cc  >> 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)