A short survey of Mass & Energy
In this article I demonstrate that ...
. . . . relativistic mass rather than rest mass should be considered as the
successor to mass in classical pre-relativistic mechanics.
. . . . the m in E=mc2 represents
relativistic mass and not rest mass. If one sees this m as rest mass an incorrect idea
emerges from the relation E=mc2. A professor at Leiden University who sees
this
m as rest mass wrote in his lecture text (see page 11):
"Mass is energy in the rest frame. Energy is conserved, mass is not. Mass can come into existence and can perish."
This quotation states that mass and energy are not equivalent. Yet numerous text books state that mass and energy are equivalent. This contradiction disappears when m is seen as the relativistic mass.
"Mass is energy in the rest frame. Energy is conserved, mass is not. Mass can come into existence and can perish."
This quotation states that mass and energy are not equivalent. Yet numerous text books state that mass and energy are equivalent. This contradiction disappears when m is seen as the relativistic mass.
. . . . statements such as "mass can be converted into
energy"
are incorrect. The liberated energy has exactly the same mass as the mass that seems to
have
disappeared. See for example page 27 up to and including page 30, including
footnotes.
. . . relativistic mass obeys Newton's three laws,
so
Newtonian and relativistic dynamics appear to be one and the same, once we
accept
that fields also have relativistic mass. See page 27 up to and including 34,
including footnotes.
. . . . Some physicists confuse rest mass
and
rest mass sum. At the same time, they say that only rest mass has to be
seen
as mass, while relativistic mass is a misleading (or a confusing or even
a
wrong) concept, because rest mass is a relativistic invariant whereas
relativistic mass is not.
However, rest mass sum is not a relativistic invariant.
See
page 69 and 70. Thus, by referring to "rest mass" when they
actually
mean rest mass sum, they render the premise of their argument for
not using relativistic mass invalid (on top of the fact that the logic
of
their argument is flawed).
. . . the centre of mass can be
used
in relativistic mechanics as a useful notion. Until now it has
taken French leave with the coming of relativistic mechanics.
See page 53 to 64.
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