the topic today is alpha beta gamma
these are the three first letters of the
greek alphabet but that's not the topic
the topic is the paper by alpha
beta and gamma which became known as the
alpha beta gamma paper it's a fairly
famous paper it's one of those papers i
guess that's sort of less well-known
than it should be in the sense that it
really is a sort of defining moment in
science
and yet it's mostly known for the fact
that it was a rather bad pun the way the
authors were set up than about the
scientific content of it
let me talk to you about alpha's work
he imagined the universe
at about three minutes after its
inception
he believed that the universe started
with a big bang and the particles he
knew about in 1948 were the neutron
which i represent by a nice white
neutral thing and a proton which is
black in this picture so i'm going to
imagine there was about seven
protons to each neutron in this stage of
the universe after about three minutes
there will be electrons but we'll forget
about them and there are
photons and we'll forget about them just
concentrate on the protons and neutrons
now if a proton and neutron get together
they stick
and at a certain stage they will hit
together very
rapidly and some of them will stick
rather like these two coming together
and if i put electrons around there i'll
make a deuterium atom if i put electrons
around a proton i'll get a hydrogen atom
so this is the bare
a deuterium this is the bare hydrogen
but you haven't got electrons sticking
to these because the system is so hot
the system i mean the universe is so hot
it's enormously hot any electron that
would try to get onto this is evaporated
away almost instantaneously so this
proton and neutron could get together
and make a pair and another one can make
a pair and these two
deuterium nuclei they can come together
and actually they stick together they
make an alpha particle which is the
nucleus of a helium-4 atom a helium atom
and this
pair could join up as well and make
another helium atom it was the first
time that anyone
sort of seriously thought through the
consequences of a hot big bang at the
university starting in a very hot
condensed state
and figured out what that would do in
terms of synthesizing the heavier
elements producing elements heavier than
hydrogen
so by 17 minutes
all of these neutrons have bound
themselves into helium nuclei and that's
all you have left now nothing much
happens in the universe for the next
350 000 years
by which time the electrons have cooled
so much that it's now possible for
electrons two at a time to come onto
this helium nucleus and make helium
atoms and electrons can come onto this
proton and make a hydrogen atoms so
alpha came up with the idea that you
could calculate the later stages of the
universe how many atoms of each type of
form where do atoms come from
and though so he says by weight there is
a quarter of the universe made up of
helium-4 and by weight
that three quarters of the universe is
made of hydrogen and if you look at
interstellar space
you find that three quarters of the
universe is made of hydrogen and about a
quarter is made of helium it was a huge
deal i guess at the time it sort of
wasn't taken terribly seriously because
no one really believed in a hot big bang
at that point and so it was really a
slightly hypothetical well if there were
a hot big bang then what would the
consequences of it be we're talking now
about stuff that was going on in the
first three minutes of the universe
stuff that that was really telling us
how things came together in the early
universe to build
what were made up of the elements so by
doing this calculation and working this
out he was able to show evidence
from astronomy which supported the big
bang
so the paper said that
that all the elements could be explained
by this process of big bang nuclear
synthesis the in these first few seconds
of the universe you could actually make
everything all the way from hydrogen
deuterium helium all the way up to the
heavy elements
and what we now know is that actually
most of the heavy elements are actually
made subsequently in in the centers of
stars rather than in the big bang itself
this caused a big stir ralph alpha with
his supervisor george gamoff who worked
together on this project decided to
publish it
only
gamoff had a
sent a wicked sense of humor which was
rather naughty he decided it would be
more fun
with ralph alpha and george gamorf to
slip in the middle of the name hans
bethe who was his big friend and then
you would have a paper by alpha
better
and gamoff
alpha beta gamma the paper has been
known as alpha beta gamma
henceforth it's a little bit of a fraud
because in fact hans beta the middle
author didn't actually have anything to
do with it he just was a mate of gamops
and gamos thought it would be a good
joke to put his name down as one of the
co-authors but people thought it was
funny all except for ralph alpha who
felt really cheated that somebody who
did no work got his their name on his
fundamental piece of work so he was
really rather embittered by the whole
thing so alpha sort of this this was his
phd this week so
just to illustrate how groundbreaking
this this work was and it was realized
at the time
normally when you defend your phd so you
write your phd and you you sort of you
have to defend it you have to defend the
content to experts in your field okay so
in england typically for example you
will have a couple of academics that
will sort of probe you on the content of
your phd and you have to defend that
and that's about it there's no one else
there it's just you
two guys in a in a room somewhere and at
the end hopefully after maybe four hours
or so three four hours you you sort of
they give you a tick and they say yes
you defended it properly or they don't
and it's bye-bye
and
in alpha's case
there were 100 over 100 people at his
phd defense the press was there but he
he wrote on the paper to the editor um
alpha
beta in absentee
gamut
and so it was meant to be a joke
and the editors i think showed the paper
to better and he looked at it he said oh
this is a very amusing title i like that
title and then he read the paper and
thought well this is quite good physics
he might even be right
so he scrubbed off the in absentia and
and so it was partly better's fault for
allowing that to go ahead it's quite an
entertaining rather weak kind of pun
there are you know there are famous
stories about people about authorships
of papers there's a story of somebody
who wrote a paper in the first person
plural so we did so and so and it was
actually a single author paper and he
got a note back from the journal saying
you can't do that if you're a single
author you have to say i and he couldn't
be bothered to change all the all the
weeds into eyes so he put his cat down
as a co-author on the paper
i did hear uh supposedly that the cats
then subsequently actually got invited
to give talks at conferences
[Laughter]