An artist's explanation of "dyson sphere", an artificial celestial body used to wrap stars and develop their energy. (Source: Vedexent/wiki/CC-BY-2.5)

Although Dyson has left, his famous idea of finding aliens may last forever. Dyson, a famous quantum physicist, died on February 28th at the age of 96. In an interview in 2003, he recalled how he first put forward the "Dyson sphere" theory, which may reveal the existence of advanced alien civilization. 1960, this theory was put forward in the paper "Looking for infrared radiation sources of artificial stars" published in Science magazine. Dyson wrote in his paper that scientists began to search for signs of alien civilization with radio telescopes. This kind of radio is a huge medium for searching for aliens, but only if aliens are willing to communicate. If aliens remain silent, you need to use a red-hot sensor to find the residual heat they give off from space.

"Unfortunately, I added at the end of the comment that we are looking for an artificial biosphere." In 2003, Dyson said in a 45-minute interview that this interview can be seen on YouTube's MeaningofLife. He imagined a satellite cloud object that might be disguised as dust from a distance, and he added that his words ignited an accidental classic legend. Science fiction writers use this theory to imagine that biological clouds are surrounded by a sphere-it must be a huge sphere. In addition, some fantastic ideas came into being, which were finally reflected in the movie Star Trek.

On March 22, 2000, Freeman, a physicist at the United Nations Church Center in new york? Dyson (Photo: Jon Nassau/new york Daily News Archives-Photographed by Getty)

Dyson's daughter gave him a video about Star Trek: The Next Generation (1987), also called Legacy, Dyson said. After hearing the painful call on the famous Federation starship Enterprise, the plot began. Fans of the film recalled that the play was a sequel to Star Trek: The Original Series, in which james doohan played montgomery scott, also known as Scott. The crew searched for the source of the call in space and found a huge Dyson sphere (depicted as a solid spherical object) around the star. According to Star Trek's Alpha Memory fan website, if we want to build such a sphere in our own solar system, it should be big enough to extend into orbit like Venus (the play explains that the Dyson sphere is two-thirds as big as the earth's orbit, while Venus's orbit is bigger. ) "I have seen this film, yes, it is clearly marked as Dyson sphere; It looks interesting, but it's total nonsense, "Dyson said in an interview. He also said that "Dyson sphere" was a misnomer, because his original inspiration came from science fiction writer Olaf? The idea put forward by Stapleton in the novel Star Maker in 1930s.

By wrapping stars and exploiting artificial celestial bodies with the energy of stars, it is possible to create advanced civilizations (source: Karl? Carter, artist data map)

"Ruins" show us the popular understanding of Dyson's sphere theory, which envisages a giant structure surrounding the star to absorb the energy of the star as much as possible. Therefore, it is conceivable that people were shocked when scientists announced that a star had abnormal changes in 20 15 years and its brightness fluctuation was not obvious. The observation team put forward many conjectures, including that this may be the practice of Dyson sphere in the real world.

Although this star (named KIC8462852) is an unremarkable celestial body, it is hotter and brighter than the sun. From the perspective of the universe, it is not far away from us. It is located in Cygnus, about 1480 light-years away from the earth. The researchers obtained the abnormal light fluctuation of the star, and its mission design can observe the star for decades at a time and find an alien system. Data from the Kepler mission show that the brightness of a star drops by 22% in a few days or a week. In fact, it was not first discovered by astronomers, but was detected by citizen scientists when checking Kepler's work through the crowdsourcing interstellar hunter project on the website of Galaxy Zoo.

In 20 15, the research team led by astrophysicist Tebertha Boyakin (formerly Yale University, now Louisiana State University) could not explain the darkening and brightening of natural phenomena such as dust for the first time. The paper published by this team in the Monthly Bulletin of the Royal Astronomical Society quickly aroused great repercussions, saying that this star is commonly known as Tabitha Star, and it was officially named Boyajian Star after its discovery. She owes the idea of showing dyson sphere to the space station to one of her colleagues, not to her. One of the best achievements of this paper is that it promotes more cooperation between astronomers and other researchers exploring alien civilizations. In the interview, she added: "We are looking up at the same sky and pursuing the same goal, but we are not well integrated. We don't attend the same meeting or even read the same article. "

But they received an invitation to use the Allen telescope array at will, "because it is good for the public," she said. This extra time using the telescope helped the Boyajin team have a short rest. In 20 17, when the telescope was aimed at it, the star dimmed and brightened many times, as discussed by her team in a paper published in Astrophysics Journal Express in 20 18. "It was really exciting, because we could observe it in real time and trigger other observations to really study what happened in front of this star," Bo Jin Ya recalled. As a result, she added, we got a "complete amount of data" because they detected the brightness of stars in different colors of light.

Bai said that when the research team found that blue light was blocked more than red light, it was suggested that the obstacles were not solid, but like a perfect science fiction dyson sphere. "You can imagine that if there is some solid in front of the light source, it will completely block all the light," Bai explained.

By 20 19, some astronomers supported some explanations, such as the cluster of comets or dust clouds, which led to the strange behavior of this star, but Boyakin thought that this star deserved more research. In fact, she is writing some new papers about KIC8462852 star. "We still need a natural explanation," she said. "Usually, when there is dust around the star, there will be excessive infrared rays, which means that there are longer light waves in the infrared rays, but we can't see them at all." "On the basis of these observations," she continued, "we have another very strange question about this star, that is, not only does its brightness decrease in the short term, but its long-term change can be traced back to a century ago. It's 20% brighter than before. All this is so confusing. "

Some people insist on Dyson's sphere hypothesis, which leads to another view: maybe the structure will change the light pattern over time. She added that this star KIC8462852 may have been a mystery until her research team found another similar star for comparative analysis.

"Nature is far more creative than us," she said. Perhaps NASA's transit exoplanet survey satellite (TESS) can extract signals from a sky area it studies, as long as the signals are generated within 300 days. In contrast, Kepler observed the same area for four years, including two years when KIC8462852 was dormant between sudden darkening. The transit exoplanet survey satellite (TESS) rotates in different areas of the sky once every 27 days, and switches the hemisphere perspective from south to north about once a year (and vice versa). In the process of rotation, some horizons overlap each other, so a small area can be studied for several months at a time.

Gaia's flight plan from Europe is unlikely to send an "aha" signal. This flight plan monitors the operating characteristics and brightness changes of one billion stars. Boyakin said that because Gaia keeps moving in different positions in the sky, it can't monitor for a long time-which means that if it finds something interesting, any observation will be short-lived and it must follow another task.

When the international community was excited about her discovery, she received a letter from an acquaintance of Dyson, asking her to contact a very famous physicist. Dyson was 9 1 year-old. She sent an email to Dyson, briefly explaining her work and how scientists tried to explain the behavior of the star KIC 8462852. To her delight, Dyson replied and congratulated her fifteen minutes later.

"This is a new creature in the celestial zoo, and it will become very important." I read a part of Dyson's reply to her email for nothing. He compared her team's discovery with the gamma ray burst discovered by Vela satellite in 1970s, which was mainly used to detect nuclear tests. Dyson wrote in an email that the team members behind the discovery of gamma-ray bursts revealed the discovery to him and said that these researchers "hesitated to publish this discovery" because "the explosion seems to challenge the laws of physics." In an instant, the energy generated by gamma ray bursts is equivalent to the life of the sun10 billion years. Dyson encouraged them to show their current findings to the public, and believed that other explanations would emerge over time. Therefore, publishers need to take the lead and inspire several competitive explanations within a few decades.

A generation later, 199 1 year, the Compton Gamma Ray Observatory of NASA launched into space, and found that there was an explosion every day, which was emitted from the air. Compton found that these explosions were divided into two characteristics-long life and short life-and it was not until 2005 that these two sources were determined. Long-lived explosions come from very strong supernova explosions, which are called Supergiant star nova. When two remnant stars (called neutron stars) collide with each other to form a black hole, or when the black hole devours the neutron star, a brief explosion will occur.

When two neutron stars merge, gamma rays burst. Source: Sohu)

"This is a lovely email," Bai said of Dyson. She added that his theory was still related to astronomy. Scientists have been trying to solve a problem, why we haven't found intelligent aliens, and people on earth have been looking for it in the vast universe for decades. Bai Jinya said: "Even though we have searched countless places on dozens, hundreds or even thousands of planets, we still haven't found the signal that intelligent life screams at us with megaphones and says," We are here. "

Author: Elizabeth Howell-life science writer

Mad Seven on Mars

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