Looking up at the night sky, you will find that the stars are twinkling all the time. Research shows that this phenomenon is caused by the uneven distribution of temperature and density in the atmosphere. For the extragalactic radio source, due to the long distance, small angular diameter, and the interference of ionized gas in the upper layer of the earth and interstellar space, there will also be a star-like flicker phenomenon.
Hewish of Cambridge University (Anthony? Hewish, 1924-) The research team found that the intensity of small angular diameter radio sources generally fluctuates by 0. 1 arc second. In order to eliminate this fluctuation, it is necessary to build a tall radio telescope. To this end, they built a huge radio telescope at 1967. Its rectangular antennas are 470 meters and 45 meters, and are composed of 16 128(=2048) dipoles with an area of 18000 square meters. Love (Bernard? Sir Lowell said it was "the most expensive in the history of science". The sensitivity of this radio telescope is very high, which provides a good observation means for the discovery of pulsars. One of the radio observers in the hewish research group is a female doctoral student. What's her name? SJ bell (S. jocelyn? Bell). Where is she from? 1965, he joined the radio astronomy group and studied for his doctorate here. She also helped to install this huge antenna array. After installing the antenna, Bell needs to collect enough data to write his doctoral thesis. Therefore, since July 1967, she has made a detailed analysis of the 400-foot recording paper tape every four days (it takes four days for the telescope to scan the whole sky). Because the computer supporting the antenna has not been installed yet, we can only check the recording tape inch by inch with Bell's eyes. This is a very boring job. Bell should not only separate all kinds of artificial radio signals from the paper tape, but also mark the radio signals sent by the real radio body. During the observation, the careful Miss Bell found a series of strange pulses with exactly equal time intervals. She reported to his tutor at once. After discussion, they decided to continue the observation with the newly installed high time resolution fast recorder. 1967165438+1October 28th finally got a clear continuous pulse chart. The pulse period is very short, only 1.337 seconds, and the period is very stable. The pulse moves with the apparent motion of the celestial body, and the pulse comes from the direction of the fox. What kind of pulse signal is this? Why is the signal period so short? Why is the signal period so stable? A bold idea, a rational idea of advanced life. Are aliens welcoming us? People even think that if there are such aliens, they must be short and don't need to get solar energy from plants, and their skin may be green. In this way, the imaginary "little green men" was born. What tempting speculation, what inspiring ideas. Bell disagreed with little green men. She gave this radio source an interesting name-traffic lights (Belisha? Lighthouse). She thinks that this radio celestial body has a fixed position, and the direction and speed of antenna reception are unchanged, unlike LGM. If LGM does it, their planetary motion will affect the speed of the signal, which will lead to the so-called "Doppler shift", but this effect has not been found in several months of observation. Bell then discovered three celestial bodies with radiation pulses. It is impossible for LGM to simultaneously transmit radio signals in the same frequency band on four celestial bodies so far apart. Bell and hewish published a report entitled "Observation of a Fast Pulsating Radio Source" in the February issue of 1968. In the report, they tried to explain the nature of this celestial body and thought that it might be a white dwarf or neutron star.
Research course of neutron stars
The study of neutron stars can be traced back to the 1930s. 1932, British physicist chadwick (James? Chadwick, 189 1- 1974) discovered neutrons, which caused great repercussions in the scientific community. German physicist Werner? Heisen-berg, 190 1- 1976) and the Soviet physicist Ivan ningke (1904-) put forward new views on the structure of atomic nuclei. It is said that the news has just reached Copenhagen, and only 24-year-old Landau (1908- 1968) proposed a new celestial body-a cold and dense celestial body composed of neutrons. 1934, the famous astronomer bud (Walter? Baa-de, 1893- 1960) and supernova expert zwicky (fritz? Zwicky, 1898- 1974) independently put forward the concept of neutron star through astronomical observation. They pointed out that supernovae are the intermediate state of the transition from ordinary stars to neutron stars, which link neutron stars with supernovae. 1939, zwicki thought that there might be neutron stars in the famous crab nebula. In the same year, American physicist J.R. Oppenhei-mer (1904-1967) and his student Volk-off also proved the existence of neutron stars in theory and put forward its model in detail. Is the supernova explosion completely destroyed, or what remains have it left? There is still some uncertainty in theoretical analysis. Especially about the hypothesis of neutron star density, the density of white dwarfs is high enough, and the density of neutron stars is higher. Neutron stars are only about 20 kilometers in diameter, but the center density can reach 10 ton/cubic centimeter, which is similar to the density of atomic nuclei. Moreover, Tschengji's hypothesis that there is a neutron star in the center of the crab nebula is too bold and bizarre. Although neutron stars may exist, astronomical observers seem to have little interest in finding such celestial bodies. So theorists can only put it on the shelf and neglect it for decades. The discovery of stars that can radiate pulses confirms the neutron star hypothesis. In fact, as early as 1950s, some people recorded the strong pulse signal of pulsar radiation many times during the background survey, but they missed it because it was difficult to distinguish. It can be seen that the discovery of pulsars is accidental, but it also reflects certain historical inevitability. This is not only manifested in theoretical prediction, but also with the improvement of radio technology, it has created technical conditions for this discovery, especially the unique sensitivity of young Bell in capturing this extraordinary opportunity, which has provided a guarantee for this discovery.
Who should be the discoverer of pulsars?
The discovery of pulsars provides observational evidence for the theory of neutron stars and supernovae, and adds important content to the theory of stellar evolution. Such an important discovery has also caused controversy among many people. Interestingly, the debater did not include Bell himself. This may be because she is too modest! Many people believe that Bell played a key role in the discovery of pulsars. 1968, astronomer Smith of Jordalbank Radio Observatory in England pointed out that pulsars were discovered by Bell, but Hervish played an important role in this discovery. In 1969, Jastrow pointed out that the discovery of pulsars should be attributed to Bell, without mentioning Hervish's name. In his book Exploration of the Universe, the cautious author Abel was initially very vague about describing the discovery process of pulsars. But by the time it was reprinted in the 1980s, it was already clear that Bell was the discoverer of pulsars. Miss Bell made an outstanding discovery in her research work and won the Nobel Prize in physics for her tutor Hervis, because Hervis's analysis of the new celestial body confirmed for the first time that it was a neutron star. In addition, the chapter introducing famous astronomers also includes Bell's name, which makes her bathe in the brilliance of Copernicus, Newton, Einstein and other superstars. Different attitudes towards this debate have also led some scientific institutions to adopt different methods when awarding prizes to pulsar discoverers. The outstanding ones are 1973 Michelson Medal awarded by Franklin College in the United States and 1974 Nobel Prize. Franklin College noticed the controversy about the discovery of pulsars, conducted a detailed investigation, and finally awarded both the Bell Prize and the Hervish Prize. The Nobel Prize is the most authoritative prize in the world, but it is obviously not enough to understand the process of pulsar discovery. It awarded the award to Hervis alone, ignoring Bell's important contribution, which made the award unfair. This is an inappropriate mistake. Such a mistake is hard to forgive. No wonder the famous British astronomer Sir Huo Yier (Sir? Fred. Huo Yier, 19 15-) was attacked by this. In the year after he won the Nobel Prize, The Times of London published Huo Yier's talk. He believes that Bell should share the Nobel Prize with Hervish, and criticizes the investigation conducted by the Nobel Prize Committee before the award. He even regarded this award as a scandal. Huo Yier thought Bell's discovery was very important, but her boss kept it a secret for half a year. At the same time, the boss is busy stealing the girl's discovery, or objectively speaking, it is a kind of theft. Later, Huo Yier wrote another explanatory letter, which said, "There is a tendency to misinterpret Miss Bell's achievements. Because this achievement sounds simple, it seems that you just need to look for it from a large number of records. In fact, this achievement is the result of her serious reflection on the phenomenon that past experience thought impossible. "
Hurvis's poor defense.
Hervish has a secret about 1974 Nobel Prize, and his contribution to Bell is rarely mentioned. It is said that Hervish only won the Nobel Prize in 1974, and only mentioned Bell's work when he delivered a speech as usual. He also wrote to The Times in response to Huo Yier's criticism. Hewish means that Bell's work was completed under his telescope and guidance, and only under his guidance can the properties of newly discovered stars be clarified. The reason for delaying the publication of the paper is to make necessary verification. Hervish's defense is clumsy. Thomas Gold, an astronomer at Cornell University in the United States? Gold, 1920-) thinks that Hervish's guidance has nothing to do with the discovery of pulsars, and his observation guidance is essentially different from the phenomenon discovered by Bell. Gold said, "He went to Jambers to locate the flashing wireless power supply, but she noticed another signal and tracked it in her own way." . That's true. According to Bell's memory, she discovered the pulsar in June+10, 5438, and it took some time to prove it later. After hearing Bell's report on the phone, he thought the pulse was artificial. Then, Bell's observation from Christmas Eve to the early morning found a second celestial body with radiation pulses. Hewish didn't take this discovery seriously until now, and confirmed the second pulsar discovered by Bell in June+10/mid-October, 5438. This historical fact shows that Bell is well-deserved as the discoverer of pulsars. After Hervish won the Nobel Prize, besides criticizing Huo Yier and Gold, some people criticized the prize from the front or side. Xipu Gate (Hanry? L. Shipman) only mentioned Bell in the book Black Hole, Quasars and Universe, but avoided talking about himself and the Nobel Prize he won. More interestingly, the famous astronomers R.N.Man-chester and J.H.Taylor wrote on the title page of the book Pulsar (1977 edition): "For Jocelyn Bell, The praise here is a tribute to Bell's honesty and diligence, and also an implicit criticism of 1974' s unfairness in awarding the Nobel Prize. So many comments, in addition to criticizing the lack of solemnity in awarding the Nobel Prize, are also obvious to Hervis.
Scientific activities under the background of materialization
Scientific activity is a creative cognitive activity. Judging from the ability required to carry out this activity, its outstanding feature is that the research object should be knowledgeable, active in thinking and quick in response, so it is essentially an intellectual activity. As scientific activity becomes a social activity, it is carried out in an environment of mutual communication and mutual restriction. In this kind of activity, it is also a bit like the work of workers and technicians in the workshop. Many of them are "masters" and "apprentices". The old-fashioned relationship between master and apprentice often shows that the master should impart general operational skills and knowledge, and the apprentice should make some contributions while accepting these skills and knowledge as a valuable reward. Under modern conditions, there are still some traces of the mentoring relationship in traditional industries. Interestingly, there are some similar relationships in scientific isomorphism. This relationship, on the one hand, enables the knowledge system and research activities to be inherited and developed, on the other hand, enables the scientific identity itself to be maintained and continued. Harmonious mentoring not only provides a good research environment, but also really promotes the development of science, for example, Barrow and Newton, Rutherford and Bohr, Bohr and "his children". However, the actions of Hervish and the Nobel Fund Committee in Britain have caused different arguments from the above examples. Braud and N.-Wade in the United States once pointed out sharply: "In the past, the relationship between master and apprentice was based on mutual care and learning from each other's strengths, but today, in order to obtain equipment, research funds and other materials, it is often necessary to connect them. From the example of finding pulsars, we can see the disadvantages brought by this completely materialized relationship. " Braud and Wade put it right. This "materialistic" relationship will inevitably bring some unfair things, one of which is the "distortion" of priority. RobrtK。 Me-rton, an American scientific sociologist, put forward "the spiritual temperament of modern science", one of which is "publicity", that is, the * * * or * * * enjoyment of scientific achievements. Scientific knowledge is the wealth of mankind, and the rights that scientists get from the law are limited. Usually, priority is a part of this limited right, which marks the social recognition or (mainly) peer recognition of scientific discovery. Modern scientific research results are mostly published in scientific magazines in written form, and scientific achievements recognized by peers are mostly learned by reading such magazines. However, as mentioned above, the "materialization" of the mentoring relationship makes the signature abnormal. The discovery of pulsars is a typical example. When they published an article in 1968 (which was the basis for Hervis to win the Nobel Prize), Hervis was "naturally" ranked first in the signature due to the unpaid contribution of "apprentice". As he said, because Bell used his telescope. But this gives the outside world an illusion that Hervis is the main discoverer of pulsars, and others are only members of the research team. This practice basically monopolized the priority of pulsar discovery, and through this practice, he "naturally" won the "recognition of his peers." This is why Huo Yier and others are quite dissatisfied with this. In addition, the priority of pulsar discovery has not caused more sharp debate, but also depends on Bell's humility and comity, which has won the admiration of many colleagues for Bell's good moral cultivation. The "materialization" of the mentoring relationship will also affect the intellectual combination or intellectual complementarity between mentoring in the scientific community. Because the leader of the experimental research group can control the equipment and funds, he can trade money and intelligence with the apprentice and share the research results of the latter. Especially when it is difficult for the boss to complete a project or task, he may try to tap the intellectual advantages of his subordinates and make them succeed. Maybe it's not bad. Tragedy is often that his subordinates lose too much. This is also the tragedy of Bell. This materialization runs counter to the selflessness of scientific research. Selflessness refers to "influencing scientists' behavior to develop in the direction of caring for the truth, and finally bringing corresponding recognition to scientists." Generally speaking, the unfairness of Hervish's winning the Nobel Prize is also reflected in his initial improper "confidentiality" measures for his research. Even at the urging of his peers, he disclosed only one pulsar in the February 1968 article, but concealed the other three pulsars. Its purpose is obviously to gain priority without failure, but also to "monopolize" their discovery. In the late 1930s and early 1940s, some scientists put forward the idea of taking "secrecy" measures in countries such as Britain, France and the United States in order to prevent Nazi Germany from obtaining information about the chain reaction. Although the reasons are quite good, there are still many scientists (mainly French scientists) who are resistant to this. The reason is simple: this is not in line with scientific research practice and the principle of no self-interest. Therefore, hewish's "secrecy" violates the basic principles of scientific research.