Imagine the following scenario. You are out on a beach enjoying the sun.
It's a warm summer day.. And then boom!
A darkening of the midday sky.
Not only that you start to experience a sunburn, all over your body. Before anyone notices what's going on, an airplane that was flying above you just moments ago starts to fall down.
By this time maybe just a person or two could connect that it is the oxygen that has been annihilated. Well this sounds scary but at least that's the kind of answer I found when googling "What happens if oxygen disappeared on earth?"
Sunburn darker sky and combustion engine failure made up the top three answers.
And with simple physics explanations we know these claims are true. Without ozone our planet will be exposed by the UV lights causing you to get sunburned instantly.
Without oxygen that makes up the atmosphere we won't be able to see the blue sky. And without oxygen, fire and combustion are impossible and jet propulsions fail shortly.
But is this a bad enough experience? "Fine I got sunburns, but my skin's probably going to recover from this soon". Is that really the worst that could happen?
You know we are capable of transcending this and I'd say there are more within it that our minds can never comprehend.
So I started digging on "What happens if oxygen disappeared" and almost assuredly, the result shocked me. Before I jump into details, here are some facts to make you feel better. Our planet is stable and is capable of sustaining us for many centuries.
Even if we lose about 20-50% oxygen molecules on Earth we would still carry on with life. Because that would mean the only difference is that the partial pressure of oxygen in the air halves and around 10% thinner at sea level. Remember that the air is made up of 21% oxygen molecules. So when losing some amounts of oxygen molecules, air will be lighter.
Some aircrafts would experience some trouble flying but nothing too significant.
After all, oxygen exists in many forms that include ozone and the free diatomic molecules in the free air. So when Earth slowly loses the oxygen in the air humankind could possibly find alternatives that include the catalytic breakdown of water into constituent elements.
At the end of the day, we'd still have sufficient oxygen that can make us survive for many generations.But remember when I said "..so when losing some amounts of oxygen molecules".
Oxygen molecules, and NOT oxygen atoms. There's a clear distinction and sadly there's a ton of explainer that didn't even try to explain the implication of losing oxygen atoms instead of oxygen molecules.
So let's talk about this. What happens now if you lose all the Earth's oxygen atoms say for just three seconds.
Well, take a look at this. The vast ocean that covers up to 70% of the Earth's surface consists of a mixture of oxygen and hydrogen (H2O). This means that losing oxygen atoms will leave behind monoatomic particle which is hydrogen.
And because hydrogen is lighter than air, it will eventually evaporate into the atmosphere and possibly could bleed into space. Now consider us humans. We are essentially a bag of water, that has been at least dignified. Our blood is made of a liquid element called plasma and it contains salt, protein, and water.
So just like before, the total disappearance of oxygen atoms would burst us into fine particles. But not only us, all the water bodies including the ocean, seas, and lakes and even the interior part of the Earth would burst. At this point, you might be wondering "Why burst?"
Well, you could look at the enthalpy scale.
Breaking the oxygen-hydrogen bond instantly results in a state up to 463 kJ/mol.
And to put this into perspective, heating up water from 0 C (32 F) to 100 C (212 F) is only about 4 kJ/mol.
This means that the breakdown of the water molecules for the whole water bodies existing on a planet will result in the release of this gigantic energy.
Earth would potentially glow like the sun, for at least some time before it fades out.
From a distant view, it wouldn't be difficult to confuse our home planet with a little star.
Since almost everything is aligned to oxygen the removal of this atom means losing the very essence of our life. So going back to the beginning. If the only effect of losing oxygen is sunburn and experiencing a darker sky.
We would be utterly thankful. For humans or super-beings, we can just manage that.