Kind: captions
Language: en
but word is the conformal cyclic
cosmology of yeah we're starting to talk
about something before
yes that's singular a big and I was just
thinking of myself how boring this
universe is going to be you've got this
exponential expansion this was
discovered early in the in this century
aged my dear 21st century people
discovered that these supernovae
exploding stars showed that the universe
is actually undergoing this exponential
expansion so it's a self-similar
expansion and it seems to be a feature
of this term that Einstein introduced
into his cosmology for the wrong reason
he wanted a universe that was static he
put this new term into his cosmology and
to make it make sense it's called the
cosmological constant and then when he
got convinced that the universe had the
Big Bang he retracted it complaining
them this was his greatest blunder the
trouble is it wasn't a blunder it was
actually right very ironic and so the
universe seems to be behaving with this
cosmological constant okay so this
universe is expanding and expanding
what's going to happen in the future
well it gets more and more boring from
well what's the most interesting thing
in the universe well as black holes the
black holes more or less gulped down
entire clusters of galaxies the class
it'll swallow up most of our galaxy we
will run into Andromeda galaxies black
hole that black hole will swallow and
they will get bigger and bigger and
they'll basically swallow up the whole
cluster of galaxies
golf it all down pretty well or most of
it maybe not all most of it okay that'll
happen too there'll be just these black
holes around pretty boring but still not
as boring as it's going to get it's
going to get more boring because these
black holes you wait you wait and you
wait and you wait and wait and
unbelievable thing for time and
Hawking's black hole evaporation starts
to come in and the black holes you just
it's a clarity Deus finally evaporate
away each one goes somewhere disappears
with a pop at the end what could be more
boy that it was boring men now this is
really boring there's nothing not even
black holes
it's colder and colder and colder and
colder than ever this is very very
boring now that's not science is it but
it's it's emotional so I thought who's
going to be bored by this universe not
us we won't be around it'll be mostly
photons running around and what the
photons do they don't get bored because
it's a part of relativity you see it's
not really that they don't experience
anything that's not the point
photons get right out to infinity
without experience anytime it's the way
for where your relativity works and this
was part of what I used to do in my old
days when I was looking gravitational
radiation and how things behaves
infinity infinity is just like another
place you can squash it down as long as
you don't have any mass in the world
infinity is just another place the
photons get there the gravitons get
there what do they get they run to
infinity they say well now I'm here what
there's something on the other side is
there the usual view it's just a
mathematical notion there's nothing on
the other side that's just the boundary
of it a nice example is this beautiful
series of pictures by the Dutch artist
MC Escher you may know them the ones
called circle and it's a very famous one
with the angels and the devils and you
can see them crowding and crowding and
crowding up to the edge now the kind of
geometry that these angels and devils
and habits that's their infinity but
from our perspective infinity is just a
crime as a place okay there's a clause
and the in just the word you're saying
infinity is just a place oh I have for
the most part infinity sort of even just
going back yeah infinity is a
mathematical concept I think this is
what I think there's an actual physical
manifestation in which way does infinity
ever manifests itself in our physical
universe well it does in various places
you see it's the thing that if you're
not a mathematician you think oh I'm
finished yeah I can't think about that
mathematicians think about it finish me
all the time they get used to the idea
and they just play around with different
kinds of infinities and it becomes no
problem
but yeah you just have to take my word
for it now one of the things is you see
you are taking Euclidian geometry
well it just keeps on keeps on keeps on
going and it goes out to infinity now
there are other kinds of geometry and
this is a what's called hyperbolic
geometries but like euclidean geometry
is a little bit different it's like what
aja was trying to describe in his angels
and devils and he learned about this
from coxeter and he think that a very
nice thing I trying to represent this
infinity to this kind of geometry so
it's not quite York Lydian John which is
a bit like it that the angels and the
Devils inhabit and their infinity mind
this nice transformation you squash the
aver infinity down so you can draw it as
this nice circle boundary to their
universe now from our outside
perspective we can see their infinity as
this boundary now what I'm saying is
that it's very like that the Infinity
that we might experience like there's
angels and devils in their world can be
thought of as a boundary now I found
this a very useful way of talking about
radiation gravitational radiation and
things like that it was a trick
mathematical trick so no what I'm saying
is that that mathematical trick becomes
real that somehow the photons they need
to go somewhere because for their from
their perspective infinity it's just
another place now this is a difficult
idea to get your mind around so that's
why cause one of the reasons because
mom's just are finding a lot of trouble
taking me seriously but to me it's not
not such a wild idea what's on the other
side of that infinity you have to think
why am I allowed to think of this
because photons don't have any mass and
we in physics have beautiful ways of
measuring time there are incredibly
precise clocks atomic and nuclear clocks
unbelievably precise why they be so
precise because of the two most famous
equations of 20th century physics one of
them is Einsteins e equals mc-squared
what's that tell us energy and mass
our equivalent the other one is even
older than that still 20th century only
just max planck e equals H nu nu is a
frequency H is a constant again Lexie E
is energy energy and frequency are
equivalent put the two together energy
and mass equivalent Einstein and in
frequency equivalent Max Planck put the
D together mass and frequency are
equivalent absolutely basic physical
principle if you have a massive entity a
massive particle it is a clock with a
very very precise frequency it's not you
can't directly use it you have to scale
it down so your atomic and nuclear
clocks but that's the basic principle
you scale it down to something you can
actually perceive but it's the same
principle if you have mass you have
beautiful clocks but the other side of
that coin is if you don't have mass you
don't have clocks if you don't have
clocks you don't have rulers you don't
have scale so you don't have space and
time you don't have a measure of the
scale of space and all scale you have is
if you do have the structure that what's
called the conformal structure you see
it's what the angels levels have if you
look at the eye of the devil no matter
how close to the boundary it is it has
the same shape but it has a different
size so you can scale up and you can
scale down but you mustn't change the
shape so it's basically the same idea
but applied to space-time now in the
very remote future you have things which
don't measure the scale but the shape if
you like is still there now that's in
the remote future now I'm going to do
the exact opposite now I'm going to go
way back into the Big Bang now as you
get there things get hotter and hotter
denser and denser what's the universe
dominated by particles moving around
almost with the speed of light when they
get almost with the speed of light ok
they begin to lose the mass to therefore
a completely opposite reason they lose
the sense of scale as well
so my crazy idea is the Big Bang and a
remote future they seem completely
different one is extremely dense
extremely hot the others very very
rarefied and very very cold but if you
squash one down by this conformal
scaling you get the other so although
they look and feel very different
they're really almost the same the
remote future on the other side and
claiming is that one of the photons go
they go into the next Big Bang you've
got to get your mind around that crazy
idea taking a step on the other side of
the place that is infinity ok but I'm
saying the other side of our Big Bang
now I'm going back into the Big Bang
that was the remote future of a
previously on previously on and what I'm
saying is that previously on there are
signals coming through to us which we
can see and which we do see and these
are both signals the two main signals
are to do with black holes one of them
is the collisions between black holes
and as they spiral into each other they
release a lot of energy in the form of
gravitational waves those gravitational
waves get through in a certain form into
the next DeYoung that's fascinating that
there's some I mean maybe I'm maybe you
can correct me if I'm wrong but that
means that some information can travel
yes from another eon exactly that that
is fascinating I mean I've seen
somewhere described sort of the
discussion of the Fermi paradox you know
that if there's intelligent life yes
being you know communication me
immediately takes you there so we have a
paper I have my my colleague waha
Gossage on who I work with this on these
ideas for a while we have a crazy paper
on that yes so looking at the family
paradox yes right so so if the universe
is just cycling over and over and over
punctuated by have the punctuated the
singularity of the Big Bang and then
intelligent or any kind of intelligent
systems can communicate through for me
on T on why
haven't we heard anything from our alien
friends because we don't know how to
look that's fundamentally the reason is
we I don't know you see it's it's
speculation I mean the SETI program was
a reasonable thing to do but speculation
it's trying to say okay maybe not too
far away with a civilization which got
there first before us early enough that
they could send our signals but how far
away would you need to go before I mean
I don't know we with so little knowledge
about that we haven't seen any signals
yet but it's worth looking it's worth
looking what I'm trying to say here's
another possible place we might look now
you're not looking at civilizations
which got there first you're looking at
those civilizations which were so
successful probably a lot more
successful than we're likely to be by
the looks of things which knew how to
handle their own global warming or
whatever it is and to get through it all
and to live to a ripe old age in the
sense of a civilization to the extent
that they could harness signals that
they could propagate through for some
reason of their own desires whatever we
wouldn't know to to other civilizations
which might be able to pick up the
signals but what kind of signals would
there be I have a foggiest
you