Was the equivalence of mass-energy referred to the rest or kinetic mass? [closed]

Can you explain if einstein's M=C refers to the rest mass of the electron which iss turned into energy by annihilation or to the relativistic/ electromagnetic mass or both?

Since at the time positron, antimatter and annihilation was not known I would say that it referred only to the electromagnetic one, what is the truth?

• This is not a history question. You can find the answer by looking up the meaning of the formula anywhere Aug 21, 2018 at 11:38
• @CarlWitthoft, there are contrasting answers, else i wouldn't have posted here. As I said the point is to establish if historically einstein could refer to annihilation of rest mass Aug 21, 2018 at 16:11
• Aug 21, 2018 at 21:45

Albert Einstein was only 26 (the year 1905)when he published the brief, 3-page article that announced the equivalence between mass and energy, known today as E=mc2 .

In the original paper, Einstein uses V instead of c for the speed of light, and L instead of E for energy.

Today's world famous formula is simply explained in words. Anyway, the message is fascinating: as the speed of light is constant, the energy inherent to a body is proportional to its mass, with a huge constant of proportionality (c2 = 90 billion joules in each kilogram of mass).

Remarkably, Einstein proposed an experiment to test his daring theory - and this is where good science can be instantly recognised.

The discovery opened vast new horizons for physics.

As an example, Arthur Eddington - a forefront supporter of Einstein's theories - realised in 1920 that the mass difference between four hydrogen atoms and one helium atom would provide enough energy to power our Sun, thus solving one of the major physics puzzles of that time.

Although Einstein achieved a definite conceptual advance in equating the mass of an object with its total energy content—whether or not it is moving, whether or not it has an electromagnetic field—we can also credit Hasenöhrl for unambiguously recognizing that heat itself possess an equivalent mass, and physicists before him for providing a chain of shoulders on which to stand. E = mc^2 is the short punch line to a long and winding scientific story. for details see-https://www.scientificamerican.com/article/was-einstein-the-first-to-invent-e-mc2/

• thanks, could you please say explicitly what is the conclusion of your research? was he referring the formula to every kind of mass, rest, kinetic/electromagnetic, heat etc ? Aug 22, 2018 at 6:21
• @user157860-Einstein achieved a definite conceptual advance in equating the mass of an object with its total energy content—whether or not it is moving, whether or not it has an electromagnetic field—one can also credit Hasenöhrl for unambiguously recognizing that heat itself possess an equivalent mass, and physicists before him for providing a chain of shoulders on which to stand. E = mc2 is the short punch line to a long and winding scientific story.... Aug 22, 2018 at 12:35