W.A. Hiltner and the Beginnings of Modern Astronomy in Chile

Note: Though this website is primarily devoted to the history of the Veblens and Herrontown Woods, there are occasional posts about my astronomer father and Yerkes Observatory--an institution with some parallels to the Institute for Advanced Study.

This post began with a sentence that astronomer Stephen "Shec" Shectman wrote in an email to me about the role my father, W. Albert Hiltner, played in the trajectory of astronomy in the 20th century. 

"Al of course installed the first telescope on Cerro Tololo, while the administrative structure of the observatory was still being set up."

Shec's email got me wondering. How special was that first telescope? Cerro Tololo is a mountain in northern Chile, 8000 feet up in the Atacama Desert--an extremely dry stretch of the Andes where half of the world's land-based astronomical research is now conducted, with more giant telescopes under construction. Where did Cerro Tololo and that modest telescope sit in the history of astronomy? Was it the first modern telescope in Chile? In South America? In the southern hemisphere?

My brother Bill had recently sent me an old family photo of that very telescope. On one of his trips to the mountain in the 1960s, my father was evidently so excited to start observing that he got the 0.9 meter telescope up and running before a dome had been built to house it. There were no worries about rain in the desert during the dry season. 

In the mid-1960s, my father took our family along on a couple of his trips to Tololo, where telescopes were just beginning to sprout. 

60 years later, seeking to understand that telescope's place in history, I have done some research on telescopes in the southern hemisphere. Many had been built in the north, but the southern skies had gone relatively unstudied. Northern telescopes could not see the center of the galaxy, the Magellanic Clouds, nor countless other celestial objects visible only from the southern hemisphere. One notable telescope in the south was a 36" telescope built in 1903 on San Cristóbal Hill in the middle of Santiago, Chile, by the University of California's Lick Observatory. This telescope would of course have become less and less useful as Santiago grew and light pollution increased. South Africa drew some interest from European and American universities as a site for telescopes, culminating in the construction of the Radcliffe Telescope in 1948. At 74", it was the largest telescope in the Southern Hemisphere at the time. 

During this same stretch, in the first half of the 20th century, many observatories were being built in the north. After founding Yerkes Observatory in 1897, with the world's largest refracting telescope, the great visionary George Hale moved to Caltech in California to build a 100" reflector on Mount Wilson, and the 200" at Mount Palomar. Yerkes looked to western Texas for darker skies and a larger telescope. My father would take us along on his trips to Texas to use the 80" at McDonald Observatory. 

The sleepy pace of astronomy in the southern hemisphere ended in 1958. The story begins, surprisingly, at Yerkes Observatory, on the outskirts of a little town called Williams Bay in southeastern Wisconsin, where I grew up. For the first half of the 20th century, rural Wisconsin offered an adequate escape from urban light pollution, and enough dark, clear, photometric nights to advance knowledge. Even in the 1960s, most of the University of Chicago's astronomy faculty lived at Yerkes, widely regarded as "the birthplace of astrophysics." 

My father would serve as director of Yerkes for a stretch in the 1960s, but in 1958, a prominent astronomer by the name of Gerard Kuiper was director. That was the year Yerkes also served as birthplace for what would prove to be a great blossoming of astronomy along that extraordinary stretch of desert extending north from Chile into Peru. Astronomer Frank Edmondson tells the story in his book about the evolution of AURA--a fortuitous acronym for the Association of Universities for Research in Astronomy. Throughout my father's career, from the 1940s through the 1980s, he participated in an ongoing search for drier, darker corners of the planet to collect light from the universe. His interest shifted from rural Wisconsin to drier parts of the country--McDonald Observatory in Texas, and Kitt Peak outside Tucson, AZ--with the desert of northern Chile beckoning as a final frontier for land-based astronomy. 

In May of 1958, a Chilean astronomer named Federico Rutllant traveled to the U.S. "seeking help to build up astronomy in Chile."  His timing was auspicious. The Russian's launch of Sputnick in 1957 had sent shockwaves through America, focusing new interest on the heavens above and greatly expanding government funding of research. Yet Rutillant aroused little interest during his visits to west coast observatories. Only when he came to Yerkes and met with Gerard Kuiper and my father did he get the response he sought.

According to my father, "The three of us, that is Kuiper and Rutllant and myself, were sitting in Kuiper's office. And Rutllant at that time, at least it was my impression, was very discouraged about getting any cooperation from American institutions to build an observatory in Chile. And I can so well recall in our discussion my remarking to Kuiper, 'Well, how about Chicago trying it?" 

It turned out that the University of Chicago was not in a position to fund it, nor was AURA, which had just formed the year before. Fortunately, just days before Rutllant's visit to Yerkes, my father's proposal for a research project entitled "Galactic Field Studies" had been submitted to the Air Force. That proposal was ultimately adapted by the Air Force to fund an astronomical research station in Chile. 

Now, it's one thing to find interest and secure funding, but another altogether to figure out where to site an observatory. The Atacama Desert offers many mountains to choose from. An astronomer named Jurgen Stock was sent by AURA to test the skies above and sources of all important water below. Among the many factors, a mountain must be low enough to be accessible in winter, but high enough to stand above the fog that reaches inland from the coast each night. 7-8,000 feet proved ideal.

According to a timeline of AURA, in August 1961 a 0.41-m telescope was hauled on mule back up the 8000 foot mountain, Cerro Tololo, to test the site. An article by Hilmar Duerbeck, National and International Astronomical Activities in Chile 1842-2002, says the mountain was officially chosen for the Cerro Tololo Inter-American Observatory in 1962, and the first small telescopes went into operation in 1965.

My father took the family along on a couple of his many trips. We would stay in a house called Casa Tres on a hill overlooking La Serena, the coastal town where the observatory had its headquarters, and sometimes head up to the mountain. It was a two hour trip on dirt roads with steep, breathtaking, nerve-racking dropoffs as we wound our way 8000 feet up the mountain. My brother and I would hold Kleenex over our noses in an attempt to filter out the dust seeping up through the floorboards of the van. If it was night, jack rabbits with outsized ears would scamper off the road ahead of us. A southern hemisphere's version of a saguaro cactus stood like a sentinel at the final turn before we reached the top.

My older brother Bill remembers the evolution of the observatory this way: "Dad had been making trips there for some time. I don't know the sequence of events, but at some point a road was cut (I recall Dad talking about how big the bulldozer was) and the top of the mountain was blown off and leveled. When we were there in 1966 there were already several small telescopes installed. If I remember, two 16", a 36" (probably the one in the photo), and a Schmidt camera. All were under domes. They were probably relocated from U.S. observatories, and used for final site evaluation."

That conflicts with the account in Frank Edmonson's book, which has the 36" being installed a year later:

"During Hiltner's third period as Acting Director, January-May 1967, he had the 36" telescope mounted in the open on a concrete pad in order to carry out observations while the dome was being installed. There was little risk in doing this because it never rained at this time of year."

That year my father also hired Puerto Rican astronomer Victor Blanco as the second director of the Cerro Tololo Inter-American Observatory, ushering in 14 years of his highly capable leadership. Blanco oversaw installation of a 4 meter telescope that would become the most productive telescope in the southern hemisphere during that era. The telescope, sister to the 4 meter on Kitt Peak in Arizona, was later named in Victor Blanco's honor.

AURA's success in establishing the first observatory in the Atacama Desert in Chile drew the interest of European nations that had previously focused their interest on South Africa. Both the climate and the political climate in South Africa were problematic, however, and in 1963, a mountain north of Tololo called La Silla was chosen for the European Southern Observatory (ESO). 

Carnegie, which had been unreceptive in 1958, also realized it needed to invest in an observatory in the desert of northern Chile to stay competitive. During our visits to Cerro Tololo in the mid-1960s, we'd sometimes drive to the next mountain over, Cerro Morado, where an astronomer named John Irwin (tall man on the left in the photo) was living with his wife. Only now, researching the story sixty years later, do I realize his job there was to find a suitable mountain for Carnegie's observatory. In 1966, he found the right mountain, named Las Campanas for the bell-like sound some of the rocks make when struck.

My research left some questions. Was that 0.9 meter telescope my father got up and running, reportedly in March of 1967, a first in some way for astronomy in the Chilean desert? ESO's timeline says their 1 meter telescope on La Silla "witnessed first light" in November of 1966, but that seems a stretch if the road to the mountain had only been completed earlier in the same year. 

Another interesting tidbit is a story of La Silla stating that Gerard Kuiper made the "first explorations of the Andes" in March of 1959. Might my father have been part of that initial expedition? 

Other great observatories have since been built in northern Chile, named for the mountains they were built upon. John Irwin participated in initial site selection for Cerro Pachon, close to Tololo and home of the Vera Rubin telescope. In the 1980s, my father was project manager for the Magellan Telescopes on Las Campanas. ESO built another observatory eight hours north at Paranal.

Astronomical facilities in northern Chile continue to grow, taking on massive dimensions. The Vera Rubin telescope is 8.4 meters across. The Giant Magellan Telescope on Las Campanas will combine seven mirrors, each 8.4 meters across. And the Extremely Large Telescope being built by ESO will have a combined diameter of 39 meters.

And it all began with a fortuitous meeting at Yerkes Observatory in 1958 of Chilean astronomer Federico Rutllant, Gerard Kuiper, and my father, W.A. Hiltner.

Fun fact: In the 1980s, the famed educator Neil deGrasse Tyson would do research for his dissertation on the 0.9 meter telescope at Tololo.

The author, sixty years ago, who at the time specialized mostly in throwing rocks off the side of the mountain.

How Sailing Helped Hatch Yerkes Observatory's 41" Telescope

Exploration of Veblen House history got me interested in the history of my father and his colleagues in physics and astronomy, which includes some Nobel Peace Prize winners and pioneering women:

There are two scientists named Albert that I know of who loved to sail. One was Albert Einstein, who discovered his now legendary love for sailing at the age of 18 in Switzerland, around the time he was hatching his revolutionary theories of the universe.

The other was my father, astronomer W. Albert Hiltner, whose love of sailing grew during his years at Yerkes Observatory, just up the hill from beautiful Lake Geneva in Wisconsin. Neither Albert was discouraged by an inability to swim, though my father at least wore a life jacket, and finally learned to swim at age 60. While my father took to racing sailboats later in life, Einstein actually savored the lulls, when he could pull out his notebook and jot down ideas, or, as described in one article, listen "to the gentle waves endlessly lapping against the side of the boat".

And there are two telescopes I know of that came into being through a mutual love of sailing. Thanks to retired astronomer Adolf Witt, we now know the story. The two telescopes are twins, separated at birth. One resides in the south dome at the world-famous Yerkes Observatory, known as the birthplace of astrophysics, the other at the University of Toledo in Ohio. 

The idea for their creation likely came when my father was visiting colleague John Turin to sail on Lake Erie. Both had gotten their PhD's at the University of Michigan, with my father going on to become director of Yerkes Observatory. John Turin became chair of physics and astronomy at UT. 

What made the two telescopes special was the material used to make the mirrors. Ordinary glass can expand or contract, depending on the temperature inside the observatory's dome. But Owens Illinois in Toledo came up with a glass-ceramic material called CERVIT that could be ground to a precise shape like regular glass, but would not warp as the temperature changed. This zero-expansion quality allowed the telescopes to capture more precise images in the heat of summer and cold of winter.

My father combined a passion for astronomical research with a drive to improve the instrumentation available for astronomers. This played out in the 1960s when he installed two new telescopes at Yerkes and updated the famous 40" refractor in the big dome. In the '60s and '70s, he worked to build new telescopes at Kitt Peak in Arizona and Cerro Tololo in northern Chile.

In the 1980s, after retiring from the University of Michigan, he became project manager at CalTech for the design of two 6.5 meter Magellan Telescopes--twins that now live together in a building on top of Las Campanas in Chile. The 6.5 meters refers to the width of the mirror.

For astronomy afficionados, I include Adolf Witt's full telling of the story of the twin 41" reflecting telescopes below. Full disclosure: they are actually 40" reflectors, but are nicknamed 41" to avoid confusion with the famed 40" refracting telescope at Yerkes.

Googling physicists who love sailing brings up Einstein, of course, but also a Nobel Prize-winning physicist by the name of Anton Zeilinger. In an interview, he describes his love of sailing this way:

"It’s the answer to life, the universe and everything. You go there and you sail and you are happy and everything is fine. Sailing is very special. I was thinking about why sailing is so special for me. It’s probably because when you sail, you are completely occupied by that activity. Both your mind and your body. You have no time to worry about anything else. You are completely immersed in something. That’s it."

Total immersion--mental and physical--is certainly a big part of sailing's appeal. One is continuously responding to the wind, coordinating tiller and sail while keeping an eye on the weather and anticipating what's up ahead. What I love, too, is how sailing requires collaborating with nature, not seeking to dominate but instead accepting and working with what the elements offer on that day in that moment. Both sailing and observing required a keen awareness of the elements. Was it a good day to hike down to the lake for a sail? Would my father later head up to the observatory to observe that night? The answer was always above us, in the play of wind in the tops of the trees, or the clarity of the sky. At Yerkes in the 1950s and '60s, my father would catch the wind in a sail on Lake Geneva to move the boat forward, then stay up all night catching light in a telescope to move astronomy forward. He could not control the elements, but made the best of what wind and light came his way.

The interview with Anton Zeilinger also touches on randomness, which Zeilinger says is "a very nice feature of the universe." Funny, then, to find an old family photo with my father standing behind the stripped down remains of the C-Scow we sailed for many years, named "Random." Each spring, there'd be the wonderful smells of sanded cedar and varnish as the boat was prepped for another year, until the leaks and the rot made it better fit for one last journey to join the Homecoming bonfire.

One other thing about John Turin and sailing. After he died prematurely of an illness in 1973, his wife Sybil became a leader in helping women become part of the sailing world. As this Toledo Blade article describes,

If there is a glass ceiling in the business world, then there was a taut piece of canvas stretched across much of the sailing world. It kept women out of some clubs and made it difficult for them to take part in competitive racing in others.

 Sybil Turin helped change that. 

For anyone curious about Yerkes Observatory in the 1960s, wants to learn more about the twin 41" telescopes, or read about Sybil's breaking of barriers for women in sailing, click on "read more," below. 

Astronomy and Family: The 1945 Eclipse

This post comes as many prepare to head off to hopefully witness a total eclipse tomorrow, April 8, 2024.

There are a couple Princeton connections to the total eclipse that took place on July 9, 1945--one being a "Princeton Party", presumably from Princeton, that journeyed to Montana for the event. The other has to do with a renowned astronomer named Chandrasekhar, whom Princeton sought to add to its faculty the following year. But I primarily want to tell of a familial connection I have to that eclipse nearly 80 years ago.

From a biography of my father, astronomer Al Hiltner: "In 1945 Hiltner and Chandrasekhar went to Canada to photograph a total eclipse of the sun. This represented a unique collaboration with the theorist Chandrasekhar, for I believe that the paper showing those photographs remains the only observational research paper ever published by Subrahmanyan Chandrasekhar." My father had just joined Chandra, a future Nobel Prize winner, on the faculty at the University of Chicago's Yerkes Observatory.

I found these photos, probably taken by my father, online. That may well be the family tent in the background, more often used for canoe trips, with Chandra standing in the foreground, maintaining the formality of a suit in the outback of Manitoba, Canada. 

They had chosen to set up on "a slight ridge commanding a clear view of the eastern sky some five miles southeast of Pine River."

It looks like they even installed a fence around their site, perhaps to discourage cattle or other animals from disturbing their equipment.

The combination of all their preparations and some good luck made for a successful mission:

"On July 9th morning the eastern sky was cloudy, but the drifting clouds produced a clear region some twenty-five minutes before totality. The entire sky clouded over again half an hour later."

By July 1945, Germany had surrendered and Japan would soon thereafter. According to wikipedia, Chandra worked in the Ballistics Research Laboratory at Aberdeen Proving Grounds during WW II. He would surely have collaborated with Veblen, who oversaw scientific work at Aberdeen. That Princeton offered Chandra a position one year later, after Veblen's close friend, Henry Norris Russell, retired, may not be coincidental. Princeton's interest resulted in the doubling of Chandra's salary, as U. of Chicago increased his pay to match Princeton's offer. 

Vera Rubin--The Courage of Her Curiosity

A friend sent an article from the Atlantic Magazine announcing that a telescope is being renamed in honor of the great astronomer Vera Rubin. That article in turn has led to autobiographies by Ruben and another great astronomer, Margaret Burbidge, both of whose careers intersected with my father's.

Largely government funded, the Vera C. Rubin Observatory is the first national U.S. telescope to be named after a woman. Though the story has no direct connection to Oswald Veblen, it is congruent with his heritage and legacy. In the late 1800s, when women had far fewer options for pursuing higher education, Veblen's parents and grandparents sent all their children to college, daughters and sons alike. One generation attended Carlton College, the next the University of Iowa, which has the distinction of being the first public co-educational university in the U.S..

Oswald would take that familial heritage into his career in Princeton, where he used his position of influence to help the great mathematician Emmy Noether, displaced after the Nazi takeover in Germany find employment in the U.S.. Veblen took the lead in helping find her a position at Bryn Mawr and inviting her to be a Visitor at the IAS. By that time, 1933, Veblen had left Princeton University to become the first faculty member at the Institute for Advanced Study, which was non-discriminatory from its inception. Princeton University, on the other hand, was men-only until 1975. When Vera Rubin expressed an interest in attending Princeton for graduate studies in 1948, the university would not even send her an application. Princeton ultimately came around, giving her an honorary degree in 2005.

Vera Rubin, who was a lifelong advocate for women in science, was herself inspired by a woman astronomer born 110 years earlier than herself, Maria Mitchell. Demonstrating the power of history and legacy, Rubin reportedly chose to attend Vassar College because Mitchell had been a professor of astronomy there 80 years prior.

The story of Vera Rubin has its most direct connection here to my own family's history. The first connection I discovered is geographical. Cerro Pachon, the mountain in northern Chile where the Vera C. Rubin Observatory is nearing completion, is only a half hour from Cerro Tololo, where I spent some free-range halcyon days as a boy, exploring the desert and tossing rocks off the edge of the mountain while my father, W. A. Hiltner, was on extended observing runs.

Another connection is also through my father's career, which intersected to some extent with Vera Rubin's, as in this 1971 photo with my father on the left and Vera Rubin's on the right (courtesy of the AIP Emilio Segrè Visual Archives, Dorothy Crawford Collection), and to a much greater extent with the work of astronomer Margaret Burbidge. A NY Times obituary from 2016 states that "Dr. Rubin, along with Margaret Burbidge ..., was a “guiding light” for a generation of female astronomers."

If it's possible to encapsulate major contributions, "Rubin’s work in the 1970s provided convincing evidence that dark matter existed," while Margaret Burbidge and her husband and fellow astronomer Geoff Burbidge, "were best known for their work in the mid-1950s describing how stars synthesize nearly all the chemical elements in the universe, from carbon and iron to lead and uranium."

The Burbidges, originally from England, along with two other great scientists, Fred Hoyle and William Fowler, stirred things up in the astronomy world with their progressive thinking. Their names were very familiar in our household, growing up.

In reading the interviews and autobiographies of Vera Rubin and Margaret Burbidge, I was gratified to discover the role my father played in Margaret's career early on. This was at a time when many institutions of higher education considered astronomy a men-only profession. Margaret's application in 1945 for a Carnegie Fellowship in Pasadena was rejected due to her being a woman, and in 1948 Vera Rubin, as mentioned, was not even allowed to apply for graduate studies at Princeton University. The largest telescope, at Mt. Palomar, would be unavailable for women until Rubin broke through that barrier in the mid-60s, famously taping the figure of a skirt on the bathroom door to create a women's bathroom.

There were no such restrictions at the University of Chicago's department of astronomy, and its two renowned observatories in Wisconsin and Texas. My father was on the faculty at U. of Chicago, based at Yerkes Observatory in Wisconsin. In 1951, he was able to arrange funding for Margaret to take a position there, and later came up with a way for her to get coveted observing time on the 82" telescope at McDonald's Observatory in Texas. From her autobiographical essay:

Before the cold Yerkes winter set in, Geoff and I prepared a program to submit for McDonald observing time ... But the time for submission was past; since we wanted winter time when the December Milky Way was up, we were too late. Here the never-to-be-forgotten kindness of Al Hiltner came to our rescue. He had set me to work on prevention of internal reflections and scattered light in a spectrometer for calibrating coude plates at McDonald, and he had a month (I believe) scheduled for photometry at McDonald. He said there would be many nonphotometric nights during this period, and if Geoff and I could get ourselves to McDonald ... we could have the non-photometric nights for spectroscopy ...

Gratifying, too, was reading Burbidge's and Rubin's descriptions of their burgeoning curiosity as children. It brought back memories of growing up among astronomers who loved their work, in a family where curiosity and creativity were valued. Science for me has always been about beauty and exploring the magnificence of creation. 

 Vera Rubin describes her curiosity about the world and her active imagination:

As a youngster, more questions followed. Why did the pictures on my bedroom wall jump back and forth on each side of my finger as I lay in bed blinking my eyes? How did water drops in a stream know on which side of a rock to pass? Could I, a lazy child, devise a street on which one sidewalk went uphill and one side downhill, so that I could always walk downhill? A little later, the questions were more conventional. How many license plates can be made with three numbers and two letters? This puzzle I solved as we drove to our new home in Washington, D.C.

Margaret Burbidge describes it this way:

At age 4, before beginning school, my first view of the beauty of stars in the summer sky during a night-time boat crossing from England to France was the earliest step toward a lifetime love of astronomy. Then I developed an early interest in arithmetic and in numbers (especially large ones with many powers of ten to write out and contemplate); this began in my first years in school. I had learnt to read before going to school, so books were a continuing delight. My parents gave me books written for children on all the natural sciences, and reading these was coupled with both my mother's and father's willingness to show me and tell me about the wonders of the seashore, of flowers, plants, and trees (both my sister and I became passionate tree climbers throughout Hampstead Heath, near which we lived). My love of flowers is lifelong, and has been inherited by my own daughter.

And later in her youth:

When I was 12 or 13 years old, my grandfather gave me Sir James Jeans' popular books on astronomy. Suddenly, I saw my fascination with the stars, born at age 4, linked to my other delight, large numbers. That the nearest star is 26,000,000,000,000 miles away revived those excitements of my first school years (although falling short of my then favorite contemplation, 1 followed by 36 zeros). I decided then and there that the occupation I most wanted to engage in "when I was grown up" was to determine the distances of the stars. My mother recalled telling me, as I lay on my stomach on the floor reading the wonders described by Jeans, that it was bedtime, and that I pleaded for a little more time: "Mum, it's so exciting!" 

Combined with the intellectual and emotional delight--and resonating with Veblen's hiking and woodchopping ways--was the pleasure Margaret found in the physicality of exploration, whether climbing trees as a kid or spending nights in the dome of an observatory with the heavens above. My father came to astronomy after growing up on a farm, and brought that appetite for physical work and resilience against the elements with him, donning insulated underwear for long nights in the Wisconsin winter, where the best nights for observing were also the coldest.

Margaret put it this way:

I often think about the joys of work in an open dome, under the stars, next to the telescope, joys denied to most younger astronomers and students who must sit in a warm console room, facing a television guiding screen and many complex computer interfaces, well removed from the telescope itself. 

Smuggling that avid curiosity and sense of wonder into adulthood not only enriched their lives. It likely helped Vera Rubin and Margaret Burbidge break through (or find ways around) the barriers they encountered as women in a profession dominated by men. One sentence in Vera Rubin's autobiography stood out. In 1960, Rubin had just arrived in the Netherlands for an International Summer Course in Science. There she heard lectures from some of the world's greatest astronomers--Jan Oort and the Burbidges among them. "Initially," she wrote, "Oort terrified me, but I soon had too many questions to stay silent."

Thus the title of this post: The Courage of Her Curiosity. In the 21st century, when so many people hold convictions, sure they are right when surely they are wrong, we would do well to turn to curiosity as a better source of courage.

(Vera Rubin posing with Kitt Peak Observatory in the background--an institution my father played an important role in developing, and where a telescope bears his name. It was at Kitt Peak in 1968 that Vera Rubin and Kent Ford made discoveries that would transform our understanding of the universe. Thanks to AIP Emilio Segrè Visual Archives for these photos.)