Could You Be Living Inside A Black Hole?

A black hole is a region of spacetime from which gravity prevents anything, including light, from escaping.

The theory of general relativity predicts that a sufficiently compact mass will deform spacetime to form a black hole. Around a black hole, there is a mathematically defined surface called an event horizon that marks the point of no return. The hole is called “black” because it absorbs all the light that hits the horizon, reflecting nothing, just like a perfect black body in thermodynamics. Quantum field theory in curved spacetime predicts that event horizons emit radiation like a black body with a finite temperature. This temperature is inversely proportional to the mass of the black hole, making it difficult to observe this radiation for black holes of stellar mass or greater.

Objects whose gravity fields are too strong for light to escape were first considered in the 18th century by John Michell and Pierre-Simon Laplace. The first modern solution of general relativity that would characterize a black hole was found by Karl Schwarzschild in 1916, although its interpretation as a region of space from which nothing can escape was first published by David Finkelstein in 1958. Long considered a mathematical curiosity, it was during the 1960s that theoretical work showed black holes were a generic prediction of general relativity.

The discovery of neutron stars sparked interest in gravitationally collapsed compact objects as a possible astrophysical reality.

Black holes of stellar mass are expected to form when very massive stars collapse at the end of their life cycle. After a black hole has formed it can 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.

Despite its invisible interior, the presence of a black hole can be inferred through its interaction with other matter and with electromagnetic radiation such as light. Matter falling onto a black hole can form an accretion disk heated by friction, forming some of the brightest objects in the universe. If there are other stars orbiting a black hole, their orbit can be used to determine its mass and location. These data can be used to exclude possible alternatives (such as neutron stars). In this way, astronomers have identified numerous stellar black hole candidates in binary systems, and established that the core of our Milky Way galaxy contains a supermassive black hole of about 4.3 million solar masses.

Man’s best friend

Before the evolution of wolf into dog, it is posited that Man and wolf worked together hunting game.

Wolves were the superior tracker but man was the superior killer, thus wolves would lead man to the prey and man would leave some of the meat to the wolves. This working relationship eventually led to the evolution of dogs, although there is controversy as to the exact nature of that transition.

Some say wolves evolved naturally into dogs, wherein the wolves that worked best with humans slowly began to assimilate and pass their domesticated genes down. Others say that humans took wolf pups and raised them to be domesticated. Either way, man and dog formed a working relationship. Previous to the 19th century, dogs, other than lap dogs, were largely functional. Used for activities such as hunting, watching and guarding, language describing the dog often reflected these positions within society.

According to the Oxford English Dictionary,

In the oldest proverbs and phrases dogs are rarely depicted as faithful or as man’s best friend, but as vicious, ravening, or watchful.

Beginning in the 18th century, multiplying in the 19th and flourishing in the 20th century, language and attitudes towards dogs began to shift. Possibly, this societal shift can be attributed to discovery of the rabies vaccine in 1869.

The earliest citation of the actual word choice is traced to a poem printed in the The New-York Literary Journal, Volume 4, 1821:

  • The faithful dog – why should I strive
  • To speak his merits, while they live
  • In every breast, and man’s best friend
  • Does often at his heels attend.

In 1870 Warrensburg, Missouri, George Graham Vest represented a farmer suing for damages after his dog, Old Drum, was shot and killed. Vest’s closing speech included this quote, “The one absolutely unselfish friend that a man can have in this selfish world, the one that never deserts him and the one that never proves ungrateful or treacherous is his dog.” In 1958, a statue of Old Drum was erected on the Johnson County Courthouse lawn containing a summation of Vest’s closing speech, “A man’s best friend is his dog.”