What is a black hole?
Today we’re going to be discussing black holes. Stephen Hawking said in his book brief answers to big questions it is said that.
Fact is sometimes stranger than fiction and nowhere is that more true than in the case of black holes black holes are stranger than anything dreamed up by science fiction writers but are firmly matters of science fact.
So today, we’re going to have a deeper look at what black holes are by understanding their structures and effects on the universe.
1. How a Black Hole forms
To understand how black holes are formed, we must understand how stars die. So stars remain stable because of the perfect balance between the force of nuclear fusion pushing outwards of the star and the force of gravity pushing inwards of the star.
What’s happens when a star dies ?
The force of nuclear fusion isn’t strong enough to withstand the force of gravity; hence the star collapses into itself. The death of a star can lead to multiple outcomes depending on its mass. If the star’s mass is between 0.5 and 8 solar masses, it will result in a planetary nebula leaving behind a white dwarf. If the star has between 8 and 25 solar masses, it will create a supernova type 1, leaving behind a neutron star. If the star has more than 25 solar masses, it will create a supernova type 2, leaving behind a black hole.
How exactly does that work? how does it start turn into a black hole ?
Here’s a common analogy, if you have a cannonball and you shoot it straight up to the sky eventually, it’s gonna come back down right; if you shoot it faster with more power, it’s gonna take longer to come back down. Eventually, you shoot the cannonball fast enough that it escapes the earth’s gravitational pull and never comes back down. A star of over 25 solar masses dies while it’s collapsing into itself. Its gravitational pull increases and keeps increasing to the point where nothing can escape the gravitational pull, not even light. If you were inside a black hole and a photon was your cannonball, and you were to flash a light upwards outside the black hole, it would simply fall back.
Black holes are points in space with infinite densities with a strong gravitational pull that nothing can escape, not even light.
What does that mean?
In terms of the geometry of space, you know that gravity is the consequence of the curvature of space-time caused by an even distribution of mass. What a black hole does is that it creates an infinitely deep hole in the fabric of space-time, so the curve it creates is infinitely deep.
Now you may ask yourself, if nothing can escape the gravitational pull of a black hole, then why is the whole universe in a black hole right now?
2. How they’re structured?
This is because of the way black holes are structured. There are three main parts of a black hole. First, the singularity lies at the very center of the black hole. It is the point of infinite density where the black hole’s mass is squeezed into an almost zero volume. Then there’s the event horizon which is the point of no return. Anything surpassing that point will fall into the black hole and never come out. The last main part of a black hole is the accretion disk, a spiraling disk of material dust and interstellar gas spiraling towards the black hole.
3. Different types of black holes
There are four types of black holes.
- stellar black
- intermediate black holes
- miniature black holes
- supermassive black holes.
We’re going to be focusing on stellar and supermassive black holes. The other two are pretty self-explanatory. Stellar black holes are the black holes whose formation we explained earlier. They get created from stellar death, and their mass typically varies between 5 and 10 solar masses. Supermassive black holes are the largest known black holes and live at the center of galaxies.
These black holes have a mass that ranges between millions to even billions of solar masses. There are several theories on the formation of supermassive black holes. They may come from the collapse of very dense stellar clouds or multiple stellar black hole collisions.
What happens when we throw something into a Black Hole?
Let’s see, when you burn a book, the information in the book doesn’t disappear. It turns into ashes, but the information is still there. The universe likes its information. It doesn’t like to create new information, and it doesn’t like to destroy existing information. But again, what if you throw that book into a black hole?
In the 1970s, Stephen Hawking discovered that black holes aren’t entirely black; they emit Hawking radiation. He showed that black holes can evaporate, that their masses can be turned into energy, and that energy can leak out of the black hole. If the information didn’t leak out with hawking radiation and the black hole goes away, then what happens to the information? This is known as the information paradox and is yet to be solved.
What’s interesting is that scientists have a pretty clear idea of what would happen if you were to fall into a black hole! What happens is that the gravitational pull at your feet would be so much greater than at your head that you will stretch and form a spaghetti in a process known as spaghettification. Black holes are still one of the universe’s biggest and most fascinating mysteries, so I’m here to tell you to stay curious.
Photo credit: Pexels
Originally posted 2020-07-22 14:22:00.