A Walk in the Woods

MARTIN NATVIGproblem with the results.”Heintz found minute variations in thesensitivity of the plates, causing the sizesof the images of Barnard’s Star and thestars with which Barnard’s was being comparedto vary slightly. He also questionedthe precomputer mathematical methodsthat Van de Kamp had used to interpret hisdata—methods that Heintz claims were“too crude to remove small optical imagingerrors.” Given that the margin of error indetermining a deviation was very narrow—within 2 microns (far less than the diameterof a hair)—was it possible to concludethat a wobble existed at all?Heintz began to duplicate Van deKamp’s comparison studies and foundother variations in plates taken in the1940s and 1950s. He noted that, in 1949,the telescope had been disassembled andcleaned. Could the changes in the positionsof the lenses make it more likely for awobble to appear? In 1973, an astronomervisiting the Sproul Observatory showedthat, in fact, this could have occurred.The most embarrassing challenge didnot come from Swarthmore but from otherobservatories, which were following scientificcustom by attempting to duplicate Vande Kamp’s work. After a decade of observingBarnard’s Star, none of these observatoriesfound evidence of a planet.When Heintz mentioned to Van deKamp that he, too, was having difficultyduplicating Van de Kamp’s work, “I wasdenounced among his friends—includingtop administrators—as a nasty characterand probably mentally disturbed,” HeintzV A N D E K A M P T H O U G H TT H A T T H E Q U I E T , S E R I O U SG E R M A N R E S E A R C HA S T R O N O M E RW O U L D F A I T H F U L L Y C A R R YO N H I S W O R K .H E N E V E R E X P E C T E DT H E C R I T I C I S M H E L A T E RG O T F R O M H E I N T Z ,W H I C H H E C O N S I D E R E DV E R Y D I S L O Y A L .“I CAN TELL YOU,” SAYS HEINTZ (SHOWNABOVE IN 1979), “I DID NOT WANT TOEMBARRASS A COLLEAGUE. I WAS NOTCOMFORTABLE AS THE [BEARER] OF BAD NEWS.THERE WAS NO SATISFACTION IN IT.I TOOK REFUGE IN MY OWN STUDIES, IN MYTEACHING, AND WITH THE TELESCOPE. IT’SSTILL QUITE A USEFUL INSTRUMENT.”THE 24-INCH REFRACTOR IS NOW USEDFOR VARIABLE STAR RESEARCH.remembers. “I was told that I should donothing about it, and that his observationswould eventually be confirmed. This Icould not believe because, with the variationsin the exposures alone, there did notseem to be enough to make any conclusioneither way.”Any friendship between the two scientistsended when Heintz published the firstof a series of scientific papers on the subjectin 1976. The papers shed the first publicdoubts on the accuracy of Van de Kamp’smethods.“It was the interpretation that was atfault,” said Gaustad. “The effect hethought he saw was so small that it couldnot be distinguished from the ‘noise’ in themeasurement.“Van de Kamp felt betrayed. For theremainder of his life, he insisted that hisresults were correct and that he had founda planet. It’s important to keep in mind,though, that, in terms of the rest of Van deKamp’s career, he did very important, accuratework, and that the field of astronomyis richer for it.”Still believing that he would one day bevindicated, Van de Kamp returned toHolland in 1981. He died in 1995, a yearafter Heintz published his final word onthe subject. After extensive remeasurementsof the Sproul plates and comparisonwith other telescopes’ results, Heintzdeclared in the Astronomical Journal thatVan de Kamp had been wrong.“Nowadays, when you hear aboutBarnard’s Star,” adds author Halpern, “it’salmost like a warning that things that can’tbe wrong just might be wrong. In retrospect,what happened at Swarthmore tooksome of the sting out of admitting a mistake.”In 1991, when British astronomerAndrew Lyne said—in error—that he’ddiscovered a planet orbiting a pulsar, heannounced his mistake at a meeting of theAmerican Astronomical Society soon afterwardand was given a standing ovation.“What I did,” Heintz says, “was showthat you can’t use photography to look forplanets.”In the past decade, using entirely differentmethods and instruments, scientistshave found some 30 stars with planetsorbiting around them. TJournalist and novelist Bill Kent is a frequentcontributor to the Bulletin.M A R C H 2 0 0 131