E=mc^2-->energy has mass?

Question

Does
E=mc^2
mean that energy has mass?

Answer 1

What is it about "=" that so few seem to understand? "=" means "is equal to", not "may be converted to". E=mc^2 means the total energy content of an object in its center of mass frame is equal to mc^2. This makes mass a measure of total energy. Since an object with mass, therefore, already has energy, it's not technically correct to say that mass can be "converted to" energy. In an atomic bomb, the nuclear binding energy of nuclei is converted into radiation energy, which is then converted into heat and blast (hydrodynamic) energy, reducing the mass of the transmuted nuclei left behind. Since that's somewhat of a mouthfull, people usually just say "mass is converted to energy" .

Answer 2

The problem with this simplistic analogy is that it is impossible to force energy to produce matter. It happens at very small scales, but because of entropy, free energy or energy in the form of light or heat is much much more likely than energy being forced to be structured mass. The reverse process, however, is done. Nuclear explosions are a result of the reverse process, that is, mass converting into energy. It should be noted that not all of the uranium/plutonium mass is annihilated in a reaction, so you do not see explosions which would cripple the world ( that little 9x10^16 joules you have up there). Only a small amount of the material actually annihilates. To understand just how serious this is, just open a book and look at the mean life of a particle such as a pion, which gives up the great majority of its mass when it decays into an electron/positron and photon.

Answer 3

E=Energy M=Mass C=The speed of light(186,000miles per second)

Thus energy=mass*speed of light squared. Convert mass into energy and a huge amountof energy will be released.

Answer 4

More correctly e=mc^2 means that mass can be *converted* into energy, and energy can be *converted* into mass.

Answer 5

Energy has a mass-equivalent that generates gravity, yes.

Answer 6

My understanding is that mass is really energy. Thats the theory anyway.

Answer 7

yes, and energy can be transformed into mass and mass can be transformed into energy

Answer 8

dude,

it doesn't mean that what u think actually
M-> means that a body with certain mass (thats obvious...as all the bodies has certain amount of mass in it).
C-> it is nothing but the speed of the light it is around 3x10^8 m/s
E-> it is the energy of the object or the body for which ur calculating ( nothing but the body with mass M as given above)

so Einstein derived this equation to find the energy for a body with known mass....
thats it,,...it doesn't mean energy has mass........

fine.......
cool........

Answer 9

no

it means that you can convert mass to energy, like in the atomic bomb.
http://en.wikipedia.org/wiki/Binding_energy#Nucleus_binding_energy


or you can convert energy to mass like in pair production
http://en.wikipedia.org/wiki/Pair_production

HOW IS THIS WORTH 4 DOWNS? I've answered, not incorrectly and similarly to a lot of others, and supplied links to extra information so he can read for himself!