Finally, A Black Hole Captured
Black hole, a point of Infinite compactness;
Perforation in the timeless emptiness
Of outer space, deep space, a place
Of absolute no legroom:
A space/place I’ve no words for.
Where (if one can use a where)
The gravity is such a weight, so great
No light can come away.
It can’t escape, it can’t get out
No matter how you pout or shout;
Electro- radiation quanta
In a spectrum we can measure
Which we choose to christen photons,
In a wavelength spectrum of all colors we can see!
Oh my, oh me!
Partly wave/and particle
To which the journey in a vacuum
At the speed of dash_ kilometers a second
We’ve assigned the name of Light
Is swirling energetically -
Which sounds as if it’s very busy
When the only thing is seems to do
Is eat. How sweet!
A wobbling hole whose only job
Is gobbling up, down, on and in
A not two-day but ever-daily binge.
How droll!
A hole of black
From which no something or no nothing’s ever, ever
Coming back!
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More Bits Of The Puzzle
Now that we’ve captured,
More than pictured
One small hole, one little black, galactic hole
(for after all
it’s only fifty-six our suns) -
One wonders:
“What is black hole knowledge good for? And,
“Where do we go from here?”
I answer in my inexperience and ignorance -
My lack of information, cluelessness and innocence:
All knowledge of that kind must lead, by definition to
more knowledge of some kind;
Putting more and more bits of the collage, bits that we
find
So that we understand more of the whole.
And isn’t that the goal?
To understand the whole?
A black hole is a region of spacetime with such strong gravitational effects that nothing (not even particles or electromagnetic radiation such as light) can escape from it. Black holes of stellar mass are expected to form when very massive stars collapse at the end of their life cycle. After it forms it may continue to grow by absorbing mass from its surroundings. By absorbing other stars and merging with other black holes, supermassive black holes of millions of solar masses may form. There is general consensus that supermassive black holes exist in the centers of most galaxies. The idea was 1st proposed by English clergyman John Michell in a 1784 letter. His simplistic calculations assumed that such a body, which he called a "dark star," might have the same density as the sun and concluded that it would form when a star's diameter exceeds the sun's by a factor of 500 if the surface escape velocity exceeds the speed of light. The French Pierre-Simon Laplace physicist went further in his work on gravitational collapse and suggested there could be massive stars with gravity so great that not even light could escape from their surface. In 1915 Albert Einstein developed the theory of general relativity, which predicts that a sufficiently compact mass can deform spacetime to form what early 20th-century, physicists called a "gravitationally collapsed object". A few months later Karl Schwarzschild found a solution to the Einstein field equations, which describes the gravitational field of a point mass and a spherical mass. And a few months after that Johannes Droste wrote more extensively about its properties; these solution had a peculiar behavior at what is now called the Schwarzschild radius, where it became singular, meaning that some of the terms in the Einstein equations became infinite. In 1924 Arthur Eddington showed that the singularity disappeared after a change of coordinates; 2 years later he commented on the possibility of a star with mass compressed to the Schwarzschild radius and noted that Einstein's theory allows us to rule out overly large densities for visible stars since "a star of 250 million km radius could not possibly have so high a density as the sun. Firstly, the force of gravitation would be so great that light would be unable to escape from it, the rays falling back to the star like a stone to the earth. Secondly, the red shift of the spectral lines would be so great that the spectrum would be shifted out of existence. Thirdly, the mass would produce so much curvature of the space-time metric that space would close up around the star, leaving us outside (i.e., nowhere)." It was not until 1933 that Georges Lemaître realized that the singularity at the Schwarzschild radius was a non-physical coordinate singularity.
ReplyDeleteIn 1931, Subrahmanyan Chandrasekhar calculated that a non-rotating body of electron-degenerate matter above a certain limiting mass has no stable solution, and in 1939 Robert Oppenheimer predicted that no physical law was likely to intervene and stop at least some stars from becoming gravitationally collapsed objects. He interpreted the singularity at the boundary of the Schwarzschild radius as indicating that this was the boundary of a bubble in which time stopped, so he called the collapsed stars "frozen stars", because to an outside observer this phenomenon would occur at the instant where its collapse takes it to the Schwarzschild radius. In 1958 David Finkelstein identified the Schwarzschild surface as an event horizon, "a perfect unidirectional membrane: causal influences can cross it in only one direction," thus extending Oppenheimer's results to include the point of view of infalling observers and therefore interpretating the phenomenon as a region of space from which nothing can escape. in the early 1960s Robert H. Dicke compared the phenomenon to the Black Hole of Calcutta, notorious as a prison where people entered but never left alive. (In 1756 Siraj ud-Daulah, the Nawab of Bengal, held 164 British and Anglo-Indian soldiers and Indian civilians
ReplyDeleteprisoner for 3 days in Ft. William in June 1756; during the 1st night 143 of them died from suffocation and heat exhaustion.) The term "black hole" was 1st used in print by "Life" and "Science News" magazines in 1963, the year Roy Kerr found the exact solution for a rotating black hole. Two years later Ezra Newman found the axisymmetric solution for a black hole that is both rotating and electrically charged. In April 2019 the Event Horizon Telescope project released the 1st-ever photograph of a black hole at the center of the huge galaxy Messier 87, about 55 million light-years from Earth. The black hole has a mass estimated to be 6.5 billion times more massive than our sun, almost the size of our entire solar system. The Event Horizon Telescope is a group of 8 radio telescopes on 5 continents which all observed the same areas of space over the course of 1 week in April 2017. sorting through the vast amounts of data took months. The data was equivalent to 5000 years of mp3 files recorded onto a 1/2 ton of hard drives which were analyzed by supercomputers for months to get the image. The crescent-shaped emission ring and central shadow are gravitationally magnified views of the black hole's photon ring and the photon capture zone of its event horizon. The crescent shape arises from the black hole's rotation and relativistic beaming; the shadow is about 2.6 times the diameter of the event horizon.