Black Hole: We finally see it!
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April 10, 2019, is a historical moment since finally humans can see the black hole image for the very first time.
It is such a long journey and takes works from so many people who involved. But, this moment is reminded me with my bachelor thesis, I wrote about the black hole. My writing based on Laura Mersini-Houghton's paper and Stephen Hawking lecture on the black hole in 2014. Resuming their works, Mersini-Houghton brings up a hypothesis that black hole is not even formed at all theoretically. Besides, Stephen Hawking, who credited over the black hole idea, also revise this idea at a talk that given at the fuzz or fire workshop, The Kavli Institute for Theoretical Physics, Santa Barbara, August 2013. He said that there is an absence of event horizons, it means there are no black holes: it is based on the sense of regimes from which light can’t escape to infinity. However, he delivers the concept of apparent horizons that persist for a period of time. It suggests that black holes should be redefined as metastable bound states of the gravitational field.
Blackhole misconception
Back in the old days, I often get questions about black holes. This is related to the thesis work I did at that time. Many people are mistaken about black holes. I often say black holes are friends of the sun! I mean, they are both stars initially. As we know stars have a life cycle. They were born, they live, and they died.
Starting from a singularity and returning to the singularity. The Big Bang Theory, which is one of the universe’s creation theories, states that the universe originated from a singularity that expanded with a Big Bang. It was stated through this theory that the existence of the universe began in 13–14 billion years ago by a large explosion. The universe is in an initial state (after an explosion) that is a high temperature, tight and in the form of a uniform particle fog, and expands rapidly. But the conditions before the big explosion have not been explained and what caused the explosion.
Slowly the universe cools and processes until then gravity begins to form stars and galaxies from gas clouds. Once formed, the star will experience a fusion stage. Thermonuclear fusion is a process that occurs in the star’s core through various stages of the combustion of hydrogen, helium, carbon, neon, oxygen, magnesium, and silicon. The fusion process will continue until finally the star’s fuel runs out accompanied by a star’s gravitational collapse. The duration of the fusion process to the final evolution stage of a star depends on the mass of the star. Black holes, white dwarf stars, and neutron stars are massive stars that represent the final phase of the evolution of a star’s life. Stars with masses more than 8 times the mass of the Sun will end their fate through supernova phenomena. In some cases, a star with a mass equal to 20 times the mass of the sun is found or more will experience a more severe end by experiencing hypernova; an explosion that was more powerful than a supernova until it finally left a black hole.
Now, let us embrace this moment of joy. I still wonder how far science will bring humans in space. Because there will still be many scientific theories formulated. However, as much as a theory is proven correct, but once the theory is proven wrong, it is indisputable. This is what scientists do: they prove a theory is wrong, not prove the truth of a theory.
”Black holes aren’t as black as thought.”
Stephen Hawking
References:
Glendenning, N.K.,2007, Special and General Relativity with Applications to White Dwarfs, Neutron Stars and Black Holes First Edition, Springer, England, California.
Hawking, S. W., 2014, Information Preservation on Weather Forecasting for Black Holes, arXiv: 1401.5761v1 [hep-th] 22 Jan 2014.
Mersini-Houghton, L., 2014, Backreaction of Hawking Radiation on a Gravitationally Collapsing Star I: Black Holes?, Physics Letter B 738, 61–67.
Originally published at my previous personal blog on April 10, 2019.
