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Two potentially life-friendly planets found orbiting a nearby star

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201–210 of 391 posts

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

#201
post #107

The note that it's an old star makes me worry though. If they're older then us, and habitable, were they inhabited? Our current era is a few hundred years of real, directed technological development. A few thousands years either side of that and who knows what we'd be looking at, but you imagine that - hopefully - the general progression of technology is forward. So if they were inhabited, what happened to them? Are…

> Are they exactly at our level of development? If so, then at just 12ly away, we could converse with them within (many of) our lifetimes.

The odds of that are effectively zero. Over a multi-billion year development line, being within 100 years of one-another is effectively impossible.

They are either unevolved animals, or have already merged into the Great AI or whatever happens when intelligent species evolve.

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

#202
post #107

The note that it's an old star makes me worry though. If they're older then us, and habitable, were they inhabited? Our current era is a few hundred years of real, directed technological development. A few thousands years either side of that and who knows what we'd be looking at, but you imagine that - hopefully - the general progression of technology is forward. So if they were inhabited, what happened to them? Are…

Do we know that intelligent life is an evolutionary inevitability? Most of these discussions seem to assume that it is, but I haven't read any biologists mention this.

What we can infer from the gradual evolution of various species on Earth is that brains do seem to evolve larger, more complex, more efficient - though are often bottlenecked by other costs.

If you look at a snapshot of all life on Earth over tens of millions of years, the average brain size of dominant species has clearly increased.

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

#203

Earlier quoted context omitted.

> And if we are going to build an underground colony....then why not start with one here on Earth? Because if an asteroid hits Earth or if the world superpowers decide to go full nuclear, the underground colony in Mars will survive (unless superpowers decide to nuke that from here as well...)

I'd argue that a colony at the bottom of our own ocean would survive literally any event of any magnitude, maybe except for a direct asteroid strike. In terms of survivability of the human race, that's a better project to start with - and of course then move on to other planets, but underwater/underground colonies would give us lots of insights into living in such environments permanently.

Fair point, but then we forgo learning how to build a rocket to leave this rock should there ever be a need.

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

#204
post #183

Earlier quoted context omitted.

I had high hopes, but TBP is a terrible novel. It certainly has some fascinating ideas, but just as many ludicrous ones that are equally central to the plot. Not to mention Liu is absolutely terrible at anything relating to characters: dialogue, character development, etc.

I agree - I read the trilogy and enjoyed it somewhat but I wouldn't recommend it to others (unlike e.g. Hyperion Cantos or Fire Upon the Deep, etc). The amount of suspension of disbelief for some questionable premises is very high. e.g. the real-time comms developed by one of the races breaks down one of the key axioms.

I read TBP and A Deepness in the Sky at the same time. Despite the "big ideas", TBP isn't even in the same league. Can't bring myself to read the second TBP book, just don't care. Did buy a Fire Upon a Deep recently, looking forward to it.

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

#205

"Seen here in an illustration" This half-hearted attempt to say that the impressive-looking image of The Nearby Star was in fact an artist's impression of what a Red Dwarf might look like, made me laugh. Is it seen here? Or is it an illustration? I suspect someone changed the copy just before publishing

If you see a picture of the surface of a star that's not our sun, it's certainly an illustration. No such image exists of any other star.

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

#206

Earlier quoted context omitted.

I had high hopes, but TBP is a terrible novel. It certainly has some fascinating ideas, but just as many ludicrous ones that are equally central to the plot. Not to mention Liu is absolutely terrible at anything relating to characters: dialogue, character development, etc.

Yeah. Having read all three, they were interesting but not anything I'd re-read. The opening of TBP had me hoping -- being a big Neal Stephenson fan -- that the whole book would involve a lot more of the historical context of the early PRC, and then it all went somewhere completely different. I strongly feel that the first bit of the book set in the past is the best part of the entire trilogy. The idea of Chinese sci…

> historical context of the early PRC

I mean, China has censors. I get the feeling it had to be a somewhat veiled metaphor, although it felt extremely obvious too.

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

#207

I saw a study recently, unfortunately I can't locate it now. It discussed the possibility of there having been past civilizations on Earth, hundreds of millions or even billions of years ago. The conclusion was that this can't be entirely ruled out. It noted how few actual fossil remains we have for what we know of dinosaurs, and that there's a lot of space left in those gaps for all the evidence to have been destroy…

Maybe it was this?

Gavin A. Schmidt, Adam Frank: The Silurian Hypothesis: Would it be possible to detect an industrial civilization in the geological record?, https://arxiv.org/abs/1804.03748

I found it through an article in The Atlantic that may or may not have been linked on HN recently.

https://www.theatlantic.com/science/archive/2018/04/are-we-e...

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

#209
post #87
post #65

Earlier quoted context omitted.

Because then it would be a double planet.

It depends on how big the "main" planet is, I guess. But I think we are running into definitional issues here, and it gets technical very fast. First, IAU does not recognize the term "double planet". Second, a body which is large enough to reach hydrostatic equilibrium (i.e. a sphere) but has not yet cleared its orbit is technically not a planet. So I don't know where this leaves us. A Jupiter-sized planet with an Ea…

TFA said the planets were rocky and 1.1g.

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

#210

Earlier quoted context omitted.

> Let's say the origin of life is a million to one filter, and the successful development of sentience is another million to one filter. Those are actually pretty high odds for those two events, and the combination of those two togehter is enough to make it likely we're alone in the Milky Way. I mean, not really? Doesn't the Milky Way have ~100 billion stars?

(million: 1)^2 * 100 billion gives an estimate of ~0.1 stars in the Milky Way that host life.

Indeed. But then developed it hitch hikes a ride on asteroids and spreads virally. See Dr Zubrin’s recent discussions https://www.centauri-dreams.org/2017/12/21/interstellar-comm...
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