is missing, the amount missing is exactly equal to the mass equivalent to the energy released by the combustion process, as calculated by the formula e=mc2.
Let's try a thought experiment.
Imagine that you have a helium atom whose nucleus consists of two protons and two electrons. These four particles are held together by the strong nuclear force.
Imagine now that one could somehow separate this nucleus into two identical nuclei each containing one proton and one electron. The act of separating these tightly bound particles would require enormous forces operating over a small distance. Once the separation has been accomplished sufficiently to result in two deuterium nuclei, one should then weigh each particle.
What Einstein's theory predicts is that the "binding energy" which is added to the system will be measurable as an increase in mass of the two resulting particles such that the sum of the two particles is greater than the initial mass of the helium atom.
When we run this process in reverse, the binding energy is available to do "work" and we normally see this energy as the fireball and radiation of a fusion bomb.
Now consider what happens when you stretch a metal spring. You are causing forces to act upon a collection of atoms. Acting under the influence of that force, the atoms change position. As they change position, "work" is being done on the atoms as they move through a distance experiencing the force which is holding them together. The energies holding atoms in a solid together are typically much lower than nuclear binding energies because the forces holding atoms together in a spring are electromagnetic forces.
Nevertheless, the atoms in the spring become less tightly bound and the energy stored could theoretically be measured as an increase in mass of the system. The reason we don't measure such mass changes is because it is many, many orders of magnitude smaller than the mass changes caused by nuclear forces.
Similarly to the nuclear case above, if we now release the metal spring it can be made to do "work", that is the energy can leave the system and be observed in objects outside the spring. We could run a clock with the released spring, for example. As the spring relaxes, it exerts a force on the mechanism of the clock, causing motion. The atoms of the spring will move under the action of the electromagnetic force and the atoms will become more tightly bound than in the extended state of the spring. The mass of the entire spring will then be less by the amount predicted by Einstein's equation. But far too little for our instrumentation to measure.
I had the same reaction to that paragraph. I don't think any matter is destroyed when a battery releases energy or when gasoline burns. But I'm not a physicist.
I have to remind myself that a news article must pass through the filter of a reporter and an editor. And they typically don't hold doctorates in the subjects they cover. So some inadvertant scrambling of fact is possibly the case.
Did you ever see that classic Bugs Bunny cartoon - a very old one, I believe - based on the Aesop fable of the Tortoise and the Hare ? Bugs is done in by an organized campaign involving a dozen or so turtles. After losing the race, he muses to himself, "You know, I think there's something fishy going on around here", whereupon the dozen or so turtles thrust their heads on screen and intone in unison,
"EHHHHHHHHHHHHHHH, IT'S A POSSIBILTEEEEEEEEEEEEEEEEE !!!!!!!!!!!!!!!"
Actually, those were examples of mass being converted to energy.
I didn't believe it either, but several months ago I had it explained to me in a manner I could follow.
As strange as it seems to someone who, like me, never advanced beyond high-school physics, matter-to-energy conversion and vice-versa does apply to chemical and mechanical reactions. Just to so slight a degree that it is not worth bothering with for explaining simple quotidian events.
I thought E=MC2 is what happens in fission and fusion, the result of splitting or adding protons from an atom.
The gas in the car is chemical energy.