Comment by saiya-jin | Hacker News Reader

Comment by saiya-jin | Hacker News Reader

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If we stick around on Earth only, eventually something will wipe us out. Asteroids hit roughly every 60 million years (we are already overdue on this one), super-volcanoes can be much more frequent, ie once every million years. There are cosmic events that we have no clue about, ie some hypermassive gamma ray burst cone sterilizing Earth (and probably rest of solar system, but most probably not hitting nearby stars). Or we will just fuckup environment so much we will make it completely unlivable for higher life, ie runaway greenhouse effect.

Even if mankind is quite resilient, our current society is super fragile to much smaller catastrophe, and we may actually loose the ability for inter-planetary travel easily.

We really need to diversify our location. That's not the goal of this century, and probably not even the next one, but to have some skeleton seed of civilization elsewhere than here is a logical must, and Mars is easiest and closest one. So better start doing some baby steps towards that direction immediately when we can, rather than pour trillions into more than useless warfare.

I used to think we should fix issues here on Earth before moving elsewhere, but the problem is, we won't. Its dangerously naive idea. Rather we should accept that mankind is flawed and accept and work with flaws, compared to wait for some utopia to happen here and then expand.

Just to note, despite the media hyperbole they get, a stray gamma ray burst directly bathing our earth would probably not do anything close to what you described. Probably worst case scenario: total ozone layer depletion. Bad, very bad for the food chain and for a large part of photosynthesis, but not cataclysmic in the sense of being a sterilizing event.

https://www.cambridge.org/core/journals/international-journa...

I may still cause human extinction, even if life as a whole survives

Extinction, no. Gamma ray bursts last for anything from a few seconds to a couple minutes or so. This means that it would only saturate one side of the world with its own direct ionizing radiation. This would severely harm or kill most plants on that side along with many other thin-skinned organisms, but it wouldn't outright kill larger animals and large plants and it wouldn't directly do anything to lifeforms on the opposite side of the planet.

The ozone layer would then of course shrink worldwide, yes, and this would collapse a large part of photosynthesis, causing a probable food chain collapse, but we're impressively adaptable and at the very least, millions of human beings would stay alive sustaining themselves with food grown or raised under adaptive conditions. The rest of nature would also adapt based on what survives, as it always has with previous cataclysms. This would probably help us too.

In other words, humanity would suffer terribly and billions would probably die, especially since this kind of event would be so sudden and unstoppable, but we wouldn't all die and the many survivors would repopulate as the ozone layer regrows too (which would happen over a few decades since it regenerates itself from solar radiation). But yes, bad. There is a theory that a gamma ray burst caused the Permian-Triassic event, the Great Dying, and 95% of life on Earth was extinguished during that time, though much of it was much less adapted to unexpected radiation than many lifeforms on Earth are now, so things could be less severe next time.

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