yeah so there's i wanted to talk about a
paper here it is it's called the
symmetry and simplicity of the laws of
physics and the higgs boson which isn't
a a particularly catchy title what what
about the saying is done and madasena is
a big shot right i had to say that
generally doesn't do this sort of thing
which is you know talking about it's
almost like an outreach paper he's
describing the you know the fundamental
laws of physics as in gauge symmetry uh
spontaneous symmetry breaking the way
the higgs works
and he's done it using an analogy of
economics so what what's his economic
analogy then for to describe all this to
understand really fundamental physics
the standard model just from economics
and that's almost belittling economics
it's uh it's really simple what what mel
the cena uh starts with he starts by
trying to explain gage symmetry and he
talks about
three you know bunch of countries so i
want you to imagine three countries so
one can be the uk maybe the us
brady you want me to make the other one
australia don't you but i'm not going to
i'm going to make it spain because i'm
off spanish
okay so you've done excellent uh
excellent maps there in the country yeah
yeah they are they're sort of nicely
placed actually aren't they
i can't even be orientated right
anyway but and then so you've got these
three countries
and uh i want you to imagine bridges
between the countries and on each bridge
there is a bank
now
each bank can you know set an exchange
rate between the currencies as you cross
the you know cross between the two
countries are you going to draw little
banks you can draw me to draw a little
bank yeah okay let's draw a little bank
put bank on it here do i have to draw
three banks every one yeah okay let's go
i know
i'll put bank on this one because it's
good it's going to spain in it right
this one all called bank as well right
okay so there's these banks there's
banks on every bridge you can change
money at these banks now the banks set
the exchange rate
they don't make money they're not
they're not in it to make money so the
exchange rate works the same both ways
so for example um on the at the uk us
border you've got um maybe one pound
to say let's say three dollars quite a
generous exchange there's no charge any
commission either okay so and as just to
emphasize if you if you went with a
pound that way you'd get three dollars
and you came went with three dollars
this way you get a pound back there's no
money making by the banks here here you
know maybe one pound to two euros okay
and here we've got say
let's say a dollar to a euro just for
simplicity let's just start off with
this scenario now you can ask yourself
can i make money
so you think of a speculator can a
speculator make money
and uh and you can immediately see that
he can right just by going around going
you know going around the country's in
the right order so for example you start
with two euros here in spain you go to
england it turns into a pound you then
go to america it turns into three
dollars and then you come back to spain
again and it's now three euros so you
made a euro
okay so you can see so so what your
measures there are speculators and then
they go around and in this case they
want to go around in that direction
so this in a way what what what
maldasena says this is like says the
speculators are like electrons or
charged particles
and they're going round
in this sort of the electromagnetic
field which is set up by the banks
through their exchange rates okay so the
exchange rate set up the electromagnetic
field and the electron or the
speculators move around in it so this
explains this process
and of course if i change the exchange
rates it changes how the electron the
speculators will move okay so they might
go in a different direction they may not
move at all if i made it so that um
so that all exchange rates were
one-to-one
okay there's going to be no movement of
the speculators so this is sort of
explains the you know electrodynamics
the the nice thing about it as well is
is that miles cena argues that
if
the banks don't want to run our money
okay if i had this set up forever
eventually speculators would go round
and round and round and round and
eventually the banks would run out of
money so he says the banks don't want to
do that so what they do is they can
change their exchange rates
so they to protect themselves from this
and if you work out this actual the
equations that govern that
it turns out that they're the same as
maxwell's equations that describe
electromagnetism so it's kind of
beautiful right so it's you really do
have electromagnetism going on here
speculators you've said are electrons
yeah
what other banks the banks are like the
gauge field they're the sort of
electromagnetic field if you like in
this scenario or it doesn't have to be
electromagnetic field it can be
associated with the with the uh weak
force for example
um so what's an example of a transaction
where electrons are making money in
nature
well that's where they're interacting
with the uh electromagnetic field
so that would be precisely that so
they're moving in the electromagnetic
field
because essentially in this scenario
it's like moving through the banks you
know making money and along the way in
the analogy what is money
in the analogy what ah now that's a good
that's good we are going to come to that
so
money in a way is a little bit like
energy here at least the money that you
gain is a little bit like energy that's
what madison argues so that's kind of so
in a sense um
this brings us to we'll come to that
important point in a moment one more
question in the analogy what are
countries
points in space that's important as well
okay so each point of space is is a
country here
okay so you're literally moving around
space here so but what's an important
aspect of this is that any given country
is free
to change its currency
okay so for example the guys in america
could change make you know half the
value of the dollar
if they wanted to and all that would
mean is the banks would just
change what they meant by a dollar in
their exchange rate and it wouldn't
change how the speculators moved and how
they could make money and it's the same
that's gauge symmetry in the in physics
the other important aspect of this
scenario is that um
let's suppose they are all one-to-one
exchange rates okay
so now we know that we're calling this
like the vacuum configuration okay
because the electrons don't move in this
because the speculators don't move
there's there's no risk the fields don't
make anything happen the banks aren't
making anything happen there's no
movement of the of the speculators here
but there is an interesting aspect to
this which is which is important
let's suppose that all exchange rates at
the moment are now one-to-one
okay
so uh electrons don't want to move
around can i can i
can i maintain that situation by
changing exchange rates in one of the
banks so let's suppose this guy here
changes one dollar to two euros can i
can can i maintain the scenario
of say no movement of speculators well
you can because this bank can respond
and change it the value of its euro
okay so if you double the your the
amount you know the exchange rate of
yours here and just double it here it's
still a a no movement situation you
can't make money in this scenario and
that's an important distinction okay
that so what's that saying is it costs
no nothing it doesn't cost the banks
anything to change the exchange rate
okay it's costing an analogy it costing
no energy
to sort of
to the field here and this is this is
analogous to a massless particle so the
gauge fields are behaving like massless
particles it costs them no energy to
change the exchange rates okay now what
happens when you throw the higgs in now
the higgs doesn't doesn't we don't we
don't use the higgs to give mass to the
to the particles of the electromagnetic
field uh it's it's done with the with
the weak force and and you know the sort
of w and z bosons those kinds of things
but you can still think about this kind
of scenario
and uh so what's what is the higgs well
the higgs is gold so all exchange rates
are let's say they're all one-to-one no
money can be made by speculators in this
scenario but now i add some gold to the
game and let's suppose there's some the
price of gold in the uk i have no idea
if this is a sensible price one kilogram
is one million pound
okay
now
in the us
one kilogram of gold is worth two
million dollars so all exchange rates
are one to one can you make money now
previously you couldn't until i
introduced the gold you couldn't make
money now
you can make money it's very easy to see
how to make money in this snow you just
start off
you buy some gold in england with your
million pounds you've got a million
pounds haven't you braided
okay
so you you buy some gold in your million
pounds you then go to um america you
turn that into
you go and sell your gold in america for
two million dollars and then you go back
to england and it turns into two million
pounds so you made a million quid okay
so you can see that suddenly the
situation has changed again okay so
suddenly this gold has changed
the picture there's another thing that
you should realize is that in a sense
the what's important here is the price
of gold you could redefine the currency
in any given country so that the price
of gold is always 1 million
okay let's suppose we do that
okay so his price of gold is always a
million so now we're going to redefine
at the dollar so a new dollar okay
instead of being
the new dollar it's going to be
instead of being two million dollars for
a kilogram of gold i might have put a
pound sign in front of that
instead of it two million dollars for a
kilogram it's going to be instead it's
going to be
one million new dollars
okay i'll put an n in front of it
okay
okay and it's still a million pounds but
now the banks have to respond to that
okay so they have to halve
the number of dollars in their exchange
rates so it's now one to two so let me
just draw at the side here probably
easier so this is now
one to a half
a half to one
and one to one okay in response to that
the fact that the price each each
country has changed its currency so the
price of gold is always a million so now
you can see you can you know you can see
that you can make money through the
exchange rate but suppose you now had a
scenario
where um
all exchange rates were one-to-one the
price of gold is one everywhere one
million everywhere all exchange rates
are one-to-one now that's a scenario
where you can't make money
price of gold is fixed everywhere as one
million
the exchange rates are all one-to-one
you can't make money in that scenario
now before
um
we said that a bank could change this
exchange rate okay and other banks could
respond and you could still have a
scenario where you can't make money so
there's no cost in no cost to the banks
however
now when the gold comes into play if one
bank wants to change this exchange rate
another bank can't respond to that in
such a way as to guarantee there's no
money making
because you could always pass between
those two countries
for which the first bank changes
exchange rates and then you can make
money carrying gold in your pocket
carrying gold in your pocket exactly so
this is now so what so this is
fundamentally different so what's
happened it's now become impossible for
the banks to change their exchange rates
and maintain the status quo of no money
making its cost of energy what this
means is is the
this is analogous to the gauge field
having gained mass having gained energy
okay it costs them it costs them to uh
to change the exchange it now cost them
okay just as it costs you to move
a massive particle if you like it's kind
of analogous to that so this is this is
the standard model in action this is
exactly how it works so that adding the
gold breaks you know essentially gives
mass to these um
to these to this gauge field it's
essentially what it's doing it's giving
mass to the max it's making it harder
for the banks so they can't just play
around with their exchange rates now in
such a way that they can guarantee that
the speculators don't make money that
can't happen now one one guy changes the
exchange rate
then that's it you can make money there
is one final final twist to it is
where's the higgs particle in this story
okay so the higgs particle to see the
higgs particle of course there's nothing
physical in a sense about the precise
price of gold in any given country
because i could always redefine
my currency okay so i could always make
it one one it can be two million dollars
but i can change that to one million new
dollars okay that's no big deal
however what you can introduce is silver
into the game now and now there is
something physical which is the
difference in between the price of gold
and silver in a given country something
like that would be the higgs particle
what do i take from this about the
nature of nature
like it almost seems like mass is bad
for nature like like almost like nature
wishes mass didn't exist because it
ruins this perfect setup they had that's
exactly i think that's completely right
brady
the master requires the introduction of
mass requires the uh you know breaking
symmetry
okay you're breaking that symmetry this
is spontaneous symmetry breaking okay
that's what we call it and that's what
the higgs does it responds to the
sponsor there's a symmetry which is
spontaneously broken
to give mass to the air to the gauge
bosons and and you see it here in the
bank analogy you add gold to the game
and suddenly the banks don't have this
symmetry anymore that they can just play
around the exchange rates and it doesn't
cost them anything so is it almost like
like
mass us you and me is sort of this
aberration or this thing that just this
wart on the backside of nature if you
like yeah yeah yeah i mean
one thing that we know about about
nature is that it you know symmetries
are broken you know and and uh
you know for example um you know super
symmetry that we talk about looking for
at the lhc that would be great for doing
solving some problems like the um like
say the cosmological constant problem
but we can't use it because it's broken
in nature so it's no good to us
okay so yeah actually put it this way
life would be easier for physicists if
we could solve all of all lots of very
difficult problems if we had loads of
symmetry and we could just uh you know
we could say oh this this value this
thing is zero because it's because of
symmetry so physics would be easier if
physicists didn't physically exist yeah
phys the problem is that physicists
wouldn't exist if these shoes were there
but they could solve the problems
went into the garden and drank tea under
the shade of some apple trees so he's so
he's kind of recalling
an anecdote here of him just hanging out
with isaac newton and what they're
talking about that's right and then
newton starts remembering the apple tree
story amidst other discourse he told me
he was just in the same situation as
when formally the notion of gravitation
came into his mind