Einsteins E=mc2 . Should Newton , De Pretto , Preston, Hasenohrl
and Soddi, Planck be given credit for discovery of E=mc2. ?


The French chemist Antoine Lavoisier (1743-1794) was the first to
formulate a law of conservation of matter in chemical reactions. The
concept of inter-conversion of mass and energy has been studied by
various scientists qualitatively, even before Einstein.

1. Newton has quoted in his book €˜Opticks in 1704 that

"Gross bodies and light are convertible into one another...",

After about 200 years Einstein derived mathematical equation for
Newtons perception i.e. ˆ†L =ˆ†mc2 where ˆ†L is light energy
emitted when mass ˆ†m is annihilated and is speed of light. It is
the rarest coincidence in between Newtons hypothesis and
Einsteins mathematical derivation.

2. S. Tolver Preston proposed that a vast amount of energy can be
produced from matter in his book Physics of the Ether in 1875.
Preston determined that one grain could lift a 100,000-ton object up to
a height of 1.9 miles. This deduction yields dE  dmc2.

3. Jules Henri Poincaré in 1900 applied the calculations in a
recoil process and reached at the conclusion in the form, mv = (E/c2)c.
From the viewpoint of dimensional analysis, E/c2 takes on the role of
a €˜mass associated with radiation, which yields E=mc2.

4. Olinto De Pretto speculated E=mc2, implying that when v=c , then
E= mv2 becomes E=mc2 , in 1903-04. But Pretto neither gave
specific derivation nor mathematical calculations. Bartocci claimed
that Einstein was aware of De Prettos speculation of E=ˆ†mc2 ,
which was published about a year before.

5. Fritz Hasenohrl in 1904, concluded: €œto the mechanical mass
of our system must be added an apparent mass which is given by,
m=8E/3c2 where E is the energy of the radiation.€? In a later paper
he further improved result that mass exchanged is, m=4E/3c2. Ebenezer
Cunningham in 1914 in the book The Principles of Relativity showed that
F. Hasenöhrl, had made a slight error in his calculations. If errors
are removed then the mass exchanged is m =E/c2 or E = mc2. Thus in this
regard Hasenohrls contribution is the most significant, before
Einstein.

6. Frederick Soddi and M. Henri Becquerel both have predicted that in
radioactive emissions the mass of body decreases i.e. energy of
radiations is at the cost of mass.

7. Max Planck in 1907 made an in-depth investigation of the energy
"confined" within a body, but he did not use Einsteins approach at
all. Planck derived an expression m-M= E/c2, for heat energy and mass
and interpreted that

€? The inertia mass of body is altered by absorption or emission of
heat energy. The increments of mass of body are equal to heat energy
divided by square of speed of light.€?

Planck acknowledged Einsteins previous derivation but did not agree
with correctness of Einsteins derivation.
Should these scientists be credit of doing basic work in assisting the
discovery of E=mc2 ?

Today, E=mc2 is regarded a sole province of Einstein.
Complied from various sources.
If some scientists is left , please add. I think one is JJ Thomson

Main sources for compilation
100 Years of E=mc2
https://www.novapublishers.com/catal...oducts_id=4554
AJAY SHARMA 30 Sep 2006.