LOGBOOK N°76

OCTOBER 2043

Somewhere in carina-sagittarius arm

You may be wondering why you should be interested in black holes when those objects are far, far from us and do not impact us directly and live their lives peacefully. A lot of you probably have in mind this scene in Christopher Nolan’s Interstellar where you can see that gigantic black hole. Or, maybe not, because it’s far too old now. Well, you are not asking yourself the good questions because Black Holes are probably the most fascinating objects ever and could even be considered as the biggest objects in our Universe.

However, we don’t really know what’s behind those objects and that’s undoubtedly why it makes them so mysterious. Mysterious and yet so terrifying because even light cannot escape from a black hole and Stars are literally devoured by them.

A lot of theories revolve around them but we will discuss them later. First, let’s continue our journey in the incredible world of Black Holes. Let’s discover what they are… or are not… 

Black holes are the result of the implosion of a Star due to the loss of its stability. To put it simply, the main ‘job’ of a Star is to fuse hydrogen into helium. Fusion happens in its core and this type of fusion particularly creates energy in the form of radiation. What makes a Star stable is the balance between gravity and radiation. In fact, as you all know, gravity (Hi Newton!) is a force exerted by a body with an important mass that will attract other objects. That being said, gravity will exert a force against the radiation. This war will take thousands or even millions of years, but good (gravity) will triumph. Indeed, the star sacrifices a lot of its soldiers (hydrogen) to create more powerful soldiers (helium) and so energy. However, stars that are heavier, will eventually start the fusion of more complex elements like iron which in that case, will not produce energy. This will lead to a decrease in energy and so to the implosion of the star. The balance in the force is therefore broken. The star war is lost. The implosion of the star will either give birth to a neutron star or in some other cases (if the star is big enough) a black hole. In that precise case, the entire mass of the star will collapse to create a black hole.

So, you may be wondering, “If your aim is to find a black hole, and if it’s black, how will you be able to see it?”. Well, we give it the name “black” hole because this massive object cannot reflect or emit any light and so that is why we call it black. However, when black holes devour other objects, those objects will heat and so they will emit X-rays and that is why we can actually see black holes. Basically, the “black” part is called the Event Horizon and whatever crosses the Event Horizon cannot escape. Also, the “hole” is known as the singularity but let’s get deeper into it if we may say. What exactly is a singularity? To make it short, the singularity is situated at the center of a black hole and represents the place where the gravitational field is concentrated.

However, we don’t have enough information about it.

What could possibly make it so unique is that time doesn’t flow the same way according to the point of view. In fact, if you fell into a Black Hole, you would see time pass quickly whereas from another point of view, watching something fall into a black hole will seem slow.

And by that, I mean what would happen if you fell into it. Well, the moment you cross the Event Horizon, you cannot escape. Certainly, death will await you. Again, we don’t know for sure.

As we understand it, black holes are objects that could possibly suck everything from tiny objects to massive ones. And, by everything, could they possibility delete information?

Well…