[gentle music]
- Norman Gilliland: Welcome to University Place Presents.
I'm Norman Gilliland.
Perched atop a hill overlooking Lake Mendota in Madison
is the Washburn Observatory.
It has been observing movements in the sky by stars and planets
and other entities since the 1880s.
And along the way,
it has transformed the way we think about the universe.
We're going to find out how from my guests.
And they are Jim Lattis,
the director of the UW-Madison Space Place,
and Kelly Tyrrell, science writer.
And they are co-authors of the book Chasing the Stars,
published by the Wisconsin Historical Society Press
in 2024.
Welcome to University Place Presents.
- Jim Lattis: Thank you, Norman.
- Kelly Tyrrell: Yeah, thank you, Norman.
- Looking at the observatory itself
is a fascinating thing because there it is, pretty much
now in the middle of a campus, a university campus,
although it is prominent as it overlooks the lake still.
Why did it get chosen back in the 1870s?
- Jim: Yeah, it was on the western edge of campus
at that point.
Part of the large expanse
that stretched westward that used to be called
the University Farm at times.
And it was far enough away from the city.
But although the city was small at that time,
but far enough away from what modest lights there were,
but also smoke, sources of smoke,
and things like that which did eventually
engulf the observatory anyway,
but it was pretty much the western--
the westernmost structure of the university at the time.
- And whose idea was it?
- So it was Cadwallader Washburn,
who was a former governor and a very successful businessman.
And he was a political ally and associate of John Bascom,
who was the president of the university.
And they had it in mind
to transform the university with a research institute there.
- John Bascom was the university's sixth president,
and he believed in coeducation
and saw the university as a place
where you could bring students together
and really sort of stake a claim for the university
as a research institution.
And at the time,
having an observatory was somewhat similar
to having a Department of Computer Science today.
It was a way to establish a university as a research entity.
And he modeled it after places like Harvard and Michigan.
- Wisconsin always had this thing
about Harvard, didn't they?
Would be the Harvard of the Midwest.
- That's, something like that, yeah, yeah.
- What kind of telescope, though,
if we're talking 1880 or so?
- Well, so telescopes of, research telescopes of that day
were almost invariably what we call refracting telescopes.
Instead of having a big mirror,
the way modern research telescopes have,
it would have a lens as big as you could afford,
a lens up at the front of that telescope.
And Washburn specified that he wanted a telescope
that had a lens bigger,
well, comparable to or larger than Harvard's.
- There we go again. - Yeah, that's right.
And so Harvard's telescope,
the one that he was comparing to was a,
is, they still have it, a 15-inch telescope.
That means the lens,
the diameter of the lens is 15 inches.
That's how astronomers talk about the size of the telescope.
So we have one that's 15.6.
We often say 15 1/2 inches.
And that pushed Harvard down one in the rankings.
And so that telescope was the third largest
in the United States when it was installed
up there at Washburn Observatory.
- Norman: What were they looking for?
What were they looking at?
- Well, so astronomy of that era was very different
than what we think of astronomers doing today.
We often use the term astrophysics today,
which helps distinguish between what astronomers do today.
And astronomy at that time was carried out
with a number of specialized techniques
that amounted to measuring the positions of stars in the sky.
That was not the only thing astronomers did,
but it was the primary work of astronomers.
Sometimes, they were measuring positions of the sky
in the sense of measuring one with respect to another,
so that you might, say, make up a star chart,
a star atlas or something.
But sometimes they were measuring one star
with respect to another of stars that are in systems,
gravitational systems of stars.
And you measure the positions of one with respect to another,
to observe their orbits
and try to derive information about those star systems.
- You have a notion of how far they could actually see?
- The ability to see into the universe
does increase as your telescopes get bigger,
but it's just a question of how dim an object you can look at.
You can see pretty distant things, even with your eye...
[chuckles] ...just with the unaided eye.
So what, but what we usually think of
is that these telescopes were not specially designed
to detect, say, really dim galaxies.
The kind of things that we do look for
to tell us how the universe has evolved.
And so that's why they could get by
with much smaller apertures, 15 1/2 inches
compared to, say, you know, our large telescopes these days
have mirrors measured in meters. [Norman chuckles]
And so they have penetrating power
into space vastly greater.
That wasn't the primary goal of these telescopes.
- One thing that I think surprises people that
the instruments at a place like Washburn was doing too
was actually measuring very accurate time.
And so you could look at the transits of stars
across an instrument like the meridian telescope
that Washburn was equipped with,
in addition to the refractor that we've discussed.
And by getting very accurate celestial time,
observatories could then sell that to industries
like the railroad and watchmakers,
who were very interested in establishing very,
very specific and very accurate timing.
- I think--
So what would that instrument have looked like?
- Jim: That's a meridian circle telescope there.
And the second director of Washburn Observatory,
Edward Holden.
A meridian telescope like that was designed
to measure the positions of stars
very accurately with respect to the horizon
and the zenith.
And so when a star passed through the field
of that telescope, it was on the local meridian.
And an observation like that,
an astronomer can turn that into a very exact time.
So basically, they would find the time with an instrument
like that, like that meridian circle,
and then set the observatory clock
from that observation with that telescope.
And then the observatory clock was the master clock
that was used ultimately for the,
to provide time signals by telegraph lines.
- All this done by hand?
How would they have done these charts?
- The observing was done literally looking
through the telescope,
"eyeball at the eyepiece" astronomy
and noting, pressing a button really,
when the observer saw the star move through there.
And that fundamental measurement could be used
for actually a lot of different purposes,
in addition to just the very practical one
of finding accurate time.
They would come up with tables of numbers.
Let's say they were using the meridian circle telescope
to come up with star positions for something like,
they used to do stellar parallax measurements,
which gets you distances to stars and things like that.
You're writing all those things down by hand.
And that's just the number that you get,
the time that you get from observing.
And then the circle part of the meridian circle
gives you another number.
You put those two numbers down.
Those are your observation.
And then, there's a long series of calculations
you have to go through to turn that into a position on the sky.
And that was the sort of thing that, of course,
in those days was carried out completely manually.
No, there were no electronic computers or anything
to do that kind of work.
- And what kind of staff for Washburn?
- So in the early days, Washburn had a director,
and the director was a professional astronomer.
And Edward Holden,
who we saw at that beautiful meridian circle telescope,
was hiring assistants from his courses.
He was hiring students, men and women
to play a variety of roles in the observatory.
In this particular area, era, in the late 19th century,
it was very atypical for women to be afforded time observing.
It was believed that night work was not for women,
and so most time on the telescope
actually making those observations
was reserved for men.
But the student assistants, which included women,
they were the ones who were performing
those hand calculations on big, long spreadsheets,
really taking the observational data that the observer
or the astronomer was making at the telescope
and translating that into useful data.
- I'm just wondering what kind of majors
these students would have had.
- Yes, so at the time,
there was nothing like an astronomy major
[laughs] at the university.
Many of these students were,
might be science majors, for instance.
Just a very generic major.
Holden had a joke that, that the--
I'm sorry, it was Joel Stebbins.
He was the fourth director,
and he had a joke that women were just as capable as men
at astronomy, but probably much neater.
[Norman laughs] And probably was very true.
But one thing that was somewhat unusual at Washburn
and with Edward Holden in particular,
is he did have, some of his female assistants
were actually afforded time observing.
Alice Lamb, for instance, is one of the student assistants
that we have quite a bit of record on.
And she and her eventual spouse, Milton Updegraff,
were student assistants under Holden,
who, when Holden left for a different job
at Lick Observatory in 1885,
Alice and Milton basically kept the observatory running.
So between the two of them,
they were at the telescope making observations.
They were publishing in the publications
of Washburn Observatory.
And Alice would go on to accompany Milton
over to Argentina, actually,
where his astronomy career continued.
She really desired a career in astronomy,
but that did not pan out for her in the era.
- Do you have a sense of--
You mentioned the Lick Observatory,
and there were, of course,
many others in the country by this time.
We get into the late 19th century.
Do you have a sense of to what extent they were competing
and to what extent they were collaborating?
- There was a lot of collaboration in the sense
that these, the astronomers would always share results.
In fact, Kelly mentioned the publications
of the Washburn Observatory, which were published
for many decades.
The patterns of science were shifting
in the early 20th century,
and astronomers started publishing in journals.
But the publications were printed up largely for,
in part for sharing results,
but in part to have something to trade to other observatories
for their publications.
And so there was a very active network
of these sorts of things, of astronomers sharing data,
and then they would specialize in areas
that they were well-equipped for.
So the Washburn Observatory, for example,
was an early specialist in coming up
with these stellar parallax measurements
that came from that meridian circle.
And other observatories, Lick, for example,
had different specialties, in spectroscopy, for example.
We could say the same thing about Yerkes Observatory.
So they had different specialties,
and the astronomers had different interests.
The competition, maybe was friendly.
I'd have to say, yeah.
- One thing that ultimately set Washburn Observatory apart
from some of the other observatories of the era.
We've talked about Harvard.
Harvard really invested heavily in the early 20th century
in photographic astronomy.
And so, they were using their telescopes
to essentially take pictures of the sky the same way
the Hubble telescope does today.
And they were then looking at those pictures
and making observations and measurements there.
Washburn made a different choice,
and I think Jim can speak a little bit
to how that choice was made and what that ultimately led to.
- In the earliest days,
it was these position measurements
that we were just talking about,
and it did lead to certain applications that, for example,
figuring out the orbits of these binary stars
based on position measurements, which is very laborious work,
by the way, because again,
all those observations are done "eyeball at the eyepiece,"
and then data reduction done during the daytime.
And it resulted in,
in some cases in insights into the nature of stars,
into the masses of stars and things like that.
Very early contributions to what we might now call,
what we would probably call astrophysics
in terms of thinking about the,
the actual physical nature of these things.
What's the mass of a star?
But that style of astronomy
was changing very rapidly in the early 20th century,
in part because of photography, because astronomers found
that eventually they could make observations of star positions
more accurately photographically than they could
with an instrument like a meridian circle.
So, Washburn, if it had followed the patterns
that it had in the late 19th and very early 20th century,
Washburn Observatory would have been pretty much obsolete
by the '20s, when modern astrophysics started coming in.
But the fourth director of Washburn Observatory came here,
actually had been a student at the Washburn Observatory
for a year earlier in his career,
came here as the fourth director
and was experimenting with the electronic measurement of light,
and measuring the quantitative measurement of light,
which we call photometry,
was something that could be pursued
either photographically or electronically.
And most astronomers were much more comfortable
with photographic methods.
But the electronic methods could give you much better results,
much more accurate results.
But very few astronomers were willing to mess around
with electronics of the 1920s.
Think of a radio from the 1920s.
In fact, Stebbins would occasionally say,
"Well, think about a radio attached to the end
of the telescope."
This enabled them to do science
that nobody else was doing
because no other-- very few other astronomers,
I won't say none, but very few other astronomers were willing
to learn the electronics.
And Stebbins was,
and he also partnered up with physicists
to help him develop these instruments.
And they were able to come up with science
that was very important in the early days of astrophysics
in terms of understanding not only the natures of stars,
for example, but even the structure of the galaxy.
- But if we're looking at photoelectric photometry,
is that Stebbins that we're seeing
still eyeballing through the telescope?
- Jim: Well, no.
That's one of the interesting things I like,
that it looks as if Stebbins is looking through the telescope.
He's actually looking at a microscopic meter.
He doesn't see the light from the telescope.
It goes into that detector tube.
And what Stebbins sees through that little microscope
is a microscopic needle that's creeping across the screen,
that's measuring the microscopic current
that comes off of that tube.
So he's not looking through the telescope anymore.
It's not "eyeball at the eyepiece."
It is "eyeball at the electrometer" at that point,
but not at the eyepiece.
- Now you're talking a lot about stars,
distant objects.
Were there interest at all in looking at planets,
or are they just too close to be interesting at this point?
- Certainly, many astronomers looked at planets
when they were, say,
when Mars was at opposition and relatively close.
But actually, planetary astronomy in the 20th,
in the early 20th century
was kind of a, sort of a poor stepchild.
There wasn't very much science
that was, that you could do observing planets.
- You could get closer and closer image,
but not really learn that much about anything?
- Well, the atmosphere kind of limits you on
how much detail you can see even with big telescopes, and so--
- Norman: The Earth's atmosphere.
- The Earth's atmosphere, right.
And so, so it was--
People did planetary astronomy,
but there wasn't a great deal to be done about that beyond,
say, counting moons and measuring the phenomena
that you could see.
There were some very minor avenues
that Stebbins pursued that do amount to planetary observation.
But no, for the most part,
it was about studying problems in stellar astronomy
and the nature of stars.
In that period, it was still a mystery
how stars produce their energy.
How does that keep up for so long,
and how long will it keep up?
What are the sources of it?
So coming to terms with the nature of stars was one thing
that Stebbins could derive from the photometric astronomy--
photoelectric astronomy.
- So they gave up looking for Vulcan
pretty early on, I guess. [all laugh]
Kind of almost legendary search for this planet
that may or may not have existed in our Solar System.
- So there is a connection there
at Washburn Observatory very early.
But our first director who wanted to do that,
James Watson, died too soon to carry out his plans for that,
and nobody else followed him up on that.
- He did build an observatory in the Hill
for expressly that purpose.
- What are the astronomers at Washburn
then starting to discover about the nature of star power?
- Well, so, for example,
the trace there, that light curve
that shows the way the light changes
in what's called an eclipsing variable star.
There's a plunge in the brightness,
which is called the primary eclipse.
And then a little while later, there's a smaller plunge
in brightness that's called the secondary eclipse.
Those curves, Stebbins is measuring those
with his photoelectric photometer,
looking through that little eyepiece
and writing down those numbers.
But in the case of the eclipsing binary star.
- These are stars that are in an orbital movement
where one is passing over the other.
So that's the eclipsing part of that.
- Exactly right, yeah.
So when the one, when the dimmer one passes
in front of the brighter one, you get a big dip.
So this was known to be
that there were stars that would do this.
But the accurate measurements that Stebbins could make
allowed him to derive things
like the relative sizes of the stars.
And that diagram that you see there
is one that he published, showing the relative sizes
of these two stars.
And if from studying the orbit of the stars,
you get the masses,
then the masses and the sizes give you the densities of stars.
So this is the beginning of understanding
the physical characteristics of stars
that would lead to, not too many years later,
by the mid 1930s,
the conditions that existed within stars were enough
that astronomers could come up with their,
and physicists could come up with their theories
about thermonuclear reactions going on in stars,
and that being the energy source of stars.
But you've got to know all those basics,
mass and density and things like that,
before you can begin coming up with your theories about
where the energy comes from.
- Are they looking specifically at galaxies at this point?
- Jim: So galaxies were barely even a concept
in the early 20th century.
The word galaxy literally meant
the group of stars that we live in,
and what we now think of as other galaxies
were little smudges,
little swirly smudges out there in the sky,
and people didn't really know
if those were things as big as our galaxy
or if they were some other type of object.
But understanding the star system that we live in,
they would have called it the stellar system,
which we would now call our galaxy,
had a very important development here at Wisconsin.
Again, from Stebbins's photoelectric photometry,
because he was able to determine distances to objects
that showed how big the galaxy was
and show that the galaxy actually contains
a lot of matter that isn't stars.
And he could talk about how that affects the measurements
and how much matter that is.
So all of that stuff from
that photoelectric photometer on the Washburn telescope.
- He's quoted as saying that we "shrunk the universe"
because by being able to take those measurements,
there had been lots of conjecture
about the size of the galaxy.
And Stebbins and scientists at the time
were able to establish
the galaxy is actually smaller than we thought it was.
- Did that impression hold?
Because it seems to me it keeps getting bigger.
- [Jim laughs] No.
Actually, the number that Stebbins estimated for the size
of the galaxy is very close to the number
you'll find in modern intro astronomy books.
About 100,000 light years in diameter.
- Of the galaxy. - Give or take.
Yeah, about 100,000 light years in diameter,
the Milky Way galaxy.
- Well, we started seeing these other galaxies.
And by the way, can we see any galaxies with the naked eye
and just not recognize them as such?
- Sure.
- The Andromeda galaxy is one of the easiest.
To the naked eye,
it looks like a smudge in a dark sky,
but that is a galaxy that is visible to the naked eye.
And our closest neighbor, galaxy neighbor.
- And now we have good distances
for that kind of thing, but in those days,
they didn't really have much idea
of the distance of these things or their size.
You've got to know one or the other to figure that out.
And so it was very much up in the air.
Just what was the nature of these other things out there
that we now call galaxies?
They called them nebulas.
Spiral nebulas is what was the common term.
- Did they have a sense at all at how galaxies are formed?
Are they seeing formation of galaxies at this point?
- No, that's a much later sort of thing.
The ideas of galaxy, theories about galaxy formation
and then galaxy evolution,
and these days, a very important thing is galaxy interaction.
- Norman: Sure. - Yeah, those were--
No, those were,
those would come later, well after the Stebbins era.
- A lot of the science
that was the groundwork for that science
was being laid here and elsewhere.
But really, as Jim mentioned,
the pivot to the photoelectric effect
and really looking at electric astronomy really helped move
the astronomical field in that direction.
But importantly, it helped establish Wisconsin as a place
where innovative technologies and instrumentation
were being developed, which then also led
into additional pioneering science.
- Have they seen any collisions of galaxies at this point?
And if so, what was going on?
- No, in that period, no one was,
as far as I know, was thinking about colliding galaxies.
Certainly, there are many cases now.
There's lots of that.
That's a very important process to understand.
And it would appear that most galaxies evolve in part
by absorbing other galaxies colliding with them
and eventually merging together.
So that's pretty well understood
and constantly being studied by modern astronomers.
But that's a much later thing than what we're talking about
there in those days.
But as Kelly said, it did, that kind of work
and the development of that technology here
did set up Wisconsin astronomers
to carry on this kind of research,
much of which is done with space-based research.
The specialty here in electronic astronomy,
we could call it, set up Wisconsin astronomers
for the early days of the space age
and using early space technology
and satellites to do observations in space.
The way much of this, a lot of those great pictures
that you see of colliding galaxies
come from the Hubble telescope.
And Wisconsin astronomers were developing
the predecessors to the Hubble,
and even pieces of the Hubble
have been made, have been done here.
- In that context, what are electronic
astronomical detectors detecting?
- Jim: They're sensitive to light,
both in the optical, but also in the ultraviolet
and also in the infrared.
The thing about the ultraviolet, for example,
is that we don't get much of that,
hardly any of it on the surface of the Earth,
just enough to be a nuisance for those of us
with light complexions, but.
- [chuckles] Yeah, sure.
- But the ultraviolet light that would be useful
for astronomers doesn't make it through the Earth's atmosphere.
You've got to be above the Earth's atmosphere.
So those kind of electronic detectors
make it possible to detect light
that we couldn't observe here from Earth.
But we do have to send those electronic detectors
out into space.
And so, when the early days of the space age came along,
which basically made it possible,
then you put a-- if you can--
You got a rocket big enough to put a satellite in orbit,
you can maybe use that to do some astronomy.
And Wisconsin astronomers were well set up to build instruments
that could be launched into space
and used for astronomical observations.
So we were some of the pioneers of space astronomy
here at the University of Wisconsin.
- And that gets back then to Hubble
and some of its contemporaries
in terms of extraterrestrial astronomy.
Is that what you would call it?
- Yeah, we usually just say space astronomy, yeah.
[all laugh] - All right.
- Yeah, right.
So the, I mean, you know,
Sputnik was launched in 1957, and NASA was formed,
not coincidentally, in 1958. [laughs]
- Norman: Yeah, in a kind of a rush.
- In kind of a rush, yeah.
NASA began funding astronomers to figure out
what they could possibly do with a satellite.
And again,
the Wisconsin astronomers were very well set to explore that,
because operating an electronic detector in orbit
is way easier than operating a film camera in orbit
for any number of reasons.
And so, yeah, so that led to a pretty long line
of space instruments
coming from Wisconsin ultimately,
in building, of course,
a photometer for the Hubble Space Telescope.
And in fact, there's the instrument
being built for the Hubble telescope.
There's the Hubble telescope, but then also the instrument
that was our photometric package there.
The astronomer there on the left is Robert Bless,
who developed that instrument,
and his project manager, Evan Richards.
They and their teams produced that instrument,
which was launched with the Hubble.
So the reason there's a Wisconsin photometer
on the Hubble telescope is because Joel Stebbins
came here in the 1920s.
- That's quite a long reach for Joel Stebbins.
[Jim chuckles]
Hubble, there was sort of a little bit of a joke
going around about Hubble at first
that what, it needed bifocals
and needed to kind of make some adjustments
once it was already out there.
How did that relate, if at all, to Washburn?
- Right, the problem with the Hubble telescope
when it was first launched was the mirror
had not been correctly made. [chuckles]
- It had a-- Yes. - Norman: Problem.
- Jim: The main mirror had a,
had been incorrectly made so that it produced
out-of-focus images.
And so, yeah, that's the joke about
putting glasses on the telescope
is to correct those out-of-focus images.
- Thankfully not a Wisconsin error.
- No, [chuckles] certainly not.
But we did suffer because of that,
because our instrument then had to be used
with those very imperfect images.
And, but it badly affected
all of the instruments on the Hubble.
The saving thing, the saving thing for NASA
was that those instruments could be replaced.
And so, other generations of instruments
were installed by subsequent visits
of space shuttle astronauts.
And so the Hubble operates up to full spec today.
But that was an awkward beginning,
but not our mistake.
- A lot of details to keep up with there.
Hubble is in orbit?
- Orbit around the Earth, that's right.
- And that's how the space station could
kind of just intercept it and...
- Well, yeah, the space shuttle.
- Norman: Space shuttle? - Yeah, that's right.
You, they would launch the space shuttle into,
in such a way that it was
in the same orbit as the Hubble,
and then it could approach
and the astronauts could work on the telescope up there.
- Any risk once you get something like Hubble up there,
that the technology is going to outpace it?
- That's why it was designed to have replaceable instruments.
Some of those instruments on the Hubble today
are third-generation instruments.
And yeah, they've taken advantage of advances
in technology for better instrumentation
all the way along.
- It's been a lot of innovation since the '90s
when Hubble was first conceived.
- What--
This gets into that question that astronomers inevitably get.
But here it is, I mean.
How is something like Hubble, a big project,
expensive project, long, ongoing project,
what's its actual mission in terms of "practical" things?
Or is it all just out of scientific curiosity?
- Well, certainly the scientific curiosity is what drives us.
That's the, you know,
finding the answers to these questions
that we want to understand
how/why are there stars and how do they shine,
and where are we
and what's our relationship to the rest of the universe?
Those are back there.
But finding answers to those
are far from the only benefits that we get
from that kind of work.
- That's true of a lot of basic sciences.
It's driven by curiosity, just a human desire
to know more about the world,
or in astronomy, the universe around us.
But we don't always know at the time
that we embark on that science,
what the technology or what the findings
or the innovations might lead to.
I'm really inspired by astronomy
because I think-- not as an astronomer.
I am not an astronomer, but,
that it really just taps into this essence
of humanity, right?
This deep desire that we all possess to understand,
but that also helps us move forward as a species.
- But that said, many of the things
that astronomers have discovered about the universe
do have direct practical implications
on the Earth,
notably things like fusion energy,
the whole understanding of that sort of
thermonuclear chemistry that goes on,
comes out of investigations into the energy sources of stars
to then understand
how that can be applied here on the Earth
for everything from hydrogen bombs
to someday electrical energy from such things.
The drive to understand
the energy processes of the stars
is behind the investigations into that sort of,
that sort of physics.
So there are a number of those sorts of things.
You can go back to things like we mentioned earlier,
the timekeeping or celestial navigation.
In the early days,
those were strong motivations for astronomy
because nations needed celestial navigation.
They needed this for commerce.
And navies always needed the sort of thing.
And you needed some astronomers
who could help your ships navigate
long before there were GPS systems.
So you have lists of practical applications
and sometimes practical outcomes from these sorts of things.
But none of those are really why we're doing it.
You never know where the benefits are going to emerge.
And so, you have to kind of keep on working on the basic problems
and asking the basic questions,
and you can hope that they lead to some practical things,
and they often do.
- A good, honest answer.
That's right.
I mean, the priority is just because we wanna know.
- Jim: I think that's right.
- And what may come out of that could be a blessing.
What do we learn about fusion, then,
in these explorations of the universe?
So fusion being sort of the Holy Grail,
isn't it, of energy production here on Earth?
- Sure.
Fusion happens in a lot of different ways
in the astronomical context, in terms of the evolution of stars.
The evolution of stars is really a matter
of the evolving conditions in stars
that produce different phases of fusion,
first of hydrogen into helium and then helium
into heavier elements and so on,
and we see this happening out in the universe around us.
Those sorts of things are probably not first
in the mind of the engineers who are designing fusion reactors.
That sort of thing is pretty well understood
in the laboratory by now.
And they have very specific goals.
So I don't think there's much
of an astronomical connection anymore,
except that this, that was the motivation
for understanding that sort of physics
in the very beginning.
So the fusion
is a huge laboratory and engineering problem now.
And we do that on the UW campus too, fusion research.
But again, it has little to do with the astronomers these days.
- With a telescope like Hubble out there,
what, a couple hundred miles orbiting
well past the Earth's atmosphere.
- Yeah. - And...
- Or just past. [all laugh]
- And getting a good, clear look at things
that we could not see from Earth.
What is the role of terrestrial-based observatories
like Washburn?
- Well, so Washburn these days is a pretty small observatory.
[chuckles]
So Wisconsin astronomers have much bigger telescopes
to draw on now.
- And as we alluded to earlier, the conditions here in Madison
are no longer conducive to productive observation.
Certainly, we can observe.
- Atmospheric interference. - Yes.
- So you look for arid mountain tops and things like that.
That's where you want your telescopes these days.
- You want it high and dry and dark.
- But the Hubble is, you put it correctly to say
that its advantage is that it's above the Earth's atmosphere.
It's not an especially large telescope.
It has a mirror that's 2 1/2 meters in diameter,
which is way bigger than the Washburn telescope.
But Wisconsin has a ground-based telescope out in Arizona
that's 3 1/2 meters in diameter.
The Hubble's advantage is not in its size,
but in its positioning above the Earth's atmosphere.
So the Earth-based telescopes have their role
in being a lot bigger,
in collecting a lot more light and being able to image dimmer,
more distant objects and phenomena
than a telescope like the Hubble can.
Also, there's an awful lot of--
There have never been enough astronomers
to look at everything in the sky.
And so, the Hubble keeps busy
observing one thing after another.
But the research programs
that astronomers can come up with
way exceed the available observing time,
even with something like the Hubble.
And so observatory--
ground-based observatories all over the world
are pursuing various sorts of research programs
that can't be carried out with the time
that's available just on that one,
on the Hubble telescope.
- I guess they have the advantage of being
a little bit more accessible than Hubble.
- Well, yeah, there's that too, there's that too, yeah.
- Although these days, astronomy isn't done
"eyeball at the eyepiece" like it was at Washburn.
So data comes in, it's electronic.
And so, researchers can just access these troves of data sets
now to essentially mine any question
they wanna ask.
The competition comes in and actually getting time
on these ground-based instruments
to point the thing at the object
you are interested in looking at.
- But your comment about accessibility,
though, is well-illustrated here.
There are some of our people working on an instrument
before it goes to a ground-based telescope.
In that case, that's not a space instrument.
In that case, you can get it as close
to right in your laboratory,
but then you do still get to work on it
once it's on the telescope out there,
and you can even iterate.
We can make better ones or we can improve that one.
So access is an, especially in instrument development,
is an important advantage as well.
The space stuff, once you get it up there,
it's pretty much there.
You don't get it back usually.
- But are you saying then that
a telescope, such as the one in Chile,
or even the UW one in Arizona, can actually see
farther than Hubble, because they're so much bigger?
- Well, yeah, the way to put it would be
that the bigger the telescope, the dimmer the...
- Norman: Light source?
- The dimmer the light source it can pick up, yeah.
And that could be owing, could be dim owing to distance,
could be dim owing to being small, even if it's nearby.
So, yeah, so greater light-gathering power
is what we usually call it with the bigger--
The bigger telescope has the greater light-gathering power.
The Hubble, again, has the advantage of being
above the Earth's atmosphere, which degrades the images
that ground-based telescopes can create.
So it gets a nice, clear view of the sky.
Another advantage of being in space,
the Webb telescope that we talk about a lot these days.
- Norman: Famous now, yes.
See a lot of images from the Webb.
- But its specialty is detecting light
that doesn't penetrate the Earth's atmosphere at all,
in that case, in the infrared.
So early Wisconsin space astronomers were doing,
were exploring the ultraviolet.
And so getting your instrument in space,
whether it's infrared or ultraviolet,
is another really important reason
for developing those kinds of instruments.
- And this telescope here
is the Southern African Large Telescope.
And UW-Madison is the largest of a consortium of partners
that basically help keep this telescope operational
in South Africa.
It's in the desert, the Karoo.
This is a 10-meter telescope,
which means it just has a massive,
massive set of hexagonal mirrors
that act as a giant light bucket, right?
So it's collecting as much light as possible.
And 10 meters is a really large set of mirrors.
And it also has an instrument on it in the near-infrared.
So it can't get infrared.
But UW scientists actually worked
with South African scientists.
But here developed that new instrument
that went to the telescope in 2022.
- These wonderful pictures
that we're seeing online now everywhere,
these fantastic pictures
that are inconceivable from somebody's naked eye
standing in a clear desert climate,
cannot imagine these clouds and the colors and the...
I was gonna say galaxies,
but galaxies of galaxies of stars.
Are those actual photographs?
What is the technology?
What are we actually seeing?
Is it a computer simulation?
- Well, certainly, generally speaking,
we're seeing images created by telescopes
of different sorts.
But sometimes in the case of, say,
an image from the Webb telescope,
those observations were made in the ultraviolet,
sorry, in the infrared, infrared or far-infrared.
And so, when they put in colors and things like that,
they're basically coding.
They're assigning codes of certain colors
to correspond to certain wavelengths
that we can't perceive at all.
So those colors are sometimes called
scientific colors or false colors.
But, so those sorts of things are not an image
in the sense of what you would see in the sky
if you could be out there
at the Webb telescope or something like that.
But the ones that are created in the visual
from the ground sometimes are created the same way.
Or sometimes, they're created in such a way
that maybe if you had eyes that were 10 meters in diameter,
that maybe it would look like this.
That's all kind of silly in a way.
What the real power of these things is that astronomers
can understand the physical phenomena.
So when you see, for example,
a lot of pink in an image like that,
and this is an image from the Rubin telescope.
- Kelly: Vera Rubin. - Jim: Yeah.
Which was a very recently brought online.
That pink there is telling you where hydrogen is glowing.
And so, an astronomer can look at an image like this,
and from the nature of the image
and the distribution of wavelengths
at one point or another,
you might think of it as distribution of colors,
but it's way more specific than that.
And they can understand the composition
and the conditions,
and even things like the motions of the various parts
of an object like this.
That's a vast star-forming region.
- Kelly: The pink one is the Lagoon Nebula.
And the bluish pink at the top there is the Trifid Nebula.
- Norman: The Trifid Nebula. [all laugh]
Yeah, that sounds like a science fiction movie
from the '60s.
- Yeah, these are complex.
Maybe that's where it came from.
These are complexes of dust and gas there
where stars are forming.
And star formation is something that's very interesting
for astronomers to understand
because ultimately, planets come from that, too.
And ultimately, we come from planets.
- As Carl Sagan once famously said,
"We are all stardust." - Right.
So understanding that stardust
is understanding ourselves there, so--
- Recycled dust, that's what it comes down to.
It's a little depressing, but exciting too.
- Original sustainability.
[all laugh] - Yeah, right.
- Kelly: Speaking of images,
this is actually not just one image.
This is 678 images stacked together
that were taken over the course of seven hours
to yield a picture of these two.
- Norman: So a composite? - Kelly: Yes.
- Jim: That's a very wide field of view.
A typical telescope--
The Rubin is specifically designed to do this,
to have a very wide field of view.
And normally, to have that kind of field of view,
a typical telescope would have to make
many little pieces and stitch 'em all together,
and that would take days or worse.
- And lots and lots of computing power to make happen.
- But here, the Rubin can do it in basically minutes.
- Are we talking AI here?
- Not in the production of the image.
- Yeah, probably just a lot
of high-power computer science, that...
- Data analysis. - Mm-hmm.
- Yeah, well, yeah, there's a huge amount of computing
going into making those images,
but I don't think you would call it AI.
Now, the AI couldn't come, could come in
when astronomers have enough data to look at,
say, different examples of star-forming regions,
and then ask AI to try and generalize about what are the,
I don't know, what are the essential conditions
that go into these sorts of things
or something like that.
It might come into the thinking about the problem down the road,
but no, not the production of the image per se.
- Or asking AI to analyze patterns
that might be missed by a human observer.
- Well, as long as we're talking about star formation,
can you give us a timeline for forming,
I don't know, a yellow dwarf
or red dwarf or whatever it might be?
- Well, it sort of depends on where you start.
So out there in that star-forming region,
there are knots of molecules and gases
that are called molecular clouds.
And those clouds, under circumstances that--
There seem to be a number
of mechanisms that can trigger this.
The cloud can begin to collapse on itself gravitationally.
So if you start the stopwatch running then,
then understanding how fast that can happen is something
that astronomers are very interested in.
And studying large clouds like this,
because you can see finished stars in there
and you can see these cold molecular clouds in there.
And it varies probably on the size of the cloud
and how big the star is.
But it happens over a period of hundreds of thousands
to a million years, which is fairly fast.
- I was gonna say, "To make a star, a million years?"
- Yeah, right. - Pretty good.
- It's on a--
But then where do you stop the stopwatch?
Because they're never quite done.
Do you stop it when it's got a planetary system
and it enters what astronomers call the main sequence?
That's probably where you could agree to stop it.
But you'll--
We actually understand those sorts of things
relatively well now, not--
The problems are far from solved.
But compared to 100 years ago,
we're able to talk about these things in terms
that the astronomers of Stebbins's era
had no clue about.
In fact, even the very idea of star formation
and star and planet formation 100 years ago,
this idea of the collapse of clouds
which had been tossed around, was actually on the outs.
People didn't think that was a very good theory.
And there were some competitors.
So it's in the past hundred years,
we've come a tremendous distance in our understanding
of things like star and planet formation,
which is far to say, not to say anything
like we're close to being done.
But we have such powerful insights into that now
that it makes everybody want to know more
and understand better where, say,
planetary systems come from.
- And we're seeing more and more.
It seems to me we're seeing we're finding more,
even so-called Goldilocks planets now.
- Oh, yeah, well, I mean what's it been, 25 years?
How long have we had exoplanets?
It's finding any star systems beyond the Sun
is a relatively recent thing.
- Is that done through transits,
where you can see them crossing the face of a star?
Or is there more analysis to it?
- Well, certainly, that's one way.
Yeah, that's been one of the more productive methods
of finding exoplanets.
There are other techniques as well
that are less direct
than actually seeing that eclipse.
But the era of direct imaging of planets around stars
is, the Webb has been able to do this in a couple of cases.
We may be on the verge of that,
of seeing these things,
at least a few of them directly around stars.
But very often,
when you mention a Goldilocks planet,
you're looking for a--
This is a planet that's at the right distance from its star,
that it can have liquid water on it.
That's usually what the criterion is.
And there will inevitably be more of those
just because the number,
the total number of known exoplanets,
whether they're Goldilocks planets or not, is going up.
So, yeah, there are more and more of those.
But the planet detecting programs are going great guns.
And that's a very exciting thing these days
for astronomers too.
- One of the things that has long set Washburn apart
from so many other observatories
is the role it has in public engagement.
And can you give us kind of a history of that
and what that public engagement has produced,
other than just people fascinated by looking at stars?
- So when Edward Holden got to the observatory
as the second director,
he decided that he was going to maintain a public observatory.
So the observatory was built with an infusion of money
from Governor Washburn.
But also, Washburn helped Bascom ensure
that the telescope was supported by the state legislature.
So at the time, it was at the amount of $3,000 per year.
The state supported basically the science
that happened at the observatory.
Laugh because I think it's the first example
of public-private partnership [laughing] at UW-Madison
or the University of Wisconsin.
But Holden really valued the idea of a public observatory.
And so, so long as the observatory wasn't in use
for, specifically for a scientific mission,
it was opened to the public on, I think,
the first and third Wednesdays.
- From the very beginning. - From the very beginning.
- Wednesdays was the day from the beginning.
- Yes, and it continues. - From 1881.
- Yeah, to this day.
So from 1881 until today,
Washburn Observatory is a place that people can come
and look through the refractor.
- And then, of course,
there have always been special occasions.
When Halley's Comet came by in 1910
and people were clamoring to see it.
And this happens today too, when there's some--
- Norman: Well, it came back in 1985, right?
- Jim: It did, although that was not so good
as we couldn't really see it as well as they could in 1910.
So I don't think anybody tried to see
the Halley's Comet with the Washburn telescope.
Somebody might have, but-- - An atmospheric difference?
- Mostly orbital difference.
- I mean, it was just way-- - Oh, just a different position.
- Favored southern observers,
way over northern observers in the 1986.
But the point is that the--
When there are these things of enormous interest,
we still open up the observatory extra nights,
and they had to open up lots of extra nights
during 1910 when there were,
when Halley's Comet was in the press and in the sky.
And this still happens from time to time.
But yeah, the regular nights
are the first and third Wednesday nights,
weather permitting, of course.
And then in recent years,
the astronomy department has been doing
every Wednesday night, June, July, and August.
So once again, weather permitting.
So this is a long tradition here.
And it's, you asked about in addition
to just letting people look through the sky,
it's been great for the students and the astronomers,
especially our graduate students who run that program now,
to have an aspect of teaching astronomy
and then that way, to meet the public
and answer their questions and help them go back
to "eyeball at the eyepiece" astronomy
and enjoy the sorts of sights there are to see in the sky.
- So if I were to stop by Washburn
on some Wednesday evening,
what would I most likely get to see?
- Well, that would, that'll vary with the time of year
and what sort of things are available.
If there are bright planets, then those are very popular.
Everybody wants to see Saturn or Jupiter,
or if the Moon is up.
And the whole evening can go by and you never look at anything
but whatever planets and the Moon are up there.
- Norman: Regular planets. - Yeah, well--
- Well, some of Jupiter's moons, and that's always fun to count
how many you can see at any given time.
- So those would be typical.
But then, once you get past planets
or if you don't have any planets that night,
which certainly happens, the telescope
is very well-adapted to things like binary stars,
star clusters, and some bright galaxies.
The sky here in the city is too bright now
for galaxies to be too much.
Or nebulas like the image
that we had of the Lagoon Nebula or the Trifid Nebula.
Those are low in the south for us,
but we can pick those up.
To the eye, they don't look anything like those images.
You don't see any colors in them or anything along that line,
but we can introduce the people to a wide range
of astronomical objects with that fine old telescope.
- There's a wonderful juxtaposition
of Washburn Observatory
that I don't think you would find anywhere else
in the country, maybe not in the world,
which says so much about astronomy,
or at least people looking at the sky,
looking at the stars and the planets
over a long period of time.
And Washburn is actually on a hillside
that had three effigy mounds on it,
which clearly had some sky significance to the builders.
And here it's right next to Washburn.
What kind of a sense do you get when you go up there
and see that effigy mound right next to the observatory?
- Kelly: I think it's a really powerful reminder
that we've, as long as we've been on this earth,
we've been really curious about the night sky
and the connection between earth and water and the heavens.
I think it's a really,
important thing for us to remember that,
though we've talked about sort of
the more recent modern innovations
in technology and in science,
that as long as we've been humans,
we've been fascinated by the stars.
- Jim: It is, as you say.
It's a wonderful juxtaposition to know that
people a thousand years ago,
or whatever the date of the mounds is,
were up there on that hill.
And it was a special enough place to them
to build those mounds.
And they were, must have been aware.
All human cultures have been fascinated by the sky.
And so it's been a special place there
for that distant culture as well as our own.
- Norman: Human curiosity. - Modern, modern.
- Human curiosity carrying over the millennia.
- Yeah. - And you can see it
right there on the hill at Washburn Observatory.
Jim Lattis and Kelly Tyrrell,
it's been a real pleasure looking skyward with you.
- Thank you so much, Norman. - Thank you, Norman.
- They're the co-authors of the book
Chasing the Stars.
I'm Norman Gilliland,
and I hope you can join me next time around
for University Place Presents.
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