Tuesday, August 9

What are black holes, explained by NASA

Black holes have been, are and will be one of the most studied cosmic objects, as well as protagonists in works of science fiction with a space setting. In Engadget we have already addressed in depth the questions and answers they raise, but today we want give you a simple definition about what black holes are.

To do this, we will use the explanation provided by the NASA, with the aim that, after reading this article, know how to explain in a few seconds what a black hole is and what types are there. This will be a brief piece with the aim of offering a clear definition, but we recommend you approach the article with questions and answers, in which keys are addressed how the formation of black holes, their cosmic properties and other curiosities.

What is a black hole

Although black holes are complex cosmic phenomena, the definition could not be simpler. NASA defines a black hole as an astronomical object with such a strong gravitational force that not even light can escape from it.

All matter and radiation within the radius that the black hole encompasses is irretrievably trapped and with no way out, since the speed necessary to evade it exceeds the speed limit in the cosmos (speed of light)

Black holes are finite, with a certain size. Its spherical surface is called the ‘event horizon’ (or event horizon), this being the region of space that surrounds the black hole and that defines its limit.

This is how stars tear apart when they get too close to a black hole: the denser, the less chance of survival

This event horizon defines the limit where the speed required to evade it exceeds the speed of light (the very physical limit of the cosmos). In other words, all matter and radiation within this surface is trapped and cannot get out.


How a black hole is formed

But what about the formation of black holes? NASA explains that this phenomenon occurs when a star with a size of more than 20 solar masses depletes the fuel in its core and collapses under its own weight.

Gravity itself explains the formation of black holes. When a star collapses, a huge explosion is generated, and if it is large enough, a black hole can form

This collapse results in the explosion of a supernova that expels the outer layers of the star. If the nucleus is large enough (about three times the mass of the sun), no force will be able to counteract the remaining gravitational collapse, that is, the mass concentration of that star towards the center after the explosion.

The own gravitational contraction of the space tends to agglutinate all the mass of the star in a small space. So small and with such a high density that, to escape this gravitational force, one would have to exceed the speed of light. And this is how a black hole is born.