Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

(I'm 14 and still learning physics so I obviously don't know as much

  1. Jun 28, 2011 #1
    (I'm 14 and still learning physics so I obviously don't know as much as you smart guys yet :P)
    E=MC^2, is that saying that If you take energy (I'm guessing the electrons) out of a particle or (I forgot the name but it's a group of particles) your also losing matter, if so does that mean electrons have mass? how much?

    Sorry I'm a bit confused, this probably sounds dumb :L

    Edit: And what does he mean by C^2 (I know its the speed of light squared, but what does it actually mean within the equation)?

    I'm also wondering, what is energy itself. There is different kinds, like kinetic and so forth but what actually is energy?
  2. jcsd
  3. Jun 28, 2011 #2
    Re: E=mc^2

    It means, if we can at max extract E energy from mass m leaving nothing of mass, then ratio of E to m is the square of the speed of light.

    You may be wondering why c is there.

    Well, this equation is the product that emerged by keeping principle in mind that " No object can observe and exceed the speed of the light"
  4. Jun 28, 2011 #3
    Re: E=mc^2

    I'm not aware of an actual meaning of c2 in the energy formula. The initial expression was m = m0 + m0v2/2c2 + m03v4/8c4 + m05v6/16c6 + etc...

    He then multiplied both sides with c2 resulting in

    mc2 = m0c2 + m0v2/2 + etc...

    Because m0v2/2 was the expresion of kinetic energy he deduced that mc2 must also be the expression of an energy and because it's the sum of all those energies (some known like kinetic energy, others unknown) it must represent the total energy of the system.

    It turnes out he guessed correctly!
    Last edited: Jun 28, 2011
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook