yego.me
💡 Stop wasting time. Read Youtube instead of watch. Download Chrome Extension

Death From Space — Gamma-Ray Bursts Explained


4m read
·Nov 2, 2024

Imagine if you could gather the energy from every star within a hundred million light years. From thousands of galaxies, each with billions of stars. Imagine, you could take this kind of power, and use it to fire the biggest super-weapon in the universe. Imagine the damage you could do.

It turns out, you don't need to imagine it. These exist, and they're called gamma ray bursts. But what are these cosmic snipers? And what happens if one takes a shot at Earth? To understand gamma ray bursts, we first have to understand gamma rays.

Gamma rays are electromagnetic radiation – waves which carry energy just like visible light. Visible light is a tiny part of the electromagnetic spectrum: it's the part your eyes can see. At lower energies, there are radio waves, microwaves and infrared. And at higher energies: ultraviolet, x-rays and gamma rays.

Gamma rays are incredibly powerful. A single gamma ray photon is more energetic than a million visible photons combined. Their high energy makes gamma rays a form of ionizing radiation. Meaning they are energetic enough to break apart atomic bonds. This makes them dangerous to you and me.

Ionizing radiation disrupts the delicate biochemical machinery that keeps us alive, like a 9mm bullet through a clock. Fortunately, on Earth, the ozone layer blocks gamma rays, filtering them out before they can harm us. But if the atmosphere blocks gamma rays from space, how were gamma ray bursts (or GRBs) from space ever discovered?

During the Cold War, the USA sent up spy satellites, which could detect gamma rays from Soviet nuclear tests in space. They didn't see any bombs, but they did observe faint bursts coming from space, lasting only a few seconds. To date, this may be the only major scientific discovery made by spy satellites (that we know about anyway).

Astronomers use telescopes to see different kinds of light to make their discoveries. And these spy satellites gave them a new pair of eyes. They were a mystery for thirty years, but eventually, we discovered the source of a GRB: a galaxy six billion light years away. If a GRB can be seen from such a distance, then it must be incredibly energetic.

Releasing more energy in a second than the sun will in its entire ten billion year lifetime, making GRBs the brightest events in the universe. So, where do they come from? GRBs accompany some of the most violent, cataclysmic deaths in the universe, and the birth of black holes.

There are two types of gamma ray bursts: short and long, and each has their own source. Long GRBs last about a minute, and scientists think they are produced by supernovae: when the core of a massive star collapses to become a black hole. Short GRBs last a second and are produced when two neutron stars in a binary merge.

Over millions of years, their orbits decay by emitting gravitational waves. Once they are close enough to touch, they crash and splash into each other, forming a black hole. Both supernovae and neutron star mergers create the same thing: black holes, surrounded by a magnetized disc of gas left over from their parent stars.

In these environments, the rotation winds up the magnetic field, which funnels hot jets of particles traveling at nearly the speed of light. The gas in this funnel creates two tight jets of high-energy gamma rays, like a celestial laser gun. So, unlike other cosmic explosions, which spread out and fade, GRBs stay focused and can be seen from much further.

Any more detail would require too much mathematics for a YouTube video. The universe is full of these cosmic snipers, firing blindly and randomly into the dark, and they're hitting us all the time. On average, we detect one per day. Fortunately, most are harmless.

All the bursts we have detected so far originated outside the Milky Way, too far away to hurt us. But a nearby GRB could be disastrous. If one goes off within a few light years of us, it would totally cook the surface of the Earth, or at least, the half that's facing it. But even a more distant GRB could still end life on Earth.

And it wouldn't need to score a head-shot to kill us. If originating from a few thousand light years away, it would be a hundred light years wide by the time it reaches us, washing over the Solar System like a tidal wave. Again, the ozone layer protects us, but it's better equipped to handle the trickle of ultraviolet from the sun.

A gamma ray burst would overwhelm it, leaving us exposed to deadly solar radiation. Ozone takes years to replenish itself by natural processes, which is more than enough time for the sun to burn the Earth sterile, or at least, to kill most complex life. In fact, this may have already happened.

A GRB has been suggested as one possible cause of the Ordovician extinction 450 million years ago, that eradicated almost 85% of all marine species. Although it's pretty much impossible to prove. Gamma ray bursts could even be one reason we don't see life anywhere else in the universe. They might be wiping clean huge chunks of it on a regular basis.

It's been suggested that because of GRBs, only 10% of all galaxies might be hospitable to life, similar to us. So, are they going to kill us? Probably not. In a galaxy like ours, there may only be one GRB per millennia.

And to harm us, they must be close and directed at us. But since gamma rays travel at the speed of light, we won't know when it's headed our way until it arrives. So, there could already be a GRB on its way to kill us all, and we won't know it until it hits us, and we're dead.

More Articles

View All
You Are Enough
“I used to think the worst thing in life was to end up all alone. It’s not. The worst thing in life is to end up with people that make you feel all alone.” Robin Williams Codependency is a potentially destructive state to be in. At its core, it means th…
He Grew Up on the Streets, Now He's Making Them a Better Place | Short Film Showcase
You know you can’t change the world; you have to start with yourself. I was going down a one-way street, going backwards, and I left the house. I had my gun on my hip. I kept a blunt halfway lit, had my tennis shoes tied tight. These guys, I had to jump o…
Genetic Evolution Was a Prelude to Memetic Evolution
In fact, I’ve got behind me Popper’s book called Objective Knowledge and it’s subtitled An Evolutionary Approach and that’s no accident at all either. There’s symmetry between the theory of epistemology and the theory of evolution as we understand it. Be…
The Best Way To Launch Your Startup | Startup School
Foreign [Music] Head of Outreach at Y Combinator. So I’ve been at YC for about nine years now, and that means I’ve seen over 3,500 companies go through the program and launch at YC. One of the things my team does is help companies with their first launche…
Taking Landscape Photos | National Geographic
Being confirmed as a finalist, nothing like this has ever happened to me before in my life. I still can’t believe I made it to this point. I can only hope that my photographs give people a sense of who I am. My name is Nina Ritchie, and I live in Chinle,…
Will The Market Crash If Trump Loses?! #shorts
What Donald Trump has said, if he loses, is that there’ll be a depression, that there’ll be a market crash. What do you think of that? Ah, Donald being the Donald, you got to vote one way or the other based on policy because both sides are being absolutel…