Black holes have been a significant point of interest for science fiction writers and scientists both for many years now.
But why? What are they? How do they form?
At its very simplest, a black hole is a star of sufficient size collapsing in on itself to produce a singularity, a point of infinite density with a gravitational pull that not even light can escape.
Many of you are probably familiar with the term event horizon, it gets thrown around a lot.
The event horizon is the ‘line’ surrounding a black hole which marks the point that whatever enters will be sucked into the singularity. This process is known as spaghettification, an intriguing term if I say so myself.
It refers to how an object gets stretched out as it is pulled into the singularity. See below.
It is easy then to grasp onto the idea that black holes will suck in anything and everything.
But Hawking and friends discovered that black holes actually emit radiation, a startling discovery that contradict much of their previous work.
However, as the true scientists they are, they took this in their stride and developed a new model.
The basis of this idea has ties with virtual particles.
All throughout space, the space that you are occupying too, particles and antiparticles are popping into existence, colliding with each other and disappearing.
As each particle is equal and opposite to each other, in energy and mass, no law is broken.
However something interesting happens on the edge of event horizons!
As virtual particles pop into existence, some may fall into the black hole while the other is projected outwards.
So not perhaps the emission you had envisioned, I know it wasn’t quite what I was expecting.
A proposed use, although it is much more a fanciful theoretical idea than anything, is using black holes to ‘travel through time’.
It wouldn’t really be travelling through time though, but the effect would be similar.
It has been explored through general relativity that time slows down around massive objects, time also slows down around objects going close to the speed of light.
If one was to go really, really fast and get in orbit around a black hole they would experience the passing of time at a much slower rate than those on the outside.
Theoretically, someone could travel years into the future only spending an hour in orbit.
As I’m sure some of you have noticed, I have quite an interest in space and all things astronomical.
I think that perhaps one of the greatest ideas to come from studying space was the idea that we are all very small.
I would like to leave you with three more readings.
A Brief History of Time, by Stephen Hawking, is an incredibly accessible and insightful look into key concepts of physics. Not to mention it is genuinely delightful and witty.
The other two books are science fiction novels that I have loved to read many times.
Foundation by Isaac Asimov is the start of series that explores the political aspects of inhabiting other planets, especially given the doom of their home.
Ender’s Game by Orson Scott Card was a thrilling and engaging read that remains not only one of my favourite sci-fi novels, but one of my favourite novels of all time.
Please do not judge it based on the terrible movie adaptation.