After 50 Years, Stephen Hawking's Theory On Black Holes Proven Correct
Researchers found that as per the calculations, the total surface area of the combined black hole was greater than the sum of the two smaller black holes. This observation solidifies the area law that claims that the size of black holes does not decrease over time.
One of Stephen Hawking¡¯s famous theorems has been proven after researchers observed ripples created in space-time by the fusion of two black holes.
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The theorem was first proposed in the year 1971 that claimed that it was impossible for a black hole to decrease in size over time. The theorem was based on Einstein¡¯s theory of relativity that defined gravitational waves and black holes.
Physicists have always been in awe of the black hole area theorem as it works on a similar thermodynamic principle that entropy cannot decrease over time. It increases at a consistent pace, and the new observations further strengthen this theory.
The research, led by astrophysicist Maximiliano Isi from the Massachusetts Institute of Technology, used data from gravitational waves released when two black holes fused into one.
They split the gravitational wave data that was registered by the Advanced Laser Interferometer Gravitational-Wave Observatory (LIGO) into two categories -- before and after the merger. They used both measurements to calculate the surface areas of the black holes in each category.
Researchers found that as per the calculations, the total surface area of the combined black hole was greater than the sum of the two smaller black holes. This observation solidifies the area law that claims that the size of black holes does not decrease over time.
Lead author Maximiliano said in a statement to Live Science, "A black hole's surface area can't be decreased, which is like the second law of thermodynamics. It also has conservation of mass, as you can't reduce its mass, so that's analogous to the conservation of energy."
Space.com highlights that the larger mystery, however, is when researchers try to integrate general relativity with quantum mechanics. At this moment, all the rules start to fall apart and the area law actually gets shattered.
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This is because black holes cannot shrink, according to general relativity, but they can as per quantum mechanics. Hawking had also developed a concept dubbed Hawking radiation where a fog of particles are emitted at the edges of a black hole caused by random quantum effects. This causes the black hole to shrink and evaporate over a timeline several times more than the age of the universe.
This phasing out could happen over timescales that are long enough to not violate the area law in the short term -- a small consolation for physicists.
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Isi added, "Statistically, over a long period of time, the law is violated. It's like boiling water, you're getting steam evaporating from your pan, but if you only limit yourself to looking at the disappearing water inside of it, you might be tempted to say the entropy of the pan is decreasing. But if you take the steam into account too, your overall entropy has increased. It's the same with black holes and Hawking radiation."
He concluded by stating, "I'm obsessed with these objects because of how paradoxical they are. They're extremely mysterious and confounding, yet at the same time, we know them to be the simplest objects that exist. This, as well as the fact that they're where gravity meets quantum mechanics, makes them the perfect playgrounds for our understanding of what reality is."