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PBS Features Einstein's Famous Equation
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."
The anonymous post above already mentioned that p is for momentum and the equation is framed in a way that accounts for quantum mechanics, not just classical (Newtonian) physics. I found a good explanation here:
http://encyclopedia.laborlawtalk.com/MassScroll about halfway down to the section header "Relativistic relation among mass, energy and momentum".
By the way, IANAP (I am not a physicist) but I had fun taking physics in college as part of my computer science requirements. And by funny coincidence this post is actually related to my sig. I don't remember where I first saw that (it was in college many moons ago). I always thought it was funny and clever, a good tip of the hat to Mr. Shakespeare, and a good way to describe the universe.Quantum mechanics: the dreams that stuff is made of.
If this is the same program as this Channel4 production, then I highly recommend it. Although undoubtedly it has nothing to offer the Slashdot crowd from a science standpoint, the human face it puts on scientists we all too often only know from their work is excellent.
The symbol c in the subject equation, and generally, stands for the speed of light in a vacuum, 299792452 meters/second. In any other medium light travels slower than c, by a factor equal to the inverse of the index of refraction. Id est, for water the index of refraction is about 4/3, so light travels through water 3/4 as fast as it does through vacuum.
While people may have set up interesting media through which light travels at some odd speed, no one has ever observed light traveling through a vacuum at other than c. Indeed, it's a bedrock principle of relativity that it cannot.
Interestingly, the eerie blue glow you see coming from nuclear reactor cores that live at the bottom of pools of water (called Cerenkov radiation) is emitted by particles coming from the core that are traveling faster than the speed of light in water (although of course slower than c). The blue light is a sort of "optic boom" similar in its origin to the "sonic boom" you hear from aircraft exceeding the speed of sound.
Nah, the formula is right E=mc^2, except the mass m is the RELATIVISTIC mass, defined as m_0/sqrt(1-(v/c)^2). m_0 here is the mass of the body at rest. But indeed, the rest mass m_0 is a better quantity to use. See for example http://math.ucr.edu/home/baez/physics/Relativity/S R/mass.html