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A comment on Observable Universe contains 10x more galaxies than previously thought (2016). Parent comment

Re:Observable Universe contains 10x more galaxies than previ... by esarbe on Thursday January 04, 2018 @08:21AM (#16070122)
I agree with you in that we will probably never have contact with another sentient species of extra terrestrial origin. The distances are to vast, the lifetimes of civilisations and even species too short and so on.

However I do think that you vastly underestimate the probability of life. Take a look at https://en.wikipedia.org/wiki/Earliest_known_life_forms . See how quickly life appeared once the earth had cooled down? It's almost immediately!

I'm pretty convinced that almost all star systems have some complex energy conversion cycles that could be classified as life. Let's not make the mistake of assuming all life has to be carbon based.

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Re:Observable Universe contains 10x more galaxies than previ... by e40 on Thursday January 04, 2018 @01:04PM (#16072484)
See how quickly life appeared once the earth had cooled down?

https://en.wikipedia.org/wiki/Panspermia

I find this a compelling possibility.

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Re:Observable Universe contains 10x more galaxies than previ... by Balgair on Thursday January 04, 2018 @06:00PM (#16074920)
Highly unlikely.

DNA's 'half-life' is about 500 years. Meaning that each nucleotide-bond has a 50% chance of breaking every 500 years.[0] At the time scales of interstellar travel, DNA based life is very unlikely to survive.

EDIT: This then means that DNA based life was likely a local phenomenon. This also means that other planets may have done the same and that a 'interstellar seed' is not required.

[0] https://www.the-scientist.com/?articles.view/articleNo/32799...

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Re:Observable Universe contains 10x more galaxies than previ... by blauditore on Thursday January 04, 2018 @10:19AM (#16070914)
But it's fairly likely to be carbon-based, as carbon is the simplest existing element with the maximum amount of valence electrons. And generally, simpler (= lower ordinal number) means more stable, as well as more likely to arise (as less energy is required, e.g. in stars).
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Re:Observable Universe contains 10x more galaxies than previ... by zamalek on Thursday January 04, 2018 @05:16PM (#16074594)
There are other theoretical biochemistry possibilities[1]. Silicon, for example, works well in low-pressure environments. It's an immense stretch of the imagination to think about life-forms that use semiconductors to do useful work, but is certainly a fun thought experiment.

[1]: https://en.wikipedia.org/wiki/Hypothetical_types_of_biochemi...

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Re:Observable Universe contains 10x more galaxies than previ... by blauditore on Friday January 05, 2018 @01:46AM (#16077024)
Yes, it's possible, just less likely. How much less likely is hard to tell, but I if you hear hoofsteps, you first think of horses, not zebras.
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Re:Observable Universe contains 10x more galaxies than previ... by AnIdiotOnTheNet on Thursday January 04, 2018 @12:58PM (#16072420)
It may not be based on elemental matter, or matter at all.
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Re:Observable Universe contains 10x more galaxies than previ... by blauditore on Friday January 05, 2018 @01:48AM (#16077032)
Hmm, true. But then, interaction with elemental matter life forms (like us) would become terribly difficult; it might be hard to even notice there's a life form existing in anti-matter.
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Re:Observable Universe contains 10x more galaxies than previ... by wu-ikkyu on Thursday January 04, 2018 @02:43PM (#16073385)
Do you think the periodic table contains all the elements in the universe?
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Re:Observable Universe contains 10x more galaxies than previ... by woodandsteel on Thursday January 04, 2018 @05:07PM (#16074527)
Yes, since from what I understand, any heavier elements would be so unstable they wouldn't last a billionth of a second.
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Re:Observable Universe contains 10x more galaxies than previ... by blauditore on Friday January 05, 2018 @01:52AM (#16077040)
That's the general assumption, even though there might be another stable "island" of fairly stable isotopes for higher-order elements than observed so far. But as I said, they'd need to be created first through nuclear fusion of lower elements, so their existence is obviously less likely, let alone life forms evolving on top of them.
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Re:Observable Universe contains 10x more galaxies than previ... by marcosdumay on Thursday January 04, 2018 @12:59PM (#16072423)
> See how quickly life appeared once the earth had cooled down?

What if life can only appear as a planet is finishing to cool down?

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