What happens at the centre of a black hole?

Many people see black holes as one of the most fascinating objects in space. However the name actually contains a mistake which many people never notice, black holes are no holes in space, rather they are 3D spheres in which a great amount of matter is packed into a small area. For example, a black hole can be the mass of ten suns packed into a sphere the same size as New York, to compare: 1.3 million Earths fit into the sun so 13 million Earth's should fit in New York. Because such a great amount of mass is packed into a small area, the density of a black hole is enormous and therefore it’s gravity is magnificent as well. In fact the gravitational force is so strong that even light can’t escape the gravitational pull of a black hole, which is why a black hole appears to be a dull hole in space even though it is actually a sphere. Light is radiation, weighs close to nothing, this shows, once again, that the gravity inside a black hole is so strong even the lightest imaginable things cannot escape.

The exact size of a black hole can be difficult to estimate, because a black hole pulls radiation towards itself therefore we aren’t able to catch light or any other form of electromagnetic radiation because none of it is able to escape from the black hole's pull. Because of this we aren’t able to see the black hole directly, nonetheless we can see the effects of a black hole. For example when a black hole passes through a cloud of dust and meteors, the black hole will suck all the objects towards itself and so leave an empty space.

The size of a black hole itself is difficult to estimate, their diameters can differ from literally a couple of metres to hundreds of miles. The most important thing to know is that all mass inside a black hole is trying to squeeze into a so called ‘’singularity’’. This gravitational singularity is an infinitely small ring which contains infinite mass and where gravity becomes infinite as well (there are some other things that become infinite but let’s stay with these three). Because all the mass in a black hole will want to go into that singularity which can be seen as an infinitely small space (because the centre can be set to be as big as one wants), the mass is infinite as well as there will always be more particles that want to go into that singularity. Since mass and gravitational force are connected, gravity in this case becomes infinite as well. When talking about the centre of a big hole. this is where the well-known funnel image comes in to play. Whenever an object enters a black hole and it nears the singularity, it will be stretched out (also known as spaghettified) because of the weird gravitational pull in the black hole. Following this the object will completely lose dimensions and eventually it will disappear into the singularity (making the infinite mass even greater).

We can also apply the image of a black hole to our own solar system:
The sun is necessary to maintain life on Earth like we know it nowadays. One day however, the sun will be ‘’burnt out’’. When that day comes and the Sun starts to collapse under its own gravity, the Earth’s climate will completely change: the temperatures are soon going to be dropping until after a couple hundreds of years the average temperature on Earth will near the absolute zero, 0 kelvin (-273.15°C). However; this might not actually ever happen because, before the Sun has even become big enough to be able to collapse under its own gravity to form a black hole, it must first expand until its size has almost tripled (the greater an object’s mass, the greater the object’s gravitational force). If the sun expands to such a level there is a good chance the Earth will be ‘’swallowed’’ before the sun even starts shrinking again. In addition to this planets like Jupiter and Saturn will start to close in towards the sun. Jupiter and Saturn’s gravity is fairly big as well, so they might pull Earth towards them, causing a collision between the planets.

Fun fact: for the Earth to become a black hole, all the mass of the entire Earth has to be mashed into a sphere the size of a marble. This shows how much mass is needed in an extremely small space for something to become a black hole.