Supernovae: Our Origins.

Supernova explosions are undoubtedly one of the biggest explosions in the universe. They're so bright that when they occur, they outshine entire galaxies containing hundreds of billions of stars.

To put this into perspective, let's take an example. In the 1940s, a small nuclear bomb was put to the test. The scientists in charge who were in a bunker several miles away from the bomb site, wore protective goggles that make it so dark you can barely see anything. One of those scientists was curious about the extent of the blast so he took off his goggles, turned towards it, and through the only tiny window in the bunker, he saw what he describes as “an unimaginably bright light.”

And that's a nuclear bomb.

Let's consider a hydrogen bomb which is a thousand times stronger, hence a thousand times brighter than a nuclear bomb.

Imagine you held a hydrogen bomb right next to your eyeball and detonated it, the explosion would still be a billion times less bright than the event if the sun was to go supernova. That's how immensely bright supernova explosions are, but what exactly goes into the process? What causes such tremendous explosions? Chemistry and physics.

Any star cycle is basically the same. nuclear fusion, in which smaller elements fuse together in the star's core to form heavier elements. For 90% of its life, Hydrogen fuses to form Helium.

Then as the temperature reaches 200 million kelvin, hydrogen runs out. The specifics are complex so here is the simple process.

Hydrogen - Helium

Helium - Carbon

Carbon - Neon

Neon - Oxygen

Oxygen - Silicon

Then at 2.5 billion degrees, silicon fuses into Nickel which decays into Iron.

And the process stops here. Both fission and fusion reactions stop at iron.

So now there is an iron core building inside the star. Essentially, a star remains in equilibrium from the energy that it gives out through the fusion of elements and the gravity that pushes it into itself. It's a balanced cycle, but stars have limited fuel, and at some point in time, it runs out.

When the iron core building inside the star becomes 1.4 times solar mass, which is called the Chandrasekhar Limit, the pull of gravity becomes so strong that something spectacular happens. The electrons which were free, now have no room left to move. Hence they're forced to return to their lowest energy states. The protons in the nucleus absorb these low-energy electrons, and in this process, neutrinos are released.

Since there are no electrons left, the core collapses, unable to produce further energy. The core collapses at about 25% of the speed of light, which is about 75,000 m/s.

The electrons have been absorbed by the protons, which means there are now only neutrons left, making the body a neutron star.

In a supernova, a stupidly big number of neutrinos are released, around 10^58. These neutrinos simply don't fly away. The iron core that is building inside the star traps these neutrinos and absorbs their energy. And this is what makes a star go supernova.

Think about it. The particle that is one of the least reactive particles in the universe, a particle that does basically nothing, is the reason for one of the biggest and brightest explosions in the universe.

Even though a supernova is bright enough to outshine entire galaxies, that's not where the majority of its energy is spent. Only about 1/100th of 1% of its energy is spent in the form of light energy. 1% is released in the form of KE and 99% of energy is released in the form of neutrinos.

Our sun is not big enough to go supernova, it is about 5 times too small. And even if it did go supernova, that would take around 5 billion more years and we would be gone way before that. Supernovas are rare. In our Milky Way, which consists of about a hundred billion stars, only about 1-2 supernovas occur every century.

Betelgeuse, which is a star about 650 light years from Earth (if you traveled at the speed of light, you would require 650 years to get to Betelgeuse) is expected to go supernova in the near future. And if we are lucky enough we will get to witness this historical event. It might be the biggest thing of the century if it happens.

Betelgeuse will appear brighter than the moon, for three months in the night sky. If Betelgeuse went supernova tomorrow, we would be able to see the effects in the year 2673. If we can see the effects tomorrow, then Betelgeuse died and underwent a supernova in the year 1373. That's crazy when you think about it.

A certain isotope of Iron, Iron-60 was found in the bottom of the Pacific Ocean which was deposited there 2.6 million years ago and comes from a supernova. Studies show that the effects of that supernova were so deadly that it wiped out around one-third of the earth's megafauna.

So far, supernova explosions seem like such destructive events and somehow, we are perfectly far away from such events, events that we couldn't have avoided in any way possible.

But we kind of owe our life to these destructive and violent events. Around 4.6 Billion years ago, a Supernova shockwave triggered a collapse of gas and dust that condensed to form our solar system. This means there is a possibility that we wouldn't be here if it wasn't for a supernova.

It's fascinating to me how unbelievably small we are on this tiny planet Earth. And how the things that matter so much to us are nowhere near relevant in the big picture. Imagine you're in a dark swimming pool, and there's nobody around you, as you open your eyes you see that it has no walls, it's an endless space of darkness. Yet somehow, despite the darkness, there is something so beautiful about the universe.

Amidst our busy lives, amidst the problems that we have in our days, look up at the stars some night and just wonder about your place in the universe, not as a person, not as an individual, as a species. As a human being, give your mind a chance to be at peace by looking up at the vast universe and just, wondering. A single burst of gamma-ray is enough to wipe our entire solar system out, and we would never even see it coming. Somehow everything is perfectly and intricately present for us human beings, only for us to not even appreciate the beauty of it.

“We are all in the gutter, but some of us are looking at the stars.”

You're only given a limited time to live, to wonder, to think, give yourself a chance to be curious. There's a universe in all of us. The vast majority of darkness, yet some things just make it so beautiful that all of the darkness is overlooked.

Space is fascinating.