A black hole is a bottomless hole in spacetime from which not even light can escape. Black holes are in many ways stranger than anything that has been dreamt up by science fiction writers.
Stephen Hawking once described the effect a black hole would have on a human body.
If you fall towards a black hole feet first, gravity will pull harder on your feet than your head, because they are nearer the black hole. The result is, you will be stretched out longwise, and squashed in sideways
He then goes on to say that
If the black hole has a mass of a few times our sun, you would be torn apart, and made into spaghetti.
This process is now referred to by scientists as spaghettification.
Around 1 star in every 1000 end their life as a black hole. This means that of the 100 billion stars in our galaxy astronomers expect there to be around 100 million black holes.
So given these numbers what are the odds of a black hole appearing nearby and destroying the planet?
Who, What, Where, When and Why?
A stellar black hole is formed when a high mass star collapses in on itself. The sun is a low mass star and in a few billion years when it is at the end of it’s life it will become a red giant star and then a white dwarf. Panic over? Not quite!
Black holes are believed to exist both in deep space and within galaxies including our own. Scientist also believe that there is a supermassive black hole at the centre of each galaxy.
Scientist can’t see black holes directly because light cannot escape from them. But, they can see the effect the gravity of a black hole has on the stars and gases nearby.
To date only around 12 black holes have been identified and the nearest one, in the system V616 Monocertosis, is around 1600 lightyears away. The nearest supermassive black hole is at the centre of our milky way galaxy, 28,000 lightyears away.
The worry is that there may be other black holes nearby that we haven’t been able to identify. The first signs of which could be a distortion in the orbits of the planets in our solar system.
It is worth knowing that the probability of encountering a black hole is relatively low. Our solar system is around 4.5 billion years old and in all that time the planets have been going around the sun without any serious interruption.
NASA have even taken the time to address earth’s possibly destruction by a black hole.
Black holes do not wander around the universe, randomly swallowing worlds. They follow the laws of gravity just like other objects in space. The orbit of a black hole would have to be very close to the solar system to affect Earth, which is not likely.
That being said, the universe is a strange and unpredictable place and with the current level of technology we are unlikely to be able to detect all possible threats from space.
The Panel of Experts
What Would Karl do?
Karl was heading to the local Walmart to buy some new tools and materials. He had watched a documentary the evening before about big oil and decided that he was going to build a wind turbine for his backyard.
He wanted to do his bit to combat global warming as he believed it the biggest threat to humanity.
He looked up into the sky and was amazed to see what looked like Jupiter whizz by. “How strange” he thought.
He then unexpectedly began to be stretched out like spaghetti.