What are Gamma rays?
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| Image showing the Gamma rays which are terribly harmful |
Gamma rays are electromagnetic radiations- waves which carry energy just like the visible light.
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 which means they have enough energy to break an atomic bond.
Paul Villard, a French chemist and physicist, discovered gamma radiation in 1900 while studying radiation emitted by radium.
Why Gamma rays are very much harmful to humans?
As Gamma rays have enough energy to break a bond, it is very dangerous to the humans because ionizing radiation disrupts the delicate biochemical machinery that keeps us alive, like a 9mm bullet through a clock.
Due to its high penetrating power, it can damage bone marrow and internal organs.
How we are saved from the Gamma rays?
We should be very much thankful to our Earth because the ozone layer on the Earth blocks the Gamma rays and filtering them out before they can harm us.
What are Gamma ray burst?
Gamma-ray bursts (GRBs) are short-lived bursts of gamma-ray light, the most energetic form of light.
Lasting anywhere from a few milliseconds to several minutes, GRBs shine hundreds of times brighter than a typical supernova and about a million trillion times as bright as the Sun.
How dangerous are Gamma ray bursts?
Gamma ray bursts are very much harmful and can show a destructive effect on our life.
It can destroy the Earth’s ecosystem even if it is 5000 to 8000 light years away from us.
What causes Gamma ray burst?
There are two possibilities for it-
- One theory suggests that it can be the result of a collision between a neutron star and a black hole or between two black holes.
- Another idea says that it is the result of colliding two neutron stars.
How were the Gamma ray bursts(or GRBs) from space ever detected?
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| It's showing the disastrous Gamma ray burst |
During the cold war, the USA sent up spy satellites which could actually 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 for 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 mystery for thirty years but eventually, we discovered the source of GRB: a galaxy which is 6 billion light years away.
If a GRB can be seen from such a distance, then it might be incredibly energetic.
Releasing more energy in a second than the sun will, in its entire ten billion year lifetime.
Where do Gamma rays 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 burst:
● Long Gamma ray burst
● Short Gamma ray burst
Long GRBs last for a minute, and scientists think that they are produced by supernova: when the core of the massive star collapses, it becomes a black hole.
Short GRBs last for a second, and are produced when two neutron stars in a binary merge.
Over millions of years, the neutron stars 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 supernova and neutron stars mergers 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 lazer gun.
So unlike other cosmic explosions, which spread out and fade, GRBs say focused, and can be seen from much further.
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, scientists detect one GRBs per day. Fortunately, most are harmless.
There is a telescope known as Fermi Gamma Ray Space Telescope with the help of which we can detect Gamma rays.
What would happen if Earth was hit by a Gamma ray burst?
All the bursts scientists have detected so far, originated outside the Milky Way, too far way to hurt us.
But a nearby GRB could be disastrous, if one Gamma ray goes off within a few light years of us, it would totally cook the surface of the Earth. Or at least, the half portion 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, ozone layer protects us, but its better equipped to handle the trickle of ultraviolet from the Sun.
A Gamma ray burst would overwhelm it, leaving us exposed to the 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 eradicate almost 85% of all marine species. Although it's pretty much impossible to prove.
Gamma ray burst could even be one reason we don't see life anywhere else in the Universe. They might be wiping clean huge chucks 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.
Can a Gamma ray burst destroy Earth?
It depends on how close the Gamma ray burst is beamed straight towards Earth.
But it is very unlikely to get a Gamma ray burst hitting Earth.
But then also if a Gamma ray burst hit the Earth by such a low probability, would have finished us.
Are the Gamma rays going to kill us?
"Probably not"
In a galaxy like ours, there may only be one GRB per millenia. And to harm us, they must be close and directed at us.
But since Gamma ray travels at a 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.
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