Unusual forms of life

[Djamila]

Okay, that's done.

Tell me, why do you think that this deep sea could not have developed without the conditions on the earth's surface as they are?

 

[standing_on_one_foot]

In case you're curious, by the by, our sun is more likely to expand on us and become a red giant and then go the planetary nova route (which has, oddly enough, nothing to do with planets).

 

[standing_on_one_foot]

Okay, that's done.

Tell me, why do you think that this deep sea could not have developed without the conditions on the earth's surface as they are?

It could have, since conditions on the Earth's surface have doubtless changed since these beasties showed up. But without the sun, I don't think you would have the Earth in the first place, and you wouldn't have liquid oceans. It would just be too cold.

 

[Djamila]

In case you're curious, by the by, our sun is more likely to expand on us and become a red giant and then go the planetary nova route (which has, oddly enough, nothing to do with planets).

Red giant, really? I never knew how they were formed, but I just assumed they were formed that way from their beginning.

Why does our sun have more of a chance of doing that first? Is that the normal route?

An what is the plantary nova route?

 

[Djamila]

It could have, since conditions on the Earth's surface have doubtless changed since these beasties showed up. But without the sun, I don't think you would have the Earth in the first place, and you wouldn't have liquid oceans. It would just be too cold.

But it would have to be liquid around these hot vents, yes? Or would it just form like... a tunnel through the ice all the miles to the surface?

 

[standing_on_one_foot]

No, red giants are just a part of a sun-like star's life cycle. If a star isn't big enough, it won't be able to supernova. I think you need to be several times bigger than the sun to do that.

Planetary novas involve the star's outer layers going off, eventually leaving what will, if I recall correctly, be a white dwarf.

 

[standing_on_one_foot]

But it would have to be liquid around these hot vents, yes? Or would it just form like... a tunnel through the ice all the miles to the surface?

It's likely you'd get some liquid near the vents (very unlikely that this would reach the surface, though. I suppose it's possible life could develop there. It just seems fairly unlikely.

 

[Djamila]

Oh cool. Is a Red Giant created by the same process within the star that would cause a larger one to supernova?

 

[standing_on_one_foot]

As I recall (and it's been awhile since astronomy), the ones that will supernova get to the red giant phase too, they just take it a step further.

A link on star life cycles: http://imagine.gsfc.nasa.gov/docs/teachers/lessons/xray_spectra/background-lifecycles.html

 

[Djamila]

That was really interesting. I wonder how common they are?

 

[Valjean]

Stars go through a regular series of life stages. These vary with the star's mass.
Sol. our sun, will expand as it uses up it's hydrogen fuel. It's temperature will decrease and it will go from a yellow star to a red one. As it's size increases beyond Earth's orbit our planet will be consumed and incinerated.

No planet could possibly survive a stellar nova, but your question about Earth's fate without its star is interesting.
First, without Sol's gravity all objects orbiting it would head off into space in a straight line -- forever. Earth's temperature would quickly approach absolute zero (-273, C.). Earth's axial rotation would continue, of course, so the frictional heat from the moving liquid mantle might be maintained for a few hours. The heat from radioactive decay would continue as well, and might buy our planet a few more minutes before it was frozen surface-to-core.

 

[Sonic247]

This thread reminded me of I time we visited a cave when I was a little kid (because of the whole "living without sunlight thing") And when a heard that there was fish that live in caves I though it was the coolest thing. Especially because they were white (spooky) and couldn't see. The coolest thing about these fish is they have no eyes, they don't need them, what I just found out though is that you can get this fish for your aquarium. I should start a thread on animals that live in caves

 

[Valjean]

This thread reminded me of I time we visited a cave when I was a little kid (because of the whole "living without sunlight thing") And when a heard that there was fish that live in caves I though it was the coolest thing. Especially because they were white (spooky) and couldn't see. The coolest thing about these fish is they have no eyes, they don't need them, what I just found out though is that you can get this fish for your aquarium. I should start a thread on animals that live in caves

Blind fish -- they ain't nothin'!

Consider the bacteria that live their slow motion lives deep in the Earth's crust, eating minerals, ignorant of sunlight. Every couple thousand years they may accumulate enough energy to reproduce and create a copy of themselves.
How terrifyingly frenetic our surface lives must appear to them!

 

[Guitar's Cry]

Could there be nitrogen-based life, for example, on a gas planet that bursts to existence everytime that face of the planet in pointed towards the cold light of a very distant star - and then fades away as that face of the planet rotates into darkness?

I like that! Kind of like desert life after a rain storm. Considering that bacteria in their dormant state can survive some pretty extreme conditions, I see this as very possible.

 

[Valjean]

Dormant state?
Google extremophiles and you'll find organisms active and reproducing in conditions that would kill an "ordinary" organism in a fraction of a second!