i'm going to tell you about the thesis
that louis de bruy
normally pronounced broglie by the
english who don't know how to pronounce
his name correctly anyway he was a duke
duke de bruy and in 1924 he submitted
his thesis to a panel in
paris
and they couldn't make head nor tale of
it
and as a result he almost failed his
exam
but they decided on reflection that they
ought to send the thesis to einstein to
have a look at it because it was up his
street they thought and he wrote back
and said it was the first
glimmer of light in the worst of our
physics enigmas and therefore he ought
to get the
the award of his degree her doctorate
and five years later
he got the nobel prize for the material
in his thesis because it opened up a new
field of physics completely and he was
the first person who got a ph d thesis
as the basis for his nobel
award so in many ways he was a
strikingly original and strange figure
and yet nobody's heard of him except a
small group of physicists
einstein postulated that light
could be thought of as being made of
particles which he called corpuscles but
these days we call them photons
and these are particles of light with a
well-defined energy related to their
frequency of the wave and he's thinking
of the waves actually behaving as if
they're particles traveling along
hitting a metal surface and one particle
of light kicks out one electron it's a
one for one process and therefore he
thought of it as a particle
and these particles
also must
have a wave aspects because
electromagnetic waves are waves de
broglie takes this idea and has
has the imagination to think that maybe
all fundamental particles all
particles such as an electron could
behave as if they're waves as well
because if light does it's a wave and a
particle maybe an electron is a wave in
a particle at the same time
now this
is a stupid idea every time you come
across it for the well every time i come
across it still i think it's a crazy
idea and everybody thought it was a
crazy idea the examiners thought it was
a crazy idea
and the only person they thought would
have an inkling as to whether it was
right was einstein that's why they sent
the thesis to it this is my picture of a
particle say an electron this is a very
small particle well it's microscopic
size but imagine it's a particle like an
electron at the same time this is my
picture of a wave it's something that
waggles around
and travels along
in space so it might be moving
so you can have a particle which is
moving and these are two
different aspects of how an electron
might behave according to de bruy
yeah they roll away don't they if
they're the particles is a particle
moving like a wave is it a wave made of
particles what actually is it well
i can't answer that in english language
because it's screwy it does both at the
same time and when you ask a particular
experiment you'll say oh it's a particle
if you do a different experiment you'll
say oh it's a wave and depending on the
question you ask you'll get different
answers so it's both things at the same
time and yet it's neither does that mean
you physicists just haven't been clever
enough to figure out that it's something
else
that's one point of view and that was
the point of view that de broglie took
after he got his nobel prize he thought
he was the godfather of this sort of
physics and he hated the quantum
mechanics that came afterwards
no we've worked out oh not me
schrodinger
and durack and all these
wonderful guys we've worked out a
mathematical language we shall describe
it but we haven't got a mental picture
which goes with that so the mathematics
covers it all but as soon as you try and
explain it to somebody else it is screwy
it is so screwy that i don't really
understand it myself but the mathematics
works so this picture of it being both a
particle and a wave
is a nightmare to explain to students so
this electron
you could think of it as an electron
going around a proton and here i would
have a classical particle going in an
orbit around the proton just as the
earth goes around the sun and that would
be the simplest picture
and it was the picture that
boy used to work out his theory only he
had to invoke some quantum hypothesis
de bruy would take a wave
and he'd say oh i can wrap this in an
orbit round here and if i do it
carefully
this wave
comes back on itself and then goes round
again and i got one two three four five
different nodes where it's
sticking out
and that wave is self-perpetuating so he
gets out what we call quantization it
has a certain number of wavelengths
going around look the real beauty of
this is once you've understood the
electron behaves as a wave
just as light does
you can make an electron microscope so
just as you can take a lens and and to
get the light to go through and focus it
at a point and get a sharp image on your
camera well you can do the same thing
with electrons and put it through
something which focuses them to a point
and you have an electron microscope so
this opens up the possibilities of
looking at things on a smaller and
smaller and smaller scale and opens up
whole areas of understanding of of how
particles behave on the small scale
so he came up with this stupid idea
einstein thought it was really clever
heisenberg and
well it's more than heisberg it's
schrodinger it comes up with an equation
for a wave and you get this wave
function and as soon as you come across
that you're losing all aspects of
reality you're just getting a
mathematical formula
and after that
de broglie thought this wave function
was something physical and real but most
people threw that away it's as though he
had the most beautiful idea which
unlocked this pandora's box of physics
and after that he couldn't cope with the
new world that he created and other
people could and he hated it and he
wanted to make this wave a real thing
but it's not
so this is the the reason why i got the
nobel prize he opened up the field and
created he did the seminal work that led
to the new
type of physics and we've been
struggling to explain this to everybody
ever since because although we can do it
mathematically and calculate incredibly
accurately it's screwy it's completely
completely screwy
so if you don't like it blame de broglie