SPEAKER 1: Good
evening, everyone.
Thank you for coming
out tonight to our first
ever TEDxUChicago 2016 salon.
My name is Putter
Thepkanjana and I
am one of TEDxUChicago's
student speaker Salon chairs.
I am greatly excited
and very honored
to be joined tonight by
Professor Wendy Freedman
and Professor Michael Turner.
Wendy Freedman is a John and
Marion Sullivan University
Professor of Astronomy
and Astrophysics
at the University of Chicago.
Professor Freedman joined the
faculty in September 2014,
following a distinguished
30 year career
at the Observatories of
the Carnegie Institution
for Science in Pasadena.
Among her scientific
achievements at Carnegie,
Professor Freedman was
a principal investigator
for a team of 30 astronomers
who carried out the Hubble Key
Project to measure
the current expansion
rate of the universe-- an effort
that began in the mid 1980s
and completed in 2001.
While the Crawford H. Greenewalt
Director of the Carnegie
Observatories,
Professor Freedman
initiated the Giant
Magellan Telescope Project
and served as its founding
chair from 2003 to 2015.
The GMT will be a 25
meter optical telescope,
poised to be the world's
largest ground based telescope
when it's completed in 2021.
Michael Turner is a theoretical
astrophysicist and the Bruce V.
And Diana M. Rauner
Distinguished Service Professor
at the University of Chicago.
He's also director of
the Kavli Institute
for Cosmological
Physics at Chicago,
which he helped to establish.
And the past president of the
American Physical Society.
Turner helped to pioneer
the interdisciplinary field
of particle astrophysics
and cosmology.
And with Edward Kolb, initiate
the Fermilab Astrophysics
Program.
He led the National
Academy study course
of the cosmos that laid out the
strategic vision for the field.
Turner's scholarly
contributions include
predicting cosmic acceleration
and coining the term dark
energy.
Showing how quantum fluctuations
evolved into the [INAUDIBLE]
for galaxies during cosmic
inflation and several key
ideas that led to
the Kolb dark matter
theory of structure formation.
We will now begin by screening
Professor Freedman's TEDGlobal
2014 talk.
This new telescope might show us
the beginning of the universe.
Enjoy.
MICHAEL TURNER: So
what's going on with GMT?
Why don't you give us an update
on where the project is now?
WENDY FREEDMAN: So actually,
there's been a lot of progress
since that was filmed.
I mentioned that the fourth
mirror was about to be cast,
and that has been cast.
At the point when
I was speaking,
we were in the middle
of trying to negotiate
an agreement-- a legal
basis for the partnership
to go ahead for construction.
And that was negotiated
and 10 partners
signed a document that
allows us to move forward
with actually doing the
construction for the project.
So that was a huge step forward.
On the mountain now, there's a
considerable amount of activity
that's happening.
The dormitories for
the workers that
are going to do the
construction-- that's
now underway.
And the polishing of the second
mirror will happen shortly.
So incrementally
continuing to push forward
and keep on schedule.
MICHAEL TURNER: And there
was a big event in November.
The president of Chile--
Yeah, tell us about the big--
WENDY FREEDMAN: We had a
groundbreaking ceremony
of this.
And the president of
Chile, Michelle Bachelet
came and it was an opportunity
for people within Chile
to actually see the construction
beginning on the mountain.
And on Las Campanas,
which is the site,
there are some rocks where
the reason for the name of Las
Campanas is-- it
means in Spanish,
las campanas, or the bells.
And there are rocks that ring.
So we had a giant rock
and the president of Chile
was able to ring the bell
and inaugurate the telescope.
So officially, we've
started construction.
So it was very, very fun event.
MICHAEL TURNER: Now how many
students do we have here?
Lot of students.
So do you all know your
University of Chicago history?
So where did Hubble
get his degrees?
OK, so if I ask more
questions like that,
you know the right answer.
So we're building the
biggest telescope,
but give us a little
background on-- this
is not the first time Chicago
has done things like this.
WENDY FREEDMAN: So
going back to-- I
don't know if you know the
name George Ellery Hale.
And George Ellery Hale
was the first director,
first chair of the Astronomy
and Astrophysics Department
of the University of Chicago.
And started astronomy
and astrophysics here.
He then was lured
out to the West Coast
and he is the
astronomer that began
the building of the telescopes
at Mount Wilson and at Palomar.
And that's Edwin Hubble, who did
his degree here, and then was
lured out by Hale
to the West Coast
and where Hubble made the
discoveries of other galaxies
and the expanding universe.
And so Chicago subsequent
to that built up
a very strong department
in theoretical astrophysics
and studying the background
radiation from the Big Bang.
It's a world leader there.
But in optical
astronomy, it became
involved in survey telescopes.
But large optical
telescopes were something
that Chicago really
had not participated in
until now with the GMT.
It's a full partner
in the enterprise.
And then you lured
me back out here so--
MICHAEL TURNER: So I know
you're new to Chicago
and you may not know all our
mottoes, but one of our mottoes
is I know what
works in practice,
but does it work in theory?
You all know that, right?
Can anyone get me that t-shirt?
Raise your hand if you can
get me that t-shirt and see--
WENDY FREEDMAN: You've
understood already
that Michael lives in a
fantasy world that is theory
and it's our job as observers
to make sure that they
stay grounded in reality.
MICHAEL TURNER: So we're very
proud of Hale, who four times
built the largest telescope.
And for those of you who
wander south of the Midway--
have people been to the Oak
Wood Cemetery, Oak Woods?
It's really an amazing place.
I forget if it's 64th or 63rd.
Hale is buried there-- William
Rainey Harper, Jesse Owens.
But back to astronomy here--
WENDY FREEDMAN:
And of course Hale
was the person who built Yerkes.
And we didn't mention that.
[INTERPOSING VOICES]
MICHAEL TURNER: He built Yerkes.
WENDY FREEDMAN: Which was
at the time, the biggest--
MICHAEL TURNER: That was
his first largest telescope.
And famously, another part of
University of Chicago history
is that he was very
entrepreneurial.
Is that a word you associate
with the University of Chicago?
Very entrepreneurial.
And so we went to Harper
after building Yerkes,
which was a 40 inch telescope--
the world's biggest telescope.
And he said, the
future of astronomy
is in the hills of California.
And Harper said,
I wish you well.
But now we got Wendy.
I think it was a good trade.
So I wanted to ask
about-- you were
talking about the
exquisite resolution of GMT
and talking about seeing
that dime-- I think
it was a dime-- from
Rio to Sao Paulo, which
would be quite a trick, given
all that wiggling atmosphere.
And did people notice
those green lights
coming out from the telescope?
And normally you think of
telescopes collecting light,
so tell us a little
bit about how
you got that extraordinary
resolution because I think
most people know that
the atmosphere wiggles
and that's why stars twinkle.
And tell us about that.
WENDY FREEDMAN: So that's been
the real limitation of building
telescopes on Earth and
why we did so much better
after the launches of the
Hubble Space Telescope--
as we get above the
atmosphere and the blurring
that's caused by turbulence
in the atmosphere.
And so what astronomers have
developed in the last couple
decades is a technique
called adaptive optics
that allows you
actually to change
the shape of your mirror.
And those green
lights, yellow lights
that you could see coming
out of the telescope
are lasers that we use-- that
are sodium lasers that shine up
into the atmosphere
where there is
a layer in the atmosphere
itself of sodium atoms.
And those are
reflected back down.
And they act, essentially,
as artificial stars.
And if there were
enough stars that
were bright enough in the
sky that we could have
a star in each of the
fields we were observing,
we wouldn't need the lasers.
But they act as a good
substitute for a star,
and then that information comes
back down at the speed of light
very fast.
And it allows you then
to deform the mirror
and change its shape
so that you can correct
for the turbulence in
the Earth's atmosphere
and that's what will allow
us to get this factor of 10
increase in resolution compared
to what we can do with Hubble.
So it's a huge leap
forward, compared to what
we've been able to do before.
MICHAEL TURNER: I mean,
it's a complicated system.
WENDY FREEDMAN: It's a
very complicated system.
These mirrors are very thin.
So in fact, the
corrections are done
with the secondary
mirrors so the mirrors
that-- I was talking
about being made
at the University
of Arizona that
are 8.4 meters in diameter.
Each one of those
seven mirrors will
have a secondary
mirror, which is
near the top of the telescope.
MICHAEL TURNER: I
think we saw those.
They're about yea
big or something.
WENDY FREEDMAN: Yeah, they're
about a meter in diameter
and they're much thinner.
And because they're
smaller, they
can be deformed
much more quickly.
And the primary mirrors will
have, essentially, pistons
that you push and pull
on the back of the mirror
and change the shape
of the primary mirrors
at various points.
There would be 4,700
of those actuators
on the back of the primary.
And that's updated
every 30 seconds.
But the secondary mirrors will
be updated on millisecond time
scale.
So that's what allows you make
these really rapid corrections
to correct for the turbulence
in the Earth's atmosphere.
MICHAEL TURNER: So
that's really a big deal.
So I was whispering
in Wendy's ear--
so could you really-- are the
adaptive optics good enough so
that we could actually see
that dime in Sao Paolo?
WENDY FREEDMAN: First of
all, you wouldn't point it
to the horizon.
You wouldn't actually
observe in Sao Paulo.
But yeah, we could do that.
In principle, that's achievable.
MICHAEL TURNER: So
one of the things
that we do at the University
of Chicago-- so exoplanets.
Everybody knows
about exoplanets.
Those are planets
around other stars.
And we've got two faculty
members and a third one
joining us.
Lesley Rogers is
going to join us.
WENDY FREEDMAN: I know at
least one student out here
has had Jacob Bean as
a professor and studies
exoplanets.
MICHAEL TURNER:
What will the-- it's
technologically very exciting
and challenging to build
the GMT, but of course,
that's not why we're doing it.
We want to do it to answer
big scientific questions.
And one of them is this
question about are we alone?
Are there other planets
that harbor life?
And so maybe we should
talk a little bit
about where we are on
that and what GMT can do.
WENDY FREEDMAN: So one
of the immediate things
that GMT will be able
to do is-- right now
there are candidate
planets-- exoplanets that
have a mass comparable
to the mass of the Earth.
And I say candidates because
there's nothing sensitive
enough right now
that could actually
measure a mass that's as small
as the mass of the Earth.
Jupiter's and Saturn's--
they're more massive.
Even Uranus and
Neptune now-- it's
possible to measure
those masses.
But to get masses,
you need velocities.
You actually have to measure
the orbits of those planets.
And that will require GMT.
And it will be the
first telescope
that will have the capability
of actually measuring
a velocity of an
Earth mass planet.
So that would be
the first thing--
is to actually establish
that there are planets
with the mass of the Earth.
Then it will be possible--
because of the size of GMT
and its sensitivity, you can
actually disperse the light.
Not just measure a
velocity, but actually
measure the chemical
composition of the atmosphere
of the planet.
So if there are things
like water and ozone carbon
dioxide in the right
ratios in the atmospheres
of these planets, GMT will
be able to detect that.
So it will be capable of
looking for signatures of life.
And then-- and I'd say
this is next generation.
It won't happen in
the first generation.
But actually, imaging a planet.
And that's not to say that we
get the big, pale blue dot.
But because these
mirrors are so precise,
you can actually-- once you know
what the orbit of the planet is
and where it is,
you can mask out
the central star that the
planet's orbiting around.
And then actually image
the planet itself.
And that would be a
really exciting discovery.
So that a lot of
places where GMT--
in fact, the atmospheric
measurements--
no other telescope that's
even being planned right now
will have that capability
and its first instruments
to be built on those telescopes.
MICHAEL TURNER: So we'll have
an undergraduate lab imaging
Earth-like planets around
other stars in what?
Year 2025, maybe?
WENDY FREEDMAN: Sure.
MICHAEL TURNER: OK.
And one of the things
that I find-- I
mean, we're both cosmologists
so we do the big picture,
how the universe
began, and all that.
And so we'll get to that, but
we feel like-- how many people
are interested in exoplanets?
Yeah.
OK.
How many people have
heard of Planet Nine?
OK.
So one of the most exciting
things in exoplanets to me
is that we had no
idea-- we were certain
that there would be other
planets around other stars.
That just because of the numbers
you gave-- 100 billion galaxy,
100 billion tries
in each galaxy.
And we had no idea
what it would be like.
I mean, the simple
thing is-- well,
it must be nine planets
or maybe eight planets.
And of course, what we found--
WENDY FREEDMAN: And big planets.
Or you had small planets
inside, then big planets.
They're all on a plane.
MICHAEL TURNER: And
so what did we find?
WENDY FREEDMAN: That the
other solar systems are not
like that.
And essentially,
the predictions were
you could never have a
planet as big as Jupiter
in close to its central star
and Jupiter has a very massive,
gaseous atmosphere.
And the predictions were you
couldn't have that much gas,
it would be blown away
by the parent star.
And the first planets
that were found, in fact,
were just like Jupiter
essentially, but really
close in.
MICHAEL TURNER:
Closer than Mercury.
WENDY FREEDMAN: Yeah.
Yeah.
Quite extraordinary.
And many of the
planets have orbits
that are inclined to
the plane just orbiting
in the same direction.
And as the central
star is rotating,
and so that was a surprise.
And now it turns out that maybe
the most common type of planet
has something like
the mass of Neptune.
It's more massive
than the Earth.
And so most of the solar systems
that have been discovered
really don't resemble our own.
MICHAEL TURNER: In fact, it
was exactly what you're saying,
it's the surprises.
Until you go out there and look
or ask a really smart theorist.
WENDY FREEDMAN: Yeah.
I was being polite.
I didn't say that
theorists predicted
that we shouldn't find any.
What we did.
MICHAEL TURNER: But for me,
one of the interesting things
that we've learned-- so
we're learning about these
exoplanets, but
of course, then we
learn about our
own solar system.
And so one of the
things we've learned
is that the planets move around.
So these-- they're so-called hot
Jupiters aren't always there.
They go in, they go out.
And so one of the things--
I'm not an exoplanet guy
but I talk to our exoplanet
guys and soon gals.
And the following statement
they believe is true,
is that the number of planets
in our solar system has changed.
We've lost some, there
undoubtedly in the past
were more, they've moved
around, and that brings us
to Planet 9, which is what
was discovered in California.
So you--
WENDY FREEDMAN: I left
California, but yeah.
So for those of you who
haven't read about it,
a few weeks ago a prediction
by an astonomer at
Cal Tech and his
colleague that there
should be another planet way
far out in our own solar system.
And the way that they're
inferring that it's there is
there are some rocky bodies out
in the outer part of the solar
system-- the so-called
Kuiper Belt--
and the orbits of those are--
MICHAEL TURNER: Let's
see, where was Kuiper?
What was his institute?
WENDY FREEDMAN: The
University of Chicago.
MICHAEL TURNER:
OK, just checking.
WENDY FREEDMAN: And so as you
recall, Pluto got demoted.
It got flung out of
our own solar system,
it's a dwarf planet, it doesn't
have the capability of clearing
out the area in its vicinity.
And the orbits of these
other Kuiper Belt objects
that have been found
in recent years
seem to suggest that
there's something out
there that's perturbing
them, and that's
causing them to have
the orbits that they do.
And so this thing is
predicted to be very massive--
I think it's 10 or 20 times--
MICHAEL TURNER: Like a Neptune.
WENDY FREEDMAN: --the
mass of the Earth.
And it's not seen yet, so
it's not an actual discovery.
But it appears to be
inclined about 30 degrees
to the plane of
the solar system,
and out there waiting
to be discovered.
So it's got the community
really thinking about how
to go out and search for it.
It would be very faint--
it's very far away--
but it suggests that
there are actually
nine planets in the solar system
after all, if they're correct.
MICHAEL TURNER: And
it's a wonderful story
because we had this picture
of a static solar system,
neat and tidy.
And actually they move
around and we've lost some,
so now there'll be theories
about how did Planet 9 get out
there?
And what's the story
about Planet 9?
WENDY FREEDMAN:
What perturbed it?
MICHAEL TURNER: Was there
Planet 10, but it went bye-bye?
And then the other
thing that's really
fascinating-- you
brought up Jupiter
and you brought up the habitable
zone-- so we don't know
precisely what you would need
to have a planet where you could
have life.
So water is a simple one.
We think now with
Jupiter, that it's
kind of a protector
that keeps you
from getting bombarded by
asteroids and things, that
shepherds them away.
What are some of the-- Well,
I guess you want a star that
lives a long time and is pretty
quiescent so it doesn't--
WENDY FREEDMAN: Doesn't have
a lot of x-ray emissions,
so that we have lots
of unhealthy radiation
that's bombarding us.
The orbit inclination of the
Earth is tipped 23 1/2 degrees,
but it's very stable.
It precesses only
very, very slowly.
So if that was
wobbling around-- we
didn't have the stabilizing
effect of the moon--
that could be another factor.
But yeah, we think that
Jupiter has cleared out,
stopped a lot of massive
asteroids that might've hit us
and caused more extinctions.
So we have a lot of factors--
the geology, continents,
continental drift--
it takes a lot of--
If you had a water
world-- just water--
you certainly wouldn't have
evolved life the way we have.
So we don't know yet.
MICHAEL TURNER: Well, there was
that movie about Waterworld.
Well, maybe we are alone.
How many people think we're
alone in the universe?
No one, everybody thinks there's
other life in the universe?
Is there another University
of Chicago in the universe?
There's only one
University of Chicago.
Well, maybe we ought
to-- exoplanets are OK,
but cosmology is really cool.
And you mentioned dark
matter, so maybe we
should talk about dark matter.
And in cosmology, we're very
excited because we know what
the universe is made out of.
And it illustrates
what Wendy was
saying about these surprises.
So we have the ingredient
list for the universe.
It's 5% atoms, it's
25% dark matter,
and it's 70% dark energy.
And atoms-- I bet everyone
knows about atoms,
that's what we're made out of.
Does anyone in
the room know what
the dark matter is made out of?
Good.
WENDY FREEDMAN: Darn,
could've had a Nobel Prize.
MICHAEL TURNER: And
then the dark energy
is even more mysterious.
So we're at this
point in time where
we've got the ingredient
list, but we don't quite
know what the pieces are.
And maybe we ought to
start with dark matter
because you mentioned
it in the TED Talk,
and then it just came up--
you mentioned it again.
How can you with Planet 9--
because the universe is so big
we can't go there, so it's
based on what we can see.
So if you can't see it,
how can you really see it?
WENDY FREEDMAN: Yeah.
So in the same way-- so in
fact in our own solar system,
the existence of
Neptune was predicted
because the orbit of Uranus
had a discrepancy in it.
If there hadn't been
something else--
MICHAEL TURNER: It
didn't agree with theory.
WENDY FREEDMAN: That's right.
MICHAEL TURNER: And
the theory was correct?
Is that what I'm--
WENDY FREEDMAN: Yeah,
you could count that one,
but there was Vulcan.
There was another planet, there
was a tenth planet in fact,
inside the orbit of Mercury
predicted by theorists.
But that turned out to be--
MICHAEL TURNER: Not
at Chicago, though.
WENDY FREEDMAN: Another theorist
got that one right, though,
because it was
Albert Einstein that
predicted that the change
[INAUDIBLE] of Mercury.
But anyway, sometimes
you learn something else,
but theoretical predictions
interface with observations.
But in the 1930s, an
astronomer at Cal Tech
noticed that when he looked
at the motions of galaxies
in a nearby cluster
called the Coma Cluster,
they were moving too fast.
If you added up all the
mass in the cluster,
then those galaxies
should've been long gone.
They wouldn't have been
bound to the cluster.
Essentially nobody
believed him them.
It was too strange--
MICHAEL TURNER:
It's too bad that we
don't have a picture
of him, because if you
showed his picture you would
know why no one believed him.
He was a very
cantankerous guy who
was half as smart as
he thought he was,
which was still deadly smart.
But he didn't--
WENDY FREEDMAN: Are
we allowed to say
how he described his
colleagues in this audience?
MICHAEL TURNER: Oh, yeah.
WENDY FREEDMAN:
So his colleagues
at Cal Tech-- the
other faculty members--
he described as
spherical bastards.
Why?
Because they were bastards
no matter what direction
you looked at them in.
So that gives you some idea of
the kind of personality he had.
But it wasn't only that, it
was a very strange result.
And this was the 1930s.
And in fact, other people in
the 1930s-- Horace Babcock
discovered that there were
stars in the nearby Andromeda
galaxy that were going faster
than they should be if they
were bound to the galaxy.
And then Vera Rubin in the
late '70s-- and her colleague
Kent Ford-- observed a
lot of spiral galaxies
and noticed that the velocity
of the stars in the outer parts
were much faster
than they should be,
indicating again the
presence of some matter that
was causing these stars to
have the motions that they did.
But we couldn't see it.
And then in the 1980s, it became
possible to measure x-ray gas
in clusters.
So this is gas that's
maybe 100 million degrees
and should've
evaporated long ago,
unless there was more matter
in the cluster that was binding
it.
And then people started
to see these big arcs that
were predicted, in fact, by
Einstein-- the bending of light
as it's coming through
a massive cluster.
MICHAEL TURNER: Einstein
the theorist, right?
WENDY FREEDMAN: Einstein
the theorist, yeah.
MICHAEL TURNER: Just checking.
WENDY FREEDMAN: And
eventually the evidence
became overwhelming.
There is just more matter
there than we can see.
And in fact, there's six times
as much of this dark matter
as there is visible matter.
But we don't know what it is.
And in the 1980s, astronomers
spent a huge amount
of time trying to rule in
or out the obvious things.
Could it be black
holes or dust or gas?
Cold gas, hot gas,
failed planets,
failed stars, you name it.
And none of those things
could explain what was seen.
MICHAEL TURNER: And this is
where we cue in the theorist?
WENDY FREEDMAN: Here's
you cue, Michael.
MICHAEL TURNER: And the
University of Chicago theorists
said, you know what?
We think this is not atoms,
it's something more exotic,
it's a new form of matter.
And we now have
evidence that-- we
have an accounting of the
atoms in the universe, it's 5%,
and the total amount
of matter is 30.
So 25 plus 5, so
25 can't be atoms.
And so we think it's a
new elementary particle,
and that's an idea that my
mentor and your close friend
David Schramm-- first he
started with neutrinos,
but now we've ruled
out it being neutrinos,
but we think it's
another particle.
And this is a big
activity at Chicago.
Chicago's involved
in trying to produce
this particle-- this dark
matter particle-- at the LHC
in Switzerland.
So at a particle
accelerator or detecting it.
Because if this idea is correct,
then in this little bottle
there's one dark
matter particle.
WENDY FREEDMAN: Well, they're
going through you right now.
MICHAEL TURNER: Yeah, they're
also going through you,
but I didn't want
to scare people.
WENDY FREEDMAN: But
remember, I told you
it interacts very weakly.
We can't find it.
MICHAEL TURNER:
They're very shy.
And so we're building
detectors underground
to try to detect this.
And so this is
very, very exciting.
And if you think about
it, we've pushed ourselves
into a corner-- without going
through all the evidence--
where that's the most
conservative hypothesis,
is that it's a new
form of matter.
Anything else would
be more radical.
Most conservative is
not always most correct.
Maybe we'll even find
that out tonight,
but that's the
conservative hypothesis--
it's a new form of matter.
And now we're on the cusp
of having to verify that,
and we'd--
WENDY FREEDMAN: It's
an interesting time.
So people have been
searching for this
now for well over a
decade-- a couple decades--
and haven't found it.
And now it's getting to the
point where it come impossible.
At least the current best idea--
MICHAEL TURNER:
It's getting hard.
And maybe we're
in for a surprise,
maybe it's something
wrong with gravity or--
WENDY FREEDMAN: Or theorists.
MICHAEL TURNER: Or theorists.
That I doubt, but let's
go back to Vera Rubin.
Because in the very
beginning of the TED Talk,
you brought up this issue
of women in science.
And of course there's
been a lot of change.
WENDY FREEDMAN: Any women
scientists out here tonight?
Anyone?
MICHAEL TURNER: There
we go, at least one.
And there's been a lot
of positive change,
and we can recruit for
astronomy because sometimes it's
the young fields where
change is happening
and you don't have to be a
member of the old boys' club
to make a contribution.
And Vera Rubin is
one of the pioneers,
and she tells this
story that she
wanted to go-- now
there's a school,
I always forget the name.
There's a little boys'
finishing school in New Jersey.
What's that one
in-- does anybody--
the boys' finishing
school in New Jersey?
Some of you might've
applied there.
College of--
WENDY FREEDMAN: Princeton?
MICHAEL TURNER: Oh, Princeton.
So she applied to
graduate school there,
and they wouldn't even
send her a catalog.
I'm sure you've heard her say
this story-- they wouldn't even
send her a catalog because they
didn't want to waste the money,
because girls can't
be astronomers.
And so she actually got her
PhD at George Washington
University, from someone who we
won't talk about because he's
so interesting-- George Gamow.
And so here she is.
And I was at an event where
she described this job she had.
I think she didn't get
paid as much as the other--
how did that work, when she
went to work for the Carnegie,
and didn't she--
WENDY FREEDMAN: Yeah.
She walked in and told the
director she wanted a job.
MICHAEL TURNER: And she
would work for free.
WENDY FREEDMAN: Yeah.
And then he did pay
her, but not as much
as-- that was-- Cecilia
Payne-Gaposchkin, who was
a faculty member at Harvard.
She was paid 25% of what her
male colleagues were paid.
And then she eventually became
chair of the department.
And I think it was
finally corrected.
She probably
corrected it herself.
I'm not sure.
[LAUGHTER]
MICHAEL TURNER: But Vera then--
WENDY FREEDMAN: But
that even happened to me
when I was hired.
I was paid half as much
as the man who got hired
at the same time as I was.
But then I was a Canadian
citizen at the time.
MICHAEL TURNER: Well,
that's the real problem.
WENDY FREEDMAN: That
was the real problem.
Well, the immigration helped
me because my job salary
had to then be posted.
And then every male faculty
member came to tell me,
do you realize how
little you're being paid?
And I never would have known
if I hadn't had the immigration
issue.
So that's a-- that
still happens.
MICHAEL TURNER: And who's
the chair of our department?
WENDY FREEDMAN: No, that
was a long time ago.
MICHAEL TURNER: But now, now?
WENDY FREEDMAN: Now, it's
a woman, Angela Olinto.
MICHAEL TURNER: Yeah,
although she's-- even Chicago
doesn't get high marks on this.
So she's the first woman
chair in astronomy.
And you might say,
well-- but she's
the first woman chair
in the physical sciences
at the University of Chicago.
WENDY FREEDMAN: And I was
the first faculty member
in 100 years at the
observatories in Pasadena
and then the first
woman to be director,
so a lot of firsts still.
It's unusual.
MICHAEL TURNER: But for the
woman, for the young lady
back there who was
interested-- so
you go to an astronomy meeting
and it looks like high school.
Is that a good description?
WENDY FREEDMAN: Elaborate?
MICHAEL TURNER: Well--
WENDY FREEDMAN: I'm not sure.
MICHAEL TURNER: Everybody's
younger than you-- not than me.
I'm quite young myself.
But--
[LAUGHTER]
And everybody's high energy.
But it's very diverse--
lots of women.
Astronomy-- PhDs in astronomy
are essentially close to 50%.
WENDY FREEDMAN: Yeah.
It might be 30% still.
MICHAEL TURNER:
The PhDs or the--
WENDY FREEDMAN: I
don't think it's yet--
MICHAEL TURNER:
It's not quite 50%.
WENDY FREEDMAN: Yeah.
But it's getting there.
MICHAEL TURNER: Do
you have any good--
I know you've got at least
one-- I shouldn't say this
because now you'll have to
tell it-- some good horror
stories about being
a woman astronomer,
going to the mountain
and stuff like that?
WENDY FREEDMAN: Gee,
going to the mountain.
Well, it didn't happen to me.
But Carnegie, which had this
fellowship-- one of them
was the Hale
Fellowship, in fact.
And if you applied
for it, you were
told that they didn't give
them to women in the same way
as Vera Rubin encountered--
what could I tell you?
Luckily, that changed
by the time I got there.
MICHAEL TURNER: But
going to Palomar,
didn't they play some
tricks on you or something?
WENDY FREEDMAN: I think you're
thinking of Marget Burbidge
because at that time, there
was another astronomer.
She was married to a theorist.
And women were not
allowed to observe
on a telescope at that time.
So he had to apply for the time.
And then he had to sit
on the observing floor--
MICHAEL TURNER: To make sure
she didn't break the telescope?
WENDY FREEDMAN: Yeah.
But the excuse
that they gave was
that there were no
restrooms for women,
and that's why
they couldn't have
them come to the telescope.
And so he had guard the door
while she went to the restroom.
So it was slow in coming.
But yeah, it's
really changed now.
There are a lot of
women in the field,
and it's really nice to see.
MICHAEL TURNER: So just
another Chicago footnote
to that-- so among other
things, Wendy actually
has an honorary degree from
the University of Chicago,
as does Margaret Burbidge
and Geoff Burbidge,
her husband, actually who was
a very brilliant theorist.
But he does not have
an honorary degree
from the University of
Chicago, which is fine.
Well, not everyone
can have a degree
from the University of Chicago.
Do you have anything
more on that topic?
We're ending on a
high note, but do you?
WENDY FREEDMAN: Let's see.
I just thinking of--
so I did my thesis
at the Canada-France-Hawaii
Telescope
in Hawaii, Mauna Kea,
which was at 14,000 feet.
And the telescope had
just been commissioned
when I went out to observe.
And I couldn't figure out why
there are people following me
around and asking me, are
you OK, can you breathe,
as if I was some sort
of helpless something?
And I finally said, I'm fine.
You don't need to
keep asking me.
But it turned out there
in the couple weeks
before, they had had a big
event and they brought up
some Marines for the
commissioning of the telescope.
And they both fainted dead away.
So that if the Marines can't
hack it at 14,000 feet,
there's no way this woman's
going to be able to hack it.
But I never had any trouble
observing at high altitude.
It was fun.
So it's an interesting life.
It's different.
It's fun.
MICHAEL TURNER: Well, before,
I think at some point here,
we're going to-- do you
guys have questions?
Good.
Well, we're going to go to them.
But we'll do one more thing
before we go to the questions.
And maybe we'll talk about
the 70%, the dark energy.
And let's see-- well,
I know it's there,
but maybe you ought to tell us
what evidence-- I hear evidence
is really important in science.
Actually, it is
really important.
That was just
meant to be a joke.
But so how do we know
there's dark energy?
WENDY FREEDMAN: So that's one
of the things that came pretty
much out of the blue again.
People didn't
expect it, or there
were two groups
in the 1990s that
started to observe very bright
explosions called supernovae
to greater and
greater distances.
And we know that there's
matter in the universe.
It became increasingly
clear that there's
dark matter in the universe.
And so the expectation was
that-- so we didn't really
talk about the expansion.
But Edwin Hubble
in 1929 discovered
that the universe is expanding.
And so we see the effects
of that expansion today.
And that's the work that I
did a couple of decades ago,
was to measure very accurately
how fast the universe is
expanding.
But we expected that as we
looked back farther and farther
out into the universe,
we would see a time when
the universe had been
expanding-- earlier on,
it would've been
expanding faster
and then slowed down because
of the effects of gravity.
So we know that if you throw
something up in the air,
it's going to fall down
because of the effect,
the force of gravity, which
is an attractive force.
But instead, what happened
was the supernovae
appeared fainter, as if the
universe had been speeding up
rather than slowing
down over time.
And so that really
was a surprise
because it would be like
throwing up something
into the air and then it
takes off even faster.
And so we weren't
expecting to see that.
It actually was something that
had been predicted by Einstein.
I'm going to turn
it over to your
to sort of take over that part.
But it happened in the
intervening time-- was
it appeared to be
evidenced a few times
and then the evidence
didn't hold up.
And so people were very
skeptical about this
because it also was very
difficult to explain.
It's still difficult to explain.
But why don't you describe that?
MICHAEL TURNER: Yeah.
So the explanation
is dark energy.
So let's just say it that way.
And then we'll see, is
anyone still confused?
And so the
explanation is there's
this stuff called dark energy
and it has repulsive gravity.
And you might say, well, I
don't get that because isn't
the definition of-- isn't
the essence of gravity
that it's attractive?
And in Einstein's theory,
really weird sorts of energy
can actually have
repulsive gravity.
So it's in his equations.
And then comes the
checkered history.
So you have to trust me on that.
It's in his equation that if
you have really weird stuff--
we call it dark energy.
It has repulsive gravity.
And so the simplest explanation
is that the universe
is 70% dark energy.
So that's an explanation.
It may or may not be true.
But then, the
checkered history is
really interesting
because-- so give me
an example of dark energy.
And the simplest example-- I
bet everyone or many people
in the room have
heard this word,
the cosmological constant.
So Einstein put into
his equation something
he called the cosmological
constant to keep
the universe from expanding.
And you might say,
well, why would he
do that since Hubble discovered
that it was expanding?
And that's a whole other story
about the fog at the frontiers
of discovery, is
you're out there
and it's really confusing,
even to really extraordinarily
smart people.
WENDY FREEDMAN: So
just to-- Einstein
came up with his theory
in 1915, and Hubble
didn't discover the
expanding universe till 1929.
MICHAEL TURNER: And
there was every evidence
that the universe was static.
But even after Einstein
got his solutions,
he didn't really realize
they were-- it was confusing.
He didn't even realize
they were expanding.
And so he put in this term to
balance it, to balance matter,
and then threw it away.
And then every time
there was a crisis--
WENDY FREEDMAN: And threw
it away because of Hubble's
observation.
MICHAEL TURNER: That
the universe was--
and the fact that
he became convinced
that his theory really
predicted an expanding.
It's really confusing.
But then, probably every
20 years, cosmologists
would put in-- any time
we had a serious problem,
we'd put in the
cosmological constant.
And yeah--
WENDY FREEDMAN: And
then it would go away.
MICHAEL TURNER: And
then it would go away.
And the most recent
one was in the '90s,
where actually Wendy
and I really got
to know each other very well
because the theorists predicted
that we have a flat universe.
What's the shape of the
universe that's actually
been measured, just to check?
WENDY FREEDMAN: Flat.
MICHAEL TURNER: Flat.
But there wasn't enough matter
to make-- there wasn't enough--
WENDY FREEDMAN: But they weren't
right about what made it flat.
MICHAEL TURNER:
Well, that's-- OK.
I get to tell my
part of the story.
So we--
WENDY FREEDMAN: He
was closer than most.
MICHAEL TURNER: We start
simple and say it's matter.
And it turned out we didn't know
the amount of matter very well.
And the matter
stocks were really
rising, just like the market.
And it looked like they
were going to hit 100%.
And there was a
market correction
and it came down to 30%.
And so there are the theorists.
We had really good
arguments that you
should have a flat
universe and you
should have the so-called
critical density
to make it flat.
And so a couple of us
came up with the idea,
again, of the
cosmological constant.
And then others came
up with the idea
that maybe the Hubble
constant was very small,
but that's another story.
So it turned out to
be one of those--
I like to call it the
most anticipated surprise,
in the sense that
it was out there,
but it was too crazy to be true.
But then it turned
out to be true.
And now we have to figure out
what it is because we really
don't we have a name for it.
But it's like dark matter.
We don't--
WENDY FREEDMAN: Which
Michael gave the name for it.
MICHAEL TURNER: Yeah.
And we really don't have
any idea what it is.
In fact, it's even
worse than that.
We have one idea for what it is.
And it's an
extraordinarily good idea.
It's the energy of nothing, the
quantum energy of the vacuum.
And so you might say, well,
that sounds really good.
And so the quantum
energy of the vacuum--
that sounds really good.
So that's virtual
particles in the vacuum.
So does it give
the right answer?
And the answer is pretty close.
WENDY FREEDMAN: Close
enough for theorists.
MICHAEL TURNER: Yeah.
So that's only off by
55 orders of magnitude.
[LAUGHTER]
And so now we--
WENDY FREEDMAN: It's the biggest
discrepancy in all of science.
MICHAEL TURNER: So
this is where theorists
get really defensive, is
that, well, actually, Wendy,
our prediction is infinity.
And infinity is not a number.
How many mathematicians
do we have in here?
So y'all know infinity
is not a number.
So if you've got
infinity for your answer,
you didn't really get an answer.
So you couldn't have
gotten the wrong answer.
WENDY FREEDMAN: Nice try.
MICHAEL TURNER: Yeah.
I see the smart ones in
the room get that argument.
So anyway, it's a
very, very big puzzle.
And remember, why are we
even interested in this?
This is more than
2/3 of the universe.
It controls the destiny
of the universe.
So this is a big, exciting time.
And I'll just mention
one thing and then
we'll go to your questions.
So another activity at Chicago
is the Dark Energy Survey.
And so that's a
big project where
we're trying to figure out
what the dark energy is.
And we don't have time
to talk about that.
Maybe somebody'll ask.
