Exoplanets

[Unbeliever]

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!

[Baruch]

You will find that any Goldilocks planet is already claimed by the bear tribe ;-)

[Unbeliever]

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.

[Baruch]

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 ;-)

[trdsf]

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.

[Unbeliever]

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.

[trdsf]

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.

[Cavebear]

And, interestingly, I have read that our radio and TV signals are essentially static a few light year out.  It might be that no signals of intelligence travel very far in any detectable way. 

[trdsf]

And, interestingly, I have read that our radio and TV signals are essentially static a few light year out.  It might be that no signals of intelligence travel very far in any detectable way.

True.  Our radio and television signals would be very difficult to pick up even as near as Proxima Centauri, and virtually impossible to pick up any further out, because signal attenuation follows an inverse square law - twice the distance, 1/4th the signal, ten times the distance, 1/100th the signal.  The best way to identify other ETIs is probably going to be identifying planets (or large moons) within a star's habzone and doing spectrographic analysis, looking for oxygen or acetylene  or other gases that probably require a biological presence to explain -- or, ironically the best sign of all, atmospheric pollutants -- and then bearing all appropriate resources down on that world, sending relativistic probes and listening very closely in case they're broadcasting to be heard.

[Unbeliever]

It's likely that any intelligent species out there will have evolved from a predatory species, just because it takes more brains to hunt and kill prey than to simply munch leaves and hide. So we should hope they don't know about us!

[trdsf]

It's likely that any intelligent species out there will have evolved from a predatory species, just because it takes more brains to hunt and kill prey than to simply munch leaves and hide. So we should hope they don't know about us!

That's a point mentioned by Helen Keen in her BBC Radio 4 series, It Is Rocket Science, and a good one.  The only reasonably good refutation of it is to consider the possibility that that's the course evolution took here, but that intelligence and predatory behavior are not necessarily inextricably linked.  Sufficiently nutritious vegetation (or its equivalent), for example, can provide the necessary energy for a large brain as well as meat did for us.

Of course, another good reason to keep our collective heads down is because if you want to know what encountering a more technologically advanced civilization is like, you can ask the (remaining) indigenous people of North and South America and Australia.

[Unbeliever]

Sufficiently nutritious vegetation (or its equivalent), for example, can provide the necessary energy for a large brain as well as meat did for us.

Maybe, but I think nutritious plants wouldn't provide enough of a challenge to make intelligence useful, much less necessary.

[Baruch]

It's likely that any intelligent species out there will have evolved from a predatory species, just because it takes more brains to hunt and kill prey than to simply munch leaves and hide. So we should hope they don't know about us!

That is exactly why the Elite are the master-class, if not the master-race.

[trdsf]

Maybe, but I think nutritious plants wouldn't provide enough of a challenge to make intelligence useful, much less necessary.

Hadn't thought of that, good point.

I mean, I expect that land based hunter-gatherer omnivores are the most promising basis on which to evolve an intelligent species.  I would like to come up with a reasonable way to get herbivores to sentience, just to build the case for them.  I think a carnivorous or omnivorous aquatic species would have a better chance at sentience, though -- you can get to a primitive mechanical society without fire, but of course that's going to be limited without an ability to extract ores.

[Baruch]

Hadn't thought of that, good point.

I mean, I expect that land based hunter-gatherer omnivores are the most promising basis on which to evolve an intelligent species.  I would like to come up with a reasonable way to get herbivores to sentience, just to build the case for them.  I think a carnivorous or omnivorous aquatic species would have a better chance at sentience, though -- you can get to a primitive mechanical society without fire, but of course that's going to be limited without an ability to extract ores.

Humans aren't the Federation, we are the pre-breakout Borg.