1.
“Which phrases not to say in Physics”

2.
 Example 1; “Particles
that have zero rest
mass”
 Example 2; “Photons are
particles having zero rest
mass”
 Example 3; “Electrons
don’t have zero rest
mass but photons do”
 Reason; such wording
are inconsistent with
Reality, Physics Theory !
 No entity in the Universe
has a “zero rest mass”
Not electrons, not
photons.
 Fact 1; Particles can only
have “non-zero” rest
mass, these are particles
that will never have zero
mass in any frame. Eg
electrons.
 Fact 2; Particles that
have “zero” mass will
have so in all frames of
references, but rest does
not make sense for
them, there are no rest
frames for them and no
rest mass, Eg photons.
Zero-rest-mass means [m = 0 and v = 0] such a situation can never arise.

3.
 Example 1; “There are 2 types
elctric charges, positive and
negative” [yes there are]
 Example 2; “An object is
neutral; because equal &
oposite electric charges cancel
each other” [its true]
 Reason; But such wordings can
be misleading and incomplete
towards reality !
 Fact 1; There are 3 types
of electric charges,
positive, negative and
neutral. [and not just two]
 Fact 2; Neutral charges
are not only produced if
equal and opposite
charges are present,
 but also physically there
are neutral charges, they
are electrically neutral,
independent of other
type of charges.
Neutrino, and photons are
examples of neutral charges,
independent of other two types.

4.
 Example 1; “Atomic bombs are
based on equivalence of energy E
and mass m” [Yes they are]
 Example 2; “When energy vanishes
an equal amount of mass must be
prduced” or “when mass
disappears equal amount of energy
must be replaced” [tricky] Or
“Energy is equivalent to mass so
photons have effective mass” [X]
 Reason; such wordings can be
tricky, misleading and incomplete,
inconsistent or incorrect, with reality
! They sound innocent until misused
in actual calculations.
 Fact 1; Energy is equivalent to
mass, only if; there is mass to
begin with. is not valid
for photons. Such energy does
not have an associated mass,
only momenta;
 Fact 2; For other types, the
matter particles; part of the
energy is equivalent to mass
and part of it is equivalent to
momenta, and momenta can
be independent of mass, eg
for waves;
In general energy is equivalent to both mass and momenta at the same time,
in special case of photons; energy is equivalent to momenta only, but in other
special cases, energy released can be equivalent to mass only, differences
between initial and final configurations masses can release equivalent energy.
2
mcE 
2242
cpcmE 
pcE 

5.
 Example 1; “The rules of Quantum
Mechanics are valid at the small scale
only” [X]
 Example 2; “Quantum Mechanics
would not be valid at the scale of our
day to day world” [X] or “error of
Quantum Mechnaics are always small
at the scale of large objects” [X]
 Reason; such reasoning are ill
founded, misleading and incomplete,
inconsistent or incorrect, with reality !
 Fact 1; Most of the processes
are actually semi-classical in
nature. That means they are
semi quantum mechanical as
well.
 Fact 2; Biological and
Chemical scales are almost
always quantum mechanical,
for their precise understanding,
DNA, molecules, enzymes you
name it, whether or not we
understand them, are not
classical structures, if they were
we would already understand
them.
No purely classical system, either purely quantum system or semi-classical
semi-quantum system. Explains thermodynamics, photography, cosmological
processes, effects scale up due to correspondence principle. Also semi
classical pictures/models work for that reason. Eg Hydrogen atom.

6.
 Example 1; “Nothing moves faster than
light” [tricky]
 Example 2; “Nothing surpasses the
speed of light, there is a limit on the
speed at which objects or information
can be passed” [true but tricky]
 Reason; such reasoning can be
misleading and/or fairly complicated,
inconsistent or incorrect, with reality !
 Fact 1; Its not light its photons and only
a single photon in vacuum which has
this privilege. We better use “Physically
nothing moves faster than speed-of-
light” Light itself is complicated.
 Fact 2; Light always means a
classical Maxwellian wave of
electric and magnetic fields
that move at the speed-of-
light in vacuum, an empirical
constant.
 Fact 3; Only a single photon in
vacuum, moves at the speed
of light of Maxwell waves.
More photons, the property of
zero invariant mass is changed,
and if they are not in vacuum
further obstacles can reduce it.
 Fact 4; Group velocity and
phase velocity are different
and bring further complicacy.
Only in very restricted sense Light moves at a speed that nothing can surpass.

7.
 Example 1; “Gravity is not
responsible for people falling in
love. [unless as a dramatic license
in a movie]
 Example 2; “Gravity is responsible
for things falling” [incorrect]
 Reason; such (Ex. 2) reasoning
can be misleading and physically
inappropriate with reality !
 Fact 1; Its not gravity which makes
things fall. It just makes them fall
faster.
 Fact 2; Things fall at the
same rate irrespective of
their masses. But gravity
makes different masses fall
as faster as each other.
 Fact 3; In Physics fast means
speed, but faster means
acceleration and gravity is
the same amount of
acceleration for all masses
under same condition.
Objects always fall faster, and not just fall, due to gravity, they do not fall due
to gravity though.

8.
 Example 1; “Satellites are in
freefall around gravitational
objects whose orbit they are
traversing” [misleading and a
misnomer]
 Example 2; “Objects in freefall
are weightless”
 Reason; such (Ex. 1 and 2)
phrases can be misleading and
confusing !
 Fact 1; Satellites are not
in freefall around
gravitational objects,
they are under
gravitational freefall
 Fact 2; Free Particles in
Physics means free from
forces. Potential Energy
is zero. Forces are absent.
 Fact 3; Freefall on the
other hand means free
from forces except the
gravitational forces.
Freefall actually means “gravitational freefall”. The objects are falling under
the influence of gravity and not on their own accord, Pot. energy is not zero.

9.
 Example 1; “Gravity attracts light as
light has effective mass” [X]
 Example 2; “Gravity attracts light as
energy is equivalent to mass and light
has energy and thus effective mass” [
again incorrect, see slide 3]
 Reason; such reasoning of a
phenomenon also known as
Gravitational Lensing, are poor
understanding of basic Physics, can be
highly misleading and physically
inappropriate !
 Fact 1; Such fallacious
reasoning develops from
mixing the old classical theory
of gravity which is based on
masses of objects and the new
classical theory of Einstein
known as General Relatvity as
applied to gravity.
 Fact 2; The deflection of light is
twice that of the ratio of
Schwarzschilds radius of
gravitational objects and
distance of radiation from such
objects.
 Fact 3; It is simply due to –ve
potential energy requirement,
light loses some of its energy
and can’t travel straight.
Gravity being an attraction between masses leads to falsity light has mass.
See Gravity as a negative potential energy of “Light with energy” & any Mass

10.
 Example 1; “Quantum Mechanics
means wave particle duality so no
more waves and no more particles”
[bad understanding]
 Example 2; “Quantum Mechanics
means wave particle duality so wave
and particle properties are to be
shown by objects at the same time,
they are kind of new entities now” [X]
 Reason; such reasoning of a
phenomenon also known as Wave
Particle duality, are poor
understanding of the philosophies of
Physics, can be highly misleading and
physically inappropriate !
 Fact 1; Wave Particle duality
simply says now the same
object will show wave
properties in some situations
and particle properties in
others, never together. This is
known as complimentarity
principle, wave and particle
proeprties are merely
exclusively complimentary.
 Fact 2; In some situations wave
property are dominant, in
some situations only particle
properties are dominant.
Almost ideal waves and almost
ideal particles are possible.
Basically rest mass of particles
being very small bring wave
property to such particles with
mass.
More than deBroglie wavelength or momentum, rest mass of matter particles
carry sign of their wave propeties. Very massive means less wave behavior

11.
 What would be the last
inconsistency in this list?
 I could not find one for now. But
given the flow of arguments
there would be tons of others.
 Why not find one more? Its so
interesting.
 If you find one contact me
g6pontiac@gmail.com
 I also write at mdashf.org
 Other slideshares here
are interesting. Some are
highly technical, some
are not, if you find any
idea not so
comprehensible, send an
email or drop a
comment.
Take it as a fun thing to
do; and discuss and find
one for yourself !