Professor Wulff Heintz
By Bill Kent
|
|
|
Professor Wulff Heintz |
In our hi-tech world, much of this opposition remains comfortably in the past. No religious leader has forced a modern-day Galileo to recant his findings, and no 20th-century scientist suffered like the monk Giordano Bruno, who, in 1600, was burned at the stake for suggesting that the universe could contain an infinite number of stars with planets whirling around them.
But there remains within the field of scientific endeavor a risk almost as perilous, whose consequences can have devastating results: the possibility that, after years of searching for--and thinking you have found--the truth, a colleague comes to you with results that question your findings.
It is almost ironic that just such a series of events occurred almost 40 years ago at Swarthmore in the Department of Astronomy.
What happened at Swarthmore between Peter Van de Kamp and Wulff Heintz is very significant within the astronomical world because it underscored the unpredictable consequences inherent in all serious re-search," says Paul Halpern, a physics professor at the University of the Sciences in Philadelphia, who wrote about the two Swarthmore astronomers in his 1997 book The Quest for Alien Planets: Exploring Worlds Outside the Solar System. "Stories like this happen often in science, but you don't hear about them much because, let's face it, people like to hear about the upside in making important discoveries, not the downside."
Indeed, the scientific world responded with nothing but praise in 1963, when Van de Kamp, now deceased but then a professor of astronomy and director of the Sproul Observatory, announced that he had sufficient evidence to suggest that he had found a planetary system beyond the solar system.
Though scientists and science fiction writers had assumed that other such systems existed in the universe, the actual discovery of one was like finding astronomy's Holy Grail. The 1963 announcement made Van de Kamp, already a beloved figure on the Swarthmore campus, one of the most famous astronomers in the world.
Sarah Lippincott Zimmerman '42, professor emerita of astronomy and director emerita of the Sproul Observatory, who was Van de Kamp's research associate and later director of the Sproul Observatory, remembers him as "a charming man, interested in a great many things outside of astronomy."
A native of Holland, Van de Kamp came to Swarthmore in 1937 and rapidly established himself as a witty, charismatic personality and virtuoso pianist. He conducted the College orchestra in the 1950s and hosted "Charlie Chaplin Seminars" in Clothier Hall, where he showed films from his collection of Chaplin silent comedies while performing the piano accompaniment. A fan of both classical and American popular music, he composed tunes that he named after the stars he observed. Musical satirist Peter Schickele '57 composed "The Easy Goin' P.V.D.K. Ever-Lovin' Rag" for Van de Kamp's 70th birthday. During his life, many accolades included the naming of an asteroid for Van de Kamp in 1980 by the International Astronomical Union as well as several professional honors.
"He was this wonderfully energetic Dutchman," remembers John Gaustad, the Edward Hicks Magill Professor Emeritus of Astronomy. "He was well known in the field for the work he'd done at Swarthmore in astrometry--the precise measurement of the positions of stars--all of which was excellent and quite reliable. But he was best known for the work he did on Barnard's Star."
The star Van de Kamp chose for his planetary quest was a rather faint red dwarf called Barnard's Star after the astronomer who first charted its rapid motion, Edward Barnard. It is a mere six light years away from Earth and had been previously photographed at the Sproul Observatory as far back as 1916. Beginning in 1937, Van de Kamp took tens of thousands of photographic plate exposures of Barnard's Star as it moved across the night sky. He studied these images, looking for a small perturbation, known as a "wobble," in the star's path. Such a deviation could be caused by the gravitational pull of one or more planets orbiting around the star.
In 1963, after 26 years of research, Van de Kamp announced that a planet about one-and-a-half times the mass of Jupiter was orbiting around Barnard's Star. After announcing his discovery, Van de Kamp, by then 64, went on an international search for a scientist who would teach more astronomy courses at Swarthmore, continue the observatory's long-term astrometric mission of mapping stars, and further his work on Barnard's Star.
The successor Van de Kamp found, Professor Emeritus of Astronomy Wulff Heintz, was almost his opposite in style and temperament. According to Gaustad, Van de Kamp thought that the quiet, serious German research astronomer would faithfully carry on his work. "He never expected the criticism he later got from Heintz, which he considered very disloyal."
Born in Würzburg, Germany, in 1930, Heintz had an early interest in math and science. "I used to love the blackouts during the bombing runs [of World War II] because they made it so much easier to see the stars."
He also developed a profound skepticism when his father, a physician, was persecuted by the Nazis merely because he was employed in a Jewish-run hospital. "The Nazis were liars and bullies. I learned to question everything until I could be sure of the truth with my own eyes and my own mind."
At the University of Munich, Heintz became well known within the field for his work in astrometry, especially in the identification of double stars (to date, he has found some 900 of them and has done significant work in the identification of barely luminous "brown dwarf" stars). He was also eager to teach courses in cosmology--the study of the origin of the universe--and other aspects of astronomy that had not been offered before.
"It seemed a perfect fit for me," recalls Heintz, whose office is now in the observatory's former darkroom. "I had my own studies that I could pursue. I was looking forward to teaching in America. All of this I was very excited to do."
Heintz came with his family to Swarth-more in 1967, where, he says, he and Van de Kamp were close friends until 1970, when Van de Kamp asked him to continue the Barnard's Star observations and gather more data.
Heintz recalls that Van de Kamp kept the evaluation of the photographic plates largely to himself, but the younger astronomer "suspected there might be a problem with the results."
Heintz found minute variations in the sensitivity of the plates, causing the sizes of the images of Barnard's Star and the stars with which Barnard's was being compared to vary slightly. He also questioned the precomputer mathematical methods that Van de Kamp had used to interpret his data--methods that Heintz claims were "too crude to remove small optical imaging errors." Given that the margin of error in determining a deviation was very narrow--within 2 microns (far less than the diam-eter of a hair)--was it possible to conclude that a wobble existed at all?
Heintz began to duplicate Van de Kamp's comparison studies and found other variations in plates taken in the 1940s and 1950s. He noted that, in 1949, the telescope had been disassembled and cleaned. Could the changes in the positions of the lenses make it more likely for a wobble to appear? In 1973, an astronomer visiting the Sproul Observatory showed that, in fact, this could have occurred.
The most embarrassing challenge did not come from Swarthmore but from other observatories, which were following scientific custom by attempting to duplicate Van de Kamp's work. After a decade of observing Barnard's Star, none of these observatories found evidence of a planet.
When Heintz mentioned to Van de Kamp that he, too, was having difficulty duplicating Van de Kamp's work, "I was denounced among his friends--including top administrators--as a nasty character and probably mentally disturbed," Heintz remembers. "I was told that I should do nothing about it, and that his observations would eventually be confirmed. This I could not believe because, with the variations in the exposures alone, there did not seem to be enough to make any conclusion either way."
|
|
|
Professor Peter Van de Kamp |
"It was the interpretation that was at fault," said Gaustad. "The effect he thought he saw was so small that it could not be distinguished from the 'noise' in the measurement.
"Van de Kamp felt betrayed. For the remainder of his life, he insisted that his results were correct and that he had found a planet. It's important to keep in mind, though, that, in terms of the rest of Van de Kamp's career, he did very important, accurate work, and that the field of astronomy is richer for it."
Still believing that he would one day be vindicated, Van de Kamp returned to Holland in 1981. He died in 1995, a year after Heintz published his final word on the subject. After extensive remeasurements of the Sproul plates and comparison with other telescopes' results, Heintz declared in the Astronomical Journal that Van de Kamp had been wrong.
"Nowadays, when you hear about Barnard's Star," adds author Halpern, "it's almost like a warning that things that can't be wrong just might be wrong. In retrospect, what happened at Swarthmore took some of the sting out of admitting a mistake." In 1991, when British astronomer Andrew Lyne said--in error--that he'd discovered a planet orbiting a pulsar, he announced his mistake at a meeting of the American Astronomical Society soon afterward and was given a standing ovation.
"What I did," Heintz says, "was show that you can't use photography to look for planets."
In the past decade, using entirely different methods and instruments, scientists have found some 30 stars with planets orbiting around them.
ALUMNI DIGEST / BACK PAGES/ BOOKS BY ALUMNI / COLLECTION / EDITOR'S NOTE / FEATURES / IN MY LIFE/ LETTERS / PROFILES / ARCHIVE / TALK BACK
Swarthmore College. Copyright 2001
