Exactly 102 years ago (1905 September 27) Einstein wrote a very short
paper. Einstein starts referring to a body at rest with energy E. I
want to know what kind of energy is that E. Being the body at rest,
the kinetic energy is excluded. Then, what other kind of energy a body
at rest can have in 1905?

RVHG (Rafael Valls Hidalgo-Gato)