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Two potentially life-friendly planets found orbiting a nearby star

nationalgeographic.com

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Re: Two potentially life-friendly planets found orbiting a nearby star

#331

Post by dwaltrip »

codesushi42 wrote: post #323
abtinf wrote: post #289

Earlier quoted context omitted.

Well, that’s just a matter of time. But I was referring to the parent comment’s system.

It's also a matter of space. Maybe you are unfamiliar with the concept of space-time and what a light year really measures.

You misinterpreted the comment. They were discussing a single star system with multiple habitable planets.

If more than one planet in the system gave rise to an intelligent species that develops a civilization, things would likely get very interesting very quickly.

Re: Two potentially life-friendly planets found orbiting a nearby star

#332

Post by 420basteit »

rdm_blackhole wrote: post #306
caymanjim wrote: post #190

Earlier quoted context omitted.

> So if they were inhabited, what happened to them? Are they exactly at our level of development? Earlier? Hopefully. Because later poses some real big questions - does technology top out about where we are now - no FTL travel, no really big radio transmitters or stellar engineering? No probes to nearby star systems? Did they even make it past the nuclear age, or avoid wrecking their climate? You get more than one ch…

> While finding intelligent life would be great, finding any life is nearly as great. That would actually be worrisome. If we found and detected microorganisms on nearby planet e.g 12 light years away from earth, then that means we are probably headed for extinction. The reason is the theory of the Great Filter. Given that we have not been able to observe any kind of activity outside of our solar system, it means tha…

I think you have a slight misunderstanding about the great filter.

If we found only microorganisms on the other plant that should indicate that the filter is behind us, life having died out on that planet before even reaching large scale organisms let alone technology.

If we find ruins of civilization and technology on the planet at either about the same stage as us or more advanced, then we can assume that the filter is ahead of us.

Re: Two potentially life-friendly planets found orbiting a nearby star

#333

Post by JudgeWapner »

rdm_blackhole wrote: post #306
caymanjim wrote: post #190

Earlier quoted context omitted.

> So if they were inhabited, what happened to them? Are they exactly at our level of development? Earlier? Hopefully. Because later poses some real big questions - does technology top out about where we are now - no FTL travel, no really big radio transmitters or stellar engineering? No probes to nearby star systems? Did they even make it past the nuclear age, or avoid wrecking their climate? You get more than one ch…

> While finding intelligent life would be great, finding any life is nearly as great. That would actually be worrisome. If we found and detected microorganisms on nearby planet e.g 12 light years away from earth, then that means we are probably headed for extinction. The reason is the theory of the Great Filter. Given that we have not been able to observe any kind of activity outside of our solar system, it means tha…

ok, assuming you mean that nuclear war is the threat to all civilizations (because once we advance to the point of developing nukes, eventually some asshole deploys them irrationally).. why isn't this a solved problem? I.e: create underground societies that are nuclear-powered and sustainable for centuries, and impervious to nuclear attack?

Re: Two potentially life-friendly planets found orbiting a nearby star

#334

Post by MR4D »

ithkuil wrote: post #240
dunkmaster wrote: post #218

Earlier quoted context omitted.

If you're locking the area to a fixed area out of the 365 discrete areas, the birthday paradox isn't applicable anymore. Birthday paradox only says something about whether a pair exists among all areas.

So you're in a room with N people and learn that somebody else shares your birthday. Can you conclude that is this likely that other people in the room also share the birthday with somebody else?

Thanks for posting. This is exactly what I was trying to say (but you said it better).

Re: Two potentially life-friendly planets found orbiting a nearby star

#335

Post by hueving »

TheOtherHobbes wrote: post #290
derekp7 wrote: post #132

Earlier quoted context omitted.

Also, from 12 ly away, I'm sure that Sol would appear to have at least 3 habitable planets (Venus, Earth, Mars).

Sol does have three habitable planets. Plus some moons, at a push. Habitability isn't a Boolean. It's hugely dependent on history, context, and resources. The more Boolean distinction doesn't have a name - but if it did, it would be something like Stable Evolutionary Potential. Mars and Venus both fail on that. The moons fail on it now, but may pass when the Sun turns into a red giant. The Earth has offered it for lo…

>The Earth has offered it for long time, with some uncertainty about the near future.

What uncertainty is that? Nuclear winter won't even wipe life off the planet.

Re: Two potentially life-friendly planets found orbiting a nearby star

#336

Post by dwaltrip »

isostatic wrote: post #142
metalchianti wrote: post #136

Earlier quoted context omitted.

Yes. How many people do you need in a room to be confident that one of them has the same birthday as you?

How confident? Even with an even distribution of birthdays it's possible to have a billion people in the room that don't share your birthday. Very unlikely, but as there's only about 20 million people with your birthday, and 7 billion without, it's quite doable.

"Very unlikely" is a severe understatement. With only 100k people, the odds of no one else having your birthday is 10^-120. With a million people, it is 10^-1192.

And with a billion people... apparently, there are over a million zeroes between the decimal place and the first non-zero number. That is a pretty damn small probability.

Here is the code I used in python 3:

   from decimal import Decimal
   print((Decimal(364) / Decimal(365)) ** num_people)

Re: Two potentially life-friendly planets found orbiting a nearby star

#338

Post by abtinf »

mabbo wrote: post #89

Being that close also offers us a better ability to examine it. The nearer the star, the more arc-seconds (or tiny fractions thereof) the star will appear in telescopes. 12ly is ridiculously close! It also tells us something interesting. If we presume there's nothing special about our little corner of the universe, then the distance to the nearest potentially habitable planets gives us an estimate of how many habitab…

Light Year has a technical meaning, but it is so large that I can't relate to it at all. So I tried to figure out a different unit of measure, and I came up with what I call an "Earth Escape Year" or EEY.

From Earth, the escape velocity for our solar system is 42.1 km/s. EEY is the distance traveled for 1 year at that escape velocity. It is the maximum amount of time it would take to reach an interstellar object directly launching from Earth -- any slower and you can't get there at all. 1 LY = 7,121 Escape Years. The upper bound time to reach these planets is about 85k EEY.

Re: Two potentially life-friendly planets found orbiting a nearby star

#339

Post by codesushi42 »

dwaltrip wrote: post #331
codesushi42 wrote: post #323

Earlier quoted context omitted.

It's also a matter of space. Maybe you are unfamiliar with the concept of space-time and what a light year really measures.

You misinterpreted the comment. They were discussing a single star system with multiple habitable planets. If more than one planet in the system gave rise to an intelligent species that develops a civilization, things would likely get very interesting very quickly.

Not likely. Even traveling to a planet as "nearby" as Neptune by conventional means would take 12 years. Hardly within shooting range, and who knows whether our civilization will survive long enough for us to make it to even the edge of our solar system.

And the OP was referring to a nearby star system, within "sublight year" range. Even < 1 light year could mean very, very far away.

Re: Two potentially life-friendly planets found orbiting a nearby star

#340

Post by kevin_thibedeau »

JauntTrooper wrote: post #327
kevin_thibedeau wrote: post #304

Earlier quoted context omitted.

We should be colonizing the moon first, then Phobos or Deimos. Then, once established, we can conquer the martian gravity well with local resources.

Phobos and Deimos are very, very tiny. The diameter of the Moon is 2,160 miles. The diameter of Phobos is 14 miles. Deimos is 8 miles. (For scale, Mars' diameter is 4,200 miles).

That is the point. It's easy to land and get off a tiny moon and there is material to make a habitat out of rather than sending it all from Earth.
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