AROUND BLACK HOLES
Due to its incredible mass and disproportionately small size, black holes are extremely powerful. So powerful in fact that they can affect different aspects of space and even time itself. Let's learn more about this.
Space-Time
I have talked before about the fabric of spacetime, but if you don't remember here is a quick refresher.
Albert Einstien theorised that space and time were one in the same thing, that they were just 2 parts of Spacetime. Spacetime fuses the dimensions of space and the 1 one dimension of time into a single 4D continuum. Here gravity is just a warp in the fabric, in turn, warping space.
If the gravity of small masses objects warps spacetime, then imagine how much of a warp black holes can create. These wraps are extremely powerful and can affect the way the objects around them move such as planets and stars, even LIGHT. That is where gravitational lensing comes.
Gravitational Lensing
One of Albert Einsteins more famous theories is that the universe is set on the fabric of spacetime. This fabric is like a mattress and objects with a lot of mass or gravity act like bowling balls on this mattress, bending its surface. And when you roll a small marble next to it, the marbles path curves and goes towards the bowling ball. This effect is gravity. Essentially what Einstien was saying was that objects with mass bend the spacetime fabric, the more gravity, the bigger the warp. He then goes on to predict that if an object warps spacetime it should also warp the light passing over it.
As usual, he was correct.
We call this warp Gravitational Lensing.
https://www.youtube.com/watch?v=XCwWxrx1SIU
As you can see in this picture, there is a light source, which could be anything from a star to a galaxy, there is a place where the light is reaching and in-between those 2 there is an obstacle of some sort that has enough mass to bend light coming from the light source. For example, there wouldn't be much gravitational lensing if an asteroid was in between a galaxy and earth.
Normal Gravitational Lensing
http://scienceblogs.com/startswithabang/2011/04/20/how-gravitational-lensing-show/
The rule that the larger the mass the bigger the distortion still applies, so due to their immense gravity BH's can warp light s much that they orbit the BH a few times before reaching our eyes! This creates some BEAUTIFUL images
The ring around the BH is the light being distorted, and it is called Einsteins Ring in honour of the great scientist that predicted it. Of course, this is not an actual picture of a black hole, no, it's just an illustration. The first picture of a black hole should be taken about sometime this year (2018)!
Is anyone else SUPER excited to see it? No? Just me... ok then...
ANYWAY, now that we have established that black holes can affect energy, let's move onto matter.
Matter
The matter around a black hole would be affected by the gravitational force. This means that planets and gas clouds alike (at a certain distance) would be pulled towards the BH. Matter can even orbit black holes at a certain distance just as it would any other object as long as it stays away from the Event Horizon. But what is the Event Horizon??
Time
To understand this we have to go into Time Dilation and Einstein's special relativity which I will go into, but first there here is a simple explanation.
As Einstien figured out, time is not absolute. It depends on your reference frame and the rate at which you are moving. Time behaves strangely making it seem very malleable with perspective. If one person if falling into a BH with another person watching them, the falling person would appear to slow down as they approached the EVENT HORIZON of the BH and right when they hit it, they would appear to freeze. Whereas from the perspective of the person falling, it would seem that the universe is speeding up around them. This happens because of the difference in speeds between the person falling in and the person watching is huge. The effect seen here is called Time Dilation.
Falling in
Here is a word for you, Spagittification. I swear I didn't make that up. It is a real phenomenon that would happen if you happened to fall into a black hole (which I would not recommend, by the way, its an extremely painful way to kick the bucket).
Whats spaghettification? Well, as I mentioned before, the immense gravitational force of a black hole only really works at close distances making the amount of gravitational force on spaces a few centimetres apart would be huge.
Suppose, you are watching as your friend Bob gets to close to a black hole.
(This drawing is very inaccurate btw but we cant roll with it for now)
Right now the difference in force on Bob's head compared to his feet is ginormous. It's so big in fact, that by the time Bob reaches the event horizon, his whole body is stretched kilometres in length but only as wide as a strand of hair. Fortunately for Bob, this whole process would probably take less than a second to complete until he is ripped apart(if that's any comfort). Keep in mind that this process only