hi good news dr. Lewin responded to my
previous video with three new videos
science time but before getting to the
science let's address the drama a little
so I made a video disagree with dr. Liu
in a scientifically well decorated ex
professor at MIT the disagreement was on
that dr. no-win said reach off voltage
law or KVL doesn't hold when magnetic
fields are involved the first two video
responses dr. Lewin made were
explanations as a response to the flood
of my viewers commenting under his
videos maybe he made those videos
without watching my video the rumor has
it it's only a rumor the person who says
he has a master's degree makes the
following statement the entire reason
dr. Rubin was willing to give up
voltages was due to bad protein such a
ridiculous statement I have not been
able to find that video and the needle
even exists
I feel like he's telling me he actually
watched my video but to save me the
embarrassment I should remove my video
anyway dr. Levine didn't find my video
I'm using he assumed I don't agree with
Faraday's law and I don't agree with his
measurements and in the comments he said
that my video is dedicated to discredit
his lectures and his insulting and an
embarrassment considering I have a
master's degree it is equivalent to say
the earth is flat
no not flat earther call me an idiot but
but a flat earther it is fine people I
don't have any problem with dr. Lewin
please don't try to defend me by
bothering the man well if you watch my
previous video you will see how much I
actually agree with dr. Levine I would
never try to discredit his lectures for
no reason he has around 300 lectures in
his channel and I suggest everyone
watches them they are great in the
process of this back and forth a lot of
people left comments with majority of
them being pretty respectful to both
sides but there are always these
oddballs who leave bad comments I'm sure
dr. Lewin received his fair share of
unnecessary bad comments from my viewers
as I did from his fans here is a few of
them written for me obviously the
balding skin with a single eyebrow does
not understand potential theory in nonk
it feels electro boom shut up on the
topic
didn't you take an applied
electromagnetics class in your degree as
another EE I'm embarrassed for you and
when I left a comment under dr. Levine's
video somebody said don't worry dude
pray to Allah he will solve your problem
go to a mosque nearby he knows kvl
better than this walter lewin moreover
both Khrushchev and Faraday are in
heaven so just request Allah to ask them
for a solution and my hero
our young Kasim said what the hell is
wrong with you boy I chuckled both of us
chose believe on the internet and should
deal with the consequences personally I
don't care about bad comments but I do
apologize to dr. Lwin for receiving a
similar wave that wasn't my intention
it's not a political debate and we are
not looking for votes it's about science
and facts and in science we don't need
people who blindly follow somebody we
need people who put their preference
aside and look at hard facts and judge
accordingly in his third video although
he still didn't agree with me which is
totally fine dr. Lewin did a good job of
calming both sides down allowing for a
more civilized discussion and I
appreciate it that's the end of the
drama but don't leave now hold my hand
let's go through this journey together
it's a long and tough journey but coming
out of it we will learn much more let's
do it so as dr. Lewin suggested I
contacted his ex colleague professor
John Winston Belcher a current MIT
professor a great man with his own
series of scientific awards and
achievements he spent so many hours with
me on this and made this beautiful MIT
quality report which I share with you in
the description I'll get to that a bit
later now let's go all the way back if
you have watched my electro boom 101 I
showed that voltage is basically defined
as the amount of potential energy
available to move unit charge or V is
equal to the energy acting on charge
divided by charge and of course work or
energy is equal to the force applied to
the charge times the distance that the
force travels with the charge now what
happens if the charge moves in a closed
loop in the presence of this force it is
like gravity it doesn't matter if you
move sideways because the gravity always
points down the mass will lose its
potential energy as it
gets closer to the earth and will gain
the same amount back when you return to
the same point so the sum of all
energies stored or produced by gravity
is zero in a closed loop basically you
take out only what you put in that's
called the law of conservation of energy
for the same reason the sum of all
energies acting on the charge in a
closed loop must be zero we can divide
these by Q to get voltage and we arrive
at the original definition of
Kirchhoff's voltage law some people call
him Kirk off I call him Kirchhoff's it
is based on the law of conservation of
energy and says at any point in time the
sum of all voltages in a closed loop
must be zero let's create an electric
force you know if you have a tiny charge
you in the presence of a stationary big
charge Q there will be an electric force
between them repelling or attracting
depending on the polarity let's assume
they attract for the sake of simplicity
I'll avoid vector and curl math let's
keep it simple so it's easy to
understand according to Coulomb's law
this force is equal to some constant
times the tiny Q times the big Q divided
by a square of their distance
the tiny Q starts moving due to this
force let's assume charge Q moves by a
very small distance of Delta L where we
can assume the force almost remains the
same because like a short force is a
function of distance so the work done
with that force in that tiny distance or
Delta W is equal to the force in that
spot times the distance for extremely
small distances we can write this as DW
equal to the F times DL and if the
charge moves a distance of L from point
A to B to get the total energy of work
we integrate the energy which is
integral of F DL from point A to B so
the voltage between points a and B would
be that energy divided by Q or integral
of F TL divided by q q is not a function
of L so we can take it inside an
electric force divided by charge is
defined as electric field which is equal
to a constant times Q divided by square
of distance and from these we conclude
that voltage from point A to B is equal
to the integral of e DL from point A to
B and like I said before if we move the
charge in a closed loop the
of all energies and so all the voltages
in the loop will be zero so in an
electric field only the sum of all
voltages is the closed loop integral of
e DL equal to zero
later on Michael Faraday revolutionized
our understanding of magnetic fields and
with the help of James Maxwell they came
up with the Faraday's law and Maxwell's
equations
I of course fully comply to those laws
and have nothing against them according
to Faraday's law if we have an open
surface surrounded by a closed loop the
closed loop integral of e DL which is a
voltage generated by electric fields
around a loop also known as
electro-motive force is equal to the
rate of change of magnetic flux Phi
through this surface in time and this
magnetic flux is all the B magnetic
fields passing through the surface
enclosed by the loop and is equal to the
magnetic field times the surface area
remember I showed in the presence of
electric fields only the closed loop
integral of e DL is zero what as soon as
we have magnetic fields through the loop
this won't be zero anymore and we have
to follow Faraday's law now watching dr.
Levine's first response video I noticed
that he believes this to be Chris offs
voltage law if that was in fact the
definition of KVL I would hundred
percent agree with dr. Lewin that it is
a special case of Faraday's law where D
Phi over DT is equal to zero which means
there are no magnetic fields but that's
not the definition of KVL KVL says that
the sum of all voltages in a loop must
be zero but then you might say that the
voltage is integral of e DL but that's
not true
voltage is any energy per unit charge
not just energy from electric sources is
that it
first dr. Lewin believed that voltage is
only defined by electric forces because
looking at his second response and other
videos it seems he doesn't think of dy
over DT as a different entity you see
he's showing F minus ma equals zero is
the same as F equals MA what he's trying
to explain is that in this equation
force is equal to mass times
acceleration
ma is just the value of F and is not a
separate entity so writing it as f minus
ma equals to zero is pretty pointless
which is true but similarly he thinks
that minus D Phi over DT is only the
value of this integral and it's not a
separate entity what that's not true
these two are two different entities
that exist in a circuit with their
values equal in a closed loop like when
you balance your weight with your friend
on a seesaw the value of your torques is
equal but you are two different people
but it returns to the definition of
voltage what if voltage is defined as
the effect of electric fields only now I
know that dr. on the wing defines it
like that and with that definition all
his videos make perfect sense but who's
right in his second video he refers to a
paper written by Robert Romer published
in American Journal of physics back in
1982 I read the paper and have a copy of
it in my description if you're
interested it's a great paper focused on
what the meters would measure based both
on math and actual experiments and they
both match and also they match dr.
Levine's experiments and mine what Romer
does is that like dr. Levine and I he
has a loop of wire with two different
resistors one at each side and a
changing magnetic field passes through
the middle and also he has two identical
meteors connected across the same point
in the circuit shown as these resistive
components he imposes some specific
conditions on his setup and shows that
meters read different values each meter
reads the voltage across the resistor on
their side I did the same experiment in
my previous video I showed that it was
true and provided some explanation in my
setup I had to impose my own conditions
because unlike Romer my coil was pretty
small so the fields could close before
passing the main loop or could create
uneven fields so in my setup the
condition was that the probe wires had
to run very closely to the loop wires to
make sure they are exposed to the same
magnetic fields as the main loop which
is the same idea as in Romer setup now I
can easily explain it mathematically
this is also explained beautifully in
professor Belcher's
and he created he provides such great
detail that you can see how the charges
move in the loop with your own eyes in
my setup I twist the wires at this point
all the way to the scope to make sure
that the scope and this extension of
wire are not affected by the field but
for calculations we can model the scope
as this tiny resistive component across
these points the scope resistor can be
one mega and our loop resistors are much
smaller in kilo ohm range and the
connecting wires have insignificant
resistance we can assume zero if the
field is going through the page that way
the induced current is this way
according to Faraday's law the closed
loop integral of e DL over the main loop
is equal to minus D Phi over DT the
change of magnetic flux through the loop
we can split this integral into two
pieces one from A to B and one from B to
a we know that the integral of e DL over
ideal inductors and wires is zero
because they have no resistance and only
work with magnetic fields so the
integral of e DL from point A to B is
only the voltage across resistor one and
from B to a is only voltage across
resistor two so we get V r1 is equal to
minus D Phi over DT minus V r2
now if you go through a different loop
through the probe wires and the scope on
this side and main loop on the other
side we get a similar thing that the
scope voltage on this side is equal to
minus D Phi over DT minus v r2 because
the same flux passes through our loops
so basically the voltage of scope 1 is
equal to V r1 and based on similar
calculations on the other side voltage
of scope 2 is equal to minus v r2 math
matches our readings I never disagreed
with dr. Lu in on this and confirmed it
in my previous video in his paper
Roman never disputes KVL but in a
section titled voltage across an
inductor he expresses his confusion and
discomfort around what happens to the
fields in an inductor then he mentions
two books that help him find peace one
of those books is the fine man lectures
on physics by Fineman Layton and sands
if you don't know dr. Fineman you should
really check his Wikipedia page he was a
fine man pun intended a huge scientist
and an all-around great
with many contributions to science both
professor Belcher and I read Roma's
paper and chapter 22 of fine mans book
on AC circuits and we also found peace
let me explain the book explains that
for every component like an inductor or
a capacitor it is best to use a lumped
model meaning that all the fields are
contained within the component and don't
leak outside doing this makes it easy to
calculate the voltage across the
component and the voltage across the
inductor is minus L di over DT despite
the fact that the integral of e DL
through the inductor is zero this is a
real voltage across a magnetic component
and doing so the book shows that the sum
of all voltages in a loop is zero and
KVL holds so professor Belcher also
concluded that dr. Fineman himself and I
have the same definition for voltage and
the KVL holds in all cases although
maybe I shouldn't assume myself at the
same rank but then you might ask if KVL
and Faraday's law do the same thing why
do I push for KVL it's because KVL is
much easier to work with over time and
frequency domains see if we have a
circuit like this knowing that KVL holds
it's very easy to calculate the circuit
impedance which is that resistor in
series with these two in parallel which
is the impedance of the inductor times
impedance of the capacitor over this
Plus that which is equal to that I can
easily calculate my LC resonance
frequency by finding where this becomes
zero I just replace s with J Omega and
calculate my frequency Fineman book
explains that by making suitable
approximations in a lumped model it is
possible to ignore the great
complexities of the fields inside the
object a separation is made between what
happens inside and what happens outside
this is important to know because even
if the fields are not contained and
leaked outside
we still have an inductor and defined
voltages everywhere and KVL holds but
this creates huge complexity in our
calculations because now the leaking
fields affect all the components and
wires in the circuit that we have to
take into account which is almost
impossible because now there are so many
new variables introduced that we might
easily overlook our simple
loop and probe was the easiest example
of uncontained fields the fields closed
around the entire circuit and effect
everything every piece of wire and even
the resistor itself becomes an inductor
and the secondary of a transformer one
of the examples people brought to
disprove my conclusions was that what if
the entire loop was made of a uniform
resistive element and we take these two
points and the induced current I would
create two different voltages across the
same points based on Ohm's law what you
must understand is that a real resistor
is only ideal if it's infinitely small
as soon as it has any dimensions it at
least has an inductance series with it
especially something this long remember
to make it easy you have to produce a
model using lumped elements you pull out
the resistance and the secondary
inductance and put them in series for
each half of the circuit if you assume a
uniform field through a loop and D 1 and
D 2 are the length of each side this is
what you get an unknown voltage across
these points and KVL holes there is an
interesting experiment in one of
Professor Belcher's assignments that
kind of looks like this and shows the
effect of uncontained fields we have an
AC supply in series with a resistor and
a loop of wire and on this side we
measure some voltage and on the other
side we measure zero volts here's what I
have the supply connects with this
alligator clips to this resistor and the
loop and I'm measuring across the loop
with these wires when I'm probing on the
power supply side I read around 40
millivolts and now if I move the wires
to the other side of the loop hmmm I'm
reading 20 millivolts instead of zero
it's half of the previous voltage I
should read zero volts but instead I'm
reading half of this voltage because I
introduced a new probing problem both my
AC supply and probe are coming from the
same scope see if you can figure out
what's going on on the other hand if I
create an inductor with contained fields
mic winding around the toroid core all
the fields are contained in the core and
my readings are not affected by where I
probe here I replace my loop with a
toroid and a few windings and you see it
doesn't make any difference if I probe
on this side or the other side
okay let me explain why we didn't reach
zero on the first test if our AC supply
and the probe are isolated of course we
read zero volts they're a simple
engineer like me would explain it by the
fact that every piece of wire is an
inductor if we have a voltage V induced
on the main loop we would also have half
a V induced on equal length of probe
wires exposed to the same fields that
subtract from V and we read zero volt
difference there a more proper
scientists like Roma would say that the
scope voltage is the integral of e DL
over the main loop on the scope side
which is zero now in my setup the AC
supply and the scope ground are not
isolated and shorted through the scope
the simple engineer would say or sure
you just shorted across that voltage on
one of the probe wires so the scope
would read half the voltage that's not
wrong but it's a bit misleading what if
we short across the probe wire with a
piece of wire that runs closely to the
probe wire it doesn't make any
difference and we still read zero there
because the fields closed around all of
them the more accurate reason is that
the ground through the scope creates a
large loop if Phi is the magnetic flux
through the loop half of it closes on
the top side through air and half of it
on the bottom through the ground loop so
like the case of terrowin where all the
fields were contained in the core here
the majority of the fields are contained
around the probe wire and are too far to
loop around the shorting ground wire and
affected this is as if the probe wire is
an inductor shorted by a piece of wire
there is a string current running
through it but the voltage across it is
0 this is how we are shorting the
induced voltage across the bottom probe
wire and read half a voltage at the
output instead of zero you can of course
write the Faraday's law around the loops
and get the same results
Thank You professor Belcher for helping
me with this