Black Hole #shorts
Channel: Public Domain Video Content
Date: 2022-11-28

Black Hole

A black hole is a region of space from which nothing, not even light, can escape. According to the general theory of relativity, it starts existing when spacetime gets curved by a huge mass. There is a sphere around the black hole. If something goes inside the sphere, it can not leave.
This sphere is called the event horizon. A black hole is black because it absorbs all the light that hits it. It reflects nothing, just like a perfect black body in thermodynamics. Under quantum mechanics, black holes have a temperature and emit Hawking radiation, which makes them slowly get smaller.
Because black holes are very hard to see, people find them by the way they affect other things near them. The place where there is a black hole can be found by tracking the movement of stars that orbit somewhere in space. Or people can find it when gas falls into a black hole, because the gas heats up and is very bright.
This can be found by telescopes on Earth or by Earth-orbiting telescopes. Inside a black hole the rules of physics are very different. Astronomers have found evidence of supermassive black holes at the center of almost all galaxies.
In 2008 astronomers found evidence that a supermassive black hole of more than four million solar masses is near the Sagittarius A* part of the Milky Way galaxy.


#shorts

Text:

CC BY-SA 3.0, https://simple.wikipedia.org/wiki/Black_hole

Images:

By Urbane Legend (optimised for web use by Alain r) - en:Image:BlackHole_Lensing_2.gif, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=1668218
By ESA/Hubble, CC BY 4.0, https://commons.wikimedia.org/w/index.php?curid=78156
By Event Horizon Telescope - https://www.eso.org/public/images/eso1907a/; JPG saved from full size TIFF and converted with maximum quality level 12 in Photoshop 2019., CC BY 4.0, https://commons.wikimedia.org/w/index.php?curid=77916527