Earth-sized planet found in Proxima Centauri's habitable zone

[Simon_Jester]

This is why I brought up the 'essays' example. Losing your essay repeatedly and having to start over doesn't mean you put less care and effort into producing the next one. If anything it makes you more careful and sacrifice more of your time and energy on your writing, because you have to do it over and over to get an acceptable result once.

It's still k-selection, because you're still working really hard to make each individual essay a success. High 'essay mortality' doesn't mean you spam essays or put less effort into each one. It just means more of that effort is wasted, which really stinks, because you can't actually cut out the effort even if you want to.

As noted, that's not r-selection.

R-selection is more like, oh... job applications. Most people searching for jobs produce huge numbers of applications. Spending a huge amount of time on each one is actively counterproductive in a modern job market, because the odds are pretty good that their HR department will drop your application before it's even read by anyone who can actually hire you. Shit happens, and the only way for the job applicant to flourish is to apply for so very, very many jobs that something goes your way.

[Obviously it isn't like this for everyone or in all professions, but it's a common enough experience that even if you've never gone through it, you probably know people who have]

[Guardsman Bass]

At some point technology could come where launching interstellar expedition no longer is expensive or difficult compared to total scientific and engineering knowledge base, material and energy resources available to civilization or even wealthy individuals or organizations.

Imagine autonomous factories in space that can gather required resources from asteroids and replicate to achieve necessary industrial base to build starship with little to no human oversight. If AI and self replicating technology is involved current economic model no longer works. Building a starship could be as simple as send the instructions, AI controlled robots do the rest.

That's why I'm optimistic about space colonization on longer time frames but not shorter ones. At some point, the robots will probably be so good that even if we don't have good AI, we can still remotely control the robots to do all the resource extraction, processing, and construction for us while we're still on Earth's surface. All we'd have to do is choose to live in them and pay for the costs of transportation out to them, and I think some people will do that even if it's not that many (I think it's entirely possibly that we end up with some long-term scenario where most of the human/post-human/etc population lives on Earth aside from a handful of space colonies full of researchers and enthusiasts for isolated living, while AI/modified trans-humans go on long distance exploration missions).

[K. A. Pital]

Taking a shot for another star increases the survival potential of the human race. If one of its habitats is wiped out due to sheer bad luck (asteroid strike), having a second one makes total extinction less likely.

Therefore, it is reasonable as a long-term strategy regardless of whether future population growth of humanity will remain low or shoot back up due to artificial out-of-body breeding in vats to maximize offspring and minimize risk of death and loss of health during pregnancy and childbirth.

[The Romulan Republic]

We don't need another star system to secure ourselves against an asteroid strike specifically. Mars can be adapted quite well to serve that role.

Otherwise, its a valid point.

[EnterpriseSovereign]

If humanity is advanced enough to go to other star systems, then warding off asteroids will be a relative breeze.

[K. A. Pital]

If humanity is advanced enough to go to other star systems, then warding off asteroids will be a relative breeze.

There are a multitude of other problems that you fail to take into account. For example, a collision of a planetary body with the Sun or another planet. Asteroid is just meant as an example.

What if Earth is hit by another Theia? You can alter a planet's path by just having colony ship technologies? I don't think so.

[Borgholio]

Don't forget gamma ray bursts. Those things can shake and bake an entire solar system. You'd NEED to be lightyears away to avoid it.

[Simon_Jester]

I have to say... Rogue planetoids zooming around randomly crashing into things is a very unlikely risk now that the solar system is done forming.

[Napoleon the Clown]

Don't forget gamma ray bursts. Those things can shake and bake an entire solar system. You'd NEED to be lightyears away to avoid it.

Try hundreds of parsecs, if the thing is pointed right at you. Even at 500 parsecs getting directly hit by one would cause a mass extinction. The visible light portion of one managed to get into the naked-eye magnitudes, though under very dark sky conditions, and that fucker was billions of light years away when it went off.

Good news is, we are unaware of any GRB candidates that would be close enough to cook us! Also, they are exceedingly rare on a per-galaxy basis. And if we did get hit by one that was less than 500 parsecs away we wouldn't exactly have time to suffer. Much of the atmosphere would go bye-bye in very short order.

[Borgholio]

Well if you were in the line of sight, yeah you'd need to be much farther than a few light-years away. But with luck, you'd have a colony that is not in the same line of sight as Earth so you would just sidestep the beam of radiation.

[Flagg]

I have to say... Rogue planetoids zooming around randomly crashing into things is a very unlikely risk now that the solar system is done forming.

Based on what? There are rogue planets shot out from their star systems, you know.

[Terralthra]

Octopus isn't even Latin, it's Greek. The proper plural in its language of origin would be "octopodes", "eight-feets".

[Borgholio]

I have to say... Rogue planetoids zooming around randomly crashing into things is a very unlikely risk now that the solar system is done forming.

Based on what? There are rogue planets shot out from their star systems, you know.

The odds of being hit by a rogue planet shot out from another star system is one of those events that is so unlikely, it's barely even worth mentioning. To quote Scotty, "It would be like trying to hit a bullet with another bullet, while blindfolded and riding a horse."

[Simon_Jester]

I have to say... Rogue planetoids zooming around randomly crashing into things is a very unlikely risk now that the solar system is done forming.

Based on what? There are rogue planets shot out from their star systems, you know.

Because if that were a common problem likely to actually destabilize planetary orbits, there wouldn't be stable planetary systems.

[Flagg]

I have to say... Rogue planetoids zooming around randomly crashing into things is a very unlikely risk now that the solar system is done forming.

Based on what? There are rogue planets shot out from their star systems, you know.

The odds of being hit by a rogue planet shot out from another star system is one of those events that is so unlikely, it's barely even worth mentioning. To quote Scotty, "It would be like trying to hit a bullet with another bullet, while blindfolded and riding a horse."

Yeah, but one can knock a ton of shit from the Oort Cloud towards the sun. The fact is that staying on one planet when we don't have to is stupid. The same will be true when we are capable of interstellar travel, if we don't kill ourselves first.

[Flagg]

I have to say... Rogue planetoids zooming around randomly crashing into things is a very unlikely risk now that the solar system is done forming.

Based on what? There are rogue planets shot out from their star systems, you know.

Because if that were a common problem likely to actually destabilize planetary orbits, there wouldn't be stable planetary systems.

Again, based on what? The fact that it hasn't happened to our star system (that we know of)?

[Simon_Jester]

Yes, that's a starting point. It would be possible to tell if the orbits of our solar system were regularly perturbed by random passing planetoids. Indeed, that used to be a popular theory because cosmic upheaval is fun to imagine... but it's become more and more discredited.

We're also starting to find stable systems with exoplanets that are roughly Earth-sized. This further corroborates the belief that planets don't just bounce all over the place.

Nothing we know about astronomy makes "rogue planet" a likely risk. There are plenty of other reasons to talk about interstellar colonization if you want your species to last billions of years, mind you- it's just that "rogue planet" isn't one of them.

[K. A. Pital]

Rogue planetoids have been detected. So the threat is not nonexistent, and while definetely much smaller than an asteroid hit, it is an existential threat.

Humans have a hard time coping with deep time because their lives are so short - probabilities of an extinction event are small in the mid-term perspective, but they rise in the long-term perspective.

Why risk everything when it can be avoided? Just does not make sense to me. Especially as the effort would not require to completely relocate the entire civilization, but only send a small fraction to colonize other star systems. The implications for potential long-term survivability are massive. Costs are something even a well-developed Kardashev 1 civilization could bear.

[Simon_Jester]

Rogue planetoids have been detected. So the threat is not nonexistent...

I am genuinely not aware of any examples of this phenomenon. Would you mind enlightening me as to when and where?

Humans have a hard time coping with deep time because their lives are so short - probabilities of an extinction event are small in the mid-term perspective, but they rise in the long-term perspective.

Yes, but this is still a math-based issue. We have to calculate probabilities, not just assert that "they add up in the long run." An event that still has only a 0.1% likelihood of happening over the multi-billion year lifetime of the solar system is not a good motive for action compared to an event that has a 100% likelihood of happening.

And mentioning the 0.1% event in the same breath as the 100% event can be counterproductive, because it encourages people to dismiss both events as too improbable and irrelevant to be worth worrying about.

[K. A. Pital]

http://en.wikipedia.org/wiki/Rogue_planet

But yeah, the probabilities need to be explored, and they are likely to be extremely low compared to threats from near-Earth objects. Still, even if we disregard the rogue planetoid threat as improbable even over long timespans, and say an asteroid would not be a threat to a sufficiently developed Kardashev-I, there are other existential threats which had been mentioned - gamma ray bursts. Not to mention potential threats we are unaware of, as our understanding of space and its phenomena is, at the time, severely limited.

[Kingmaker]

The expenditure of resources on hedging against extremely low probability threats needs to be weighed against other things they can be spent on. Again, there are plenty reasons to support extrasolar exploration, but I don't think fears about gamma ray bursts is going to be near the top of the list.

[Flagg]

Well, the whole "interstellar colony ship" thing is a zero reward for those in the Solar System, but a likely reward for the continuation of our species.

And no, I don't think a rogue planet will barge through the Solar System, it's just a threat that exists I had not seen mentioned.