43 replies to this topic

[scowl]

DieChecker, on 05 December 2011 - 07:06 PM, said:

I've yet to read the link, but first guess... I'd say not necessary. After all the Earth supports life deep in the crust, at the bottom of the oceans and in radioactive pools. Situations that would kill most creatures in seconds support other life just fine.

You're confusing the creation of life with the support of life.

Yes, we know that life can thrive in some crazy environments once it's abundant. We don't yet know what environments are required to create life from scratch.

[scowl]

bison, on 03 December 2011 - 12:12 AM, said:

The article linked below, from Science Magazine's website, refers to the recent predominant conjecture about the near necessity of a large moon for planet stability, and why this was thought be so important for long term survival, particularly of complex forms of life. It also discusses the new work that renders this conjecture questionable. http://news.sciencem...eds-a-moon.html

People have only speculated that it might be necessary, i.e. it's a theory. Predominant conjecture should not be confused with fact.

[travelnjones]

It may well be required for civilizations with a desire to leave their own planet.  It gave us a reasonable target and also captivated our imaginations.

[DieChecker]

scowl, on 05 December 2011 - 07:46 PM, said:

You're confusing the creation of life with the support of life.

Aren't those one and the same? An environment that can support life should also be capable of creating it, if at a much lower chance.

Quote

Yes, we know that life can thrive in some crazy environments once it's abundant. We don't yet know what environments are required to create life from scratch.

So my idea seems plausable, just maybe not as likely as, say, a warm pool with plenty of sun.

[catfishyeah]

Wouldn't living organisms be heavier? The moon does have a gravitational pull on water and all life does have water in it. So the moon is pulling everything upward, and the planet is pulling downward thus making the organisms lighter, and without the moon organisms would just be pulled downward. So wouldn't everything need to be re-evaluated? Especially the weight sistem right?

Edited by catfishyeah, 06 December 2011 - 08:04 PM.

[Muenzenhamster]

catfishyeah, on 06 December 2011 - 08:03 PM, said:

Wouldn't living organisms be heavier? The moon does have a gravitational pull on water and all life does have water in it. So the moon is pulling everything upward, and the planet is pulling downward thus making the organisms lighter, and without the moon organisms would just be pulled downward. So wouldn't everything need to be re-evaluated? Especially the weight sistem right?

The moon has a gravitational pull on everything, not just water. If you're thinking of the effect of the moon on the tides, then tell me, does your goldfish bowl have discernible tides? This only works on a global scale. I'd very much doubt that you weigh more or less with each pass of the moon. I'm not saying it's impossible, just that it is very nigh immeasurable.
Postscriptum: system is spelled s-y-s-t-e-m, not sistem.

[scowl]

DieChecker, on 06 December 2011 - 01:13 AM, said:

Aren't those one and the same? An environment that can support life should also be capable of creating it, if at a much lower chance.

No, they're not the same. People mistakenly presume that environments never change but we know that Earth's environment has gone through dramatic changes since life began here.

At some point the creation of new life on Earth stopped. All life today (except for parasitic viruses) can be traced to a single early life form. There is no evidence that since that life was created billions of years ago that additional life forms were created even though Earth has continued to have what we think are "ideal" conditions for the creation of life. That suggests that changes in Earth's environment have stopped the creation of new life even though the environment has been excellent at sustaining existing life and promoting its evolution. If the environment of today's Earth is so ideal for the creation of life then why hasn't it happened repeatedly?

Conversely it's possible for life to be created in ideal conditions that later become toxic and exterminate that life. We don't know the likelihood of that but we do know it happens.

[Cryptozological Mascot]

Moons are necessary to support werewolves.  Just sayn.

[psyche101]

scowl, on 07 December 2011 - 06:34 PM, said:

No, they're not the same. People mistakenly presume that environments never change but we know that Earth's environment has gone through dramatic changes since life began here.

At some point the creation of new life on Earth stopped. All life today (except for parasitic viruses) can be traced to a single early life form. There is no evidence that since that life was created billions of years ago that additional life forms were created even though Earth has continued to have what we think are "ideal" conditions for the creation of life. That suggests that changes in Earth's environment have stopped the creation of new life even though the environment has been excellent at sustaining existing life and promoting its evolution. If the environment of today's Earth is so ideal for the creation of life then why hasn't it happened repeatedly?

Conversely it's possible for life to be created in ideal conditions that later become toxic and exterminate that life. We don't know the likelihood of that but we do know it happens.

Early Earth Was Purple, Study Suggests - LINK

[DONTEATUS]

Was it Melancholia that made the earth Spin around?
On a real note Go see this movie even If its a bit off topic, Its a Great Dark look at the art film world. ,Kirsten Dunst is great in this flick !

[27vet]

DONTEATUS, on 08 December 2011 - 03:14 AM, said:

Was it Melancholia that made the earth Spin around?
On a real note Go see this movie even If its a bit off topic, Its a Great Dark look at the art film world. ,Kirsten Dunst is great in this flick !

Congratulations on your 10,000th post.

[lost_shaman]

scowl, on 07 December 2011 - 06:34 PM, said:

No, they're not the same. People mistakenly presume that environments never change but we know that Earth's environment has gone through dramatic changes since life began here.

At some point the creation of new life on Earth stopped. All life today (except for parasitic viruses) can be traced to a single early life form. There is no evidence that since that life was created billions of years ago that additional life forms were created even though Earth has continued to have what we think are "ideal" conditions for the creation of life. That suggests that changes in Earth's environment have stopped the creation of new life even though the environment has been excellent at sustaining existing life and promoting its evolution. If the environment of today's Earth is so ideal for the creation of life then why hasn't it happened repeatedly?

Conversely it's possible for life to be created in ideal conditions that later become toxic and exterminate that life. We don't know the likelihood of that but we do know it happens.

If simple life evolved in the protoplanetary disk and simply rained down on Earth with the water that formed the Oceans then your assumptions are not valid.

[scowl]

lost_shaman, on 09 December 2011 - 08:49 AM, said:

If simple life evolved in the protoplanetary disk and simply rained down on Earth with the water that formed the Oceans then your assumptions are not valid.

I don't see how your speculation addresses any of my points.

Has Earth's environment changed? Of course it has.

Has the creation of life on Earth stopped? With the exception of viruses, we have no evidence of any life that was created separately or independently from all life on Earth today. It can all be traced to the same early life forms.

Have the present conditions on Earth not been ideal for the creation of new life forms? Well, it hasn't happened again so something must be preventing it from happening again on Earth.

Have the conditions on Earth been good for sustaining life and promoting evolution? Look out your window.

Can the conditions on Earth change and exterminate life? Yes, the dinosaurs really died out along with millions of other species. Fortunately that tremendous change happened after a wide range of life had covered the planet. If a similar change had happened when life had just been established it very well could have been the end of all life on Earth.

[lost_shaman]

scowl, on 09 December 2011 - 08:43 PM, said:

I don't see how your speculation addresses any of my points.

Has Earth's environment changed? Of course it has.

Has the creation of life on Earth stopped? With the exception of viruses, we have no evidence of any life that was created separately or independently from all life on Earth today. It can all be traced to the same early life forms.

Right, so if that early life formed in the protoplanetary disk as opposed to Earth's oceans then your argument fails.

scowl, on 09 December 2011 - 08:43 PM, said:

Have the present conditions on Earth not been ideal for the creation of new life forms? Well, it hasn't happened again so something must be preventing it from happening again on Earth.

We don't know this happened on Earth, that's my point.

scowl, on 09 December 2011 - 08:43 PM, said:

Have the conditions on Earth been good for sustaining life and promoting evolution? Look out your window.

Can the conditions on Earth change and exterminate life? Yes, the dinosaurs really died out along with millions of other species. Fortunately that tremendous change happened after a wide range of life had covered the planet. If a similar change had happened when life had just been established it very well could have been the end of all life on Earth.

Early life seems to have survived the late heavy bombardment and every catastrophe since.  

Edited by lost_shaman, 10 December 2011 - 07:25 AM.

[scowl]

lost_shaman, on 10 December 2011 - 07:23 AM, said:

Right, so if that early life formed in the protoplanetary disk as opposed to Earth's oceans then your argument fails.

No, it's 100% supported. Early life formed in conditions that are considered inhabitable to us, therefore the pleasant conditions we enjoy on Earth today are not the conditions that form life.

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We don't know this happened on Earth, that's my point.

Yes, we don't know a lot of things but we do know every point that I made. We know that the conditions on Earth have changed dramatically in the three billion years since life was created on it and no other forms of life have been created and survived (except parasitic viruses). The formation of life seems to have happened very quickly under extremely fortunate conditions that only existed briefly. That was followed by even more extremely fortunate conditions that didn't destroy that life and allowed it to evolve to survive further climatic changes.

Quote

Early life seems to have survived the late heavy bombardment and every catastrophe since.  

Yes, on Earth. We really don't know what early life was and we don't know how close it was to being destroyed. It's possible that most life in the universe never advances beyond primitive stages before it's wiped out forever. We know that Earth was an extremely lucky set of unlikely circumstances.

For some reason many people think that every planet that might have something close to Earth conditions has just gotta have life on it because it would be like so cool! When you look at the history of the Earth, you really appreciate how improbable life is.