Re: A question about E=mc^2

ram.rachum@xxxxxxxxx wrote:
Hello,

I've been reading an article by Einstein about the mass-energy
equivalence, and I'm having trouble understanding it. This is what he
says:

"Now we can reverse the relation [of E=mc^2] and say that an increase
of E in the amount of energy must be accompanied by an increase of E/
c^2 in the mass. I can easily supply energy to the mass -- for
instance, if I heat it by 10 degrees."
Then he goes on to say that the mass will increase, but by a measure
too tiny to be noted by us.

Why does the mass of an object increase when you supply energy to it?
I don't get it. What does the mass-energy equivalence mean? That the
mass of an object should be added to its kinetic energy and chemical
energy as another category of energy?

Thanks,
Ram.

In particle collisions, nuclear reactions, pair production...
even slightly in chemical reactions, etc. there occurs a
transformation between energy and mass. E=mc^2 is a convenient
conversion equation.

Mass–energy equivalence
http://en.wikipedia.org/wiki/Mass-energy_equivalence
http://en.wikipedia.org/wiki/Mass-energy_equivalence#Practical_examples

"While Einstein was not the first to propose a mass–energy
relationship, and various similar formulas appeared before
Einstein's theory, Einstein was the first to propose that the
equivalence of mass and energy is a general principle, which
is a consequence of the symmetries of space and time".

"In the formula, c^2 is the conversion factor required to
convert from units of mass to units of energy".

See: http://www.fourmilab.ch/etexts/einstein/E_mc2/e_mc2.pdf



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