The horizon of a black hole – the boundary from which no one can escape – can never shrink. At least, that’s what Stephen Hawking said in 1971. It’s now called the surface theory of black holes Confirmed for the first time By measuring gravitational waves.
To test Hawking’s theory, physicists looked at GW150914, and First discovery of gravitational gravitational waves. These gravitational waves, discovered in 2014 by the US LIGO detector, originate from two black holes merging.
If Hawking’s fifty year old theory is correct, then the horizon area of a newly formed black hole cannot be less than the sum black hole horizon surface who joined. This seems to be true with GW150914. “The outer surface may be about one and a half times larger than the number of original black holes before the collision,” the researchers wrote. Maximilian Issy From the Massachusetts Institute of Technology, USA.
Horizon = mass and rotation
Hawking’s idea that the horizontal surface of a black hole can never shrink came about when he performed calculations using Einstein’s general theory of relativity. They found that black holes prevent the surface of the horizon from sinking due to changes in mass or rotation on its axis.
Thus, the size of the horizontal surface of a black hole is related to its mass and rotation. By measuring these two properties, using gravitational waves, you can also determine the surface.
When Hawking learned in 2015 that the LIGO detector had measured gravitational waves from merging black holes, he was thrilled. He asked LEGO researchers to test his superficial theory. Unfortunately, the analytical techniques at that time were not good enough to determine the necessary information about the mass and cycles of the black hole before and after the collision. Eagle, die He died in 2018, so he couldn’t see any confirmation of his theory.
first confirmation
It wasn’t until 2019 that Isi and his colleagues succeeded in developing an analytical technique that could reconstruct the echo of GW150914. This is needed to calculate the mass and spin of the black hole due to merging. When they published these findings, they were contacted by Kip Thorne, Nobel laureate, founder of LIGO and friend of Hawking. They were also asked to use this technique to determine the mass and rotation of black holes before they collide to verify Hawking’s theory.
Essie and his colleagues calculated that the total area of the black hole’s horizon before the collision was about 235,000 square kilometers. It turned out that the surface of the black hole’s horizon after the collision was about 367,000 square kilometers.
So for GW150914, Hawking’s theory is correct. But one affirmation is not enough. So Essie and his colleagues plan to apply their method to more measurements of gravitational waves.
Issey: “Other theorists have created models that produce things that look like black holes, but don’t follow surface theory.” Further observations of gravitational waves could confirm or deny the existence of these compact bodies.
