Allan Sandage, 1926 – 2010

By Phil Plait | November 15, 2010 5:57 pm

Astronomy has lost another pioneering scientist: Allan Sandage, who died Saturday.

Sandage worked with Hubble himself on trying to determine the size and scale of the Universe. Perhaps his greatest contribution to astronomy was refining the Hubble Constant, a measure of how fast the Universe is expanding. In a seminal paper published in 1958, he set the expansion rate at 75 km/sec per megaparsec. That means that for every megaparsec (3.26 million light years) farther away a galaxy is, it appears to be moving away from us an additional 75 km/sec. So a galaxy 100 Mpc away would recede at 7500 km/sec.

This term relates to the age of the Universe. Until this new measurement, it was thought the Universe was much younger. The lower the number, the greater the age of the Universe, and Sandage’s new number meant the Universe was about 15 billion years old. Later, Sandage thought the Universe might be even older, but using much improved methods over the years, we now think Hubble’s constant is about 70 km/sec/Mpc, very close to what Sandage estimated in 1958.

I wish I had met Sandage, but I never did. His contributions to cosmology made him one of the greatest scientists of the 20th century.


Comments (25)

  1. David

    This is a great loss. It always saddens me deeply to see the death of a great mind.

  2. Tod R. Lauer

    A great light has gone out. Sandage made seminal contributions to just about all fields of astronomy, but would best be known as the father of modern observational astronomy, if the title is not awarded to Hubble, himself. His link to Hubble has always fascinated me – the great Hubble passed on his legacy to one more than worthy of taking it vastly further. The quality and quantity of his work was immensely high. For a time he could be considered to be the greatest living astronomer. We will not see his likes again.

  3. Brian

    Allan Sandage was a central character in Dennis Overbye’s Lonely Hearts of the Cosmos. I felt Overbye saw him as the one of the last surviving links to the age when astronomy meant staying up all night babysitting a telescope in order to make a 10-hour exposure of a distant galaxy.

  4. Madwoman in the Attic

    Lucky to know him – his warmth, humor and humility belied his exalted status – a lovely, lovely man

  5. Monkey

    Weep not for that which is lost,
    Take solace in that which was left.

    We all have to bow out at some point. It was a great loss, but what he left will speak of him for time to come.

  6. Nobody who contributes so much to science can ever really die. His legacy will last as long as humans study the stars.

  7. R. Michael Rich

    Allan Sandage was a giant figure of 20th century astronomy, a living bridge between Hubble’s pioneering discoveries and the modern era of electronic detectors. Among Sandage’s major achievements are the first color-magnitude diagrams of open and globular clusters that helped to confirm models of stellar evolution. His work on the distance scale and galaxies was profound and comprehensive. His most cited work, with Olin Eggen and Donald Lynden-bell, sought to trace the galaxy’s formation from the orbits and composition of halo stars; a paper that remains highly influential even today. With regard to the public, Sandage should properly be given equal billing with his better known thesis advisor, Edwin Hubble. With Sandage’s loss, we lost a critical living link in the chain back to one of the great achievements of the American Century- the birth of modern observational astronomy, and the discovery of the cosmic expansion. An era has passed.

  8. M. Young

    It’s weird. I sometimes forget what a young science modern astronomy is, and how many of the people that have made fundamental advances are still around and kicking. Until they’re not. RIP Sandage.

  9. Messier Tidy Upper

    Condolences and sympathies to his friends and family.

    Allan Sandage will be remembered and he will be missed. :-(

    For me, I never had the honour of meeting him in person but I’ll always remember reading about Sandage’s clash with New Zealander Gerard Gilmore over the origin and structure of our Milky Way in Ken Croswell’s excellent book ‘The Alchemy of the Heavens’ where Sandage along with others was interviewed. Sandage came over quite well there despite being somewhat on the “wrong” side of that particular argument – although he was certainly on the right side of many other ones! 😉

  10. Pete Jackson

    I also wish that I had met him. He apparently was not big on going to meetings, preferring to let his work speak for him.

  11. Messier Tidy Upper

    See also :

    @5. J. Major Says:

    Nobody who contributes so much to science can ever really die. His legacy will last as long as humans study the stars.

    Especially the Hubble-Sandage variables.

    Or this asteroid named in his honour :

    Which looks like it very nearly crosses the orbit of Mars.

    Plus “blue stragglers” which he discovered in in 1953 and quasars which he helped discover as well.

  12. MikeS

    I met him once as a graduate student. We discussed religion, actually.

    Funny story: we were having a conference and someone put up a plot of the early Hubble constants, which were all somewhere in the range of several hundred. From the back of the room, we hear Sandage say, “Mine was still the lowest!”

  13. Anchor

    Allan Sandage was a giant.

    The emergence of the infant modern science of cosmology is indebted to his extraordinarily careful and precise work. He was Observer Par Excellence. He was a good and very valuable anchor (vis MikeS’ rememberance at that conference: “Mine’s still the lowest!”).

    Oh I feel old.

  14. Jearley

    The mother of one of my students worked as Sandage’s secretary, and told me that he was a great guy, and good to work for. Ho people treat their co-workers is a good way to view them as a person, and Sandage comes out as one of the good ones. I’m sorry that he has gone, but his works continues to speak for him.

  15. I had the pleasure of hearing him lecture (together with Rich Kron and Malcolm Longair) at the 1993 Saas-Fee school. Interesting, especially from a historical perspective (“When I started out, computers were about 20 years old and usually female.”), but bitterness and contempt for the high-value camp was obvious. Surprisingly, his main motivation for “knowing” that H had to have a low value was that “grand unification” firmly predicts Omega=1 and thus the Einstein-de Sitter model (lambda was just ignored) which means that a low value of H is required to make the universe as old as globular clusters etc indicate that it is. I don’t know if he really thought observations indicate low H (he actually championed “42″ in one paper!) and this tended to make him believe in Rocky-Kolb-style cardboard inflation or vice versa. Probably a bit of both, in a vicious circle. He sort of reminded me of Bill Haley playing “Rock Around the Clock” even after Sergeant Pepper had appeared. 😐

  16. You will be visited by the ghost of Sandage for linking his name to a Hubble constant anywhere near 75 km/s/Mpc!

  17. Nicholas Suntzeff

    Allan Sandage was the greatest observational astronomer of the 20th century. I will deeply miss him, and all the prickly conversations we had about cosmology, and the more relaxed conversations about everything else – RR Lyraes, open clusters, globular clusters, ELS, Tully Fisher, main sequence fitting, second parameter, Oosterhoff effect, ultraviolet excesses, the Galactic halo, thick disks … and religion. He was much more than just an observational cosmologist – he discovered much of what we take for granted, such that we don’t even refer to his papers anymore. For instance, Sandage was the key astronomer that tranlated the obscure predictions of cosmology from theorists like Tolman, into measurements that observers could make. In 1986, he urged me to take up the work on supernovae as distance indicators, and I had the good fortune of teaming up with Mark Phillips and Mario Hamuy to work on the subject, and later Brian Schmidt. Sandage had the deepest knowledge of astronomy than anyone I know, and tremendous respect for its history. I imagine if there is a heaven, Allan and Olin Eggen will be talking right now about how the only thing the young astronomers want from the older astronomers is their finding charts.

  18. Kurt Kohler

    I’m not sure this quite qualifies as meeting Dr. Sandage, but in the early 60’s he spoke about quasars to the students at Harvey Mudd College. Quasars were a very new phenomenon at that time, so few of us had ever even heard of them. The talk was fascinating, and understandable even to a sophomore like me. It was a view into the world of “real” science because so little was understood at that time about the true nature of these mysterious objects. After that, due to many student requests, he was asked repeatedly to return, but unfortunately it never happened at least while I was a student.

  19. Lest my comment above sound too negative, let me note that Sandage’s Saas-Fee lectures were quite enjoyable (especially considering that he is not actually a lecturer), comparable to those of Longair (which is saying a lot). Buy the book!

    You can see parts of it here:

    A similar review is available online:

  20. Harry Nussbaumer

    In 1993 Allan Sandage was awarded the Tomalla prize (contributions to general relativity and gravity) for his lifelong efforts in measuring the dynamics of the Universe. There I met him for the first time personally at the banquet in his honour. When in 2008 I wrote in collaboration with Lydia Bieri the book “Discovering the Expanding Universe”, I sent the completed draft to Sandage, asking him for his criticism. I was greatly relieved when I got his favourable answer, and I later suggested that he should write the foreword. This he did. His reminiscences have a very personal touch: “Fate has permitted a career for me in cosmology by the accident of timing. I was of such an age to fit into the transition period between the pioneer Mount Wilson observers of Hubble, Humason, Minkowski and Baade […] and the modern theoretical cosmologists, …”. He was proud and happy to have played the part which he played. With his death a fulfilled life has ended.

  21. Messier Tidy Upper

    Some Allan Sandage Quotes

    Allan Sandage was interviewed by Ken Croswell which noted how he began his astronomical career as a keen amateur before moving into the profesional realm under two of the greatest astronomers of the last century, Edwin Hubble and Walter Baade :

    Sandage first encountered astronomy in third grade when peering through another boy’s telescope. “I’ve known since that time ,”said Sandage, “that there was no other career.” Soon after Sandage began charting sunspots, watching meteor showers and observing the flickering of variable stars. During his junior and senior years at the university of Illinois, he participated in a nationwide star-counting program organised by Bart Bok, who had observers study the Milky Way in different constellations. As part of the project Sandage examined the constellation Perseus and counted a million stars.

    – Page 120, ‘The Alchemy of the Heavens’, Ken Croswell, Oxford University Press, 1995.

    Sandage on his favourite area of astronomy :

    “I’m really a stellar evolutionist” said Sandage, who today is actually better known for hs work in cosmology, thestudy of the entire universe. “I’m much more interested in stellar evolution than in cosmology. Stellar evolution was the exciting thing for me. It was like the origin of the species, except this was the origin of the H-R diagram. What would we know about the Milky Way, and the formation of it, if the theory of stellar evolution or the explanation of the H-R diagram or the age dating of star clusters were not possible?”
    – Page 121, ‘The Alchemy of the Heavens’, Ken Croswell, Oxford University Press, 1995.

    & Croswell’s book especially covered the clash over the famous ELS theory of our Milky Way’s formation (named for its authors, Olin Eggen, Donald L,/b>ynden-Bell & Allan Sandage) which with a a later rival theory proposed by Leonard Searle and Robert Zinn.

    “He [Sandage] is a very worthy adversary,” [Bruce] Carney said, “and a man of very broad knowledge.When you write a paper that’s challenging what he’s done, you know you’ve got to have it backed up by good dtata and a thorough analysis.”
    – Page 143, ‘The Alchemy of the Heavens’, Ken Croswell, Oxford University Press, 1995.


    [John Norris] “My working hypothesis is that both ELS and Searle and Zinn hold some truth … ELS were strong on the collapse, in which there should be some dependence on of kinematics [stellar galactic orbits esp. eccentricity in the halo] on [“metals”] abundance…


    “ELS set the ball rolling” said Zinn. “Its a classic paper. … what they discovered in their data was there’s a disk and there’s a halo. They showed that through observations of stars near the Sun you could deduce something about the structure of the disk and halo.”


    [Olin Eggen] “Just the fact that ELS is still being discussed thirty years later is something. Good God,”he said, “in this business thirty years is a lifetime.” As for Sandage he remains ELS’s strongest supporter. At the end of his 1990 paper, he listed six conclusions concerning the Galaxy’s origin and evolution, most of which reiterated ELS. In his sixth and final conclusion,though, Sandage admitted, “The only conclusion not in dispute is that the Galaxy has not always been as we see it today.”
    – Pages 144-145, ‘The Alchemy of the Heavens’, Ken Croswell, Oxford University Press, 1995.

    However Sandage’s model of our Milky Way’s formation fares as more information comes in, he will always be considered one of the giants of astronomy for the age – and as a great, dedicated, bloke too.

  22. Messier Tidy Upper

    Oops. That’s meant to read :

    ELS theory of our Milky Way’s formation named for its authors, Olin Eggen, Donald Lynden-Bell & Allan Sandage

    of course, my apologies.

  23. I first met Allan Sandage when I was in graduate school and ended up doing my PhD thesis with him. He was truly inspirational. His knowledge was encyclopedic. He was the kind of person who stood out in a crowd, but not just because of his booming voice and infectious jolly laugh. He could converse on any topic and always have something interesting to contribute. And it always seemed like he would like nothing more than to have that conversation. Many astronomers referred to him as “uncle Allan,” and he often referred to himself that way in later years. In many ways he was the charming, eccentric, curmudgeonly, uncle about whom everyone has an anecdote.

    He was prolific. He had over 200 publications, some of which are the most highly cited in astronomy. His color-magnitude diagram of the globular cluster M3, published in 1953, represented a fundamental advance in our understanding of how stars evolve and was the first serious measurement of the ages of the oldest stars in our galaxy. He pioneered this kind of study of stellar populations, which is a burgeoning field in astronomy even today.

    In his 1961 paper on “The Ability of the 200-inch Telescope to Discriminate Between Selected World Models,” he laid out a roadmap for making observational measurements of the geometry of the universe. This is one of the all-time classic papers in cosmology and set the agenda for work that continues today with the Hubble Space Telescope. Measuring the expansion rate (the Hubble constant) became a major focus of his later research. Much of what he did in this field was pathbreaking and fundamentally sound. He was not shy in pointing out the flaws in work with which he disagreed, which generally resulted in a heated debate that raised everyone’s game (even if it did stray into polemics from time to time). The fact that the most accurate measurements today — made by Adam Riess and collaborators in 2009 — indicate a a higher value than he preferred, should not diminish his contributions to the field.

    He was a galaxy cartographer and taxonomist par excellence. His “Hubble Atlas of Galaxies” became the essential reference for anyone classifying galaxies and studying their structure. His Revised Shapley-Ames catalog was for many years one of the most important resources for studying nearby galaxies and using them as tracers of large-scale structure. He carried out some of the most extensive surveys of nearby clusters of galaxies, using giant photographic plates from the du Pont telescope in Chile.

    His most cited paper is his 1962 work with Eggen and Lynden-Bell — “Evidence from the motions of old stars that the Galaxy collapsed.” This paper was among the first to use the “fossil record” of the motions of old stars in our galaxy to try to infer something fundamental about the way the galaxy formed. While the views on how this collapse took place have evolved over the years, this, like many of his other papers, set the agenda for an entire field of astrophysics.

    I have heard that Allan could be a difficult person. I never really experienced that, although I did receive a few good-natured criticisms when I strayed into working on the Hubble constant later in my career. When I was working on my PhD, he was an amazing mentor. He read every draft of my thesis chapters within a day or two and wrote voluminous comments in the margins. He told me that the most important lesson he learned when he first got to Carnegie was how important it was to write well. Of course I thought I already did write well, but I learned a lot from him about how to express myself more clearly and how to focus on what was most important. I also remember several conversations lasting many hours where we would move stream-of-consciousness from some nitty-gritty aspect of my thesis to grand ideas for using some property of galaxies as a more accurate probe of the geometry of the universe or a more sensitive test that the expansion of the universe is real. For an impressionable graduate student, the idea that one should be thinking about the universe as a whole — even while focusing on some obscure corner of it — was a fundamental lesson in how to do science.

    More than anyone else I have ever met, Allan Sandage lived astronomy. That may be why he took so many aspects of scientific disagreements so personally. Astronomy has lost one of the all-time greats, and many of us have lost our uncle Allan.

  24. Don Moffatt

    I had the pleasure of meeting Dr. Sandage when I was young, back in April of 1977. I had taken an introductory astronomy course in night school (appropriately enough) at the local college the previous year, when I was in Grade 7, and I was particularly fascinated by the cosmology section of the course. Near the end of the course I was invited to participate in a city-wide science fair, and decided to do a poster explaining the Hubble Constant and the Deceleration Parameter. I wanted to explain how the distances were found to the galaxies, but my textbook didn’t have much information beyond talking about Cepheids, and the college library wasn’t of much help. I lived in a smallish fishing and logging town in Canada.

    My dad’s secretary, Winnie, an amateur scientist herself, had given me a copy of the May 1974 issue featuring Kenneth Weaver’s inspiring article “The Incredible Universe”, which featured Dr. Sandage prominently. I thought he’d be a good person to ask (!) so I wrote him a letter explaining my project and asking how the distances to distant galaxies were found. I wonder if today’s 12 year olds could imagine how thirsty for information and how isolated I was, in those days before the web.

    To my delight, I received an envelope bearing the stamp of Hale Observatories and stuffed with papers, and a gracious, full page letter from Dr. Sandage, which I still have, saying, of astronomy, “It is the greatest profession in the world”. He said I should “try to get the main idea of each paper”, and quoted Churchill when he wrote, “If you find parts you can’t understand or don’t care for, just skip them.” Needless to say, my project was very successful. He also invited me to contact him if I was ever in the neighbourhood.

    In April of 1977 my parents took me out of school for a month for a driving trip to California. I quickly arranged to meet Dr. Sandage at Hale Observatories.

    I arrived, and was told to wait in the magnificent library, where the librarian laid out several books for me to look at (no doubt on instruction to do so). I learned that he had made a similar visit once to Yerkes, when young, to meet Otto Struve, and had been told to wait in the library. To my surprise, what I thought would be a 20 minute, potentially awkward meeting turned into a grand two hour visit with a brilliant, jolly, generous, self-effacing man.

    He was unabashedly passionate about astronomy, and absolutely delighted that I felt the same way. I would describe his speaking style as “emotive” – you knew how he felt about what he was saying. He laughed about his attempt at building a 6″ telescope (like me, he didn’t quite finish the mirror) and we talked about variable stars (a shared passion). He showed me a variety of intriguing things, including what appeared to be a homemade slide viewer on his desk that he let me look through. It contained a view of the Ring Nebula. He said that astronomers once couldn’t figure out for the life of them why planetary nebula so often looked like rings, until someone figured out that they were spherical shells and we were looking through more material when we looked through the edges. He said he looked at it now and then to remind himself how easy it was to fool himself with assumptions.

    The highlight was being taken into the plate vault, where he rummaged around and pulled out long paper envelope with a fragile plate. He extracted enough of it for me to view, turned on a light box, and asked me what it was. “A spectrogram of a galaxy”, I replied. “Yes!” he said enthusiastically. “That’s the spectrogram Hubble was looking at when he realized the universe is expanding.” I carefully gave it back to him and said “That must be the most valuable piece of glass in the world!” He let out a loud guffaw, then said, low and wryly, “Well, some might think so”.

    He met my parents in the parking lot, made some generous comments, and left me with a copy of The Hubble Atlas of Galaxies and a personal inscription in another book, saying “Best of luck in your search for the universe that will be yours in the future”. (Yes, he used the word “for”).

    I last spoke to him in 1990 when I wrote a feature about Edwin Hubble for The Globe and Mail in Canada (I asked him about the spectrogram: it was NGC 7619, and Hubble was confirming Humason’s measurements: NGC 7619 was much more distant than the other galaxies in the sample to that point, and it dramatically confirmed that the slope of the velocity vs. distance graph was linear). Unfortunately, while I did get a degree in astronomy, I was not to become a professional astronomer, but I will never forget how he made an effort to create a wonderful, life-changing experience for a hopeful kid that day on Santa Barbara Street. Rest well, Uncle Allan.

  25. Don Moffatt

    The Kenneth Weaver article was in National Geographic.


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