today it’s very exciting to be here I’m
going to talk to you about the work I’ve
been doing on part of objects called
variable stars and why I tell you about
why I think these are one of the most
interesting things about this so here’s
a picture that was taken using the
Hubble Space Telescope and this was
taken by stuck by and using a very long
exposure technique and basically they
pointed the telescope and what what
looks like an empty patch of sky and
over a period of around twenty two days
so this is what like when you take a
long exposure go around with your camera
but instead of leaving the short open
for like a matter of minutes or hours
this is like leaving the shutter open
for 22 days we might just imagine that
in your head what if I like my camera
shutter into 22 days I’m rather than
seeing the patch of empty sky and that
that you would normally see when you
just looked after that here we see and
5,500 galaxies over five thousand
galaxies now when you look at that see
these wonderful galaxies but you don’t
really see much happening you just got
these galaxies they just kind of stop
that but what why I think it’s
fascinating about the universe is that
they’re still happening all the time and
I don’t just mean on this
a love things happening on earth things
changing on edge those things changing
in space all the time stars are
exploding galaxies are moving around and
stars are moving within galaxies but the
thing that I work on is stars safety so
stars themselves again they get smaller
changing a brightness and this is this
shows you why the universe is dynamic so
this is video of me with the Hubble
Space Telescope with the photographs
taken over a period of weeks so this is
one of the styles that I work on and
when you put these photographs together
kind of like a time-lapse what you can
see is this starts pulsating and it’s
changing your brightness and here you
can see that the Stargate breaks and
fainter and those those changes in
brightness of going out through that
through space and it’s lighting up the
dust around the start and then what we
see in these ripples in the dust lyov up
and we call those like actors Annie’s
and this these changes in brightness
eliza and we can use those to work out
lots of different things about the
universe the shapes of galaxies now
these stars were first studied by a man
called John good Rick then who was an
astronomer York and we first discovered
by a british astronomer and he what he
did was he it went out and observed
these these stars called suffix he went
out every night and looks at least ours
and he did astronomy in a very different
way to what we do today so we didn’t
have things like digital cameras in in
there in the 18th century he had to go
out and look at these stars with his
telescope
well that one it kind of looks a bit
fainter than the one next to it but it
looks a bit brighter than that one and
maybe about the same as that one and he
had to do this painstaking process for
all over over again hundreds and
hundreds of times and he did this over
over months and months and eventually he
wrote this letter to the Royal
Astronomical Society describing in huge
detail how held this star Delta sadly
changed in brightness and he managed to
determine the shape of the change of
brightness of the star to such to such
accuracy but he determined how fast it
was changing and almost exactly how what
how fast the changes to what we know it
is today you did it to such a high
precision now the unfortunate thing is
that well he was working york where the
weather is pretty similar to what is
here today and because of his obsession
with a star he and he was going out in
the middle of the night in the cold of
the rain he eventually called narumiya
and he died so he died from astronomy
which is which is a bit of a shame
really and it’s also one of the things
that inspired me to leave leeds and
don’t work in pasadena
so let that be a lesson to you yep so
one of the other heroes the variable
storage on me is Han yay love it and
she’s one of my personal heroes how many
love it was another person who put a lot
of pink seeking work into studying
variable stars she was studying a galaxy
called the Small Magellanic Cloud now at
the time we didn’t actually know it was
another galaxy and she just forgave this
population of stars and but she she
stood in east eyes and she was looking
at how their their brightness is changed
and chichi drew this graph on the left
hand side Leah and she noticed that
these the period changed and their
brights estranged she wrote this
fundamental thing in his paper she wrote
the brighter variables have longer
periods and that’s actually one of the
most fundamental things we’ve ever
discovered it was so fundamental I use
it in my research every single day this
is something that we still use to this
day and it was known for almost 100
years separate career in australasia the
reason it was known as that is that
Henrietta Leavitt had the misfortune of
being born as a woman in the in the late
19th century I’m working in a
male-dominated field achene have been a
man working in this field this would
have been named after her and this paper
no pepper in 1912 would have immediately
been eleven ninety 12 but because she
was a woman working in a male-dominated
field it was written when does somebody
else’s name was written to the name of
her boss now a few years ago astronomers
finally came around to the idea that
maybe she should be given credit for her
own work and there was a resolution
through the
I’m astronomical society and the
international astronomical union to
finally get her the credit she deserved
for this fundamental piece of work and
now if you read any any paper about this
making sense that it’s referred to as
the ladder ball to give her the full
credit sugars juice and that i actually
know is whether citation if the change
to give her the poor credit so it’s not
say to the other pickering now the
reason i see that this is a fundamental
piece of work is that we know the period
if these stars if we know that hit the
rate at which they’re for taking the
period that means we can work out hub
right there because they directly
related and that’s actually a very
fundamental thing but you’re probably
doing all the time because if you know
how bright something is how brazen you
really is you can work out how far away
it is and you’re doing science like that
all the time and you just don’t even
think about it but it’s something your
brain does all the time so see you took
this light bulb oh and it had but say 10
watts now because we have energy saving
light bulbs aren’t would your thoughts
all the time but say I had it hold it
close to you and then I moved it further
away it would get fainter and it would
get smaller but it would still be attend
what light but because it was fainter
and smaller you could you would know
instinctively that it was further away
and you could work your brain work that
out give an estimate of how far it is
away and now and that thought was kind
of succinctly put together I think most
famously by the by the philosopher
father Ted cruelly he said these comes a
small but those want too far away and
that’s kind of what your brain is doing
all the time say this this thing is a
small thing and that things are far away
big but know what you’re doing that all
the time in your head is this is this
thing comes to me or is it far away and
this is the kind of thing we’re trying
to do in astronomy all the time what’s
happening on our distance scales now the
reason this is important i think is
because of the way that strongly is done
it’s a very different science or so the
sciences like chemistry or biology you
can often design an experiment in the
lab where I you can bring in material so
tools bad astronomy you can’t do that we
have one universal read one fixed
position and we can’t change what we’re
doing so then this this kind of
illustrates it right well you take this
piece of artwork and if you’re one
position in the room this is what you
get to look at you get this picture I if
you moved around and through you would
see that this isn’t the picture of an
eye it’s a 3d sculpture made up of all
these different balls and this all you
did was move your position here and they
can see if you were afloat lots of
different positions you see a completely
different sculpture and you see all
these different sizes and different
shapes just removing a position and in
astronomy we don’t have that luxury we
were fixed we can’t pick up the earth
and viewed it we can’t we put the
different galaxies and move them all we
can do is use the information we can
derive how about there the positions of
the stars from oils and their brains
it’s what all we can do is in fur and
that’s why being able to determine it as
distance is so important to us now I
said before the Hangout love it was
working on stars in this mall
my design class this is a picture that’s
not much alike that I include it here
because it’s pretty and that’s it it’s
also this balancing massage but since
then we’ve we can’t we continue to study
this much on the galaxy that I work on
myself using the same dollars that have
you ever worked on now imagine rather
than just studying room is one
population we could could break that
down in the same way that you could with
it for the eye and try and look at what
the different structures and that’s what
we did here so now we’ve got this exact
same size she was looking at the color
code by distance through the red stars
are far away and the blue sides are
close to you so this picture on the left
bottom left here is how the galaxy looks
to you if you just look at it on the sky
if you could go and look and fly over
the top of the galaxy then this picture
on the left going along the left-hand
side that’s how the God if you could try
them on the top or on the if you could
fly alongside that’s how it look on the
bottom along the bottom the galaxies
appear really elongated like a sausage
so this is how the galaxy actually looks
once you can move yourself around and we
derived up by looking at the individual
distances of the stars so here now we’ve
got two galaxies we get this much like
clouds actually part of the carrier
galaxies the large power is more tired
and the left we have a large cloud and
the right hand small cut so you can see
now why it’s called a small file smaller
than the large crowd I feel like I’m
badgley if you prefer a fly round and
fly along the top now it’s not so
obvious why there’s more flowers it’s
not bad because it’s hugely elongated
compared to the large cloud look and the
reason for that is because we think from
from doing what word like this we think
that the galaxies actually smashed
together a few hundred million years ago
which in astronomical terms is not that
and you think that they actually smashed
together and this ripped apart this more
cloud and that they actually had a
direct collision now she could fly back
around again and look at them from a
different perspective if this was the
only perspective you ever got of these
galaxies would you even knew that they
were children or would you think this
they were one now for a lot of galaxies
this is the only view we have a gap we
only received this one view and that’s
that’s an interesting thing to think
about because for some galaxies we might
think we’re seeing one galaxy but we’re
actually seeing two and we can’t change
our position and we can’t do this kind
of work so what are we missing the
signing about the universe so that’s why
we do this kind of work it’s a trying to
understand what’s really happening now
one of the words of youth quite a lot so
far is galaxy and where I say the start
but this has over five thousand galaxies
in just this tiny image and I say tiny
this is blown up really favorite it’s
actually only very tiny patch of sky and
but beforehand really didn’t work we
didn’t actually know that there were
other galaxies we thought these were
clouds clouds out at spades not clouds
just in the sky and the first galaxies
weren’t actually we’ve school in at all
plus the century ago so this day I’m
right here is edwin hubble and this
picture here is a photograph you took
for the telescope
of a gantt dramedy galaxy what we now
know is healthy but at the time he
didn’t know that but using Henrietta
let’s work and he identified sex in this
galaxy and he used her period her period
of oscillation the leather ball to
determine the distance to this object
must mean that it’s so far beyond our
own galaxy it must be a different
structure and that understanding helped
us to get that they must be something
outside our galaxy and these things
mostly their own separate things these
must be other galaxies and that was such
a huge shift in our understanding of the
universe completely changed how we
thought of ourselves is as a galaxy and
how we thought of ourselves ourselves in
the universe and that was all down to
Henrietta light its work obviously we
have to give him some credit but and
people to give him some credit I mean
they they gave him a safe Styles group
and so this is the Hubble Space
Telescope which is what is an amazing
piece of equipment it’s it was its 25th
birthday last year then it’s probably
older than many of you in this room and
but I just done amazing things but if
you think back to that green photograph
which is the time it’s the best thing we
don’t see that I’d rather now this is
the best picture we ever have a bunch
over there and this is just half black
LT this is the latest digital image of
it mate this is a picture of Andromeda
you made by stitching together
individual photos from Hubble just like
you do with a panorama on your I propose
a thing and then putting them all
together to make this
huge picture and when you print this out
it fills up an entire corridor and they
have it has a picture stood next to it
and it has its own Twitter account and
it tweets a little section like every so
often so you can just go and see what’s
in Andromeda the studies like that allow
us to disclose own whole new types of
objects and study these galaxies in
detail so we can understand what’s going
on with with the structure of my
daughter and discover things in whole
new realms of detail that we couldn’t do
before so that’s what we write so far
that’s what we’re doing right now with
this is AB equipment that 25 years old
but where we’re going that more exciting
because that’s that’s what people like
you were going to be working on next and
this is one of the most exciting things
I think that’s coming up it’s LSST and
this is a new telescope that’s going to
be that’s currently being built in Chile
but it’s an international collaboration
the UK alisis he is the large tiles go
but it’s going to scan the sky and
southern hemisphere every few nights and
what I think is the coolest part about
this is this is scale model the camera
so this is a digital camera that’s like
like the ones in your phone but this has
three over three billion pixels so your
throat covering available he has
something like 12 megapixels it has a
million times more pixels in it than the
one in your phone and it’s going to take
a photo of this guy for a few minutes so
we’re going to have huge amounts of
photos of the sky all the time with this
so will you be able to school with
classes of objects that we didn’t even
know existed we haven’t thought of yet
and that’s the kind of
going to be discovered with this and
then we have new telescopes that were
going to come on today in the next few
years and things like James Webb Space
Telescope which is in the launch next
year and that’s really exciting because
it’s going to look in the infrared and
so we can look through dust where with
telescopes that see with the same light
as your eyes just hides a lot of the
light so stuff is invisible with the
visit with optical light you can see
through the infrared light and this one
on the bottom your European two large
tiles group that’s going to be built
around but the mirror for that is there
be 40 meters wide so bigger than the
group just one mirror so we can see
further than we’ve ever been to sea
before with that so what we’ve done so
far is amazing but what we’ve done we’re
going to do in future I can’t tell you
because we haven’t all of it yet so
that’s kind of exciting so thank you very much