I like outer space. Or perhaps I should call it SPACE, to appropriate the unfathomable vastness of the cosmos. I didn’t major in astronomy at Uni, so all my knowledge comes from nights of research and a few classes I took that were, in the end, way out of my league. But I want to write about it now, as part of a general writing exercise. I’m out of practice. Again.
So, SPACE thoughts #1: Gamma Ray Bursts or; How the World Could End at Any Moment and There’s Not a Damn Thing We Could Do to Prevent It.
One of the more famous space phenomena are black holes, incredibly dense celestial bodies that have such a strong gravitational pull that not even light can escape its grasp. And, as such, they are black, invisible. There are tons of black holes in our galaxy, including one supermassive black hole (what up, Muse) in the center. But black holes get a bad rap. I mean, they’re still an incredibly destructive force that sucks matter away into an unknown space. But they’re not quite the “Hoovers of Outer Space” that they’ve been touted to be. Black holes don’t move. The reason why things get sucked into black holes is due to something getting too close to the black hole. This is the equivalent of tearing a hole in a bed sheet. If you drop something onto the sheet, the object may fall through the hole. The hole doesn’t move towards the object. That would be impossible. But I digress. We’re supposed to be talking about Gamma Ray Bursts.
Wait wait, a bit more prologue. Sorry.
Black holes themselves are a product at the end of a massive star dying. And while the black hole may be more fascinating to the everyman, the actual process of a star dying is just as incredible.
Our sun is an average star. A boring star. A C+ star. When the sun dies, it’ll puff up to a humongous size, become a red giant, and likely swallow the earth in its expanded radius, assuming we haven’t blown the world up before that. Then it will cool and shrink in size, as it expends the last bits of its energy, and eventually becomes a red dwarf. Red dwarves are small, relatively cold stars. Yawn.
The big stars, though, are quite the spectacle. These huge stars are, uh, rock stars, in a way. They live fast and die young, shining brightly for millions of years before ending their lives in a fantastic explosion. On the molecular level, here’s what happens: every star is a balance of two forces. One is gravity, which pulls all matter towards the center of the star, and the other is nuclear fusion, which keeps pushing the mass and energy out into space. As the star continues to burn its energy, the helium atoms caused by nuclear fusion begin to then fuse together, creating the more complicated elements: carbon, oxygen, sodium, etc. As the heavier elements are created, the star becomes more dense, thus the gravitational pull becomes stronger. Concurrently, the star’s available hydrogen needed for fusion is dwindling, and at some point something has to give.
Gravity wins out, and all the dense matter collapses in on itself, squeezing itself into as compact of an object as possible. The collapse causes a shockwave, and all the material not sucked into the star is jettisoned out into space. Thus, a supernova occurs. Supernovae are very pretty and leave absolutely gorgeous nebulae. They also cause gamma ray bursts.
We’re 600 words into this post, and I finally get to what a gamma ray burst is. Go me.
Anyways, as a star explodes, a gamma ray burst is emitted from its poles, shooting out far into space. A GRB is a narrow beam of extremely energetic rays, the power being something equivalent to the amount of energy the sun will expend in its entire lifetime. These things are very powerful and, potentially, very dangerous.
Most of the GRBs scientists have witnessed are very far away, somewhere in the billion-light-year range. But, if a GRB occurred close to us, say, in the thousand-light-year range, and we just happened to be in the beam’s path, things would go bad very fast. A GRB can be as short as two seconds, but there would be enough energy in those two seconds to irrevocably alter the earth.
Theoretical models have the intense wave of radiation slicing through the atmosphere and depleting up to 25% of the ozone layer. This would be a disastrous amount lost in one sitting. Those living on the side of Earth facing the blast would be subjected to lethal amounts of radiation immediately. The side facing away from Earth wouldn’t be as bombarded by harmful gamma rays, but the ozone depletion and UV radiation would likely kill them eventually. On top of that, a dramatic change to the atmosphere would disrupt many food chains and elemental cycles, leading to many species dying due to food shortages. So those humans who happen to not die of radiation poisoning would die of starvation. It wouldn’t be a pretty sight.
The thing is, we can’t predict this. We don’t know which massive stars have their poles pointed towards us. We don’t know when they’re going to explode. For many other natural disasters, we’d have projection models and years of warning. A catastrophic meteor would at least be observed a year before impact (though we wouldn’t be able to do anything about it. Sorry, Bruce Willis). We’re in the midst of extreme climate change and can observe it directly. A gamma ray burst, though, can happen at any moment. The radiation travels at near speed of light, so as soon as we see the star exploding, it would already be too late. Once the light arrives, so does the radiation.
You may say that the likelihood of a GRB hitting us is very slim. True, it is. However, it’s likely that Earth experienced a gamma ray burst in the past. It’s been theorized that the Ordovician–Silurian extinction event, the second largest extinction event in the history of earth, was due to a GRB. It’s not impossible.
So what’s to be learned from all of this? Probably nothing you haven’t heard before. Cherish every moment; live every day as if it were your last; life is fleeting; etc. But now you can append “because at any moment you could be bombarded by one billion nuclear bombs’ worth of radiation and die a painful death” to all of that!
Science is magical.