Author Topic: Exoplanets  (Read 378 times)

Re: Exoplanets
« Reply #15 on: June 06, 2017, 05:05:45 PM »
Good link, thanks!

They found a star called Trappist-1 that has as many as 7 "Earthlike" planets, any or all of which could have liquid water. This is a good time to be an astronomer!
God Not Found
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Online Baruch

Re: Exoplanets
« Reply #16 on: June 06, 2017, 07:50:26 PM »
You will find that any Goldilocks planet is already claimed by the bear tribe ;-)
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Re: Exoplanets
« Reply #17 on: June 07, 2017, 05:02:29 PM »
I'm not so sure anymore that there is such a thing as a Goldilocks planet. Liquid water apparently can exist in many more contexts than was previously thought, and life can exist in many more places than previously thought.

It's not like humanity will ever find any other planet we'll be able to live on. I think that, to some extent, sci-fi authors have done the world a disservice - they've made too many people believe that finding another home for humanity is a fairly simple matter, so we can trash the Earth and just go find another one out there somewhere.
God Not Found
"FRAUD. The life of commerce, the soul of religion, the bait of courtship, and the basis of political power."
Ambrose Bierce

Online Baruch

Re: Exoplanets
« Reply #18 on: June 07, 2017, 08:42:29 PM »
I'm not so sure anymore that there is such a thing as a Goldilocks planet. Liquid water apparently can exist in many more contexts than was previously thought, and life can exist in many more places than previously thought.

It's not like humanity will ever find any other planet we'll be able to live on. I think that, to some extent, sci-fi authors have done the world a disservice - they've made too many people believe that finding another home for humanity is a fairly simple matter, so we can trash the Earth and just go find another one out there somewhere.

Yes, and all alien races, thanks to our radio and TV transmissions, already speak American (not British) English ;-)
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Offline trdsf

Re: Exoplanets
« Reply #19 on: June 08, 2017, 11:27:06 AM »
I'm not so sure anymore that there is such a thing as a Goldilocks planet. Liquid water apparently can exist in many more contexts than was previously thought, and life can exist in many more places than previously thought.

It's not like humanity will ever find any other planet we'll be able to live on. I think that, to some extent, sci-fi authors have done the world a disservice - they've made too many people believe that finding another home for humanity is a fairly simple matter, so we can trash the Earth and just go find another one out there somewhere.
And that's what happens when you write speculative fiction in the absence of hard data.  Until only about 25 years ago, extrasolar planets were strictly theoretical, and it was broadly assumed that if we started finding other systems, they would be generally similar to ours: orderly, with the rocky Earth-likes close in and the gas giants far out.  Which, using the principle of mediocrity, wasn't an unreasonable assumption to make.  Now we know that planets are in all sorts of weird orbits, around all sorts of stars, but that's not the fault of the SF writers.  And some of them did assume terraforming marginally habitable worlds (and even uninhabitable ones), or a ubiquity of intelligences on worlds utterly hostile to Terrestrial life.

If there's a problem with public expectations derived from fictional worlds, it's with those who assume that fiction necessarily maps reality, and with an education system that relies on cramming data rather than critical thinking.  It's not with the creators of the fiction.

As far as defining Goldilocks zones, I think we need to start talking about that in terms of different degrees of 'just right', and without sharp lines between them.  So a Class I Goldilocks zone is suitable to the development of microbial and extremely simple multicellular life, but unlikely to be able to support anything more complex.  A Class II zone might support plants and simple animals, but lack anything that pushes evolution forward -- a good environment, but too stable.  And a Class III zone is stable over the long term but variable within limits over the short term, permitting complex life to arise and challenging enough that natural evolution continues to progress rather than finds a stopping point.  Or something like that.
"It's hard to be religious when certain people are never incinerated by bolts of lightning." -- Calvin and Hobbes
"Confused? At a loss for what to do? Wow, sounds like you're human. Good luck." -- Welcome to Night Vale

Re: Exoplanets
« Reply #20 on: June 09, 2017, 05:46:43 PM »
Yes, and all alien races, thanks to our radio and TV transmissions, already speak American (not British) English ;-)
Only the ones that are within about 70 or so light years. Farther than that and they can't yet know about us at all. They may, though, be aware that there's life of a simple kind here. They just don't know about our civilization, as yet.
God Not Found
"FRAUD. The life of commerce, the soul of religion, the bait of courtship, and the basis of political power."
Ambrose Bierce

Offline trdsf

Re: Exoplanets
« Reply #21 on: June 10, 2017, 10:29:57 PM »
Only the ones that are within about 70 or so light years. Farther than that and they can't yet know about us at all. They may, though, be aware that there's life of a simple kind here. They just don't know about our civilization, as yet.
Actually, if they have sufficient technology to detect our planet in the same way that we spot exoplanets, and if they are capable of resolving Earth independently so they can do a spectrographic analysis of our atmosphere, we're potentially detectable out to nearly 200 light years from the gunk we were putting into the air.
"It's hard to be religious when certain people are never incinerated by bolts of lightning." -- Calvin and Hobbes
"Confused? At a loss for what to do? Wow, sounds like you're human. Good luck." -- Welcome to Night Vale