Light Entering Black Hole: Observed or Not?

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Discussion Overview

The discussion centers around the question of whether there is observational evidence for light entering black holes and subsequently disappearing. Participants explore the nature of black holes, the evidence for their existence, and the implications of light behavior in their vicinity.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant questions whether there is direct observation of light entering a black hole and disappearing.
  • Another participant notes that while black holes were once theoretical, they are now inferred from various high-energy phenomena, though direct observation remains elusive.
  • It is suggested that the absence of visible light from a massive object can indicate the presence of a black hole, rather than focusing solely on light that cannot escape.
  • Evidence from X-ray binaries is presented as supporting the existence of black holes, with details on how matter behaves around these objects and the implications for their mass.
  • Some participants discuss the indirect evidence provided by the orbital motion of stars around supermassive objects in galactic cores, suggesting these must be black holes based on their mass and size.

Areas of Agreement / Disagreement

Participants express varying views on the nature of evidence for black holes, with some focusing on indirect observations and others questioning the lack of direct evidence for light entering black holes. The discussion remains unresolved regarding the clarity of observational proof.

Contextual Notes

Participants highlight the limitations of current observational techniques and the challenges in directly observing black holes, as well as the dependence on interpretations of indirect evidence.

spidey
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this may be very silly question but i want to confirm with you guys...Its been said when light goes into black hole it can't escape but do we have any proof or observation for light entering a black hole and disappearing..has anyone observed light entering black hole and disappearing?
 
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Until recently, black holes were only a theoretical curiosity with no observational support. Now, the presence of black holes has been inferred in numerous studies from various high-energy phenomena such as quasars, X-ray binary systems and the motion of stars in the inner Galaxy. Nobody has ever directly observed the blackness of a black hole though, but the next generation of optical interferometric telescopes should be able to come close.
 
Well, one thing about black holes is that if you detect an extremely massive object and you can't see it, that's because it's a black hole. It's not so much the light going in and not coming back out that matters, but the fact that it isn't generating any itself. Before supernova: bright star. After supernova: nothing visible, but presence of a massive object still detectable.
 
russ_watters said:
Well, one thing about black holes is that if you detect an extremely massive object and you can't see it, that's because it's a black hole. It's not so much the light going in and not coming back out that matters, but the fact that it isn't generating any itself. Before supernova: bright star. After supernova: nothing visible, but presence of a massive object still detectable.


Do we have any solid proof or observations that there are heavy massive objects but not visible? how can we know that there is a massive object?
 
Observations of X-ray binaries provide evidence for black holes formed from stellar collapse. An X-ray binary, so named because it emits X-ray radiation, consists of a dark compact object orbited by a normal star.

Pairs of stars often orbit each other in binary systems. If massive enough, one star of the pair may collapse, while the other member of the pair remains a normal star. A normal star orbiting closely around a black hole can transfer matter to the black hole. The temperature of the infalling matter increases as it approaches the black hole, until it glows strongly with X-rays that can often be detected easily by telescopes orbiting the Earth.

So, X-ray binaries supply prime candidates for black holes, but dark compact objects other than black holes might also emit X-rays. However, a compact object more massive than about two solar masses has too much mass to be either a white dwarf or neutron star, and consequently must be a black hole. Observations of the normal star's orbital velocity give estimates for the masses of both objects in an X-ray binary. Compact objects in several observed X-ray binaries have masses that fall in range required for black holes.

Comparatively new results published in 2003 seem to indicate that in certain systems, matter falls directly into a compact object without hitting a material surface. Since black holes do not have a material surface, this gives strong indirect evidence that the matter is falling into a black hole.

Observations of the orbital motion of stars and other objects about the central cores of galaxies suggest strongly that supermassive objects reside in galactic cores. The small sizes of galactic cores suggest strongly that the supermassive objects must be black holes. Our own galaxy, the Milky Way, has a three million solar mass black hole in its core.
 
Thank you all for explaining..
 

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