Science is constantly changing and, as the article below shows, it is often a struggle to change the minds of other scientists about what is plainly seen by one person, but missed by another.
Astronomer Asks Amateur’s Help For Contemporary
Georgetown Director Urges Scientists to Search for Light Clouds
For the sake of an old man, who has spent a lifetime studying the glories of the heavens and who is approaching the end of his work, bitter at the thought that observations he is sure are correct are questioned by his contemporaries, Rev. Paul A. McNally, director of the Georgetown University observatory, yesterday appealed to amateur astronomers to search the skies for certain distant, faint, mysterious clouds of light.
Father McNally himself is convinced that they exist and that he has seen some of them. He wishes to make the Georgetown observatory a clearing house of such observations in an effort to clear up one of the most disputed points in astronomy.
Speaking before the American Association of Fixed Star Observers at the National Academy of Sciences Building yesterday, Father McNally explained that in 1811 Sir William Herschel, most celebrated of all observers of the sky listed 52 of these mysterious objects and gave their exact positions in the heavens. Apparently nobody else saw them at the time, and the dispute did not arise until a half century later, when the British astronomer, Sir Isaac Roberts, tried to check on Herschel. He found only eight of the 52 and denied the existence of the others. This caused Edward Barnard of the Lick Observatory, whose star charts have recently been published by the Carnegie Institution of Washington, to come to the defense of Herschel on the grounds that such a great astronomer couldn’t have gone so far wrong.
Sought Vainly for Evidence
Barnard, however, had tried to get evidence in vain by photographing the heavens. He kept quiet about the negative results of his plates, but Father McNally examined them last summer and found that they showed nothing. The next person to take up the work was Father Hagen, former director of the Georgetown Observatory and now director of the Vatican Observatory. He entered the work, Father McNally said, without any bias in favor of Herschel, but was surprised to find the mysterious clouds of light in almost the exact positions where the Englishman had found them a century before. After checking his observations he published them a few years ago.
Then astronomers all over the world began disputing his findings, because they have been unable to find the same things. This, Father McNally said, the old astronomer resents and his letters to the Georgetown observatory reveal an increasing bitterness and belief that his lifework has ended in failure. He has sent to Georgetown the entire collection of his sky maps showing the location where he claims he saw the nebulous areas. Meantime, the widow of Sir Isaac Roberts has entered the controversy, strangely enough in opposition to the position of her husband. She has sent Georgetown a file of his charts for checking against those of Father Hagen in the belief that the cause of the difference will be found.
There seems little doubt, Father McNally said, that such areas exist although they can be detected through the telescope on very clear nights after the observer has been in the dark for a time. Although the camera can detect objects in the heavens far too faint for the human eye, these patches cannot be photographed for some unknown reason. Every sort of device has been tried for photographing them but the resulting plates show no result. Father Hagen himself has failed repeatedly and even Prof. Hubbell of the Carnegie Institution, discoverer of the island universes, has been unable to get any record.
Urged to Search Skies
Father McNally urged that persons with telescopes take advantage of clear nights to search the skies by the Georgetown charts. There are various dark areas in the sky, he said, which seem to be of the same nature but more intense. These also defy the camera. Some have held that they are great masses of dust or meteoric material which shut off the light from the stars in some areas. These can be found quite easily. But although they seem dark when viewed through a high powered glass, they seem lighter than the surrounding sky. By first concentrating on these, he pointed out, it will be easier to detect the less intense Herschel areas. These are quite extensive and fade out gradually into the clear sky.
the great swarms of meteors offer exceptional opportunities to amateur observers, said Prof. P. Oliver, who urged that any seen while taking variable stars observations be recorded. From those visible to the naked eye, he said, there is a very rapid increase as fainter and fainter magnitudes are observed through the telescope until they begin to fall off just as rapidly as they have risen. There is no way to determine, he said, whether a fainter meteor is further away from the earth or smaller than the brighter objects unless actual parallax measurements are made, such as those formerly used to determine the distances of the nearer stars. It is especially important, he insisted, to get a better picture of those in the immediate neighborhood of the earth.
The fate of so-called novae, or new stars, after they have declined in brightness was discussed by Dr. W.H. Steavenson, former president of the British Astronomical Society. These are stars of which two or three appear in a century, mount in a few days to the brilliancy of the planets, so that they are the brightest objects in the sky, and then fade out of sight. This phenomenon is supposed to be due to stellar collisions or explosions which happen centuries before the light which tells the story reaches the earth.
The more recent novae, Prof. Steavenson said, have been identified from photographic plates taken before their appearance as very faint stars. He has compared them after their great declines and find that they go back about where they started from. From then on they hardly change at all.
Source: Evening star. [volume] (Washington, D.C.), 19 May 1929.
