What determines the life span of a black hole, and have we been able to record the final explosion of one?

 

What is a black hole?

A black hole is a region of space having a gravitational field so intense that no matter or radiation can escape; not even light. The gravity is so strong because matter has been squeezed into a tiny space. This can also happen, when a star is dying, and because no light can get out, people are not able to see black holes; they’re invisible.

Only scientists with space telescopes and tools can find black holes. These special tools can see how stars that are very close to black holes, act differently than other stars further away.

What is the purpose of a black hole?

Nothing, they are pretty much harmless entities, unless, of course, if you get too close to them, that are scattered across the universe.

How big are black holes?

Black holes can vary in size; big or small. Scientists believe the smallest black hole is the size of an atom. Black holes this small still would have the mass of a large mountain. The largest black holes are called “supermassive” and these black holes have masses greater than 1 million suns combined.

Scientists has proven that every large galaxy contains a supermassive black hole in the center of the galaxy. We have one in the Milky Way called the “Sagittarius A” Its mass is equal to 4 millions suns; it would also fit inside a very large ball that could hole a couple million Earths.

How do black holes form?

Scientists think the smallest black holes were formed when the universe began. They also think supermassive black holes were made at the same time as the galaxy they’re in. There are black holes called Stellar Black Holes, and they’re formed when the center of a huge star collapses. During this period, it creates a supernova; a exploding star which blasts part of the star into space.

Could a black hole destroy earth?

Black holes don’t go around in space eating stars, moons and planets. Black holes can indeed move through space. The really massive black holes at the centers of galaxies will stay there unless something catastrophic happens, like a direct collision between two galaxies. So, Earth will not fall into a black hole because no black hole is close enough to the solar system for Earth to do that.

Even if there was a black hole with the same mass as the sun, and was to take the place of the sun, Earth still would not fall in. The black hole would just have the same gravity as the sun, and Earth and the other planets would orbit the black hole as they orbit the sun now.

Yet, the sun will never turn into a black hole. The sun is not a big enough star to make a black hole. That just gives you a good example of how big of stars we need to make black holes, and how “small” the sun really is.

Black Hole Shreds Passing Star Video – https://svs.gsfc.nasa.gov/20228

If black holes are “black” how do scientists know they’re there?

A black hole can’t be seen because strong gravity pulls all of the light into the middle of the black hole. However, scientists can see how the strong gravity affects the stars and gas around the black hole, and from that scientists can study stars to find out if they are flying around, nearby, or orbiting, a black hole.

When a black hole and a star are close together, this high-energy light is made. This light can’t be seen with human eyes, but scientists use satellites and telescopes in space to see the high-energy light.

What is the lifespan of a black hole; what determines it?

Well, first of all, do black holes die? If so, how? Yes, black holes do die. The discovery came when Stephan Hawking discovered black holes should radiate energy due to quantum mechanical processes. (The Hawking Radiation) As a black hole radiates energy, it shrinks and the more it shrinks, the more it radiates. This is the nature of the radiative process, and so finally it will completely evaporate. However, the timescale for this is extremely long: a black hole of the mass of the Sun will take more than a billion times, a billions times, a billions times, to evaporate completely.

How do we document the explosion of a black hole?

We have never seen a black hole explode so far, but according to Stephan Hawking’s Math, the temperature of a black hole, is oppositely corresponding to its mass. Therefore, the smaller it is, the hotter it would be, and vice versa. For normal astrophysical objects, this would be unimportant, and not worth considering. A black hole as massive as the sun would radiate a temperature of about 60 billionths of a Kelvin (colder than we’d ever be.) However, we wouldn’t notice it now, but this is still a runaway process. As a black hole of this size radiates, it shrinks slightly and gets hotter. This makes it shrink faster and hotter, and so forth almost until the end of time.

 

 

 

 

 

 

 

 

 

Citations: https://www.nasa.gov/audience/forstudents/k-4/stories/nasa-knows/what-is-a-black-hole-k4.html   https://www.nytimes.com/2016/06/16/science/black-hole-questions-answers.html  https://www.quora.com/What-is-the-purpose-of-black-holes-in-the-universe   http://curious.astro.cornell.edu/about-us/87-the-universe/black-holes-and-quasars/formation-and-evolution-of-black-holes/447-do-black-holes-die-if-so-how-beginner   http://chandra.harvard.edu/blog/node/326