Freaky Fzx Friday - Stupid Conservation Laws

Your chemistry teacher told you that Matter is Conserved.  She told you that the total mass present before a reaction is the same as the total mass present after the reaction.  Antoine Lavoisier discovered this "law" in 1785 but we've modified that "law" just like most ideas of that vintage.

Your physics teacher will tell you that Energy is Conserved in a closed system.  Discovered in the early 1840s, credit is most commonly attributed to James Prescott Joule and a few others doing similar experiments around the same time.  Yup, that's also a lie.

            

Antoine Lavoisier                       James Prescott Joule

It was Al Einstein again during his "Miracle Year" who gave us more of the truth.  His paper on the equivalence of matter and energy presented the most famous equation in the universe that nobody understands.

Most people will translate that into "energy is equal to the mass multiplied by the speed of light squared" but that misses the point.  The equation says that "matter can be converted into energy and energy into matter."  The relationship is defined by the equation above and here's a derivation:

Remember those pesky endothermic reactions?  The energy sucked in was stored as matter.  And those exothermic reactions?  The energy released was matter just a moment before.  Chemistry calls it "bond energy" which is a fancy word for mass.  Actually there is a matter-energy conversion every time there is a chemical reaction but that's too complicated to teach.  Or mention.  Or even allow simple chemistry students to know because that would not allow them to learn chemistry.  Yes, that was sarcasm.

And we in physics just ignore the LAW OF CONSERVATION OF MATTER/ENERGY for our discussions of conservation of energy.  Why???!!!  We know it's true so why not at least have that discussion?  It's fun, it's mind-blowing, it's even FREAKY.

But it's also incomplete.  Full disclosure:

So energy IS created and destroyed all the time.  Matter is NOT conserved.  Since the matter change is difficult to measure, we just ignore it most of the time.  I say we shout from the rooftops or at least mention it once in a while.  FZX.