This lecture is brought to you by Science and Cocktails and ECSJ2017/Danske Videnskabsjournalister/EUSJA.
hi hi can you hear me okay well it's
going to be hard to follow that that was
really the summary of everything I
wanted to say but I'll try it's a real
pleasure to be here this is an amazing
event an amazing venue I just flew in
this afternoon and and this is waking me
up already so that's good so I hope to
have fun tonight and tell you a story
that's that will change maybe a little
bit of your perspective of the place in
the your place in the universe this by
the way is the universe in case you
wondered this is a picture from the
Hubble Space Telescope and every dot in
this image except for that one is a
galaxy not a star there are a hundred
billion galaxies in the observable
universe each containing 100 billion
stars and we're on just one of them and
even that is an amazing discovery I
wanted time to talk about that but a
hundred years ago we thought there was
one galaxy in the universe we now know
there are over a hundred billion and
that just gives a sense of how things
are changing and every day we discover
new and amazing things about the
universe and what I want to talk about
is how it's not just out there how
you're connected to the universe in ways
you may never have imagined but I want
to begin this story as a story so like
good stories I want to just say at the
beginning it's the best of times and by
that I mean that the Large Hadron
Collider is operating in Geneva and has
not created a black hole that destroyed
the world so that's very good but at the
same time it's the worst of times as
we've seen in that last video and and
and the important thing about cosmology
and science is it can take us away from
these local awful things because this
too shall pass this is just a speck in a
cosmic history so as miserable as this
may be it's just a moment and so anyway
let me begin by taking you first to a
connection that was that was talked
about in
it's in the video a little bit but maybe
put a little more content than just the
fucking the the so I like art and it's
great to see our here and it's wonderful
that there's an artist doing this right
now even as I speak one of my favorite
artists is a sculpture Rodin and I was
in the Rodin Museum in Paris once and I
started to think about something I later
wrote a book about it about the fact
that when you look at Brennan's art that
they're beautiful moments that are
captured and and there's a famous statue
that where dad has a kiss and I was
looking at that and I think you're
thinking that that kiss was immortalized
in stone forever but of course it's not
forever and the stone hasn't been around
forever the stone has only been around
for millions of years and I started to
think about what is forever what's
eternal is there anything that's eternal
and nothing is but but the closest thing
of course in some sense is our atoms and
our atoms have been in a lot of
interesting places I have my cocktail
here which unfortunately is empty and no
one has refilled it but in a case maybe
that'd be a message that people I was
getting that one that bubbles if you
want to bring me another the but my
mother used to tell me when I was a kid
and I drank a glass of picked up a glass
she said don't you you know don't touch
that you don't know where it's been and
she will be amazed by the real true
story of every atom in your body because
every atom in your body as I say is it's
just been around on earth for
four-and-a-half billion years but but
it's been around a lot longer than that
and in fact the actual atoms have not
been around since the beginning of time
in the beginning of the universe are
only hydrogen atoms and and a little
helium and some lithium which is
important for some of you I guess but
but but for the rest of us the carbon
the nitrogen the oxygen is the important
stuff and that hasn't been around for a
long time and the first connection I
want to bring
was your connection to the cosmos what
do you know is this one of the ones that
bubbles okay okay good okay not the same
one but it'll do
it's a little stronger okay
the talk may go on longer than I
intended but um so this this is uh this
was the first thermonuclear explosion on
earth it was the mic explosion in 1952
November 2nd that 7:00 in the morning I
think and briefly of course it wasn't
done as a science experiment it was done
as an experiment to destroy things and
and and great okay here we go okay well
I can have my work cut out for me
okay I'm not responsible for what I do
after those okay so it destroyed a
Pacific atoll in a microsecond in this
different thermonuclear explosion but
interestingly enough in that in that
microsecond every element that was ever
existed in the universe was also created
because thermonuclear explosions
involved nuclear fusion and that's the
process of power stars in the Sun and
that's how your atoms came to you
because the carbon the nitrogen and the
oxygen the iron was only created in the
cores of stars it wasn't created in the
Big Bang and the question is how did it
get to your body and it got to your body
thanks to stars and stars that exploded
this is uh this is an image from a
nearby galaxy about set about 70 million
light years away and it's a galaxy just
like our own if it were if this was a
milky way we'd be sort of located sort
of there in a boring suburb not
Christian or anything but but where the
earth is around and the Sun is around
our galaxy and but this is another
galaxy and what you notice about this
galaxy of 100 billion stars is maybe ten
billion stars in the center but you
notice this bright star here and this
star is shining with the brightness of
the entire center of that galaxy which
is surprising because there are 10
billion stars in there so the first
thought
you might have is that this star is just
in our galaxy and it got in the way of
the picture but that's not true it's a
star at the edge of that galaxy and it's
shining with the brightness of ten
billion stars why is that it's a star
that's just exploded a supernova an
exploding star the the brightest cosmic
fireworks anywhere when a star explodes
it shines brightly for about a month
with the brightness of a hundred billion
stars and stars and their lives
some of them as exploding stars and it's
important for us that they do explode
because if they didn't we wouldn't be
here because all the nuclear materials
that are produced during the lifetime of
that star are then it sent out into
space now we actually can observe
exploding stars fortunately for us stars
don't explode too often once every
hundred years per galaxy
fortunately they explode however because
they didn't we wouldn't be here now how
can we observe stars that they explode
only once every hundred years per galaxy
the answer is the universe is a big and
old place and rare events happen all the
time I'll stand for you to finish that
picture and then I'll move okay good
anyway so once 400 years for galaxies
well there's two ways we could study at
first we could assign a graduate student
to each galaxy because a hundred years
it's about the right time for a PhD so
that's okay and you know if the graduate
student dies it's okay because students
are very cheap so that we don't need it
but there's another way and that is to
realize that okay because the universe
is big and old these events are
happening all the time in tonight you
won't be able to see if it's cloudy but
if it ever gets clear in Copenhagen at
night you could you could take a small
hole with your hand and look up at the
sky where they're no stars and take a
hole that big and with the largest
telescopes in the world we have in chile
if you looked up in that dark spot you'd
see about a hundred thousand galaxies in
that little region and that means if you
look at a hundred thousand galaxies in a
given night
and you work things out once every
hundred years for Galaxy you'll see a
few stars explode and astronomers do
that they apply for telescope time and
they look out and if they can see enough
galaxies on a given night they'll always
see a star explode and we can study
those stars and we've been able to feed
learn about them and we've been able to
use them to study the universe that's in
some sense a different lecture but these
stars when they die they create other
star systems this was by the way the
most recent supernova that we've seen
not in our galaxy because the last
supernova that was seen in our galaxy
was about 400 years ago and amazingly
the reason for that is because most of
our galaxy is dust and we can't see the
exploding stars in our galaxy they get
obscured by dust but if we look at other
galaxies we can see them but this one
was in a neighboring galaxy the Large
Magellanic Clouds which is you can see
in the southern hemisphere and this star
exploded in February 1987 and there are
other stars that have exploded this is
the Crab Nebula there was a star that
exploded about a thousand years ago that
was seen that could be seen during the
daylight on earth when the star explodes
in our galaxy and it's interesting to me
to think about this because this was in
1060 something I forget the exact year
but there's no records in Europe of That
star exploding yet in China it was there
was a record Chinese astrologers saw a
guest star in the sky and reported it to
the Emperor and said it brought good
tidings because of course that's what
they want Emperor wanted to hear which
is what religion is all about and um and
but it wasn't recorded all in Europe and
I think one of the reasons was also
religion frankly because this the
conventional wisdom in the in the
Christian Church was that the sky was
was not only God's creation but it was
immovable and unchangeable and if you
said you saw something new in the sky
you'd likely be burned at the stake so
it's not too surprising that it was
never reported here but this was a
nearby supernova but but interesting
enough here's that supernova
1987 20 years later and you can begin to
see a ring around and I think I'll
expand it this is the material that's
being thrown up by this star all the
carbide the nitrogen and the oxygen the
iron moving at about 10,000 kilometers
per second and when stars explode they
compress the gas around them and cause
it to shine but they can also actually
cause other stars to be created this is
not a painting this is an actual image
of a stellar nursery in our galaxy where
after a supernova goes off it compresses
the gas and other stars form and about
five billion years ago
a supernova went off in our region of
the galaxy compressing the gas and
causing our Sun what is now our Sun and
solar system to eventually form 4.5
billion years ago and the material from
that supernova not only made became part
of the Sun but it eventually became part
of the earth and all the other planets
and every atom in your body as said in
that video but it's true and it's the
most poetic thing I know about the
universe every atom in your body has
been inside a star that exploded not
just one star many stars because because
in order to make up enough carbon and
nitrogen oxygen lots of stars had to
explode 200 million stars in our galaxy
exploded before the thumb form and so
the atoms in your in your body have been
part and experienced the most violent
thing in the universe and the atoms in
your left hand could have come from a
different star than your right hand but
you were literally star children and I
think that's a wonderful way to begin
this because you have a connection an
intimate connection to the cosmos it's
not just out there it's in your bodies
and your bodies provide us living
histories of the history of the universe
you like that okay folks you can applaud
for that
so I wanted so we are we are we come
from the stars but I want to come a
little closer and I want to talk about
another connection that you have that
you may not know about first of all this
is a picture take it a nice sunset
it looks like it's Los Angeles because
the sky is red some used to be pollution
but it's not that sunset happens have
been taken on this place here in Mars
the Mars is interesting to us because
Mars is a dry planet now but it we think
it originally had water as I'll show you
and the ISTE question here is first of
all we used to wonder where did the
water on earth come from earth is a
water planet but when the earth formed
the temperature in the solar system in
the region of the earth was about a
thousand degrees so it was hard for for
water to waters a volatile material and
it turns out that most of if you work
out we're being bombarded by comets
asteroids meteorites every single day in
one form or another and if you work out
over the history of the earth enough
material has been transported to the
earth by comets to fill up all the words
Earth's oceans so we thought for a long
time that maybe that's where the water
comes from but it there's a problem if
you measure the content of the water in
in comets and measure what's called the
isotopic abundance the abundance of
hydrogen and the next lightest or the
heavy hydrogen called deuterium it's
slightly different in the Comets than it
is in the oceans on earth so we didn't
quite know where the water came from
maybe it was embedded in the earth
originally to understand that we
actually look at Mars because Mars
unlike the earth doesn't have plate
tectonics it doesn't it doesn't have
volcanic activity most of the material
on the surface the earth now wasn't
always there because the earth is
churning and that material goes inside
and outside so there are very few very
old rocks on earth but in Mars the
material that's there has been there
since essentially the formation the
planet and if we could find water on
Mars and measure its abundance we could
learn about the
water on earth but in the process of
that we learned something interesting
the question is where can you learn go
to find rocks from Mars you don't have
to go to Mars you go to a place that
looks like Mars that's this place this
is Antarctica the South Pole now why
would you want to go to the South Pole
to look for rocks from Mars anyone have
an answer what I'm sure I'm getting lots
of good answers but I can't hear them
all but okay it's that the point is it's
not very sophisticated notice that this
is white okay and so it turns out
material gets kicked out of Mars by
meteors and comets and some of it falls
to earth and some of it falls to earth
here on this part of the planet but if
you find a rock out there it's not very
surprising but if you're in Antarctica
and you are Nazca do I'm near the South
Pole and you're going along the ice and
you see a rock there's only one place it
can come from up there so that's why we
look for meteorites and Antarctica it's
not because of anything sophisticated
they're just easy to find anyone could
do it I was going to go do it and if
they wanted me to do it anyone can do it
and interesting enough in this area the
Allan Hills of Antarctica about 30 years
ago this particular rock was found on
the surface of the ice and it was ooh
and it turned out to have the abundance
have the right
elemental abundance that we know it came
from Mars and then it caused a great
great furor about 20 years ago when it
was cut into small pieces and put in an
electron micrograph and when it would
that was done these things were seen
these small structures and President
Clinton at the time had a press
conference because these look just like
the oldest fossils of life here on earth
and it was our thought that
maybe this was evidence of life on Mars
now it turns out in the interim we've
been able to show that that's not the
case that these structures are actually
much smaller than the earliest fossils
of life on Earth scene gotten from
Australia as it turns out and we and we
think that you can create these kind of
structures without biological systems
but it but we've realized in the interim
something very important all throughout
the earth we found forms of life that
exist in extreme environments they're
called extremophiles and they can exist
in boiling water and acid but
interestingly enough those microbes can
live in rocks for a long time even in
dry and extreme environments that means
that if there were microbes on Mars
embedded in rocks they could easily
survive the eight or nine month voyage
through space so they got to the earth
and that means that no planet is an
island it means if there's life in one
place in the solar system it's going to
pollute the rest of the solar system at
least all the accessible places in the
solar system so the interesting question
is this life evolved on earth and I can
still use that word especially since
we're not in the United States life
evolved on earth about as soon as the
laws of physics allowed about 500
million years after the year formed I'll
have a ways to go anyway because before
that we were being bombarded by comets
and asteroids and the oceans were being
evaporated but then Jupiter formed and
basically ate up most of that material
and things subsided but life formed on
Earth extremely quickly and the question
is that's a surprise to us how did life
originate on earth we don't like know
the answer although we're getting close
but maybe it didn't originate in earth
maybe it originated on Mars and was
transported to her because early on and
hit like in Mars it was hot and wet so
if you want to know what a Martian looks
like just look in the mirror
perhaps now we don't know if that's the
answer but interesting enough we've
discovered as we've explored Mars and
the surface of Mars evidence of with our
Rovers which are a wonderful way to
explore the planet in my opinion better
than humans but we can talk about that
but we've discovered evidence of even
today water flows systems that look like
there is actually liquid water
today's still on Mars periodically and
that's incredibly exciting because not
only will be able to study that water
but it gives us hope that maybe we'll
find evidence of extinct or maybe extent
life-forms on Mars but we don't have to
go to Mars we can go to other the moons
of Jupiter and Saturn this is a
Enceladus a large block of ice which 20
years ago we just thought was a
perfectly smooth white snowball but
we've now discovered with the Cassini
satellite the Cassini mission which
explored Saturn Enceladus is a moon of
Saturn that the ice isn't smooth at all
and the fact there are water flumes and
plumes that come up water volcanoes if
you want because the gravitational pull
of Saturn is enough to produce tidal
forces that heat up inside Enceladus so
Enceladus and IO are two ice moons that
we now understand are not just dykes
moons inside of them is a water ocean
heated by the gravitational force of the
big planets they're around and when when
when the Cassini satellite flew through
these detected would look like maybe
organic materials and this material has
been protected by a thick wall of ice
maybe several kilometers thick and then
there may be an ocean underneath it's a
hundred kilometers deep and one of the
exciting things we're going to do and
maybe in the next two decades is send a
mission to either E or Enceladus to
maybe explore the surface and ultimately
drill down and we may discover life here
because all of the things that are
important for life on Earth water
organic materials and sunlight are
prevalent not just here but everywhere
in the universe we discovered organic
materials the basis of amino acids on
comets so it could be that we're not
only not alone in the universe but we're
not alone in the solar system now there
aren't intelligent beings there but
there could be microbes and if they're
if there are life-forms inside of
Enceladus those are exciting if we
discover life on Mars that could be our
cousins because we've been sending
material back and forth by comets but if
we discover life deep in the oceans of
Enceladus that material has been
protected and that could be another
genesis of life and that would be very
exciting because we find two independent
genesis of life in the in the in our own
solar system
it means it's everywhere in the universe
but ultimately we are connected in one
way or another to life in our solar
system so we are not just if we discover
life on mars as i say it's our cousin so
we're not just connected to the stars
we're connected to the other planets and
we could be martians so that's the next
cosmic connection i want to make so
we're connected to the stars we're
connected to a potentially life on other
planets but we're connected to each
other in a way that you wouldn't maybe
not imagine I wouldn't do an experiment
everyone I want everyone to take a deep
breath and then hold it in okay one two
three take a deep breath hold it in
you can't laugh while you're taking a
deep breath keep holding it keep holding
it okay let it out there was no reason
for that I just wanted to see if you do
it but but there sort of is every time
you breathe in your being connected to
all of humanity and throughout history
who's this does anyone know this is
Julius Caesar that's right the amazing
thing is and it's one of the things I
love to teach in an undergraduate
physics class every time you take a
breath you're breathing in atoms from
the dying breath of Julius Caesar when
he said ed to Brutus
every single time you breathe you're
breathing in atoms from Julius Caesar's
dying breath it's amazing but it's true
his atoms of his breath were circulated
throughout the atmosphere and because of
the processes that circulate things
through the earth and the atmosphere and
life we can actually calculate that
maybe 10 or 20 atoms of his dying breath
are in each of your breaths
but that means not just fuel your Caesar
but that means everyone throughout human
history people we think of as scary as
others are part of us they're not just
others they're part of our bodies right
now okay good this is a great
this is clearly resonates with people
who are stoned okay anyway but this is
useful think of that think of this the
next time you breathe in but I mean I
use it all the time I spend a lot of my
time I try when I can work which is
increasingly rarely mostly on planes but
if I'm alone at night and I'm working
and I'm not getting anything done which
is also usual
I remember that each time I breathe in
I'm breathing in some atoms that
Einstein breathed out when he put the
final dot on his general theory of
relativity so this is wonderful you are
breathing in atoms from virtually almost
everyone who ever lived the good people
and the bad people you're real to
breeding in atoms from Hitler when you
put the last note on what mine calm okay
and speaking of what my mum said well I
guess I can say this inner so when you
drink a glass of water or alcohol you're
drinking in atoms excreted by every
slimy thing that's ever walked the earth
in particular and this is really
interesting for some of you if you have
water take a drink right now
or even alcohol take a drink right now
every time you drink a glass of water
you're drinking and in atoms from the
sweat of your parents during their
coupling that created you
okay
I remember the American comedian WC
Fields I never said this before on a
stage but this place it seems ok
I remember WC Fields used to say about
water he said water I never drink it
fish fucking it and and now you know
it's true you're drinking it when you
come in and every time here's the
yacht's younger me this is Lucy who was
a wonderful ancestor of ours 3.2 million
years ago after Australopithecus Lucy
who we found and every time I breathing
in not breathing in atoms at Lucy
breathe out but it's not just Lucy
these are stromatolite these are these
are these are the earliest this is from
Shark Bay Australia which you can see
here these are fossil remnants of the
earliest organisms that produced oxygen
on earth the cyanobacteria that
originally originally there was no
oxygen in the atmosphere the earth all
the oxygen you breathe all the oxygen
you breathe was produced by the early
organisms on life on Earth that's one of
the reasons why when we look for life on
other planets we're going to look for
oxygen atmospheres which isn't a
guarantee of other life but I'd be a
strong signal because it's important for
life history of life on earth that there
was no free oxygen because oxygen is a
poison it burns things and if there had
been all the organic materials on earth
would have been oxidized early on but
they weren't the life created the oxygen
every way so these things puffed out
little bits of oxygen and over two
billion years in the early history of
life on earth the oxygen abundance built
up until life figured out how to use
oxygen by respiration so every time you
breathe in you're not just breathing in
battles from Julius Caesar and and and
everyone else but also the atoms breathe
out by the stromatolite over two billion
years you're connected to everything
that's ever lived on earth your connectr
the Stars the planets and everything
that's ever lived on earth okay and in
fact when I talk about this about your
what you what you're drinking when you
drink in here's another experiment you
can do take your finger and prick trick
it and take a little bit of blood and go
out to the ocean and let it drop of your
blood go in the ocean interestingly
enough if you come back a year later and
take a spoonful of ocean water
we'll be some atoms of your blood in it
it gets distributed throughout the whole
ocean you are literate Kenton so this is
a quote from Shakespeare that you
remember in Macbeth when they killed a
king and he says will all great
Neptune's ocean wash this blood clean
from my hand no this my hand will rather
the multitudinous seas incarnadine in
english that means that that i'll turn
the book ocean's red there's too much
blood on my hands and of course it's
true every time you bleed if it goes in
the oceans you'll turn the oceans red in
a very small way so those connections to
everything on earth are remarkable and
and totally unexpected I think and I
hope that gives you a different
perspective of your place but I want to
point out now I want to talk about a
different set of connections the kind of
connections that relate you to things
that are esoteric the kind of physics I
do is very esoteric and people say what
good is it and and and does it make a
better toaster or a faster car it
doesn't but it does help and I first
began to think of this when I was stuck
in in Los Angeles but the same could be
said for coming here so I can I flew in
at about 11 o'clock today from the
United States and I came from the
airport to - well that's the hotel I'm
in but you shouldn't know that anyway
and except for the beautiful women they
should all know that now but anyway um
no and so I one uses GPS then the
good-looking guys - I guess no I'm just
joking anyway um that's the problem of
drinking before speaking it's really a
mistake but and the point is every time
you use your GPS you're using you're
relying on remarkably esoteric laws of
physics that you may not know so how
does GPS work GPS works because there is
a network of satellites around the earth
and we use triangulation so these
satellites are way above the earth and
what we do is if is when in when your
transmitter is detected by two different
satellites those satellites calculate
the time that it takes for the signal to
go from the saddle
lights of the earth and back and from
that they can determine the distance to
where you are and we have two of them or
three of them or four of them they can
pinpoint your position sorry and that's
why we use we need to have several
satellites in view in order to use GPS
okay so those two satellites measure
your relative the time it takes to get
from there to there and back and and
then very carefully but they have to
have very accurate clocks to measure
your position very accurately because
light goes about one meter every
billionth of a second so if I want to
know your position to 10 meters accuracy
say then I have to have a clock clocks
on those satellites that are accurate to
10 billions of a second atomic clocks
can achieve that kind of accuracy but we
have to recognize that these satellites
are out there so light travels of 30
nanometers per 30 centimeters per
nanosecond that's 30 centimeters every
billion to the second now these
satellites are up and I'm going to use
American units here I'm sorry but eight
thousand twelve thousand miles above the
earth most of them and they're traveling
around the earth at 8,000 miles per hour
and this means that esoteric laws of
physics matter so to get accuracy of
five ten to five 10 meters 20 to 30 nano
second accuracy now relativity tells us
that if I'm moving with respect to you
my clock is thinking slowly with respect
to you this is not observable on earth
most of the time but if I want to
measure things with accuracy of
nanoseconds and things are moving in a
thousand miles per hour I have to use
this and in fact special relativity that
tells me that the ratio of the time of
two clocks depends upon this which is
where this is the speed of the of the
clock and this is the speed of light
normally because we move very small
slowly compared to the speed of light
this is irrelevant but in this case it
isn't it turns out that these clocks
because they're moving
on the earth very fast tick at a rate of
seven microseconds per day more slowly
than clocks on earth but this isn't the
only effect Einstein also told us that
if I'm standing up here my clock is
ticking at a different rate than your
clock because being at a different place
in a gravitational field also means
clock it clocks tick at different rates
and these clocks are up at 12,000 miles
above the earth so general relativity
tells me if you plug things in that in
fact because these clocks are this high
they're ticking it turns out 45
microseconds per day faster than clocks
on earth now this means that they go in
different directions that these clocks
are ticking relative to each other and
relative to clocks on earth at a time
difference of 38 microseconds per day
but 38 microseconds is 38,000
nanoseconds and that means if the makers
of GPS didn't include the facts of the
curvature of space and the effects of
special relativity things you'd never
think you need to ever think about then
your GPS would lose accuracy in two
minutes
in two minutes you'd be out by about a
kilometer and so every day in order to
get here or anywhere you go in your cars
and use GPS you're relying on the fact
that space is curved this esoteric
result from general relativity that is
remarkable so even if the most exotic
aspects of physics creep in and change
our everyday lives
now this isn't this this this is meant
to hypnotize you take a drink while
you're doing it this hidden connection
the fact that you're connected to a
curved universe is even more it's
something that that we're using in
physics nowadays in a different way not
only is space curved not only are clocks
on these satellites taking a different
rate not only is my clock here ticking
at a different rate than yours
there but every time I move around the
stage I'm disturbing space because
Einstein told us that space and time
respond to the presence of matter and
energy and when I move around and wave
my arms like I often do I'm producing a
curvature of space that's varying in
time and in 1916 Einstein realized when
he wrote down general relativity that
when I do this I'm producing a moving
disturbance and it causes a ripple in
space when I shake my electric charge up
and down I produced a disturbance and
electric and magnetic fields that is
responsible for everything in this room
the lights I see those come from that
kind of shaking electromagnetic waves
result when I shake charges up and down
and the electromagnet is light that's
how I see but Einstein showed us if I
shake am ass up and down I disturbed
space I produce a disturbance and
curvature in space and just like a
ripple on a pond that that disturbance
travels out in this case at the speed of
light and what it means is every time I
do this I'm actually changing the space
in this room and every and I'm producing
what we now call a gravitational wave
and that means and there are tons of
gravitational waves going through this
room right now and when a gravitational
wave goes through this room it much as
if it went through this screen the
length of the room gets smaller in that
direction and larger in that direction
and then smaller in that direction and
larger in that direction and that's
happening now those of you who've drunk
a few of these notices right away but it
effect is so small that we don't notice
it why don't we notice it because
gravity is the weakest force in nature
it's hard to believe that gravity is so
weak because we when you get up out of
bed in the morning you feel it right
away but that's all the atoms of the
earth affecting a single atom in your
body but gravity is the weakest force
and
and Richard Fineman gave an experiment
to show how gret weak gravity is take a
friend maybe not a friend to the top of
a high building push them off it takes
all of the atoms in the earth and their
gravitational force to pull them all the
way to the ground and maybe a hundred
meters if it's a really high building
but electromagnetism stops them in a
fraction of an inch they don't even make
a dent in the concrete because the
reason I don't fall through this stage
is not that it's solid it's mostly empty
space but the electric forces of the
electrons in my hand or in this case my
feet are repelled by the electric forces
of the electrons in the in the stage so
just the electrical forces of the
electrons in this stage are holding me
up against the entire pull of the earth
gravity is so very weak and that means
the gravitational waves I create are so
small you'd never be able to see them
here's a three-dimensional gravitational
wave moving through which looks nice but
it doesn't have any information but
those 3d images don't but the point is
if this is there we'd like to be able to
detect it if these ripples in space are
occurring all the time
are they really happening or is this a
figment of our imagination and what
amazes me is that we have built the most
amazing machines to be able to detect
these ripples in space here's the here
is a machine the largest gravitational
wave detector in the world the LIGO the
laser interferometric gravitational wave
observatory there's two copies of this
this is in Hanford Washington there's
another one in Livingston Louisiana
exactly the same and what these things
are are two arms two perpendicular arms
each four kilometers long and if a
gravitational wave comes down from above
what will happen is the length of this
arm will get a little bit smaller and
the length of an arm will get a bit
longer and then the length and that's
then the length of this one will get
smaller and that will be longer so all
you have to do is measure the length of
these two arms very carefully simple not
so simple gravity is so weak that we
calculate if the most cataclysmic
we can imagine happening in the universe
today the collision of two black holes
solar mass black holes happening in our
galaxy or some distant galaxies happen
to massive objects more massive than our
Sun colliding well they'll produce a lot
of gravitational waves it gives the more
intense the gravitational field around
the object and the more catastrophic the
event the bigger the gravitational wave
signal so we can look for two colliding
black holes solar mass black holes but
the effect is still very small in fact
we can calculate that if two black holes
collide in a distant galaxy two solar
mass black holes gravitational waves
will be produced and they'll change the
length of this arm relative to that arm
fine amount we can calculate these
alarms are four kilometers long and in
order to be able to detect this signal
we have to detect the fact that these
gravitational waves will change the
length of this arm four kilometers long
compared to the length of this arm by an
amount equal to one one thousandth the
size of a proton
now that should amaze you one
one-thousandth the size of a proton
what's even more amazing is we can do it
we can do it and then I'm not an
experimentalist and this is one of the
reasons why because I never would have
figured you could do this and in fact
it's really hard to imagine that you can
do it because if a truck hits a pothole
over here it produces a bigger signal
here so how can you how can you get rid
of that while you build two detectors
one in Washington or one Louisiana and
if a patient wave traveling at the speed
of light hits this detector and goes
through the earth eight milliseconds
later it'll go through the detector in
Louisiana so what you look for is a
signal in this detector and exactly the
same signal eight milliseconds later in
Louisiana and in September 15th I think
2015 we saw the first gravitational wave
ever discovered in the universe this is
this is
the signal and it's a signal of two
black holes colliding in a galaxy 1.3
billion light-years away causing space
to ripple and vibrate back and forth it
turns out with a frequency of about 300
cycles per second that means these two
objects these two solar mass black holes
one was 36 times the mass of the Sun the
other is 29 times the mass of Sun they
were orbiting each other a hundred times
a second before they climb - think about
that - solar mass objects orbiting each
other a hundred times a second and
what's amazing is not just that we can
detect the signal but we needed not just
the most sophisticated technology
available on earth because even the
quantum mechanical motions of the
mirrors are bigger than one one
thousandth of a size of proton so we
have to use what's called quantum optics
to overcome that but we have to use the
most sophisticated theory we can do
because if you see a random bit of noise
how do you know it's colliding black
holes you have to have a expected signal
to compare it to and the mathematics of
general relativity is very complicated
and we needed supercomputers and over
the last 20 years we needed those
supercomputers only of two years ago did
we have the technology in the experiment
in the theory and so this template sort
of smoother line is the template of what
you'd expect if two black holes collided
and we can compare the signal to the
template and we see it's a beautiful
thing and this was the signal seen in
hanford eight milliseconds later this
was a signal Tina in Livingston and the
to fit exactly on top of one another and
what we saw was a signal of two black
holes colliding 1.3 billion light-years
away and I'll show you the animation of
this it says not the visual this is an
artist's simulation but you can see when
these black holes are moving around
they're bending the space around them
and they're causing the light around
them to be perturbed so you're actually
the stars behind them look like they're
moving because the space is curving and
this is a slowdown of the actual last
two tenths of a second in the life of
this two black holes as they collide and
merge to form a single black hole and
you watch in the last moment you'll see
space jiggle and that's the generation
of gravitational waves there see it
jiggle now that's a signal we saw now
the amazing thing there's two amazing
things about this first that we saw but
secondly it was a it was a 36 solar mass
black hole and a 20 million solar mass
black hole and they combined together to
form one single black hole how massive
was that 36 plus 29 36 plus 29 anybody
who said 65 put up your hands you said
65 put up your hands knows more than
just you okay you said 65 wrong because
it's amazing
it turns out they form the black hole of
62 times the mass of the Sun three solar
masses disappeared where did those three
solar masses go to into gravitational
waves now that may not amaze you but it
should because our Sun is burning a
hundred billion hydrogen bombs every
second to produce the light that we see
and over the it's turning mass and
energy e equals MC squared over the 10
billion light year lifetime of the Sun
less than 1% of the mass of the Sun will
turn from matter to energy in two-tenths
of a second these objects turn three
times the mass of the Sun into energy
that meant stirring that two-tenths of a
second that object emitted more energy
than all the rest of the stars in the
visible universe combined it's amazing
that these things happen and we detected
it now as amazing as that as these are
interesting gravitational waves but the
gravitational waves that are interest to
me are going to be looked at by
different machine this is at the South
Pole we're looking for gravitational
waves not from the collision of two
black holes but gravitational waves that
connect us to the beginning of time we
think we're here because an event that
happened when the universe was a
millionth of a
billionth of a billionth of a billionth
of a second old when our universe
expanded by a huge amount you know
someone's trying to call me right now
hold on let me just stop that okay we
think at that time in universe was a
millionth of a billionth of a billionth
of a billionth of a second old our
universe expanded by huge amount
puffed-up from the size of a single atom
to the size of a basketball or soccer
ball if you're here in Europe in a short
instant now if two black holes colliding
produce gravitational waves if our
entire universe expands like that it'll
produce gravitational waves that are
that are we hope we'll be able to detect
one day and this is the machine we're
hoping to use to detect them among
others this is called the bicep detector
it turns out that these leave and
imprints these gravitational waves we
think leave an imprint in the microwave
background radiation that's coming at us
from the Big Bang that's coming at us
from all directions that we measured
first 30 years ago and I've now seen
more seriously in various other ways
when we look out we see this radiation
coming at us from all directions we call
it the cosmic microwave background
radiation that was emitted when the
universe was about 300,000 years old
which is when it became transparent to
radiation and we look out we have
pictures of the universe back at that
time but embedded in those pictures may
be a signal of gravitational waves that
have come at us from the beginning of
time and these kind of detectives we're
looking for them it turns out these
detectors are the South Pole they it's
not cold enough at the South Pole to use
them we have to send down liquid helium
to use these detectors because it's not
cold enough we send down that liquid
helium in the summertime does anyone
know why when when it's winter and
Antarctic it turns out you can't send
planes down there isn't that amazing I
when I first learned that I was shocked
we don't send planes dance act our
arctor in the wintertime I mean we can
go to the moon
well that was faked but we can go down
to the depths of the ocean we can go
ever but we don't send planes Antarctic
in the wintertime that's why this is one
of my favorite images this is from the
bicep detector and it's sub sunset
something happens once a year at the
South Pole so it means if you take this
picture you're stuck there for the
winter
okay just why this picture was taken by
a graduate student okay
but it turns out that this detector and
others like it that are being built may
allow us to detect gravitational waves
from the moment of creation which
connecting us to the process of produced
ultimately all the stars and galaxies we
see today
a process we call inflation and what's
really kind of interesting is that we
think that this process that caused our
universe to explode in size actually
caused space to continue to explode in
most other places our universe basically
was like a seed that condensed out of
this rapidly expanding universe but that
expansion continues even today and that
means there may be other universes being
created right now as other seeds
collapsed on without a background
expansion and inflation happens then our
universe isn't unique there are many
universes out there and it turns out
when you leave inflation the laws of
physics may change depending upon how
you leave inflation and that means some
universes may form with a lot of
galaxies some universes may form with no
galaxies some universes may form with
just the right number of galaxies so it
could be that all of the physics the
properties of our universe
are just one big cosmic accident that if
that in a different universe with the
laws of physics would be different we
wouldn't be here that makes it sound
like the universe well it basically says
the properties of the universe are are
the way they are because there are
astronomers here to measure them that
sounds religious but it's not it's
cosmic natural selection because it says
that our universe is one in which we
could evolve it'd be fascinating to find
ourselves living in the universe in
which we couldn't evolve that would be a
worth a book or two but but no one be
around to read it
and this idea of what's called a
multiverse when I first wrote a universe
from nothing five years ago was just a
pure speculation based well-motivated
speculation
unlike God but one that was pure
speculation metaphysics if you wish but
what I find amazing is we're on the
threshold of potentially being able to
measure gravitational waves from
inflation which if we could measure them
would tell us about that inflation
happened would allow us to probe that
theory and see if indeed other universes
are being created not we wouldn't be
able to see them directly but we'd be
able to test the physics that created
our universe and know indirectly that
those other universes are there just
like over a hundred years ago we knew
atoms existed but we never thought we'd
see them if this is true we'll turn
metaphysics into physics will know
indirectly that these other universes
exist and that we're not only not alone
in our universe but that our universe is
not unique and it amazes me to think
that in my lifetime we may believe and
know that where our universe isn't
unique that we are in a sense connected
not just to other all the stars in our
universe in any way but to other
universes by that act of inflation now
this cosmic accident is similar I want
to end with another cosmic accident
which is related to my new book in more
detail the greatest driver told so far
relates to a fact that we are all here
by another cosmic accident there's a
bathhouse here and I wanted to go to it
but it's going to be closed now so I
can't but let's say you're swimming in
water and you swim very fast fine let's
say I filled that swimming pool with
molasses well you wouldn't want to get
in first of all but if you did go in and
you tried to swim you'd swim much more
slowly because the molasses would
produce much greater resistance well it
turns out that we think that that's why
we're here that
is an invisible field everywhere
throughout our universe that froze in
the early history of our universe and
some of the particles in nature interact
with that field so as they move along
they experience resistance and they act
more massive those particles interact
more strongly with that field or more
massive those are particles that
interact less strongly with that miel
field are less massive and those that
don't interact with the field at all are
massless light doesn't interact with
that field but at a fundamental level
all the particles that make us up are
really massless they act like they have
a mass because that field is there now
that sure sounds like religion right
because what I said was there's an
invisible field everywhere in the
universe and it's reason we're here
and that would be religion but it's not
religion because we can detect it or we
can try and detect it how do we try and
detect it perfectly in keeping with the
video at the beginning of this program
cosmic sadomasochism we spanked the
vacuum we spanked it hard because it
turns out in quantum physics if for
every field in nature is associated with
a particle and if we take enough energy
and dump it into empty space in a single
place we'll will take that field and
we'll kick real particles out of it and
if we call that field the Higgs field
and we kick real particles out over
we'll call them Higgs particles so where
can we dump enough energy and empty
space in a single point to kick out
Higgs particles how can you do that you
create the most complicated machine ever
built the Large Hadron Collider in
Geneva Switzerland you go to Geneva and
there's the lake the fountain is over
here if you land at the airport which is
right here which I did a little while
ago you look out and you see just
countryside beautiful countryside but
underneath the countryside is a tunnel
26 kilometers around and in that tunnel
we accelerate particles at 99.999999 98
percent the speed of light in that
direction and particles at 99.999999 9 8
percent the speed of light in that
direction and we try and collide them
two places this is the French Swiss
border right here they go around
thousands of times every second without
passports
don't tell Donald Trump will be upset
but we then try and collide them in and
in fact July 4th is a big day in the
United States for no real reason
but in no cosmic reason anyway but July
4th now has a cosmic reason for
celebrating because of July 4th 2012 the
Large Hadron Collider reported 50 events
that walked like Higgs ah's and quack
like Higgs is and therefore we thought
were Higgs particles and in fact in the
intervening 5 years all the data has
told us that they have exactly the
properties of Higgs particles we
discovered that there's an invisible
field in the universe and that this
amazing story that we're here because of
that invisible field is really true I
mean it was so amazing that I was
certain it was wrong I'd written three
papers which I had in my drawer waiting
for it not to be discovered
so I could show it was wrong because I
thought nature would find another way to
do it it seemed kind of slimy to have
this invisible field everywhere but
that's exactly the kind of invisible
field that could have produced inflation
so it gives us further motivation to
think that inflation happen but that
means that we are here by a truly cosmic
accident if you look at in the winter
time in a window and look at the icicles
on a window say save this icicle here
imagine that you were a civilization
that evolved on that icicle that grew up
to that icicle to be physicist and they
discovered the laws of physics are
different along the spine of the icicle
then along the perpendicular direction
and they described those laws
theologians would explain why that
direction was special why it was meant
by God Wars will be fought over whether
it was that direction or that direction
all of this would take on incredible
significance but seen from the outside
we see it's just an accident icicles can
form in all different directions it's
just an accident our existence here in
the universe is the same kind of
accident if this Higgs field hadn't
frozen the way it did in the early
history of the universe and had frozen
in a different direction the forces and
the laws of physics we feel would be
different and in fact we wouldn't exist
but imagine that physicists on this ice
crystal figure out that you know there's
nothing special about this direction
that all the sorts of different
directions could exist and they figure
it out at 4:00 in the morning and it's
6:00 in the morning the Sun rises and
the ice crystals melt and they go away
that could be us because we've
discovered the Higgs field but we've
also discovered given the properties of
that field we've measured it could be
unstable it could melt in the future and
if it melts in the future then all the
particles that now have masks will
become massless again and that means no
structures will exist all the stars and
galaxies and everything that we feel
connected to will disappear and that
could be our future don't look get too
nervous don't sell your diamonds because
even if this were to happen and we're
not sure what happened it won't happen
in a year or in a decade or in a million
years or a billion years or a billion
billion years it'll happen in the far
future but in the far future the
universe could return to the state it
was originally in one that was not in
which life as we now see it was not
possible so those people think the
universe is designed for us it's no more
design for us than that direction is
significant we are a cosmic accident and
that's okay
that's remarkable we should feel
thankful the universe doesn't isn't any
more designed for us than it was
designed for that crystal to exist in
that direction this idea of
understanding that the universe is not
necessarily the way we wanted it to be
its humanity and its best one of the
wonderful things about being here
besides being with all of you and in
this amazing venue is this connection
between art and music and science that's
happening right here tonight because
that's the beauty of science it's not
the technology I mean science creates
technology but I almost think of it as
an unfortunate thing because the real
beauty of science is the same as the
beauty of art music and literature what
science does is change our perspective
of our place in the cosmos change our
understanding of ourselves that's what
we get when we read a good play or see a
piece of art or hear a new piece of
music it's
forces us to reflect on ourselves in a
new way that's the beauty and the force
our beliefs to conform to the evidence
of reality instead of the other way
around is wonderful to take cherished
beliefs and prove them wrong is
wonderful because it means we're
learning and that's what makes
civilization worth being called
civilization the fact that the universe
isn't designed for us has a long history
and I want to end by just going back to
the person who first showed in the
context of life that the universe wasn't
designed for us Charles Darwin so one of
the most beautiful bits of science
writing in all of science writing
history is the last paragraph of his
origin of a species that reads as
follows there is grandeur in this view
of life with its several powers having
been originally breathed into a few
forms or into one and that what this
planet has gone cycling on according to
the fixed law of gravity from so simple
a beginning endless forms most beautiful
and most wonderful have been and are
being evolved in that beautiful way he
showed how from a simple beginning the
incredible diversity of life on earth
could arise not by planning but by
natural selection bees aren't designed
to see the colours of flowers if they
didn't see the colours of flowers they
couldn't reproduce they couldn't get the
nectar and reproduce it's so simple to
see something that looks like it's
designed the appearance of design can be
an illusion and not just as it's true
for life we now see that the even for
the universe the appearance of design is
an illusion just get over it
and but at the same time science changes
and scientists themselves are myopic and
in 1863 he said in a letter to Joseph
Hooker it is mere rubbish thinking at
present of the origin of life one might
as well think of the origin of matter
now in 1863 that was garbage but I get
paid to do it now because things have
changed because the greatest story ever
told has gotten better because we keep
opening our eyes to the universe we keep
getting surprised by the universe and
we'll keep on getting surprised by the
universe and being human will continue
to be more interesting but only if we
keep our eyes open
only if we're willing to keep asking
questions and stop if we stop asking
questions
if we're afraid of what we'll learn if
we're afraid of others
all of that will stop and while it's an
issue in my country I think it's an
issue more generally I am concerned in
the current world about this fear of the
unknown of this fear of others about
this fear of what science may tell us
and that people would rather bury their
heads in the sand and not support not
just science but art music and
literature and the response to that is
the best response to that I know is by
this guy Robert Wilson
who is the first director of the first
large accelerator in the United States
the first really big accelerator the
Fermi National Accelerator Laboratory in
the 1960s he was asked by Congress will
that accelerator aid in the defense of
the nation and he said no sir I don't
believe so it is only to do with respect
with what you regard one another the
dignity of men our love of culture it
has to do with our Weaver good painters
good sculptors great poets I mean all
the things we really venerate in our
country and our patriotic about or
should it has nothing to do directly
with defending our country except to
make it worth defending and that you can
applaud to that because we've dead now
but it's a wonderful audience
that is why
that is why we can't afford to stop
supporting curiosity-driven science
research we can't afford to stop
supporting art music and literature my
country the current budget there's huge
cuts in all of that and the money is
going to build a wall to keep us out
from invisible hordes but what makes the
United States make great let's make
Denmark great what makes the world worth
living in is not the walls we build are
the arms we sell but the questions we
ask and our willingness to keep open
eyes and look at the universe so the
universe may be miserable the universe
we may be insignificant but we shouldn't
be depressed because those connections
that we've made to the cosmos tell us
about it amazing accident that brought
us here today nevertheless it allowed us
to evolve brains that can ask questions
that can turn and ask questions about
the early beginnings of the universe and
look out to the farthest elements of the
cosmos so instead of being depressed you
should enjoy your brief moment in the
Sun thank you very much
thank you
