The story begins with the discovery of Uranus. 1781March 3 1 On the evening of Sunday, the German-born British astronomer William Herschel observed the night sky with a homemade telescope and found a new celestial body, which he thought might be a comet. But later, other astronomers' observations proved that it was a big planet and was named Uranus. 182 1 year, Boide, director of the Paris Observatory, compiled the astronomical observations of Uranus for many years into a catalogue of Uranus, and calculated the orbit of Uranus according to the law of universal gravitation. He was surprised to find that the actual position of Uranus deviated from the calculated orbit. Is the law of gravity wrong, or is there an unknown planet that interferes with the operation of Uranus?
1832, Airy, then professor of astronomy at Cambridge University, gave a report to the British Association for the Advancement of Science, introducing this big problem that puzzled astronomers. There is no need to doubt the correctness of the law of gravity, so it is more likely that a big planet will be discovered. To find this big planet, we need to solve the "inverse perturbation" problem. If we know the position of a great star, we can calculate its interference with the operation of neighboring planets according to the law of universal gravitation, which is the so-called "perturbation" in astronomy. But on the other hand, it is much more difficult to calculate the position of unknown planets from the "perturbation" of a big planet, which was considered impossible by most scientists at that time.
1841On June 26th, Adams, an undergraduate student at Cambridge University, read Airy's report in Cambridge Bookstore and decided to overcome this problem after graduation. 1843, Adams graduated and stayed in school to teach. Through Charles, a professor of astronomy at Cambridge University, he asked Airy, who has been appointed director of Greenwich Observatory, for the observation data of Uranus at Greenwich Observatory. 1In September, 845, Adams obtained the calculation results, calculated the orbits of unknown planets, and gave them to Charles, hoping that Cambridge Observatory would search for new planets accordingly. But Charles didn't believe Adams' calculation, but he wrote to recommend Adams to Airy. Adams visited Airy three times at 1845, 10 and 2 1, but failed to see him and left a note. This note that has been preserved to this day lists his calculation results: the average distance between the new planet and the sun is 28 astronomical units (the distance between the earth and the sun is equal to 1 astronomical unit)-a quarter farther than the actual distance; Its position at 1 84565438+1October1is the longitude of the celestial sphere. Just as geographers mark the position of the earth with latitude and longitude, astronomers mark the position of the celestial sphere with latitude and longitude (323 degrees and 34 minutes)-only about 2 degrees worse than Neptune's actual position.
Airy took this note as important evidence for Adams to predict Neptune for the first time, but at that time he didn't believe that the young man who had just graduated from college had solved the inverse perturbation problem, and Adams didn't explain how he worked out this result. However, Airy wrote a letter to Adams, hoping to learn more about Adams' work. For example, can he also explain the deviation of saint seiya's trajectory (that is, the distance to the sun)? Adams drafted a reply, but strangely, he didn't send it.
Ellie didn't receive Adams' reply, so he forgot about it. It was not until he read Le Ye Wei's paper on June 1846 that he remembered it. Le Villiers, a teacher of the Paris Institute of Technology, began to study Uranus perturbation in the summer of 1845, and published three papers in one year. Levier's first paper, published in1845165438+10/0, accurately calculated the perturbation effects of Saturn and Jupiter on Uranus, indicating that these are not enough to explain the orbital deviation of Uranus. Levell published his second paper on June 1846, estimating the approximate position of unknown planets. After reading Le Ye Wei's second paper, Ellie felt that the result was very similar to Adams's, so she wrote a letter to Le Ye Wei and asked Adams a question, but did not disclose that Adams was also doing the same research. Levell wrote back quickly and answered Airy's questions.
Levell's reply satisfied Airy and made Airy feel the need to find new planets. But Ellie's eyesight is not good, so she can't make her own observation. He suggested that Charlie secretly look for new planets at Cambridge Observatory. Charies started observation on July 18 according to the new calculation results provided by Adams, but found nothing.
On August 3 1 this year, Le Ye Wei published his third paper, predicting the quality, brightness and more accurate position of new planets, and calling on astronomers to search for new planets accordingly. To Le Ye Wei's dismay, no astronomers seem to have paid attention to his appeal. On September 18, Le Ye Wei remembered that a young astronomer named Galle from Berlin Observatory had sent him a paper, so he wrote a letter to Galle, telling him that if he aimed his telescope at the 325-degree region of the Yellow meridian, he would find the eighth planet in the solar system that no one had seen yet. On the morning of September 23rd, Caleb received a letter from Le Ye Wei and began to observe it that night. He used an astronomical telescope to observe and quote the position of celestial bodies, while his assistant Delaitre checked the map. A few minutes later, Caleb reported seeing a star with a brightness of 8 at 325.9 degrees of the yellow meridian. Delaitre shouted, "That star is not on the map!" The next night they continued to observe the position of the constant star and found a slight movement, indicating that it was indeed a planet. On the third day, Caleb wrote to Le Ye Wei and reported, "The planet where you calculated the location really exists."
Levell wrote to some astronomers, including Airy, to report the discovery of a new planet and suggested naming it Neptune. Ellie and Charles revealed their secret plan to find a new planet, and announced that Adams had calculated the position of the new planet. They asked to name the new planet Poseidon, obviously feeling that they have a certain priority. The French are naturally skeptical: if Adams really made an accurate calculation, why didn't he publish it in a paper? Why fight for priority afterwards?
As time went on, the argument gradually subsided. The Royal Society awarded the Levell Medal in recognition of his contribution, and it is internationally recognized that Adams made an independent discovery. But the original question is not well answered. Adams doesn't dislike publishing papers as people think. He published other papers. The real reason why Adams didn't publish his calculation results like Levell's is that he has no confidence in his calculation methods and results, and has been changing the calculation results. The final result is far from the actual position of Neptune.
As mentioned earlier, Airy, Charles and Adams began to secretly search for new planets after learning about Le Ye Wei's research. Adams revised the calculation result according to Le Ye Wei's second paper, but it gave a very uncertain result ranging from 3 15 degrees to 350 degrees. Charlie has to observe a large area. Although Neptune once entered the observation range of Charies, it was not discovered. Charles's method of identifying planets is to compare the observation results at different times to see which constant star's position has changed. Because the observation range is too large and there are too many stars, Charies can only pick out the brightest 39 stars for comparison. Unfortunately, Neptune's brightness ranked 49th in Charles' observation range, so it was missed. Two days after Levie's third paper was published, Adams gave his latest calculation result: the longitude of the longitude of the ecliptic is 3 15 degrees, which is 1 1 degree worse than Neptune's actual position. So, according to Adams' calculation, Charles spent two months with nothing, while Caleb got it in a few minutes according to Levell's calculation.