>> Cathy Vrentas: Hi, everyone,
welcome to Wednesday Nite at the
Lab here at the UW Biotechnology
Center.
Tonight we welcome again Jim
Lattis to the Biotechnology
Center Wednesday Nite at the
Lab.
He has, Jim Lattis has his PhD
in the history of science,
actually from UW-Madison, and
his role is as the co-founder
and the director of the UW Space
Place, which is the outreach
center of the UW-Madison
astronomy department.
And he's developed a whole range
of outreach programs for all
ages, kids through adult.
Also, he teaches astronomy
classes at UW-Madison, and he's
led a variety of tour groups
from everywhere from Italy to
Peru and he's also published on
the history of astronomy,
including award-winning books
such as --.
So please join me in welcoming
Jim to Wednesday Nite at the Lab
today.
( applause )
>> Jim Lattis: Thank you, Cathy.
It's a pleasure to be here at
Wednesday Nite at the Lab, and
especially tonight, I want to
talk about Washburn Observatory
and this is not even a week now
since the ceremony of
rededication and reopening of
the Washburn Observatory, which
has been on campus for a long
time, but for the last two years
has been under extensive
remodeling and renovation.
And the observatory is an
important place on campus so
we'll talk tonight about its
history and at the end if we
have time we can talk even a
little bit about the renovation
of the observatory itself,
which, before I forget to say
it, is open to the public on the
first and third Wednesday nights
of each month.
I'll say that again during the
talk.
And tonight is one of those
nights, this Wednesday night.
The sky looks pretty good
tonight, so after we get done
here, if you want to go up
Observatory Hill, the
observatory should be open to
the public up there.
The graduate students in the
astronomy department take it in
turns to open up and operate the
telescope for the public, so you
can thank them for their
volunteer efforts to keep the
observatory open to the public.
So Washburn Observatory, 120
years and still on the frontier.
I gave up updating that quite a
long time ago, I suppose I
should be saying 128 years and
still on the frontier.
But 120 years is good enough.
The Washburn Observatory was a
frontier observatory just as
Wisconsin was a frontier state,
and the University of Wisconsin
a frontier university.
In the middle of the 19th
century.
In 1849 the University of
Wisconsin was founded, and
astronomy at the University of
Wisconsin had a place from the
very beginning, it was one of
the subjects that was prescribed
to be taught by our one
professor, John Sterling.
And Sterling, though, had to
teach astronomy out of a
textbook because there was no
observatory at the university.
Although plans had called for
one to be on top of Bascom Hall
at a certain point, but it never
got its observatory dome, but
they're probably just as well,
because nobody wanted to pay for
an observatory on top of Bascom
Hall despite the intentions of
the planners.
The observatory that did get
built looks more like this than
that other version, that sketch
that I showed you just a moment
ago, which was actually
completed before the observatory
itself was completed, so it
didn't quite represent what
eventually appeared up there.
This is the observatory as it
appeared shortly after its
completion in 1881.
And when we look up here at
first glance, we'll talk about
how it got there in just a
moment, but just to give you the
lay of the land there, at first
glance you look and you see the
observatory in the middle.
But you want to look, because
there are actually two other
observatories in that picture as
well, which I'll come back to in
a minute.
One of them you'll see over
there on the right-hand side of
the screen, over here, I'm
putting the cursor right over
there, can you see that?
There you see that, that little
observatory popping up there,
that was the student
observatory.
I'll talk about how that got
there in a minute.
Both these observatories, both
of the small ones, the student
observatory right there and the
other one, which was a solar
observatory, right over here, it
looks almost like a house right
there.
Both of those buildings are
pretty much forgotten on campus
by now.
Although the student observatory
is far from gone.
The observatory was moved off of
campus and stands off campus now
out in Fitchburg, you can
actually see it on the hill when
you drive out Fish Hatchery
Road, you'll see the student
observatory, which was moved
there by the Madison
Astronomical Society in the
early 1960s.
So Washburn Observatory had a
main telescope, that's easy to
see, and the big dome there in
the middle.
And the other part that was not
represented in that first early
drawing of it is this extensive
east wing right here which
housed a library that wasn't
planned in the original sketches
of the observatory.
This is how it looked until
fairly recently, it still looks
pretty much like this today,
although after the renovation
some of the trim has changed.
But the observatory looks very
much as it did there in 1881,
looking here from the lake side.
So where did it come from?
Well, of course, Washburn
Observatory is named after a
fellow named Washburn.
But this was not just any
Washburn, this was Cadwallader
Coldon Washburn, who was the
governor of Wisconsin from 1872
to 1874.
Washburn was a true frontier
entrepreneur who came to
Wisconsin in his youth from
Maine, and in Wisconsin made a
fortune as a land agent, and
then used his money as a land
agent to get himself into the
milling business, and to
eventually own a string of
mills, wheat mills, that
stretched from La Crosse up to
Minneapolis.
And the mills, the Washburn
Milling Company, later the
Washburn-Crosby Milling Company,
eventually bought up a bunch of
those other mills in Minneapolis
and formed the company that we
call General Mills.
So the General Mills corporation
really has its roots, some of
its roots, at any rate, in the
career of the same Washburn who
gave us our Washburn
Observatory.
Why did Governor Washburn want
to give the university an
observatory?
Now, that's a little bit of a
puzzle and we don't really have
anything from Washburn, who, as
far as we know, was not any kind
of an astronomer, not an amateur
astronomer.
He was not a particularly
well-educated man, nor was he
interested in science in
general, that we know of.
But it seems that what he was
interested in was seeing the
University of Wisconsin grow and
acquire a reputation as a good
school.
Maybe more specifically, he was
interested in seeing the
University of Wisconsin follow a
pattern that was emerging in
Europe, in which the traditional
idea of the university was being
modified into something that we
now call a research university.
A pattern that was being
experimented with in Germany in
the mid-19th century, in which
there was great emphasis on
research by the faculty members.
And to a lesser extent students,
but eventually an emphasis on
research by students, as well.
And a research university needs
research facilities, needs
laboratories and institutes and
that was something the
University of Wisconsin had not
had in the first 25 or so years
of its existence.
By establishing an observatory,
Washburn put the University of
Wisconsin on the map as a
research institution.
The observatory, when he
arranged for its construction,
which I'll talk about in just a
moment, the observatory was very
quickly on the list of prominent
observatories in the country
because, in part, of the way
that he structured his donation.
Washburn, while governor, saw to
it that legislation was passed
that said, when the university
acquired an observatory from a
private donor, then at that
point, from a private donor, a
telescope and observatory, that
the university, that the state
at that point, would be obliged
to hire an astronomer and take
over upkeep of the observatory.
That's easy legislation to get
passed because there was no
observatory, there was no donor,
so it cost exactly zero in the
next year's budget, so it's easy
to vote for and Washburn knew
that.
Of course, after he left office,
he donated some $50,000 for the
construction of an observatory,
and that meant that the
legislation took effect and the
state had to provide the
university with money in the
budget to hire an astronomer and
to adopt the building that
Washburn would build, would pay
to build.
Washburn took a further step to
ensure the prominence of the
observatory, of the new
observatory at the university.
And that is by specifying that
they shouldn't buy just any
telescope.
When the university acquired a
telescope with his donation, he
specified that the telescope
should be bigger than the
telescope at Harvard University.
( laughter )
Now, telescopes in
those days were refracting
telescopes.
They use a large lens at the
front of the telescope, most
modern research telescopes use
mirrors.
In any case, lens or mirror,
either one, we always talk about
the size of a telescope not in
terms of its height or its
weight but in terms of the
diameter of that lens or that
mirror.
So the largest telescope in the
United States at that time was
the one at the US Naval
Observatory which was 24 inches
in diameter.
The second largest was at the
Dearborn Observatory outside of
Chicago which had a lens 18
inches in diameter.
The third largest in the country
was Harvard University with 15
inch, a great 15 inch refracting
telescope.
>> Do you want questions in the
middle?
>> Jim Lattis: Since we've
stopped, go right ahead.
>> Since he was not interested
in science, with whom did he
consult as to what kind of, for
example, telescope to get?
>> Jim Lattis: I don't know that
he wasn't interested in science,
I only say that we don't have
any evidence about where his
motivations come from.
>> -- his own research and
consult?
>> Jim Lattis: They put together
a small committee of people from
the university who actually
visited a number of
observatories around the country
to find out what they thought
were good practices and what had
been mistakes, and to generally
collect advice.
So it was actually a fairly
deliberate process that
stretched from 1876 to about
1879 in the planning.
So third largest telescope in
the country was Harvard at 15
inches.
The board of regents of the
university authorized the
purchase of a telescope of a
diameter of 15.6 inches.
( laughter )
From the telescope
makers of Massachusetts, Alvin
Clark and sons, who were the
makers at that time of the best
optical telescopes in the world.
All the big research-grade
telescopes were Alvin Clark
telescopes in about that era.
For example, the great Lick
refractor out in California on
Mt. Hamilton,
which was being
contemplated at about the time
that Washburn came into
operation, is a 36 inch
refractor, a huge refractor,
that's a Clark instrument, the
largest such instrument in the
world, refracting telescope in
the world, is right here in
Wisconsin, on Williams Bay at
Lake Geneva, that's a 40 inch
refractor, that's a Clark
refractor.
So our refractor has a good
pedigree, but it only has about
an extra half an inch in size
over the Harvard telescope.
Nevertheless, because that's the
way astronomers have ranked
telescopes for quite a long
time, in the next year, after
1881 when the observatory
opened, by 1882, the list of
large research refractors in the
country would go US Naval
Observatory, Dearborn
Observatory, University of
Wisconsin Washburn Observatory.
So Washburn got us onto that
list and high up on that list
and set the stage for the
Washburn Observatory to have a
prestigious reputation in
astronomy, which was fulfilled
in much more, in much less
trivial ways than that
0.6 of an inch.
You had to have a scientist.
Here's the astronomer that the
legislature was obliged to hire.
The University of Michigan's
observatory, which is called the
Detroit Observatory although
it's in Ann Arbor, Michigan's
observatory pre-dated
Wisconsin's by a good bit, they
have a 12 inch refractor out
there.
And the director there was James
C Watson.
Watson is a fascinating
character from astronomy in that
period.
Watson was famous as the
discoverer of a number of
asteroids at the time.
And famous and tending over into
infamous for the discovery of
the planet Vulcan.
You're all saying, "What planet
was that?"
Planet Vulcan.
Not the planet, though, where
Mr. Spock comes from.
Vulcan was thought to be a
planet that orbited inside the
orbit of the planet Mercury, so
closer to the sun than Mercury.
If we take a little step back
into the earlier 19th century in
the history of astronomy, a
world-shaking thing happened in
the 1840s when irregularities in
the motion of the planet Uranus
were analyzed successfully by
two mathematicians
independently, John Couch Adams
in England and Le Verrier in
France.
Both of them came to the
conclusion that the
irregularities in the motion of
Uranus could be explained if
there were another planet yet
unknown beyond the orbit of
Uranus causing gravitational
effects on the planet Uranus.
And by analyzing those using
Newtonian gravitation by
analyzing the effects, they were
able to hypothesize where that
planet should be.
John Couch Adams tried to get
George Airy of the Royal
Observatory to look for the
planet and Airy said, "I'll get
around to it."
Le Verrier wrote to Johann
Galle in Berlin and said, take a
look, there might be something
here.
Galle, by good fortune, had just
mapped that region of the sky,
went back and compared his map
with the sky after he got Le
Verrier's letter, and one of the
stars on the map had moved.
He went back and looked and that
was a planet, the planet
Neptune.
A huge triumph of Newtonian
science, right, the laws of
gravitation were so dependable
that you could derive the
existence of a previously
unknown planet.
Well.
Now we come to Mercury.
Mercury has a peculiar orbit as
well, very hard for astronomers
since antiquity to try to get
the orbit of Mercury right.
But, if there were a previously
unknown planet inside Mercury's
orbit causing gravitational
perturbations on it, then maybe
you could explain these
peculiarities in Mercury's
orbit.
And astronomers set off looking
for that planet.
It's very hard to look for
things close to the sun.
So the preferred technique was
to wait until a total solar
eclipse, when the light of the
sun is blotted out by the disc
of the moon and you can examine
the sky on either side of the
sun.
But these are days when
observational techniques are
difficult and usually visual and
manual.
Watson had memorized the sky on
either side of the sun in
preparation for a convenient
eclipse that took place in the
western United States in about
1876, I think that's right.
I shouldn't have said that date,
I'm not sure about that.
I think 1876.
And during the eclipse was very
quickly ticking off the objects
he could see in the sky and
concluded that there was one
that was not on his list, and
announced the existence of the
planet Vulcan, discovered during
that solar eclipse.
A lot of other people did the
same thing and they didn't find
Vulcan, so there was immediately
a debate about this with Watson
trusting his observational
powers, and he had a reputation
for being able to recognize
parts of the sky, that was how
he discovered his asteroids, by
knowing star fields in great
detail and with great visual
acuity.
Yet, plenty of others had looked
as well and not found it, so it
was amidst this controversy that
Watson was recruited to come
here.
A very prominent astronomer and
one at the forefront of
astronomical science and
controversy at that time.
Of course, you know how that
ended.
There is no Vulcan.
It was some kind of a mistake
and the mystery persists to this
day, just what it was that, what
object could possibly have been
the thing that Watson thought he
saw.
Watson was very influential in
the early days of Washburn
Observatory.
When he came here in 1878 to the
yet un-complete observatory, he
poured a great deal of his
personal fortune into it,
building, among other things,
that student observatory,
recognizing that he wanted a
place to train students and
where they could work and not be
in the way of the research going
on at the big telescope.
And he also built the solar
observatory with the goal of
confirming his discovery of the
planet Vulcan.
You can't go chasing eclipses,
at least in those days, that
would've been pretty impractical
to chase eclipses around to
verify this discovery.
He wanted instead to examine the
sky on either side of the sun
during broad daylight, and he
thought he might be able to do
that by a special design of
telescope in which a mirror
reflected light down a long tube
into a telescope at the bottom
of the hill, and that's the
solar observatory is down at the
bottom of the north slope on
Observatory Hill there in that
photograph.
And he helped to look at the sky
on either side of the sun and be
able to detect objects in the
sky by keeping out the light of
the sun with this long tunnel.
He built that observatory but
was never able to put it into
operation because he died
suddenly in 1880.
And never lived to see the
inauguration of the observatory
in 1881.
Here we see it in a photograph
from probably about 1882,
earliest photograph I know of of
the observatory.
And now that you know where they
are, the student observatory is
easy to see over here, and of
course, here's the main
telescope that is opened up to
the public on the first and
third Wednesday nights of the
month if the sky is clear.
And right over here you see the
solar observatory just down the
northern slope.
I'm sorry, excuse me, the
southern slope of the hill over
here, that's the solar
observatory.
And over here on the north, that
is Lake Mendota over here, and
that eventually runs out to
Picnic Point, that strip of
wooded land right along there.
Here's a much lower resolution
view, again an early photograph
showing Washburn Observatory
looking from the west side,
looking east, and you see of
course the observatory up on the
hill, and now you have a much
clearer view of the solar
observatory right down there.
You can make out right here the
building, just on the horizon,
right back there above the solar
observatory, which is now the
LaFollette school, that was a
residence there, that had been
occupied by the president of the
university that was vacated and
handed over to the director of
the observatory, to the
astronomer, so the astronomer
could live just over the hill.
Not over the hill, on the same
hill, just a little ways up
there.
And finally you see off to the
right Bascom Hall before it lost
its cupola in the fire.
Question?
>> Did Watson come up with the
first solar telescope like that,
was that his idea?
>> Jim Lattis: Solar telescopes
were not very sophisticated in
those days.
His goal was not to look at the
sun, per se, but to look near
the sun in the daytime.
So it wasn't really a solar
telescope, it was, he hoped, a
dim object telescope that would
work in the daytime, I should
call it a daytime telescope.
As far as I know that was his
idea, I don't know of anybody
else who attempted such a thing.
>> I know that -- once had this
long tube solar telescope as
part of the tour, seems like a
similar type idea.
>> Jim Lattis: It is, but for
different reasons.
Yes, that is a solar telescope,
that's designed to point at the
sun and create an image of the
sun.
But the long tube there is for
different reasons from what
Watson had in mind.
But you're right, there is a
superficial resemblance there.
Here is a picture of the Watson
solar observatory from somewhat
later, undated, although I
understand that in the late 40s,
I don't have a clear record on
this, in the late 40s that
building was demolished.
Watson's successor, Edward
Holden, attempted to use the
technique, attempted to test the
technique but couldn't make it
work and gave up on it and that
actually became an apartment for
observatory assistants,
observing assistants who stayed
in what must've been kind of a
cold, dark cottage there.
( laughter )
And here we have the
view out from probably the
cupola on top of Bascom Hall
looking westward, and you see
the lay of the land out there.
Again you see in the foreground,
of the observatory, you see what
is now the LaFollette school,
the observatory director's
residence, and back behind it
the observatory itself, and then
the hill slopes down there on
the south, see the lake on the
other side.
So the observatory out there,
standing all by itself,
prominent as seen from Bascom
Hall here, became a visible
landmark on the campus, became a
symbol of the university's
research programs, and also
quickly entered the lore and the
student life of the campus as
well.
And I have a brief example of
its presence in campus life.
( music plays )
* Now it's dark
* on Observatory Hill
* Come on, let's pretend
* we're Jack and Jill
* We'll stroll to the hilltop
* where college sweethearts go
* look at the lights
* on the campus down below
* We'll learn
* what astronomy is for
* and we'll learn
* what the stars
* could have in store
* I know in advance
* that the moon
* may mean romance
* when it's dark
* on Observatory Hill
>> Jim Lattis: It goes on
from there,
that was a recording by the
Dortsey brothers from the early
30s.
Johnny Burke, you can see here,
who wrote the words, Johnny
Burke was a UW alum, and when
interviewed later in life said
that he wrote this as sort of a
tribute to the idyllic college
days of his youth.
So we know what he did on
Observatory Hill.
( laughter )
But again, just these
sorts of things don't make for
an academic reputation, and in
fact it's all the work of the
astronomers since those days
that have made the university
into now a world-class astronomy
department.
Edward Holden succeeded James
Watson for a few years and
really put the observatory on
its feet in terms of completing
the establishment.
And establishing observing
programs, establishing research
programs.
But he left here fairly soon,
recruited to become the director
of the Lick Observatory, the
great Lick Observatory which was
then in construction.
They wanted him so much for
director of Lick Observatory
that they told him he could
spend the time as president of
the University of California for
a couple of years until the
observatory was finished and he
took that job, but then as soon
as the observatory was done
moved up to Mt.
Hamilton and became its
director.
He was succeeded then
ultimately, it gets a little
complicated for a couple of
years, eventually by George Cary
Comstock, who then remained
director, after a couple
directors of short tenure,
Watson and Holden, Comstock you
can see was director from 1887
until 1922.
So a period of considerable
stability, which was a good
thing for the university,
although Comstock's science was
an interesting mixture of old
and new astronomy.
And this is exactly in the
period when what we know call
astrophysics was growing in the
astronomical community, that
required the application of
considerable laboratory and
physics education.
It required the addition of that
to the traditional mathematical
and observational techniques
that astronomers had used, and
Cary is right in that tradition.
And actually had programs that
used the traditional equipment
at the observatory in very
traditional ways and did not,
for example, adopt the up and
coming method of photography,
that was a new tool for
astronomers in the late 19th
century.
And required a lot of changes in
the way astronomers worked.
Comstock did not take Washburn
Observatory in that direction,
but he did use some of the more
traditional tools here for some
new techniques including
investigations of what he called
the effective wavelength of
starlight, and working on a
method of something called
diffraction photometry, and that
word photometry will arise again
very briefly.
Comstock was here until 1922 and
retired and was succeeded by
Joel Stebbins, who would
transform the Washburn
Observatory's research
radically.
Stebbins was the first PhD
astronomer to come here as
director.
It wasn't common in those days
to have a PhD in astronomy, and
it certainly wasn't required to
lead an astronomical research
program.
But Stebbins completed his PhD
at Lick Observatory.
You'll notice that that name
keeps coming up a lot, and in
fact, historians of science have
become accustomed to talking
about the Wisconsin-California
axis in the history of 20th
century astronomy and these
connections continue right on up
almost to the end of the, late
end of the 20th century.
Stebbins, after finishing his
PhD, became director at the
University of Illinois
observatory where he started
also like Comstock, limited by
the equipment provided in a 19th
century observatory, limited in
his research, unable to do
things that required a lot of
light, like spectroscopy or
different instruments like
photography, and instead look at
some innovative techniques that,
almost unique in the world of
astronomy, he began to develop.
He was interested in the
electrical measurement of the
strength of light, and he did
that first by finding devices
that used a little bit of
selenium, a semi-conductor,
selenium.
When light falls on selenium, it
changes the electrical
resistance of the selenium.
So you can measure the intensity
of the starlight in theory by
measuring the resistance of this
stuff.
And he actually got some useful
research results out of that
direction.
For example, he was able to
demonstrate that certain types
of stars, whose light varies in
certain ways, he was able to
establish why that light varies.
There's a category of stars
called "eclipsing binary stars.
" These are pairs of stars that
orbit around each other, that's
very common, most of the stars
in the universe are binary or
even more multiple stars.
But if the star happens, the
orbital plane of the star
happens to be in our line of
sight, such that one star moves
in front of the other star, then
the stars will alternately
eclipse each other and cause
variations in the light.
The theory was that some
variable stars were eclipsing
variable stars, but if that's
true, then there are actually
two eclipses, because you have
to have first one in front and
then the other and then they
have to switch places.
And the secondary eclipse, so
called, had never been detected,
although the primary eclipse was
visible in a famous variable
star called Algal.
With his electronic measuring
instruments, Stebbins was able
to detect the secondary eclipse,
which had been predicted by the
binary theory and thus prove
that this was a binary, an
eclipsing binary star.
That was the reason for the
variation in the star's light.
That's a pretty impressive
result.
But Algal was also a relatively
bright star, and he wanted to
extend this work to dimmer
object, and the selenium cells
would not do it.
So he started experimenting with
another technique, a device
called a photoelectric tube.
In a photoelectric device, the
photoelectric effect, this is
what Einstein won the Nobel
Prize for in the early 20th
century.
The photoelectric effect occurs
when certain, mostly metals,
when the absorb some light,
absorb a photon of light, they
emit an electron.
And that electron can be
captured in a magnetic field and
made to flow in a circuit.
So if a lot of light falls onto
a photoelectric surface, then a
lot of electrons will be
produced, you can measure that
current, and that current will
be directly proportional to the
amount of light that has reached
the photoelectric surface.
These things have to work,
though, inside a closed glass
envelope.
That won't work in the open air
the way a selenium cell will.
And so Stebbins joined up,
remember this is in the early,
roughly 1910 up to about 1920,
this was the early days when
radio technology was coming
along.
Electronic amplifying tubes were
a new things in those days.
He joined up with a physicist,
Jacob Kunz at the University of
Illinois, who was experimenting
with making these kinds of glass
tubes and Kunz started making
experimental photoelectric tubes
for Stebbins, who would then
test them on the telescope over
at the observatory.
And Stebbins was just starting
to get good results with that
technique when we hired him away
to come to Wisconsin.
He brought his research program
with him, although he continued
to partner with Kunz back at the
University of Illinois, who
would make the tubes for him,
and Stebbins would do the
astronomical research testing
the tubes up here.
Here you see a picture of an
early, one of Stebbins' early
setups, still on the Illinois
telescope over here.
Here's the photometer in the box
here connected to the end of the
telescope, and he had to measure
very small currents from these
photoelectric devices with a
very sensitive instrument called
an electrometer, which had to
hang vertically off the end of
the instrument, so this is the
electrometer right here and it's
actually on a gimble right
there, so that no matter which
way the telescope points, the
electrometer hangs vertical.
This was a very cumbersome way
of working as you might expect,
a good bit of his work was in
finding better ways to measure
that current, including better
electrometers.
Here's a picture then of the
Washburn telescope not too long
after Stebbins arrived, within
about ten years.
Stebbins upgraded the Washburn
telescope considerably in order
to further his work.
For him the Washburn telescope
was still an important part of
his research, and he took the
original telescope and remounted
it on a different mounting, so
the telescope, and this is the
current mounting that you'll see
if you go up there now.
The mounting being the, what I
mean is this pier, that you see
the telescope base on, and then
up here is the equatorial
mounting of the telescope.
Pretty much everything from here
down to the floor there was
replaced by Stebbins in the
early 30s.
The old Clark mounting he
concluded was not reliable
enough for his research work and
he needed a new one.
The optics of the telescope are
unchanged, though, this is the
1881 telescope up here, so when
you go look through that
telescope you are looking
through the original telescope.
It's only the mounting that's
been updated.
Stebbins worked on this
photoelectric, on these
photoelectric techniques and in
about 1930 was joined by a
student who had just finished
his degree in physics here at
the university, and was up on
all these latest techniques of
amplifying tubes and things like
that.
Albert Whitford went to work for
Joel Stebbins and figured out
how to build what are called DC
amplifiers, using vacuum tubes,
so that they could measure the
currents coming from these
photoelectric detectors and
observe then much dimmer stars,
to put it very simply.
So much greater sensitivity
because of the amplifiers that
Whitford was able to apply.
Whitford, starting out as a
physicist and an instrument
maker was quickly seduced into
studying astronomy, and in fact
finished his graduate work as an
astronomer, and would become a
very important astronomer.
And in fact was Joel Stebbins'
successor in 1948 when Joel
Stebbins retired.
Between them, Stebbins and
Whitford had created the field
of astronomical photoelectric
photometry, which was the first
really practical photometry.
Astronomers had been trying to
measure light levels for
centuries, but the photoelectric
photometry developed here was
the first practical method and
was copied widely at
observatories all over the
United States.
The technology developed at
Washburn was extended to
commercial products, and other
research field, and the methods
that Stebbins and Whitford
developed, the methods of
observing, the methods of data
reduction, all those sorts of
things, also became standards in
the field.
So by the time Stebbins retired
in 1948, he had created a new
field of astronomy,
photoelectric photometry, which
along with photography and
spectroscopy, historians
generally count as the three
major pillars of modern
astrophysics.
Now, just as we don't use
photographic film anymore, we
use CCD chips, we don't use
photoelectric photometers
anymore either, solid state
technology has taken over all
those sorts of, both the
chemical and the glass and
vacuum technologies.
And those, that era has sort of
passed, but it shaped astronomy
right on in to the 1960s,
especially because of the
research results that it
produced, which wasn't limited
at all to variable stars.
In fact, eclipsing variable
stars continued to be a research
activity at Wisconsin for quite
a while, because it's an
important fundamental problem in
astronomy.
By looking at an eclipsing
binary field and measuring the
characteristics of the eclipses
with your photometry, you can
determine the sizes and the
masses of the stars.
That's a really important thing,
by measuring the distribution of
sizes and masses of stars,
astronomers now understand the
evolution of stars.
But you have to have that first,
very boring work of observing
eclipses of thousands of
eclipsing binaries.
That continued here at
Wisconsin.
But Stebbins and Whitford
extended into much different
directions.
And I'll just give one example,
which is, they discovered that
their techniques could study the
matter in between us and the
stars.
Interstellar matter.
For quite a long time, it was
disputed whether such stuff even
existed, the general idea being
that space was empty, and so you
had a star, and then maybe you
have some planets, and then you
have nothing until you reach the
next star.
But in fact, by the 1930s,
astronomers had pretty well
established that when you look
up at the Milky Way and you see
all the blotchy gaps in the
Milky Way, those were in fact
not gaps but clouds of matter
that are obscuring our view of
the stars behind them.
It turns out that by measuring
very carefully the light from
different parts of the star's
spectrum, to simplify it
greatly, to say to compare the
intensity of the red end of the
spectrum with the blue end of
the spectrum, by putting filters
in front of your photometer,
Stebbins and Whitford actually
used a six-color system.
But the idea's the same.
You can measure the relative
amounts of light in the star's
spectrum and that will change
depending on how much matter,
how much obscuring matter the
starlight has passed through.
So you can actually measure,
photometrically, you can measure
the extent and contribution and
distribution of this
interstellar matter out there in
space.
So from the qualitative
establishment by photography
that the stuff was even there,
they were able to do
quantitative measurements of how
much of it was there, and what
its three-dimensional
distribution was in space.
This was of huge consequence in
understanding the structure of
our galaxy, as you can imagine.
It even came into our
understanding the size of our
galaxy.
For example.
Harlow Shapley at Harvard had
measured the size of our galaxy
by looking at the distribution
of clusters of stars called
globular clusters.
And he had attempted to measure
the distances to the globular
clusters, in order to infer the
size of the galaxy.
Based on their brightness.
But their brightness in his
model was affected only by their
distance.
But Stebbins and Whitford
recognized that the brightness
would also be affected by any
obscuring matter.
By measuring the reddening of
the light from the clusters you
can see how much of the
diminution of brightness is from
the obscuring matter and you can
correct for that effect, which
Harlow Shapley did not take into
account, he didn't have this
technology.
So Shapley's size of the galaxy
was about 250,000 light years in
diameter, about that big.
By correcting for the reddening,
Stebbins and Whitford came up
with roughly the modern size of
the galaxy, more like 100,000
light years in diameter, by
compensating for the obscuring
matter that Shapley and crew
couldn't correct for.
So it had profound effects on
our view of the galaxy, and our
place within it and lots of
things.
So this was truly the glory of
Washburn Observatory and
Wisconsin's astronomy during the
20th century.
But about mid-century, here we
are, I should repeat myself now
that we should remember that
Washburn Observatory is open on
the first and third Wednesdays
of the month, all year round,
weather permitting.
That pattern, I forgot to say,
was established by Edward Holden
right after he opened the
observatory.
Probably because he was being
pestered by people knocking on
the door after the new
observatory was opened, he
established the first and third
Wednesday pattern and we still
do that.
So around the late 1950s, a lot
of changes happened in the UW
astronomy department.
For one thing, in 1958, Albert
Whitford became director of Lick
Observatory, there we are again.
Whitford was hired out as
director of Lick, one of the
major observatories in the
country.
Whitford, before he left here,
had pretty much transformed the
astronomy department from the
way he found it when he started
there as a student in 1930.
Whitford had managed to acquire
a larger telescope for the
university, something that the
astronomers there had long
needed, the 1881 telescope being
quite an antique.
And was able to establish the
Pine Bluff Observatory.
Some of you may know it, west of
town, about 20 miles west near
the town of Pine Bluff up on the
ridge there, in 1956 they opened
Pine Bluff Observatory with a
36-inch reflecting telescope out
there.
And at that point, most of the
research from Washburn
Observatory was transferred out
there to the larger telescope
and the darker skies of western
Dane County.
Whitford also, for example, saw
to it that the astronomy
department, that the
observatory, sorry, which had
been a research institute was
transformed into a department.
And made it into a part of the
College of Letters and Science,
which was a huge help in
granting degrees and offering
classes and things like that, it
became a regular academic
department.
And he also saw to it that the
astronomy department moved out
of the observatory, where they
didn't have room to run a
department anymore, over into
Sterling Hall which was being
expanded at the time, and he
moved them onto the sixth floor
of Sterling Hall.
So the astronomy department was
almost unrecognizable by the
time Albert Whitford went to
Lick Observatory.
And lots of other things were
happening right about then too,
1958, 1957, was of course when
the Soviet Union launched
Sputnik into orbit.
And that event would change an
awful lot of things, including
life at Washburn Observatory,
because when you put an
instrument in space you can do
things with it that you can't do
on the earth's surface.
One of the things you can do is
you can extend the photometry
that you might like to do on the
surface of the earth into the
parts of the electromagnetic
spectrum that you can't observe
from the earth's surface.
This little diagram here is
trying to show that visible
light reaches the earth's
surface, but infrared light is
absorbed by the earth's
atmosphere and so is ultraviolet
light, as are X-rays and gamma
rays.
Radio waves, however, longer
wave radiation will reach the
earth's surface, and that's why
generally speaking on the
earth's surface you see two
kinds of observatories.
You see visible light
observatories, the traditional
kind that we think about, and
you also see radio telescopes.
That's the other big kind of
observatory you find on the
earth's surface, because those
are the two parts of the
electromagnetic spectrum where
the radiation reaches the
surface.
Most of the ultraviolet, most of
the infrared, X-rays, gamma
rays, all absorbed at one point
or another in the earth's
atmosphere.
But if you get above the earth's
atmosphere, you can begin to
investigate that.
And that was of great interest
to astronomers in that period,
among other reasons, because
models of how stars work were
just being worked out at that
time, very, very early
computational, theoretical
models of what's happening in a
star to produce the energy.
These early models would produce
predictions about not just the
energy in the visible spectrum
that you could measure with
visible photometers, but also
predictions about how much
energy it would radiate in the
ultraviolet and the infrared,
which is very nice, but once you
have that theoretical
prediction, you want to check on
it.
But you can't check on it from
the earth's surface.
So in 1957, well, 1958 really,
in 1958 part of the response of
the United States to the
launching of Sputnik was to form
an agency, which we now call
NASA, and to look at ways to
exploit technologies in space.
One of the ways that they had in
mind was to invite astronomers
to design instruments to go into
space.
One of the astronomers who was
interested in this idea was a
fellow named Art Code.
Arthur Code.
Art Code had actually been at
Yerkes Observatory, University
of Chicago, had gotten his PhD
there and had actually come to
Madison from 1951 to 1956 and
worked for Albert Whitford
doing, of course, photoelectric
photometry here, learning the
ropes of the technique.
And then had taken a tenured
position at Cal Tech, and moved
to California.
Albert Whitford moves to Lick
Observatory, they need a
director for Washburn
Observatory, and Art Code was
lured back to Wisconsin to
become the sixth director of
Washburn Observatory.
But Art Code came back with an
agenda, which he made very clear
to the people who were hiring
him to come back here.
And that was that he wanted to
take Wisconsin's expertise in
photoelectric astronomy into
space.
And he had already started
making connections to NASA, and
even getting a little bit of
money, proposing to build a very
small, very simple satellite.
And here you see a very early
coffee-stained drawing of Art
Code's basic idea of a
space-based photometer, a
Stebbins-Whitford photometer
inside an object that he
described as being about the
size of a garbage can, so about
so big, about so big around,
with a single telescope inside
of it, feeding light into a
single photometer, powered by
solar cells, as you see out
there.
Very small, very light, and most
importantly very cheap, and if
it didn't work, he said, you
could move on to something else.
If that one doesn't work we'll
move on to something else, it'll
be very cheap.
NASA liked the idea quite a lot.
This was not the only
astronomical suggestion they
were getting at the time,
though.
Plenty of other astronomers had
ideas for space-based
instruments, although not so
many of them really pursued them
the way Code did and provided
specifics.
Nevertheless, there were enough
of them that they decided that
what they really needed was not
just a satellite designed by
Wisconsin and another satellite
designed by Harvard and another
one designed by whoever.
But they needed a unified
platform on which to put
astronomical payloads.
So they created a line of
spacecraft called the orbiting
astronomical observatories, so
the OAOs.
Unfortunately, there's no scale
in here so you can't tell just
how much bigger than a garbage
can this spacecraft is, but the
center section there, that
center canister is about 12 feet
tall.
Right here.
About eight feet across this
way, and the solar panels span
20-odd feet across this way.
And you can see a full-scale
engineering model, essentially a
duplicate of the spacecraft at
UW Space Place on display down
there, if you come down we have
it on display.
But this is the one that
contained a Wisconsin photometry
package and was launched in 1968
into space as the first orbiting
astronomical, not the first, but
as the orbiting astronomical
observatory 2, orbiting
astronomical observatory 1 was a
solar observing, a solar
observatory.
OAO2 was designed to be a
general-purpose astronomical
observatory in space.
You could point it at anything
but the sun.
But in order to do that you need
a much more complicated
spacecraft, it's easy to find
and track the sun.
That part's easy.
But if you want to point at a
distant, dim galaxy, that's
hard.
This telescope was designed to
do that job, so in effect, it
was an early ancestor of the
Hubble space telescope, the
modern, our current
general-purpose space
observatory.
There were two instrument
packages included on the OAO2.
The one on the right, the
Wisconsin experiment package,
it's called, with five
telescopes and two
spectrometers, all gathering
their data by photoelectric
techniques so you can control
them remotely from the ground
and you can transmit their data
back to the ground.
You couldn't do that with
photographic plates in the old
style.
The expertise of Wisconsin
astronomers made it possible to
build an instrument like that
and we went into orbit alongside
another ultraviolet instrument
called the Smithsonian
Celloscope, which was designed
to produce images in
ultraviolet.
The celloscope and WEP went into
orbit together on OAO2 on an
Atlas Centaur there, and I'm
skipping over the whole part
about OAO2's predecessor, which
was a huge disaster and I'll
talk about that some other time,
or perhaps in questions if you
like.
But the second one was
successful and orbited the earth
for, still is in orbit around
the earth, but operated in orbit
successfully for about four
years as a general-purpose
ultraviolet observatory in
space.
It was OAO2 that provided the
expertise here at Wisconsin,
that brought together the
tradition of ultraviolet
astronomy and all the
theoretical and research
questions that come into that,
along with the expertise in
building instruments like this,
and made it possible for
Wisconsin to continue to build
important space payloads.
There was also very important
research results from OAO,
including, for example, the now
commonly cited fact that comets
are mostly made of water.
We heard that all the time,
comets are dirty snowballs,
they're primarily icy substances
and the most common of those
ices is water.
How do we know that?
Because the OAO2 observed a halo
around a comet called Comet
Bennett that happened to come by
while OAO2 was active, and by
measuring the breakdown products
around the nucleus, they could
conclude that those were
breakdown products from water,
water that's broken down by
ultraviolet light from the sun,
and you can measure how much of
that there was, and find that
it's the major constituent of
the nuclei of comets.
That research result, now very
commonly, if somebody says,
where did the water in the
earth's oceans come from?
One of the answer is, probably
comets early in the history of
the planet.
The reason we can even say that
is because we know comets are
mostly made of water and we know
that because of this OAO2
research result.
So as I mentioned, the OAO2 was
the ancestor, the immediate
ancestor of the Hubble space
telescope, and so when the
Hubble space telescope planning
was in full tilt, it seemed
logical that such an observatory
should have photometers on
board, and the contract went to
the University of Wisconsin to
provide a package of photometers
that would fit inside the
instrument bay of the Hubble
space telescope.
And the package of photometers,
you see it's the phone booth
sized thing underneath the foil
there, where it is in testing at
the Goddard Space Flight Center.
The package called the
high-speed photometer was
exploring a new type of
photometry.
On the earth you're always
looking through the earth's
atmosphere, which blurs and
makes stars twinkle, for
example.
You can't actually measure
variations in brightness that
happen very fast.
But without the atmosphere you
might be able to see matter
dropping into black holes that
would have light variations on
the level of milliseconds.
You'd like to measure those
things, you can't do that from
the earth's surface, but you can
from space.
So the high-speed photometer was
designed to take advantage of
the space environment to extend
photometry in yet another new
direction.
The high-speed photometer was
sent up was in the first
generation of instrument
launched on the Hubble space
telescope.
All of the original instruments
have been changed out now by
later generation instruments.
Another space-based instrument
that is in the tradition of
Wisconsin space astronomy is the
one called the Wisconsin
Ultraviolet Photopolarimeter
Experiment, or WUPPE.
( laughter )
WUPPE was under
construction at just the same
time that the high-speed
photometer was under
construction, those were very
active days for the UW astronomy
department and space astronomy
lab, which was the part of the
astronomy department founded in
order to do these kinds of
products.
WUPPE was designed also to do a
new kind of ultraviolet
photometry, in this case
measuring the polarization of
ultraviolet light.
That's why it's a
photopolarimeter.
WUPPE flew twice on the space
shuttle.
That's a cartoon there of Art
Code holding the polarization
vectors in his hands, those are
the things you analyze when
measuring polarization content
there.
WUPPE flew on the space shuttle
twice, and one of our astronomy
professors was an astronaut in
training that never actually
flew, that was Ken Nordsieck,
because the number of flights,
there were originally six
flights for this payload, but
they were cut back to two after
the Challenger accident.
But here's one of my favorite
pictures.
It's hard to see WUPPE, WUPPE is
in the picture there, although
it's kind of eclipsed back here.
This is WUPPE back there.
This is looking out the back
window of the space shuttle, out
into space and you can see Orion
there if you look carefully.
See Orion back there?
So there's WUPPE and Orion,
that's the view out the back of
the space shuttle, probably as
close as I'll get to look out
the back window of the space
shuttle.
Just a quick footnote on space
astronomy.
UW also has an expertise that
comes out of the early days of
the OAO program in not just
orbital instruments, everything
I've talked about so far went
into orbit, but it turns out
that it's very effective
sometimes to launch a payload
with a very small rocket that's
incapable of getting into orbit
but is capable of getting your
payload up a couple hundred
miles above the earth's surface,
which is high enough to do some
ultraviolet astronomy, but it's
not going to go into orbit, in
fact, it's just gonna fall back
down again after a few minutes.
So you get a few minutes of
observation time at the top of
this arc of what's called a
sounding rocket or a suborbital
rocket.
And suborbital rockets are still
a big part of our work at UW
because it's very cost
effective, especially when
developing instruments or
exploring new observational
techniques.
It costs an amazing amount of
money to build an instrument for
a satellite.
It costs a lot less to build it
for a suborbital rocket.
So if you're not sure it's gonna
work.
Better to try a cheap one on a
suborbital rocket before you
commit to a satellite.
Or if you're going to try a
measurement with a proven
instrument but you want to look
at some high-risk object, you're
not really sure if you look at
that kind of galaxy whether
there's anything interesting
there or not, you can screen out
those kinds of research
projects.
Again, with this very low-cost
method, it's an expertise that
we have here at Wisconsin.
Here's a modern sounding rocket,
that was an old-style sounding
rocket in the other picture.
The modern sounding rockets use
modified military missiles that
are solid fueled rockets like
this one right here, they turn
them straight up before they
launch them, it's being hoisted
up into position there.
Here's a payload when they come
back, if everything works out
right, then the parachute opens
and you can recover your
instrument here out in the
desert, they launched it out in
New Mexico, White Sands, New
Mexico.
Bring it back to Madison, get
your research results.
Well, those have already come
down by telemetry before the
flight is even over, but you get
your instrument back, you can
calibrate it again, a lot of
times we can fly them again, and
in fact we have such a sounding
rocket instrument on display at
Space Place, a veteran of five
suborbital flights.
Well, I wouldn't want to leave
you with the impression that we
only do astronomy in space now.
In fact, the newest frontier
that Wisconsin astronomy is
involved in is in the
construction of very large
telescopes.
Our best ground-based telescopes
are no longer in Wisconsin.
Think about January here, you
won't have to puzzle about that
for very long.
We have a very fine telescope
called the WIYN telescope,
a 3.5-meter, that's the diameter
of the mirror, at Kitt Peak
National Observatory just
outside Tucson, Arizona.
And that is a consortium
telescope.
The initials stand for
Wisconsin, Indiana, Yale, and
the National Optical Astronomy
Organization, essentially the
federal government, are the four
partners, Wisconsin is the
leading partner and the managing
partner in the WIYN consortium.
This is a very fine telescope,
produces some of the finest
optical imagery available today,
in part because of the fine
instruments that go on a very
optically good telescope.
We've got a number of unusual
ground-based telescopes,
including this one which is
mapping the hydrogen in our
galaxy, the hydrogen that makes
up most of our galaxy, the
Wisconsin Hydrogen Alpha Mapper,
or WHAM.
We always strive for an
effective acronym.
The WHAM telescope actually just
mapped everything it could see
from Kitt Peak and just over the
summer has taken up residence in
Cerro Telolo in Chile so it can
finish doing a map of all the
southern sky that you can't see
from here.
And I'll finish up with our
largest project which is one of
the largest telescopes on the
planet.
Definitely the largest one in
the southern hemisphere called
the Southern African Large
Telescope, this too is a
consortium instrument, we don't
own this instrument the way we
own the Washburn telescope.
But a ten-meter telescope in
which UW is the largest
non-governmental partner, we're
the largest university, academic
partner in this project.
Major parts of the scientific
equipment for the Southern
African Large Telescope were
made here in Madison including
this instrument that you see
over there on the right.
The Prime Focus Imaging
Spectrograph, now renamed the --
spectrograph, which is the main
instrument at the SALT
telescope.
And it sits way up here where
that says optical payload, it
sits up there at the end of the
telescope.
Here's the primary mirror of the
telescope, and you sort of see
the tress work, the structure
there, and our instrument sits
way up there on top, so it was
actually helpful to have built
instruments that have to operate
in space, in this case we had to
build an instrument that has to
hang out in mid-air at the top
of the telescope.
The PFIS is now getting an
infrared extension, so it can do
near infrared work.
And I'll finish with another new
frontier that Wisconsin
astronomers are involved in and
that is the world's first
neutrino telescope now taking
place at the South Pole.
That project is actually managed
by the physics department and
Professor Francis Haltson, but
the UW astronomers are very
involved in the ice cube
telescope, which we can talk
about a little bit more.
So we're on the frontiers of new
kinds of astronomy with neutrino
astronomy, very large telescopes
and operations in space,
different kinds of frontiers
than we started out with in the
late 19th century here in
Wisconsin, but frontiers
nonetheless.
So I'm running a little bit
over, I'll stop here, and thank
you very much for your
attention.
( applause )
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