How do foreigners think of astronomy
For modern astronomy, our channels for obtaining information are usually introduced by various media, and the most information sources in this regard are often information on the Internet.
Some unprofessional introductions, coupled with the fantasies of literati, the use of metaphysicists, and the compatible expressions of religious people, complicate the originally simple problems.
The author is not a professional physicist, he just likes to look up at the sky. However, the author just wants to know the real progress of astronomy modernity, rather than science fiction or fantasy expression. Based on this consideration, the author searched for introductions about astronomy abroad, which was also through the Internet. For example, find the introduction to astronomy on , Wikipedia, .
This is also content on the Internet. The authenticity still needs to be identified by people with more professional abilities. However, this introduction is not exactly the same as the information and expressions in this aspect searched on the domestic Internet. On the one hand, unknown statements are relatively objective; on the other hand, the materials expressed in reference have their origins. Some compilation papers taste.
The author will quote the original text and translate it. Thanks to the automatic translation software, I didn’t have to read the dictionary to know many forgotten words. The whole text it translated was really a bit unintelligible. In addition, the language order was not in line with the Chinese speaking habits, so I had to translate it again by myself. I have tried several full-text translation software, but there are still differences between each other, so I won’t evaluate the advantages and disadvantages.
For each paragraph translation, the author will use the notes to analyze or interpret it again, which is just a personal subjective idea.
Black hole (black hole)
Source: https://en.wikipedia.org/wiki/Black_hole
A black hole is a region of spacetime exhibitioning such strong gravitational effects that nothing—not even particles and electronmagnetic radiation such as light—can escape from inside it.[1] The theory of general relative predicts that a sufficiently compact mass can deform spacetime to form a black hole.[2][3] The boundary of the region from which no escape is possible is called the event horizon. Although the event horizon has an enormous effect on the fate and circumstances of an object crossing it, no locally detectable features appear to be observed.[4] In many ways a black hole acts like an ideal black body, as it reflects no light.[5][6] Moreover, quantum field theory in curved spacetimepredicts that event horizons emit Hawking radiation, with the same spectrum as a black body of a temperature inversely proportional to its mass. This temperature is on the order of billionths of a kelvin for black holes of stellar mass, making it essentially impossible to observe.
(1) , Wald 1984, pp. 299–300
( 2) , Wald, R. M. (1997). "Gravitational Collapse and Cosmic Censorship". In Iyer, B. R.; Bhawal, B. Black Holes, Gravitational Radiation and the Universe. Springer. pp. 69–86. arXiv:gr-qc/9710068. doi:10.1007/978-94-017-0934-7. ISBN 978-9401709347.
(3), ^ Overbye, Dennis (8 June 2015). "Black Hole Hunters". NASA. Archived from the original on 9 June 2015. Retrieved 8 June2015.
(4), ^ "Introduction to Black Holes". Retrieved 2017-09-26.
(5), ^ Schutz, Bernard F. (2003). Gravity from the ground up. Cambridge University Press. p. 110. ISBN 978-0-521-45506-0. Archived from the original on 2 December 2016.
(6), Davies, P. C. W. (1978). "Thermodynamics of Black Holes"(PDF). Reports on Progress in Physics. 41 (8): 1313–1355. Bibcode:1978RPPh...41.1313D. doi:10.1088/0034-4885/41/8/004. Archived from the original (PDF) on 10 May 2013.
(Note: To facilitate searching the source of the original text, the cited materials are mentioned after each paragraph, but no translation is done.)
Translation : A black hole is a space-time region that shows a very powerful gravitational effect. Even particles and light, such as electromagnetic radiation (such as light) cannot escape from it. [1]
(Note: This sentence clearly states that a black hole is not a hole, but a space-time area. Since electromagnetic waves, such as light, cannot escape, based on the understanding of four-dimensional curved space-time , there is such an invisible space-time area. In English interpretation,
hole usually means a hole, but there are still loopholes in English nouns; the meaning of dilemma, a common saying or even a bad place; the meaning of ghost place. Modern physics is connected to the world of modern physics. Commonly used metaphors to express things that cannot be explained simply and directly. Therefore, this hole refers to a special limit and curved space-time area that is bending in space-time and understanding. It cannot be directly observed, like an observation loophole on the space-time network. This is indeed a bad place for conceited physics, and there is no way to understand its internal content for the time being. This should be the original meaning of the word black hole, and once the hole is understood in a popular way, it is actually wrong. This hole is just a metaphor.)
translation: General Relativity theory believes that a sufficiently dense mass can deform space-time and form black holes. [2] [3]
(Note: mass not only has the meaning of physical quality, but also has a lot of meaning. But this sentence cannot reflect a lot of meaning in literal translation.)
translation: The boundary of this unavoidable space-time region is called the event horizon. Although the event horizon has a huge impact on the fate and circumstances of the object passing through it, no locally detectable features are observed. [4] In many ways, since it cannot reflect any light, a black hole resembles an ideal bold . [5] [6]
(Note: no, the author translates it as not any. This "any" is very strong in tone, but it conforms to the attitude of the early black hole theory. Hawking proposes that black hole radiation is a later event, and has not yet been confirmed. This sentence also expresses a helpless reality of physical observations so far. There is no observation evidence inside the black hole event horizon.
Is the black hole black? This question itself is not accurate. From the outside, we can only see the event horizon of the black hole; and inside, there is no observation result. The black hole horizon and the black hole entity feel that there is a space interval, just a personal idea. Inside the black hole, whether black or not, it is just a conjecture of theoretical physical hypothesis. )
Translation: In addition, the quantum field theory predicts that the event horizon of the bending space-time emits Hawking radiation , whose spectrum and temperature are the same as the bold body with inverse proportional to its mass. For a stellar mass black hole, this temperature is about one billionth of a Kelvin, making it essentially impossible to observe.
Objects whose gravitational fields are too strong for light to escape were first considered in the 18th century by John Michell and Pierre-Simon Laplace.[7] The first modern solution of general relative that would characterize a black hole was found by Karl Schwarzschild in 1916, although its interpretation as a region of space from which nothing can escape was first published by David Finkelstein in 1958. Black holes were long considered a mathematical curiosity; it was during the 1960s that theoretical work showed they were a general prediction of general relative. The discovery of neutron stars in the late 1960s sparked interest in gravitationally collapsed compact objects as a possible astrophysical reality.
(7), Montgomery, Colin; Orchiston, Wayne; Whittingham, Ian (2009). "Michel, Laplace and the origin of the black hole concept". Journal of Astronomical History and Heritage. 12 (2): 90–96. Bibcode:2009JAHH...12...90M.
Translation: In the 18th century, John Michel and Pierre Simon Laplace first considered objects that light cannot escape because of the gravitational field.[7]
(Note: According to Newton's gravitational equation, if light is of mass particle nature and the velocity of light is limited, then there is a possibility of such calculation results. This does not require Einstein's four-dimensional curved space-time concept of . The curved space-time concept can be used to simply calculate and derive the calculation results of this black hole.)
Translation: Although David Finkelstein first published an explanation of a black hole as a space area where nothing can escape in 1958. However, in 1916, Carl Schwartzhild had discovered the first modern solution that could describe the features of black holes based on general relativity.
(Note: Modern Western culture is very concerned about the discoverers and discovery time of theoretical development and innovation.)
Translation: Black holes have long been considered due to mathematical curiosity, until in the 1960s. Theoretical work shows that black holes are general predictions of general relativity. In the late 1960s, the discovery of neutron star sparked interest in the possible astrophysical reality of compact objects formed by gravitational collapse.
(Note: the last sentence, as a possible astrophysical reality, this expression is very physically cautious. After all, for black holes, the physics community still lacks direct internal observational evidence.)
Black holes of stellar mass are expected to form when very massive stars collapse at the end of their life cycle. After a black hole has formed, it can continue to grow by absorbing mass from its surroundings. By absorbing other stars and merged with other black holes, supermassive black holes of millions of solar masses (M☉) may form. There is general consensus that supermassive black holes exist in the centers of most galaxies.
Despite its invisible interior, the presence of a black hole can be inferred through its interaction with other matter and with electromagnetic radiation such as visible light. Matter that falls onto a black hole can form an external accretion disk heated by Friction, forming some of the brightest objects in the universe. If there are other stars orbiting a black hole, their orbits can be used to determine the black hole's mass and location. Such observations can be used to exclude possible alternatives such as neutron stars. In this way, astronomers have identified numerous stellar black hole candidates in binary systems, and established that the radio source known as Sagittarius A*, at the core of the Milky Way galaxy, contains a supermassive black hole of about 4.3 million solar masses.
On 11 February 2016, the LIGO collaboration announced the first direct detection of gravitational waves, which also represented the first observation of a black hole merger.[8] As of December 2018, eleven gravitational wave events have been observed that originated from ten merged black holes (along with one binary neutron star merger).[9][10]
(8), Abbott, B.P.; et al. (2016). "Observation of Gravitational Waves from a Binary Black Hole Merger". Phys. Rev. Lett. 116 (6): 061102. arXiv:1602.03837. Bibcode:2016PhRvL.116f1102A. doi:10.1103/PhysRevLett.116.061102. PMID 26918975.
(9), Ethan Siegel (4 December 2018) Five Surprising Truths About Black Holes From LIGO
(10), "Detection of gravitational waves". LIGO. Retrieved 9 April 2018.
Translation: A very huge star body collapses after its life cycle ends, and it is expected to form a black hole of stellar mass level. After the formation of a black hole, it can continue to grow by absorbing mass from its surroundings. By absorbing other celestial bodies and merging with other black holes, it is possible to form a supermassive black hole of millions of solar mass . It is generally believed that supermassive black hole exists in the centers of many galaxies.
(Note: The text uses stars, which means star bodies, but is usually translated as stars?)
Translation: Although the inside of a black hole is invisible, the existence of a black hole can be inferred through interactions with other matter and electromagnetic radiation such as visible light. The matter falling on the black hole forms an external accretion disk made by friction heating, forming some of the brightest objects in the universe. If other celestial bodies are operating in the orbit of a black hole, their orbits can be used to determine the mass and position of the black hole. These observations can be used to rule out confusion of like neutron stars. In this way, astronomers have discovered many candidates for star-level black holes in binary star systems and identified a radio power source called Sagittarius A* at the core of the Milky Way, containing a supermassive black hole with a mass of about 4.3 million solar.
Translation: On February 11, 2016, LIGO cooperated to announce the first direct detection of gravitational waves, which is also the first observation of the merger of black holes. [8] As of December 2018, 11 gravitational wave events have been observed, which originated from the merger of 10 black holes (and the merger of a binary neutron star). [9] [10]
(Note: The first time I directly detect gravitational waves, the author believes that the expression is inaccurate. It is the first time that the gravitational wave effect is directly detected. The current detection method is still to indirectly confirm the effect of gravitational waves by observing the effect of gravitational waves on the star body.)
(Note: The above is the summary part of the homepage of the introduction of the topic of the black hole in Wikipedia. Next, the author will translate and introduce other relevant details one by one.)
to be continued. . . . . .
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