Author Topic: Exoplanets  (Read 2745 times)

Offline Cavebear

Re: Exoplanets
« Reply #75 on: April 21, 2017, 05:53:12 AM »
Given the speed of simple life forming on Earth, it seems plausible that it occurs elsewhere.  The hard part comes when conditions exist to encourage more complicated life.  And I suspect that given certain replicable conditions, complex life could exist. 

The jump to sentient life is way harder.
Atheist born, atheist bred.  And when I die, atheist dead!  b 1950

Offline SGOS

Re: Exoplanets
« Reply #76 on: April 21, 2017, 07:43:48 AM »
Given the speed of simple life forming on Earth, it seems plausible that it occurs elsewhere.  The hard part comes when conditions exist to encourage more complicated life.  And I suspect that given certain replicable conditions, complex life could exist. 
The jump to sentient life is way harder.
Not only does it happen faster than I would anticipate, I don't see the difference between life and non-life as some dividing line that is hundreds of miles across.  Really, what's that special about combinations of molecules that perpetuate themselves?  Throw in a combination of molecules that produces some sort of animation, and a few other combinations that do things like improve detection of other molecules nearby (which atoms seem to do anyway), and next thing you know, you've got a combination of things that pulsate.  Such a thing is simple enough that no special designer or natural meta-fluke has to be involved.  Molecules just have affinities that make them combine in infinite ways.  In a sense, evolution was taking place long before life began.

Yeah?  Well what about the human eye?  OK, I suppose that one could be a miracle, especially if it happened overnight, but the ability to detect light (in other words... eyesight) has been around much longer than man by a factor that requires the use of scientific notation.  And primitive light detection systems are still in use today in lower life forms.  Yeah, yeah.  I know:  "If humans evolved form lower life forms, why are there still lower life forms?"  (now there is one impressive argument).

I remember being taught 6 universal characteristics of life back in grade school.  I guess it was supposed to be a life detection kit, so while we were  playing in the dirt, we could decide something was living rather than inert. 

Enter sentience, the big <wahoo> of life.  Now you just can't explain that <think Bill O'Reilly>, so I would propose another couple of characteristics that separate sentient life from non.

7.  The obsession to glorify its own sentience, while at the same time,
8.  Having no ability to understand its own sentience.

In fact, number 7 might be what separates man from the dolphins.

Not only do I think more life in the universe is inevitable.  I also don't even think it's big a deal.  If we ever detect sentient life elsewhere, the first thing we are going to do is figure out how to steal their inert stuff, which is really all we are after in the first place.

Offline Baruch

Re: Exoplanets
« Reply #77 on: April 21, 2017, 12:39:35 PM »
A materialist would claim ... there is no difference between life and non-life .. between consciousness and unconsciousness.  But not all naturalists are materialists.  Not all naturalists are atheists.
שלום

Offline trdsf

Re: Exoplanets
« Reply #78 on: April 21, 2017, 12:54:42 PM »
Not only does it happen faster than I would anticipate, I don't see the difference between life and non-life as some dividing line that is hundreds of miles across.  Really, what's that special about combinations of molecules that perpetuate themselves?  Throw in a combination of molecules that produces some sort of animation, and a few other combinations that do things like improve detection of other molecules nearby (which atoms seem to do anyway), and next thing you know, you've got a combination of things that pulsate.  Such a thing is simple enough that no special designer or natural meta-fluke has to be involved.  Molecules just have affinities that make them combine in infinite ways.  In a sense, evolution was taking place long before life began.
I agree, there's certainly a continuum between 'not alive' and 'alive' that passes through 'those are some weird chemicals' along the way.  There's not even a consensus on whether anything as well-studied as a bacteriophage is alive, or just following a chemical program -- and no, I don't care to get sidetracked into a philosophical contretemps about whether or not that's all anything does.  'Life' is just damned difficult to define, and I suspect most of us fall back on the traditional definition of pornography: "I know it when I see it".

I feel comfortable with the notion that a virus is 'more alive' in some sense than a phage, that a bacterium is 'more alive' than a virus, that a paramecium is 'more alive' than a bacterium (maybe)... and really, once you hit that point, there's no sense in which a human is 'more alive' than a paramecium or an amœba.  Humans are both more specialized at the individual cell level and more generalized at the organism level, more conscious, more self-aware, more any number of things, but at the biochemical level, we are not meaningfully 'more alive' than a eukaryote in the same way that we are to a virus or phage.

In light of the possibility of even simple life elsewhere in our own solar system, to say nothing of complex life elsewhere in the galaxy, it's pretty clear we can't look at 'life' as a binary proposition.  If we do, we may miss something incredible when we get to sampling the waters of Enceladus or the permafrost of Mars.
"It's hard to be religious when certain people are never incinerated by bolts of lightning." -- Calvin and Hobbes
"I thought I committed regicide today, but I committed deicide!" -- Sadie Doyle, Beyond Belief

Re: Exoplanets
« Reply #79 on: April 23, 2017, 11:37:11 AM »
Given the speed of simple life forming on Earth, it seems plausible that it occurs elsewhere.  The hard part comes when conditions exist to encourage more complicated life.  And I suspect that given certain replicable conditions, complex life could exist. 

The jump to sentient life is way harder.
And still pending in rural Missouri.
We 'new atheists' have a reputation for being militant, but make no mistake  we didn't start this war. If you want to place blame put it on the the religious zealots who have been poisoning the minds of the  young for a long long time."
PZ Myers

Offline Cavebear

Re: Exoplanets
« Reply #80 on: June 14, 2017, 08:02:10 AM »
The difference between life and non-life is probably a combination of replicability and being subject to natural selection.  A crystal can repeat itself, but there doesn't seem to be natural selection involved. 

A virus is WAY too complex to be a starting point for life.  More likely, something as simple as salty water with a few random molecules thrown in.  The other thing that makes me think the life is simple to start is that it seems to have begun so quickly after Earth cooled even slightly.  Possibly, there were several starts, too after initial extinctions.
Atheist born, atheist bred.  And when I die, atheist dead!  b 1950

Offline SGOS

Re: Exoplanets
« Reply #81 on: June 14, 2017, 09:07:50 AM »
The other thing that makes me think the life is simple to start is that it seems to have begun so quickly after Earth cooled even slightly.
It rather suggests life is inevitable, doesn't it.

Offline Baruch

Re: Exoplanets
« Reply #82 on: June 14, 2017, 12:50:46 PM »
It rather suggests life is inevitable, doesn't it.

In favorable environments ... yes.  But also with a specific history, we didn't always have so much oxygen in our atmosphere.  Life post-initio ... isn't what it was pre-initio ... because of different environmental conditions then vs now.  See pre-Cambrian geo history.
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Offline Cavebear

Re: Exoplanets
« Reply #83 on: June 18, 2017, 05:58:01 AM »
It rather suggests life is inevitable, doesn't it.
Yes.  The universe might be populated with billions of planets covered with slime and microbes.  There might be some fraction with viruses.  But as soon as DNA (or some version of it) occurs, it is OFF TOO THE RACES!

Then things "like" reptiles and mammals are inevitable.  The problem after that is intelligence.  There may not be many genetic differences between chimps and humans, but the differences are vast.

So, 99.9% of habitable planets or moons might have slime (life), some few percent brainy animals, and some vanishing small number technological self-aware critters.

The Drake equation was brilliant but WAY too short.
Atheist born, atheist bred.  And when I die, atheist dead!  b 1950