Black Holes

Nelsienid Ortiz Mercado

Black holes are known to be a section in space where the gravity prevents all things from escaping, counting the light.  By this, it is said that they have the biggest amount of gravity present in space. The theory acknowledged as, “general relativity (theory that predicts, and explains most of the features of black holes), predicts that a suitably compact mass will deform space time to form a black hole and around it there is a mathematically defined surface called an event horizon that marks the point of no return.”(4)

Physicians called them “black” because they absorb all the light that hits the horizon, reflecting nothing, just like a perfect black body in thermodynamics. “The Quantum field theory in curved space time 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.”(4)

Naturally black holes form when stars collapse at the end of their life cycle. Stars are massive and as you may remember gravity is related to mass via the equation of the Newton’s Law of Gravity, [F=G(M1M2/r2)] where the value of the constant G is 6.67x10-11. However, not all collapsing stars form black holes. In order for an object to form a black hole it has to be compressed below a certain radius, this radius is known as the Schwarzschild radius and its given by the equation of Rs=(2GM)/c2 that was discovered in 1916 by the physicist Karl Schwarzschild. So if you wanted to turn your car or any other object into a black hole you would have to compress it down to the size of a neutrino, which is about 1x10-24m wide. Which sounds really easy; right?

There is no record on how large a black hole can be. Yet, the biggest known in existence are at the centers of many the galaxies in the universe, and have masses comparable to about a billion suns and their radius would be a significant fraction of the radius of our solar system. 

According to the general relativity there is no limit to the minimum size of a black hole. A theory according to how gravity works must also take relation of quantum mechanics and such a theory has yet to be created. A number of evidence from previous work on this theory suggests that a black hole can be no smaller than about 10-33 cm in radius. “On that small a size scale, even the apparently smooth nature of space will break down into a "rat-trap" of tunnels, loops, and other interwoven structures! At least, that's what current work suggests.”(3)

There also exist some smaller versions of black holes called “quantum mechanical black holes or mini black holes.(5) Several theories suggest that mini black holes may have been formed in the near the beginning of the universe, but there is no concrete evidence of their existence. “These mini black holes have event horizons as small as an atomic particle and might have been created during the Big Bang, the moment the universe was created.”(1)

Creating mini black holes with element accelerators depend upon less energy than previously thought. “If physicists do succeed in creating with such energies on Earth, the achievement could prove the existence of extra dimensions in the universe.”(2)

Studies show that billions of mini black holes shower the Earth every day, but luckily they are so small that they would take longer than the age of the universe to swallow the Earth whole.

… Black holes contain a new universe…

References

1. Amazing Space. http://amazing-space.stsci.edu/resources/explorations/blackholes/lesson/whatisit/mini.html (accessed May 2013)

2. Live Science. http://www.livescience.com/27811-creating-mini-black-holes.html (accessed May 2013)

3. Simonetti, J. Virginia Tech. http://www.phys.vt.edu/~jhs/faq/blackholes.html (accessed May 2013)

4. Wikipedia. Black Holes. http://en.wikipedia.org/wiki/Black_hole#Properties_and_structure (accessed May 2013)

5. Wikipedia. Micro black holes. http://en.wikipedia.org/wiki/Micro_black_hole (accessed May 2013)