The Schwarzschild solution was published in 1916. It produced a vision of a universe devoid of everything except a spherical constant object and an observer. As the observer passed...

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Discovery of Black Holes

Gargantua - Interstellar

Hello Readers!

I have already explained the functioning of Black Holes in the post Black Holes. Let us trace how these monstrous objects came to be theorised and astonishingly, discovered.

The year was late 1915. During the First World War, many scientists of their time redirected their focus onto research for easy wins for their country in the war. One notable example includes Fritz Haber, who devised the Haber's Process - an industrial method that can produce ammonia. This led to a rise in food products all around the globe.

Haber realised that related nitrogenous fertilisers could also be used as explosives, and soon his invention was supplying the German armies.

Some scientists denounced the war, seeking solace and no involvement. One such person was Albert Einstein, who worked on some new equations.

Einstein found out what Newton had realised but not corrected in the laws of gravity.

Space-Time and the Schwarzschild Solution

Gravity is a weak force, and given the vast distances between two bodies, like the Sun and Jupiter, it is unrealistic to expect gravity to pull them together directly. Einstein proposed the idea of an underlying framework that supports both objects.

The distortions or curving of the originally straight medium result in the gravitational force.

Such a medium has to trace the changes to the objects along with time, hence both space and time remain inclusive. This framework is called Space-Time (an oversimplification).

This breakthrough in understanding the universe spotted the eye of Karl Schwarzschild, a German physicist sent to aid German troops to the East. He wrote back to Einstein regarding a solution to his equations of gravity.

In 1916, the Schwarzschild solution was published. It produced a vision of a universe devoid of everything except a spherical constant object, and an observer. As the observer passed along this body, its path curved towards it. This was labelled as the attraction of gravity towards the body.

In this solution, others pointed out two faults.

At the extreme centre of the body, one of the terms in the equation which is a fraction, ascends to infinity due to division by zero. It predicted infinite gravity at that point. This point was marked as Singularity and was largely left untouched. But, at a distance from the body now called the Schwarzschild Radius, another term that is a fraction, ascends to infinity. This meant that there was another singularity.

People visualised the body as a well in the even fabric of spacetime. At the Schwarzschild Radius, the curvature becomes so steep that the escape velocity is the speed of light. Essentially, another which crosses this limit is doomed to fall in forever.

Hence, you now know that this body is capable of consuming light and matter, which is a Black Hole.

Opposition

Most scientists, however, were dubious of the existence of a black hole. Because it required a large amount of energy to be concentrated in a small area. The most likely place was a supernova (refer to post Star Life), but scientists published opposing theories, suggesting that mere supernovae do not possess the prowess to degenerate into a black hole.

It was first believed that the shockwave of the supernova would blow all matter away, limiting the chances for the remnant to regain. However, evidence suggested that most matter still lurked within the vicinity of the new white dwarf.

Physicists had become obviously hostile at this point to the black hole concept. They stated that while a star collapsed on itself before the explosion, the atoms of the core would be compressed so tightly that electrons would begin to venture very close to each other. Here, the degenerate repulsion between the electrons would prevent further collapse.

Yet, this was disproved when a limit was found - The Chandrasekhar Limit above which the core would likely implode and the star would undergo supernova.

Scientists scrambled and justified that such objects would effectively destabilise physics, yet unexplained phenomena hinted at the idea of these cosmic giants. Some of these include the loss of matter of the star Cygnus X-1, which appears to be slowly consumed by some giant undetectable object, and the change of orbits of stars in the centre of the Milky Way as if being tossed around by something.

All of the debates were put to rest when the first picture of a black hole was taken.

The first image of a black hole (Messier 81) - Eso.org

Whew! A black hole undertook a big journey for humans to discover. Most scientists of the mid and late 20th centuries opposed black holes, yet it is healthy to have such debates while working on fundamental constraints of existence. You can check out other enthralling discoveries in this blog such as James Webb vs Current Cosmology, Boötes Void, Extraterrestrial Life and Universe's Doom: Three Theories.

This is where I will conclude my post.

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Thank you for reading

Aditya VN Kadiyala