XKCD: It's more than a comic

I think they're more suggesting that colonizing another planet in our solar system isn't going to do us much good. If we could terraform that planet to allow us to survive, we could do the same with Earth with fewer resources.

Any measures we would have to take to create a habitable colony or area on any foreign body in the solar system can be done more effectively and more easily on earth.

There's a lotta reason to travel in space but looking for a new planet if Earth's biosphere degrades ain't one of them.

Edited by LeGarcon on Jun 28th 2018 at 12:47:18 PM

Colonizing other worlds in the solar system is a pretty good idea for the middle to far future, for many scientific reasons. However, it is implausible in the extreme that we could move even a tiny fraction of Earth's population to another world within the next thousand years, assuming that such a world could be identified and made habitable.

That said, it doesn't hurt to diversify, and a colonization program could keep humanity as a species alive (barely) should we completely wreck this planet or some unforeseen catastrophe strike.

In the far, far, far future, we'll need to either move Earth or move off of Earth, because the Sun will fricassee us. That's billions of years away, though.

Edited by Fighteer on Jun 28th 2018 at 12:49:22 PM

True. I guess I'm combining the whole "we're wrecking our own planet" thing with the message from strip 893.

Actually, it is "only" about 800 million years away. In 600 million years, the sun will grow so bright that the weathering of rocks will increase to the point of hardening the Earth's crust and stopping plate tectonics. Carbon dioxide levels will fall and 99% of all plant life will die out.

In 800 million years, carbon dioxide will drop so low that all plant life will die out, causing oxygen to dissapear from the atmosphere, and all multicellular life, including us, will die out.

And if we somehow survived that, in 1,1 billion years, temperatures will have risen to an average of 47 degrees Celsius, at which point there will be a runaway greenhouse effect, and all the oceans will boil off.

In 2,3 billion years, the outer core freezes, the magnetic field shuts down, and the atmosphere will start depleting into space.

In 2,8 billion years, average temperatures will be around 150, and any last vestige of life will be roasted to death.

So we have about 600-800 million years, tops.

Global warming is unlikely to kill off all human beings, let alone all life in Earth. However, you can make a good case for a major human die-off in the next couple hundred years, sooner if peak oil happens. Peak oil means the nitrogen based fertilizer runs out, with an extremely negative impact on agricultural production. Since the net effect of artificial fertlizer + chemical inseticides/pesticides is to sterilize the soil, most places wont even be able to go back to the traditional methods of farming, all the natural nutrients have been leached out. Even without peak oil, tempurature changes mean that the goldilock's zone for maximum agriculture moves north, into soil and conditions that are inherently less fertile than the current locations. Since less food means fewer people, we are looking at a significant reduction in total global population.

How fast that reduction takes place will determine how much of a nightmare scenario it becomes. While it's basically too late to avoid some of the negative effects of global warming, we could still reduce the impact and spread the population reduction over a couple hundred years or so, which would at least allow us to preserve civilization. The worst case scenario makes global scale starvation, pandemic, war and population migration into major risks.

Edited by DeMarquis on Jun 28th 2018 at 3:18:51 PM

There are pie-in-the-sky proposals for dealing with quite a few of those effects. For example, we can block some of the Sun's light with the equivalent of a giant space umbrella — not literally, but it would be that in effect. A Dyson swarm could do the trick. If we can increase the blocking to keep pace with the Sun's increasing intensity, we can survive until we hit that other problem (the core freezing), or until the Sun goes into its red giant phase, at which point it's leave or bust.

The space umbrella is feasible, but I don't see how we would save the core from solidifying.

A sobering thought, by the way. Earth is 4,5 billion years old. But in 600 million years, it'll be the beginning of the end for life on earth. We will have one last mass extinction, from which life will most likely never recover again.

The full history of life on Earth is more in the past than in the future at this point.

Edited by Redmess on Jun 28th 2018 at 9:58:52 PM

600 million years is a long time even from a geological perspective. From a biological perspective, it's as long as multicellular life has existed on the planet. If we (or whatever intelligent species may exist that far in the future) can't figure out a way to block out increasing solar radiation by then, or at least move off Earth, then we deserve to go extinct.

In 600 million years our descendants, if they are any, won't be anything recognizably "human" anyway.

I thought the Sun wasn't due to go red giant until five-ish billion years from now. Was that information wrong, or is there some other thing bound to make the sun hotter and brighter?

As the fused fuel changes over time the sun's output changes along with it. It'll burn hotter and hotter as time goes on.

The red giant stage is still farther off. These events in about a billion years are due to the Sun's radiation increasing over time, raising the temperature on Earth, and Earth's core cooling down. This means Earth will be uninhabitable long before the sun goes red giant.

JWST Delays

This one charts the much-delayed launch of the James Webb Space Telescope, resulting in a prediction that it will actually launch in late 2026 as the average time to completion has decreased over the years.

...I really hope this story doesn't end with it blow up on the pad.

Missed one: Rock

Man, today's is Orwellian.

Creepy. It's like Simulacra, or a horror story where the victim's life is slowly taken over by some other entity.

It reminded me of this comic.

I had about the same reaction when my old Skype account was hacked and the hackers started asking my contacts to "lend me" money.

#2016: OEIS Submissions

Apparently it refers to this, which I didn't know was a thing.

I dont get the phone one. Whats the joke?

Pretty sure it's just what a bad idea it'd be to publish Chris Hemsworth's personal contact information.

Look it up at explainxkcd if you are not sure.

Well, I just want to say that I have never been forced to refer to Explain XKCD to understand a strip before, barring his computer engineering minutia ones. This is a first, and Ive been reading it for years.

#2017: Stargazing 2

I might enjoy living in that character's brain, just for the fact that it's so delightfully untroubled by reality.