We go about our lives unaware that in the depths of space lurk invisible monsters, destroyers, powerful enough to tear apart our sun and leave our Earth a shattered burned-out ruin. We talk about one object out there whose pull is so powerful you can never escape (from it) no matter how fast you go, not even if you travel at the speed of light. We talk about black holes.
A black hole is capable to tearing apart a star that has strayed too close, anything that comes near is destroyed. It’s hard to believe anything is powerful enough to destroy a planet or a star, but it’s true. If you put a black hole near something it will immediately starts ripping it apart.
So, What is it about a black hole that makes it so powerful? The answer is gravity. It’s the force that keeps us all stuck to the surface of our planet, if something’s heavy enough, it pulls you towards it.
Planet Earth is heavy, so heavy, in fact, that to get off it, you have to do this:
All of this, just to escape from our tiny globe. And if Earth’s gravity seems strong, imagine the pull of the sun. Our sun is a million kilometres across. This is the real heavyweight of the solar system.
But if you think our sun is big, think again. There are stars out there that are vast. Their gravity is mind-boggling. But compared to a black hole, even this star is a weakling. A black hole weighs as much as a massive star, but it’s crammed into an area smaller than a pea. A black hole is gravity gone mad, nothing can ever escape.
What could create such a monster?
Something so heavy and yet unimaginably small? an event powerful enough to create a black hole should be visible right across the universe.
Recently, we might actually have witnessed one as it happened. A team in Australia, headed by Professor Brian Boyle, spotted it. The first clue that led to his discovery came in the form of radiation -gamma rays that are invisible to the human eye. The gamma rays is the form of light that packs the biggest punch, gamma-ray bursts only last a few seconds so it’s hard to detect them. But with the help of Gamma Ray Observatory placed in space we can actualy detect them.
Back to the gama-burst, Brian Boyle’s team, guided by the space observatory, turned their ground-based optical telescopes on to the blast, in the hope of seeing it before it faded. The information was really down to the ground. The optical telescopes sprang into action, to try to localise where this burst of energy had come from. What they found was something they didn’t expect, that this light was actually coming from a supernova.
What they’d seen with their telescopes was an exploding star. But the explosion was far larger than anyone had ever witnessed before. And in the heart of that cataclysmic explosion, the researchers realised that something astonishing and terrifying had happened.
As the massive star died, a monster had been born. they’d witnessed the birth of a black hole. What Boyle’s team had seen was the death of a star so heavy that when it exploded, its mass collapsed inwards instead of blasting out into space. This star is absolutely huge.
It’s a hundred times bigger than our sun and thousands of times brighter. But it doesn’t just explode. As its surface layer blasts upwards, its core is smashed inwards. The centre of the star collapses in on itself, billions of tonnes of star stuff crushed smaller and smaller until the whole star is squeezed to a single microscopic point and from the remains of the dying star, a black hole is born.
In our galaxy, a massive star explodes and creates a new black hole every 1,000 years which may not sound like a lot, until you remember that the galaxy has been here a very long time. When a black hole is born, it never dies. Every hole that was ever created is still out there so there should be around ten million of them, somewhere.
The question is – where?