Bad astronomy | Opportunity has played a role in keeping the earth habitable for billions of years

When you look around you, you see life almost everywhere on earth. Earth seems to support life neatly: we see it in the air, in the water, in the ground, in the deep underground.

But is it inevitable? We know that there have been mass destruction events in the past, Some take over the majority of life on earth. However, there has been no event since life began and spread on Earth Absolutely Abolished life. Of course! Otherwise we would not be here to think about it.

Still, this is interesting. I.e., Despite some serious temporary events, Earth’s climate has been relatively stable for 3 – 4 billion years.

That too is different. We know that stars like the Sun grow hotter as they age, and that the Sun was about 30% dull long ago. That is, the ancient earth must have been solidly frozen, or, assuming it was Clement, the earth must now be warm. Both are not true, it is a mystery.

This is called Blurred Young Sun Contrast, And many scientists believe that there is a kind of thermostat on Earth that tends to rearrange a system so that it does not get too hot or too cold. This would be a negative feedback system, where if a condition arises to warm the earth, things will change in order to cool it again.

But we know there are also positive feedback conditions. If you release too much carbon dioxide into the air the oceans will heat up, releasing more CO₂, You will get a feedback loop that ends badly. We see now. If there is too little CO₂ The earth is solidly frozen in air.

So we were lucky, and our environment had to be stable.

So is this a coincidence, or a mechanism? Or both?

To find, A scientist conducted a brilliant experiment. He created simulations of 100,000 planets (!!), each of which provided random weather feedback, some negative and some positive, and monitored their temperatures for 3 billion years – simulating any other variables (water content, for example, or the breathable atmosphere). For simplicity, he wanted to see if a planet, like Earth, could have a temperature that could live long enough.

To be clear, simulation feedback is not based on facts like CO₂ In the air; Instead he randomly assigned planets Mathematics Feedback, strictly numerical scenarios to see what happens. He also threw large random changes at random times to simulate the external force of temperature, such as asteroid impacts or supervolcano eruptions.

Each planetary SIM was then turned on 100 times, its variations changed slightly, to see what happens to the temperature.

The point here is not to create a complete climate simulation, but to see how large a role a planet’s habitat is likely to play. He was testing two hypotheses. Hypothesis 1 has no effect on feedback, so random fluctuations rule the day; If a planet is in the temperature range where it can live for billions of years it is a pure chance. The second hypothesis is that there are negative or positive comments Guarantees Success or failure, no chance.

In other words, climate feedback really believed he could see why the earth could live so long, or that we were lucky. In a 3 billion year simulation a planet was thought to be habitable if its temperature were relatively constant.

What he found was interesting. Of the 100,000 planets, 9% won at least once (and 1,400 won in the first run out of 100 runs). Some planets were successful two or three times… In fact, he looked at 100,000 planets and had every number between 1 and 100 successful runs.

But, only 1 planet had 100 successful runs in 100 overs. This is a strong planet, which means that nothing can stop it from being a good place to live (and at least in temperature).

Overall, looking at the range of effects and how they occurred, his conclusion is that both feedback and random chance have a role to play in staying within the temperature range at which a planet can survive. While the success rate varied from model to model, it supported the notion that changing the factors over 100 had both a mechanism and a chance to play a role.

Apparently, luck supports the prepared planet.

So can this be extended to the earth, which holds our fair world by saying both the feedback we have and the random chance we have, OK Reasonable? If we rewind the tape and change the circumstances a little, will we have a world where we can still live?

I will not go that far. This seems to support the idea, but as the author says in the paper, “Simplicity and uncertainty in the design of the model means that in some respects it must be unreliable. Caution is therefore needed in extending the truth from the sample results. ”

In other words, this is a very simple test and needs to be done more complexly. After all, the Earth has approached a few times, so it’s not hard to imagine a major asteroid impact or any other factor making us dirty. But still, this simulation is an interesting first step!

It makes a prediction: most Earth-like exoplanets will be uninhabitable because it happened in most of his test runs. Earth-like planets were an exception to this. If we find that it is true it is not To prove Hypothesis, however Supports It. If we find it very real There are Living, well, it would be enjoyable, wouldn’t it?

It acts as a warning story. We really are not Know The stronger the earth, the better it succeeds and will continue to do so. It has stumbled, stumbled and shaken things up in the past, but without long-term environmental impacts. Our own species, our civilization, is now balancing on the edge of a razor. Even if the ecosystem of the earth could somehow survive, it would not take such great success to cause an unspeakable catastrophe for us.

I have a lot of issues with humans, but I wish we weren’t going extinct. Uncontrolled fitting with existing feedback strikes me as a very scary idea. Earth may be strong, but we are not.

We need to be more careful. There is a reason these things are called Warning stories.