New life, and new life forms

Given the diversity of body plans here on earth, I expect aliens to be even more diverse. My hunch is that symmetry is near-universal, and bilateral symmetry probably common due to the advantages of paired appendages for locomotion and gripping, and paired, distance-apprehending sense organs.Perhaps some intelligent life could be produced only, each individual arising from the same process but never itself reproducing. We might then see neither reproduction nor evolution: some crystalline process where impurity distributions create complex circuits, with intelligence an emergent property of that complexity.But I'll be disappointed if we don't find at least one BEM.

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Have you ever been to an American wedding? Where's the vodka? Where's the marinated herring?!
-Gogol Bordello

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Real things always push back.
-William James

I'm tempted to say my intelligence has not adequately emerged for that task.Imagine a world were thin layers of silicon or other crystalline material are laid down in a confined space--the equivalent of tidal pools, porous rock or clays where organic life may have evolved here. Maybe on our alien planet, the night winds blow dust into micro-craters, and then bake it during the day.The crystalline substrate generates electricity via some stress: heat, microwave radiation, gravity. The strata are not pure silicon; some of the impurities conduct electricity: where they conduct through and across layers, they sometimes form circuits.Eventually, enough complexity develops so that feedback processes arise; memory and awareness follow (sure, that's the fuzzy part, just like here).So individuals are produced but they never reproduce--differences between individuals would be the result of random initial conditions rather than evolution. They might live as long as their planet or star.In summary, the basic idea is simple. Since we can lay down silicon to create machine logic and memory, we may someday create true machine intelligence and awareness. Perhaps what we will invent happens naturally under dramatically different conditions on other planets.QED: Intelligence without evolution or reproduction and with nothing to do.Sounds dull.Edited by Omnivorous, : -what

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Have you ever been to an American wedding? Where's the vodka? Where's the marinated herring?!
-Gogol Bordello

​

Real things always push back.
-William James

I follow you on the sequence implications of heavier elements in our solar system, but I don't see how the timing could make us the first possible intelligent species in the universe.If the sun is about 4.7 billion years old, and the most distant observed galaxy is at 12.8 billion light years, it seems there would be plenty of time for many intelligent species to evolve before us.

I don't think there is anything special about our galaxy, sun, or us. Of course, we can't know one way or the other, at least not just yet.My problem was with thinking of us as serious candidates for the first intelligent species ever due to the sun's age and the heavier element contributions of its predecessor. I don't see any reason to believe we had a head-start over any other post-first generation star system, and surely there must be billions of them.We can see small bright galaxies about 12.8 billion light years away; I suppose we look much the same from there. Surely those galaxies, like ours, have had time to "mature" and host stars with planets.My totally worthless intuitive hunch is that intelligence is more likely to have appeared everywhere at about the same time than preferentially in some sectors of our universe: given our own intelligent behavior, it may be tragically fortunate that intelligences arise so far apart and are accelerating away ever faster.The question of heat would seem more determined by the particular star in question than the universe or galaxy overall, though I can see that stars near galactic centers or in crowded clusters might be too "hot" in the sense of radiation. But if we were sailing through "empty" intergalactic space along with our sun, wouldn't our planetary conditions remain the same, as they are now while we circle the galaxy in our spiral arm?I'm not disagreeing with crash (or anyone) with any confidence at all; I'm just trying to clarify his argument in my own mind, and so far I can't make it click in a persuasive way. I envy his present academic exposure: it's been years since I did more than skim articles, so I may simply be lacking some basic data that would illuminate the issue for me.Still, we are discovering planetary systems at an accelerating rate, and life may be as common as dirt.

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Have you ever been to an American wedding? Where's the vodka? Where's the marinated herring?!
-Gogol Bordello

​

Real things always push back.
-William James

I understand the need for time distance from the Big Puff.I also read that the Milky Way is thought to be in the oldest generation of galaxies, at about 13.6 billion years; our sun, 4.57 billion years.Let's set aside the rest of the universe for now, and consider whether we enjoy unique conditions in our own galaxy.From Wiki: Galactic habitable zone

quote:

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The location of a planetary system within a galaxy must also be favorable to the development of life, and this has led to the concept of a galactic habitable zone (GHZ), [17][18] although the concept has recently been challenged.[19]

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To harbor life, a system must be close enough to the galactic center that a sufficiently high level of heavy elements exist to favor the formation of rocky, or terrestrial, planets, which are needed to support life (see: planetary habitability). Heavier elements also need to be present, as they are the basis of the complex molecules of life. While any specific example of a heavier element may not be necessary for all life, heavier elements in general become increasingly necessary for complex life on Earth (both as complex molecules and as sources of energy).[20] It is assumed they would also be necessary for simpler and especially more complex life on other planets.

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On the other hand, the planetary system must be far enough from the galactic center that it would not be affected by dangerous high-frequency radiation, which would cause damage and harmful alterations to the DNA of any carbon-based life. Also, most of the stars in the galactic center are old, unstable, dying stars, meaning that few or no stars form in the galactic center.[21] Because terrestrial planets form from the same types of nebulae as stars, it can be reasoned that if stars cannot form in the galactic center, then terrestrial planets cannot, either.

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In our galaxy (the Milky Way), the GHZ is currently believed to be a slowly expanding region approximately 25,000 light years (8 kiloparsecs) from the galactic core and some 6,000 light years in width (2 kiloparsecs), containing stars roughly 4 billion to 8 billion years old. Other galaxies differ in their compositions, and may have a larger or smaller GHZ — or none at all (see: elliptical galaxy).

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So we have a theoretical habitable zone that is 2 kp x 8 kp, or 16 square kiloparsecs. Among the stars in that zone, our sun is relatively young (4.57 billiion years in a range of 4-8 billion years).It would appear that most of the stars in the Milky Way's 16 square kiloparsec habitable zone are older than than our sun.Note, in para 2 quoted above, that both the heavy elements required for carbon-based life and the necessary distance from the galactic center are taken into account.Why wouldn't many, if not most, habitable zone stars have supported the evolution of life, and possibly intelligence, billions of years before ours? Edited by Omnivorous, : Keep wanting to type inhabitable.Edited by Omnivorous, : 'rithmeticEdited by Omnivorous, : a tired brainEdited by Omnivorous, : No reason given.

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Have you ever been to an American wedding? Where's the vodka? Where's the marinated herring?!
-Gogol Bordello

​

Real things always push back.
-William James

I thought about the annular nature of the band while reading the Wiki text, then promptly ignored it; I'd've had to look up the formula anyway.
Thanks for the correction.

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Have you ever been to an American wedding? Where's the vodka? Where's the marinated herring?!
-Gogol Bordello

​

Real things always push back.
-William James