In Einsteins equation e=mc², why is the c² there???

Answer 1

the c's units and value accurately convert a mass value into energy; if all of a given mass were turned into energy, its amount would be that of the mass times the speed of light squared

Answer 2

Here goes, with as little math as possible:

Many people believed that, since the amount of energy released when mass is converted is so enormous, Einstein just arbitrarily chose the speed of light (a very large number) and squared it (a truly enormous number) to represent this huge release of energy.
This is not true.

Many of the equations that Einstein worked with had C^2 as a factor (the Lorentz equations, for instance, for time dilation was 1/sqrt1-V^2/C^2).
Newton's kinetic energy equation was E=1/2MV^2. However, we now know this isn't correct. When we substitute a zero value for V, the energy of the mass also becomes zero.

Through a laborious combination of equations and substitutions, Einstein found the true total energy of a moving body to be:
MC^2/sqrt1-V^2/C^2.
When we set V to zero (leaving M as Mo or rest mass), this equation simplifies to E=MC^2.

Even Einstein struggled with this solution - wondering if it was just a mathematical fluke or the reality of the way the universe works and the real equality of mass and energy. Fortunately, he had the genius to determine that it was indeed the reality - and over a hundred years later, the equation is still extraordinary, to say the least.

Answer 3

Well,as for the macro level,energy is energy and mass is mass. But
then people found out that when an heavy element atom is bombarded with neutrons and it splits,by which we know as nuclear fission,that produces a very large amount of energy as heat,the final
mass of the split atoms combined did not tally with the original value
of the mass.They found that mass is reduced somewhere along the process and so they hypothesized that the lost mass is actually converted into the large amount of heat energy. Thats why a large magnitude constant like 'c' is squared and then multiplied with the lost mass 'm' equals to the amount of energy(heat). Mathematical derivation? I don't know actually,as this is actually high level maths.

Answer 4

Einstein started with the assumption that the speed of light is absolute, that is not really relative. Then building on the work of other physicists and mathematicians (most notably, Mach and Lorenz) found that energy and mass are related by a factor of the square of the speed of light (c squared).

Answer 5

I believe that when AE was analyzing kinetics in special relativity, he found that the property we call mass was not actually a constant after all, but varied with the velocity. When comparing the change in mass with the input energy, he found that it increased by dM = dE/c^2, which he interpreted as meaning that the increased mass and input energy were somehow equivalent.

Answer 6

Energy of a moving object is mv2. Time is another dimension through which we move at c,the speed of light. Time really does fly ! So our energy when at rest in spacelike time-space is quite high. Stop moving through time (cease to exist) and you release quite a lot of energy. Which is of course what atomic bombs and power stations do. They destroy particles and use the energy so released.

Answer 7

Energy is directly proportional to mass.

The constant of proportion is denoted by C^2.

C is a constant whose value is 3X 10^8 m/s.

Answer 8

c stands for Constant..which is the speed of light. SO...
Energy = Mass, times the speed of light, squared.

Answer 9

Because that's how the forumla works out. You can find a simple derivation on wikipedia.

Answer 10

I think c=speed of light