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PBS Features Einstein's Famous Equation

Posted by Zonk on from the einstein's-party-years dept.

porp writes "On Tuesday, October 11th at 8PM EDT, PBS will feature a docudrama about Einstein's discovery of his famous E=mc^2 equation. The program will include details explaining those who came before him and the development of his miracle year. The pinnacle of which according to the program was his discovery that matter and energy are two sides of the same coin. Yahoo summarizes the program details in length." From the article: "Based on David Bodanis' best-seller 'E=mc2: A Biography of the World's Most Famous Equation,' the program explores the lives of the men and women who helped develop concepts behind each term: E for energy; m for mass; c for the speed of light; and 2 for 'squared,' the multiplication of one number by itself."

4 of 176 comments (clear)

  1. Get the formula right. by Pudusplat · · Score: 4, Informative

    E = [(p2c2) + m2c4]1/2

    --
    "If you put butter and salt on it, it tastes like salty butter." -Terry Pratchet, on Popcorn.
    1. Re:Get the formula right. by pmj · · Score: 5, Informative

      If you are going to be pedantic, you should at least put in the right form of the equation.
      E=[(pc)^2 + (mc^2)^2]^(1/2)

      --
      Are you BioCurious?
    2. Re:Get the formula right. by mako1138 · · Score: 5, Informative

      Note that the page you mention is a mirror of the Wikipedia article on mass. And it doesn't really have anything to do with quantum mechanics - we are taught non-relativistic (and time-independent) QM in undergrad courses.

      The main things to take from E^2 - (pc)^2 = (mc^2)^2:

      1. Set the mass m equal to 0. We get E = pc, or p = E/c. Thus momentum is defined for massless particles in special relativity. Newtonian mechanics can't handle this correctly.

      2. Set the momentum p equal to 0. We get E = mc^2, popularly known as energy-mass equivalence. There's subtleties to it, though; see Relativistic mass.

  2. Rest Mass by Joffy · · Score: 4, Informative

    People should realize that the M in e=mc^2 is not the widely known idea of mass. Most people think that a bowling ball that weighs 10 pounds has a set mass no matter what. But in Einstein's equation mass is more like inertia. A moving bowling ball has more mass than one at rest. So you can not simply take a 10 kilogram object and multiply it by the speed of light squared to get its energy. This means you must first complete the equation for m first, which I do not know off hand.

    So the idea of mass that most people know is called rest mass. It took me a while to realize that they meant an object could increase mass but gain no atoms or extra "material". Since most objects we can see and touch don't even go 1% the speed of light, we never notice this increase. For almost all practical cases(even a plan going mach 3) we can consider its mass to be rest mass and still be accurate to within many many decimal places.