A black hole is a region of spacetime exhibiting such strong gravitational effects that nothing—not even particles and electromagnetic radiation such as light—can escape from inside it. The theory of general relativity predicts that a sufficiently compact mass can deform spacetime to form a black hole. 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. In many ways a black hole acts like an ideal black body, as it reflects no light. Moreover, quantum field theory in curved spacetime predicts 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.
- ↑ Wald 1984, pp. 299–300
- ↑ Wald, R. M. (1997). "Gravitational Collapse and Cosmic Censorship". arΧiv:gr-qc/9710068 [gr-qc].
- ↑ Overbye, Dennis (8 June 2015). "Black Hole Hunters". NASA. Archived from the original on 9 June 2015. https://web.archive.org/web/20150609023631/http://www.nytimes.com/2015/06/09/science/black-hole-event-horizon-telescope.html. Retrieved 8 June 2015.
- ↑ "Introduction to Black Holes". https://www.socratease.in/chapters/intro-to-black-holes-1.
- ↑ Schutz, Bernard F. (2003). Gravity from the ground up. Cambridge University Press. p. 110. ISBN 0-521-45506-5. https://books.google.com/books?id=P_T0xxhDcsIC.
- ↑ Davies, P. C. W. (1978). "Thermodynamics of Black Holes". Reports on Progress in Physics 41 (8): 1313–1355. doi:10.1088/0034-4885/41/8/004. Bibcode: 1978RPPh...41.1313D. Archived from the original on 10 May 2013. https://web.archive.org/web/20130510184530/http://cosmos.asu.edu/publications/papers/ThermodynamicTheoryofBlackHoles%2034.pdf.