What is the new gravitational wave discovery? What is the significance of gravitational wave discovery
4hw.org: in February last year, LIGO announced the discovery of gravitational waves. At that time, it caused a strong sensation in both the scientific community and ordinary people. Recently, several observatories jointly announced the discovery of new gravitational waves. The so-called expert gatekeeper and outsider made up stories, and various stories came out, so what do you know about the gravitational waves? What's the significance of the discovery of gravitational waves for human beings Let's have a look!
Big news? Have aliens been found
What's the big news? It's reported that at 10:00 p.m. on October 16, Beijing time, the National Science Foundation of the United States held a press conference to announce that the laser interference gravitational wave observatory (LIGO) and the Virgo gravitational wave observatory (Virgo) first discovered the event of two neutron stars combining gravitational waves on August 17, 2017. The International Union for electromagnetic counterpart observation of gravitational waves Now the electromagnetic counterpart of the gravitational wave event. Our country's first space hard X-ray Modulation Telescope 'eye' successfully monitored the sky area where the gravitational wave source was located when the gravitational wave event occurred, and strictly restricted the radiation properties of its gamma ray electromagnetic counterpart (referred to as gravitational wave scintillation) in the high-energy area, which made an important contribution to fully understanding the physical mechanism of the gravitational wave event and gravitational wave scintillation. The relevant detection results are published in Report the historical findings in the research paper.
Wang Lifan, director of China Antarctic astronomical research center and researcher of Zijinshan Observatory of the Chinese Academy of Sciences, said that since 21:10 on August 18, 2017 Beijing time, 24 hours after the occurrence of the gravitational wave event, the ast3 cooperation team of China Antarctic Sky Survey Telescope has carried out effective observation of the gravitational wave event using the second telescope ast3-2 running at China's Kunlun station, Antarctica The observation lasted until August 28. A large number of important data were obtained and the optical signal of the gravitational wave event was detected.
What is gravitational wave
In general relativity, gravity can be explained by the curvature of time and space, according to the German voice. Suppose time and space is a trampoline: if a tennis ball is placed on the trampoline, it will only stop there quietly; if a person is sitting on the trampoline at this time, the trampoline will sink downward, and the tennis ball will roll to the sink, and the closer it is, the faster it will roll. The tennis ball was' attracted 'by the depression. The larger the weight of the body on the trampoline, the more obvious the depression, and the easier the tennis ball rolls to the depression.
Similarly, in space-time, the larger the mass of the object causing the change, the more obvious the curvature of space-time is, and the greater the 'gravity' produced. When the person sits on the trampoline, the bending of the trampoline will spread out from the center of the depression; at this time, if you use a high-speed camera to observe and play back the slow lens, you will find that the diffusion process is in the form of waves. It's like throwing a stone on a calm water surface, which will create a circle of ripples. This is gravitational wave. Gravitational waves are generated in the process of object acceleration, such as star explosion and black hole collision. Gravitational wave will cause the expansion of space-time and affect the structure of space-time.
Why should the discovery be published together in the world? Chen Xuelei, a researcher at the National Astronomical Observatory of the Chinese Academy of Sciences, told the global times on the 16th that LIGO has established an alliance, which will send relevant information to other organizations that join the Alliance for the events detected by the alliance. These institutions use their own telescopes, after detecting a gravitational wave event, to see if they can find the corresponding light wave. The telescopes of these institutions, which participated in the launch on the evening of the 16th, detected something corresponding.
What is the significance of Science
Chen Xuelei said that because the mass of a neutron star is much smaller than that of a black hole, to detect events generated by a neutron star, a higher sensitivity is required at the same distance. All in all, this discovery is not the same as the previous gravitational wave events, so it provides a new observation method of astronomical phenomena. In addition, when the two black holes merge, they will certainly emit gravitational waves, but it is not clear whether they will emit light waves, but when the neutron stars merge, they are more likely to produce light waves, so this discovery provides us with more information. For the observation of gravitational waves, only two detectors, LIGO and Virgo, are available at present, and only a few observation data are available, so the information available is limited. The observation of light wave or electromagnetic wave has always been the traditional observation means of astronomers. Together observation gives a lot of information and details, which helps us to better observe the gravitational wave.
Xiong Shaolin, researcher of the "hundred talents plan" project of the Institute of high energy of the Chinese Academy of Sciences, said, "this is the first time that human beings have detected gravitational waves and their electromagnetic counterparts at the same time, and it is a very important milestone in gravitational wave astronomy. It has epoch-making significance in the history of astronomy and physics, and officially ushered in the era of multi messenger gravitational wave astronomy. '
What's the use of studying gravitational waves
According to Chen Xuelei, at present, gravitational waves play an important role in providing an important source of information for us to further study Astrophysical Processes. Whether two black holes coexist or two neutron stars coexist, the phenomenon is very complex at the final stage. On the one hand, there are complex interactions of gravitational field, which are highly nonlinear in the end, and space-time may change dramatically. On the other hand, from the physical point of view, in addition to space-time, there is also matter. For neutron stars, the matter in them is also very dense matter. According to the general model, neutron stars are made up of many high-density atomic nuclei, most of which are neutrons. What kind of complexity will be produced when two neutron stars collide For example, we also want to know that through these understandings, we can even deeply investigate the basic physical laws of the universe. Now we have not only gravitational wave observation, but also optical observation, which provides us with a lot of information, and will have great development in the future. Interstellar crossing is the plot of science fiction, the real situation is not necessarily as dramatic as the novel, but there may be a very close connection here, and the search for these things may have very interesting physical laws.
Yang Yuguang, Secretary General of the Space Transportation Committee of IAF and researcher of the second Academy of China Aerospace Science and Technology Corporation, said that the most important significance of gravitational waves is that all human observations of nature, including astronomical observations, from the past to the present mainly rely on electromagnetic waves, that is, radar or optical wave band electromagnetic waves to detect the unknown world. With gravitational waves, we have a new way to detect nature, which is a qualitative difference. The detection of gravitational wave may make us know more about the time and space changes of black holes, neutron stars and other celestial bodies when some phenomena and drastic changes occur, so it is very useful to understand the material world.