Pulsars are spherical, compact objects that are about the size of a large city but contain more mass than the sun. Scientists are using pulsars to study extreme states of matter, search for planets beyond Earth’s solar system and measure cosmic distances.
Pulsars are considered to be “death stars” and are the products of stars exploding in the supernova phase. After the supernova exploded, there was only one “nucleus” left, only tens of kilometers in size, and its rotation speed was very fast, some even reaching 714 revolutions per second.
In the process of rotation, its magnetic field will cause it to form strong electric waves that radiate to the outside world. A pulsar is like a beacon in the universe, continuously emitting electromagnetic waves to the outside world. This electromagnetic wave is intermittent and has a strong intensity. Regularity. It is precisely because of its strong regularity that pulsars are considered to be the most accurate clock in the universe.
Discovery of pulsars
When the pulsar was first discovered, people thought it was an electromagnetic wave sent by aliens to us, and they were looking for a friend in the universe.
In 1967, Cambridge, England, built a new radio telescope, which is a new type of telescope whose function is to observe the influence of radio radiation by interplanetary matter. The entire device cannot be moved, and can only be scanned one by one by entering the field of view of the telescope by the diurnal movement of each sky area.
In July 1967, this instrument was officially put into use, accepting a wavelength of 3.7 meters. It is Jocelyn Bell, a female doctoral student of Hewesh, who observes with a telescope and handles the heavy recording. During the observation, the careful Miss Bell discovered a series of strange pulses whose time intervals were exactly equal.
Miss Bell immediately reported the news to her mentor Huish, who believed that it was affected by some kind of electric wave on the earth. However, the next day, at the same time and in the same sky, the mysterious pulse signal appeared again. This time it can be proved that this strange signal does not come from the earth, it does come from outside the sky.
Was this a civilized signal sent by aliens to us? The news media showed great enthusiasm for this issue. Soon, Bell discovered several other areas of the sky in the sky, and finally proved that this is one. A new type of celestial body that is not yet recognized-pulsars.
In 1974, this new discovery won the Nobel Prize in Physics. The prize was awarded to Huish for the discovery of the pulsar by the research team he led. Regrettably, the direct discoverer of the pulsar, Jocelyn. Miss Bell is not among the winners. In fact, in the discovery of pulsars, Miss Bell’s rigorous scientific attitude and extremely careful observation should play a key role.
Middle school students discover pulsars
PSR J0737-3039A/B Double Pulsar System
Professional astronomers are engaged in astronomical research. They have rich research experience and professional research equipment, so they can achieve impressive results. However, in the history of pulsar discovery, there is a special example. This example is that three middle school students discovered a pulsar.
Normally, after a supernova explodes, the remains of a star will be left on the original site. Such a remains may be a pulsar. However, scientists did not notice this problem, but three middle school students discovered it. As a result, these three middle school students won the Siemens-Westinghouse Science and Technology Competition Award.
In North Carolina, USA, there are three middle school students, all of whom are astronomy enthusiasts, and often discuss astronomy issues together. The data sent back by the Chandra Seca Space Telescope aroused their interest. They found that the supernova remnants at IC443 are somewhat special. There seems to be a point-shaped X-ray source, which indicates that there is likely to be a pulsar there. They reported the news to professional astronomers.
As a result, this discovery was recognized by experts. Dr. Brian, a pulsar expert from the Massachusetts Institute of Technology, commented on the results of these middle school students: “This is a real scientific discovery. All relevant personnel should be proud of this achievement. “
Pulsar is really a kind of strange celestial body, people have not yet fully understood its various characteristics, and many discoveries are not anticipated in advance. As people learn more about it, the theoretical construction in this area will become more and more perfect, and the story may not happen again.
It was August 1967. Bell, a female graduate student at the Cambridge Radio Astronomy Observatory, noticed a strange “jamming” signal on the chaotic recording tape. After repeated studies, she successfully verified that the earth received one signal every 1.33 seconds. Very regular pulse. Upon receiving this shocking news, her mentor Huish had suspected that this might be the Morse code sent by the aliens-the “little green men”, and they might be greeting the earth.
However, further measurements have shown that the frequency of pulses emitted by this celestial body is incredibly accurate and does not have the obvious rich information of the code. Next, Bell found three other similar sources, so alien signals were ruled out, because it is impossible for three “little green men” to transmit stable frequency signals to the earth in different directions at the same time.
After careful study, in February 1968, Bell and Hewesh jointly reported the discovery of a new type of celestial body in the British “Nature” magazine, and believed that the pulsar was the super dense and close proximity predicted by physicists. The strange celestial body of the black hole has a radius of about 10 kilometers and its density is equivalent to compressing the entire sun to the area of Beijing, so it has a super gravitational field.
Pulsar material the size of a ping-pong ball is equivalent to the weight of a mountain on Earth. This was an exciting and major discovery in the 20th century, which opened up new areas for human exploration of nature, and had a profound impact on the development of modern physics. It became one of the four major discoveries in astronomy in the 1960s.
However, there has been a dispute over the attribution of honor. The 1974 Nobel Prize in Physics crown was only worn on the head of the tutor Huish, completely ignoring the contribution of student Bell, and public opinion was in an uproar.
The famous British astronomer Sir Hoyle made a speech in the Times of London. He believed that Bell should share the Nobel Prize with Huish, and criticized the lack of thorough investigation by the Nobel Committee before awarding the award. He even thought that This incident is a scandal and sex discrimination case in the history of the Nobel Prize.
Hoyle also believes that Bell’s discovery is very important, but her mentor has withheld this discovery for half a year. Objectively speaking, it is a kind of theft. More scholars pointed out that “Miss Bell’s outstanding discovery made her mentor Huish win the Nobel Prize in Physics.”
The title page of the book “Pulsars” by the famous astronomers Manchester and Taylor wrote: “Dedicated to Jocelyn Bell. Without her cleverness and perseverance, we cannot get the joy of pulsars.”. In the book “A Brief History of Time”, Hawking only said that the pulsar was discovered by Bell, and did not mention Huish.
The debate about the true discoverer of pulsars and the questioning of the Nobel Prize Committee have gone through 40 years. Today, 40 years later, it has once again become a topic of concern. Looking back on the past, Huish as a mentor won the Nobel Prize, which is understandable, but it is regrettable that Bell lost the honor.
Without Bell’s meticulous pursuit of “jamming” signals, they might have missed the discovery of pulsars. If the Nobel Prize “competition” is compared to the scientific “Olympics”, then the “referees” 40 years ago obviously blew the “black whistle”, at least misjudgment, which tarnished the scientific justice authority of the Nobel Prize.
During Bell’s visit to Beijing, the author talked to her about the discovery of pulsars and her views on the Nobel Prize. She said that soon after the discovery of the pulsars, she was forced to leave Cambridge University. There was a little silence, and she bluntly stated that in the 1960s, scientific institutions generally had a tendency to ignore the contributions of students, especially female students. Tutors often call themselves “superior leaders”, steal the results of students for their own sake, and then find ways to kick the students away.
However, in 1993, when two American astronomers won the Nobel Prize for discovering pulsar binary stars, the Nobel Prize Committee took extra care and invited Bell to participate in the award ceremony, which is a kind of compensation. In 1968, after leaving Cambridge, she and Huish did not cooperate again. It was not until the 1980s that they met at an international conference and shook hands. Since the discovery of the pulsar, in addition to the Nobel Prize, she has won more than a dozen world-class science awards and has become a science ambassador.