Under The Martinborough Stars

I’ve been thinking a lot about Black Holes this week and the more you try and understand them, the stranger it all becomes. Black Holes are just weird.

The trouble is they are black which makes them impossible to see with your naked eye. You have to use other methods to know they are even there at all. 

Albert Einstein paved the way to discover Black Holes but even he thought they would be too weird to exist. Einstein tells us that space and time aren’t separate but combined which is called space-time. This is the fabric of the universe. Space-time can warp and bend especially around high mass objects. Black holes are the densest objects around, so space-time is warped. So as space-time bends you know that something massive must be causing it. Hey presto, you’ve found yourself a Black Hole.

But what do we know about Black Holes? We know there is a supermassive one in the centre of our galaxy, in fact all spiral galaxies are expected to have them at their centre. They keep the whole galaxy from falling apart. Our solar system takes 250 million years to do one orbit of this Black Hole. 

There are two basic parts to a Black Hole; the event horizon and a singularity. The event horizon is the edge of the Black Hole, past that not even light can escape. It’s the point of no return. 

Black Holes come about after a supernova, a giant star exploding itself to bits. The mass left over from the supernova is crushed into an incredibly tiny point, called a singularity, which has infinite density. This area becomes so gravitationally strong that nothing can escape, not even light. They appear black, hence the name. 

Annoyingly, a Black Hole isn’t even a hole. It’s a sphere. There is no funnel sucking in matter, no wormholes. The matter that passes the event horizon gets sucked into the centre of the Black Hole, to the singularity, where all the mass of the Black Hole resides. 

The Universe is peppered with black holes, as many as 10,000 just in our own Milky Way Galaxy. Luckily, you can’t just fall into a Black Hole, you really have to aim to get sucked in. If you are over 16km away from the event horizon you should still be able to escape, so they aren’t the vacuum cleaners of the galaxy that they are portrayed to be.

However, if you are unfortunate to get too close, you will become spaghettified. Literally human spaghetti an atom wide.

In 2019 the first ever picture of a Black Hole was taken, a herculean effort by using hundreds of telescopes across the globe, working together. Science is constantly learning new things about the Universe, so who knows what we will discover about Black Holes in the future? 

Hopefully they won’t name it after more food. Spaghetti Bolognese anyone?

Becky Bateman runs the award-winning astronomy business, Under The Stars

Photo Caption: A Black Hole visualisation  Image: NASA