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This is an apparent proof for e=mc^2 which i copied of the internet, but I have some problems with it:

"An object that emits a ray of light will recoil at a velocity v, given

by:

v = EM ....................[1]

where E is the energy of the emission and M is the mass of the object

emitting the light.

Also, the recoil distance x, of the object, will be given by:

x = vt ....................[2]

where v is the velocity of the object and t is time.

Assuming that the beam travels a distance L, and because the light

beam moves at the speed of light, the time t, taken for the beam to

travel across L, is given by:

t = L/c ...................[3]

where c is the speed of light.

Substituting [1] and [3] into [2] gives:

x = (E/M).(L/c) ...........[4]

Now because the center of mass doesn't move, we can say:

Mx = mL ...................[5]

(but I'm not sure why this is, although I know that m represents the

apparent mass of the light).

Now by combining [4] and [5] you should be able to get E = Mc^2, but I

just can't seem to get it!"

Firstly, why is v= EM?

Secondly, surely the distance travelled by the light is NOT equal to L, since the object is recoiling in the other direction so this distance will be shorter?

And thirdly, why is Mx= mL?

Any clarification on this proof would be appreciaited.

Thanks.

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# Proof for E=mc^2

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