Black Holes

The birth of a black hole is among the possible outcomes at the death of a star. Notably, a black hole is a region in time-space where nothing can escape. In the year 1784, astronomer John Michel idealized the existence of phenomenon bodies, with characters of black holes as we know them today. After Michel, various scientists, including Einstein, Newton, Kepler, Hawkins, and others, have made significant inventions concerning the formation, properties, and effects of black holes on other elements of the universe.

Black holes are one of the possible outcomes of the death of a star. However, black holes are formed after the death of only high-mass stars (Lewin, and Van der Klis 150). A high mass start is more than ten times heavier than our solar system’s star– the sun. Therefore, a black hole evolves from a high mass start, a process that may take up to tens of billions of years.

Like all stars, a high-mass start comprises hydrogen gas, which undergoes nuclear fusion process into helium. Notably, the formation of a star happens when a giant cloud of molecular gas or dust interacts with a passing star or absorbs shock waves from a supernova. Both occurrences lead to the gravitational collapse of the cloud. The conversion of angular momentum at the innermost region of the nebula is high enough to cause high-speed rotation of matter, and pressure due to gravitational collapse cause very high temperatures, a state called proton star. As temperature increases past 15 million degrees, a proton star changes to a start similar to our sun, shining for billions of years after that. Our sun has been shining for 4.57 billion years so far.

Both small and large stars undergo an almost similar process. Over time, stars expend their hydrogen content, which is the primary fuel. As hydrogen runs out, a low-mass star expands into a red giant star, while a high-mass star expands into a giant red star (Lewin, and Van der Klis 156). A small start expands again into a planetary nebula and then shrinks into a white dwarf. A massive star self implodes into a supernova to form a neutron star or a black hole. Hence, the size of a star is the primary factor that would determine the formation of a black hole. Our star is small; thus, it cannot become a black hole.

A black hole exhibits powerful gravitational acceleration, such that nothing can escape it. It is an ideal reference point for scientists to relate Einstein’s theories of relativity. Studies show that constant light flashes near a black hole are likely to appear slow than hose away from it. The effect is called gravitational time dilation. That is, an observer notices time slow down for an object approaching a black hole. However, past the event horizon, which is the theoretical boundary of a black hole, an object is no longer visible, and neither can it escape the black hole (Wheeler 179). Depending on the size of the black hole, which also depends on the size of the black hole, an event horizon has strong or weak tidal waves. For a small black hole, an object collapses under tidal waves near the event horizon, where it is stretched on two ends and pressed on sides, a process called spaghettification. In large black holes, objects may not undergo spaghettification, but go past event horizon unchanged, but cannot escape (Hawking). Within a back hole, elements are changed into iron, which is the most stable element. The gravitational collapse is so high to produce X-ray and gamma radiation as explained by Hawkins. Hence, scientists identify black holes by tracing the behavior of starts around a radiation source. Also, the amount of electromagnetic waves emitted helps to identify a black hole as large or small. Every galaxy has a super black hole, around which all solar systems revolve around. Besides, there are other black holes throughout solar systems. For instance, the Cygnus X-1 system is suspected to be a black hole due to its emission of X rays, hence the suffix X. Scientists calculate the mass of Cygnus X-1 relative to the mass of our star and its age (Liebert et al. 1). Hence, the properties of a start may help in prediction those of a black hole.

Works Cited

Liebert, James et al. “The Age And Progenitor Mass Of Sirius B.” The Astrophysical Journal, vol 630, no. 1, 2005, pp. L69-L72. IOP Publishing, doi:10.1086/462419. Accessed 3 Dec 2019.

Hawking, Stephen W. A Brief History Of Time. Bantam Books, 1998.

Lewin, Walter, and Michiel Van der Klis. Compact Stellar X-Ray Sources. Cambridge University Press, 2010.