One small star, one small planet... at least!

[Sundew]

As for tech. Life forms they need to have some sort of grasping hand and time to come up with it. Is an elephant has a grasping hand, its trunk, but doesn't have enough time to come up with tech.

Not necessarily, the octopus is very intelligent (the most intelligent invertebrate animal) and is quite capable of manipulation of objects, solving problems and learning. However, in its way of reproduction, its young are typically born after the female, which guards the eggs, is either dead or dying, so there is no way to pass learned information on to the next generation. It is interesting to note that there are octopi living on the flanks of a constantly erupting volcano where the landscape is constantly changing (as bits of rock rain into the sea) have had to abandon a solitary existence in dens, common to the species, and live in exposed colonies, and they seem to be learning from one another through observation. The other impediment to the octopus become more intelligent is that they typically have a very short life span, sometimes only one year.

So a creature would presumably need to have some way to manipulate objects, but not necessarily a hand like we have. We can all agree that dolphins are smart, live in an alien (to us) environment, and have senses that we do not possess like echolocation, but they lack the means of any manipulation of objects besides clumsily grasping it in their jaws. Our hands might be more efficient if both the thumb and little finger were opposable which would give us a better grip. If we look at the variety of life on our own planet in all its many forms, it's hard to say what form alien life might take and any guesses as to what form it might take are just that. And there is no guarantee that life exists outside our planet, it is more of a statistical idea based on the number of stars with planets in the so called Goldilocks Zone, the number of stars in our galaxy and the number of galaxies in the universe. A formidable number to be sure, but alien life is still unproven at this point in time.

[Merc14]

Not necessarily, the octopus is very intelligent (the most intelligent invertebrate animal) and is quite capable of manipulation of objects, solving problems and learning. However, in its way of reproduction, its young are typically born after the female, which guards the eggs, is either dead or dying, so there is no way to pass learned information on to the next generation. It is interesting to note that there are octopi living on the flanks of a constantly erupting volcano where the landscape is constantly changing (as bits of rock rain into the sea) have had to abandon a solitary existence in dens, common to the species, and live in exposed colonies, and they seem to be learning from one another through observation. The other impediment to the octopus become more intelligent is that they typically have a very short life span, sometimes only one year.

So a creature would presumably need to have some way to manipulate objects, but not necessarily a hand like we have. We can all agree that dolphins are smart, live in an alien (to us) environment, and have senses that we do not possess like echolocation, but they lack the means of any manipulation of objects besides clumsily grasping it in their jaws. Our hands might be more efficient if both the thumb and little finger were opposable which would give us a better grip. If we look at the variety of life on our own planet in all its many forms, it's hard to say what form alien life might take and any guesses as to what form it might take are just that. And there is no guarantee that life exists outside our planet, it is more of a statistical idea based on the number of stars with planets in the so called Goldilocks Zone, the number of stars in our galaxy and the number of galaxies in the universe. A formidable number to be sure, but alien life is still unproven at this point in time.

Can you post a link to that octopus colony story, I can't find it and I'd love to read about it. My son loves these creatures although he is partial to the cuttlefish which he thinks are smarter.

[Sundew]

Can you post a link to that octopus colony story, I can't find it and I'd love to read about it. My son loves these creatures although he is partial to the cuttlefish which he thinks are smarter.

It was from a video I saw on television, it's from Octopus Volcano, National Geographic. I found it online but it's in Arabic, there is also another one I think is in English but apparently I am missing a plug in to view it. You can Goggle it, maybe you'll find one that works. Good luck!

[Merc14]

It was from a video I saw on television, it's from Octopus Volcano, National Geographic. I found it online but it's in Arabic, there is also another one I think is in English but apparently I am missing a plug in to view it. You can Goggle it, maybe you'll find one that works. Good luck!

Got it and it is on Nat Geo Wild on Tuesday, March 18th at 10:30PM, here in the states. Thanks! I'll make sure to record it for my son (and me!).

Edited March 11, 2014 by Merc14

[Peter B]

We need to stop thinking we are unique in the universe...

Based on the comments on this thread alone, it seems few people think that.

[danielost]

What I don't understand is who are we to decide what elements create life? Alien life can be present anywhere under any conditions. Maybe they absorb sunlight as food (photosynthesis), may not drink water, may not need sunlight, or warm temperatures like us. We just don't know.

Water is the only element it's solid floats in its liquid.

[psyche101]

Evolution offers the potential for an almost infinite variety of life. To assume it would be so dull as to come up with the same answer each time seems a somewhat limited view.

I disagree, convergent evolution shows us that a good design will be seen again, and Darwin's Finches took on attributes of other known species to provide the simplest solution to fill a niche. Life itself replicates, that is how it begins - cells divide, and our solar system indicates that life requires strictly parameters to begin and flourish. If life requires an "earth like planet" to begin and survive, it seem likely that the same building blocks of life subject to similar forces in similar environments will produce similar life forms. Familiar life forms seems the simplest solution, so I feel nature would opt for just that - the simplest solution.

I find Simon Conway Morris' argument a very good one supporting familiar life on extra terrestrial planets.

[Captain Zim]

Agreed; there seems to be a certain "ideal size" for a terrestrial planet to hold life: large enough to support tectonic activity and magnetic field; small enough to not have a chokingly thick greenhouse atmosphere. Of course, there will be many unusual exceptions and our knowledge of such will grow... but I think we would see something like deep-sea squid in the oceans of Europa and Ganymede if complex life does in fact exist there.

Furthermore we can probably guess at what primate-like species would do in terms of technological development... probably rockets at first to shoot out of the atmosphere, then orbital elevators as the necessary high tensile technology is developed.

Of course, we do not know what a fundamentally alien species would do... we only have the limited examples of ourselves, our primate cousins and dolphins to look at. Octopi are weird but still seem to behave in a logical fashion which we could decode. Hive creatures made of swarms of insects? Or artificial intelligences made by such? We have seen inexplicable, alien behaviour developing in complex, emergent systems and our behaviour must seem equally complex. Most of our sense of beauty is somehow related to from choosing the right-looking monkey to breed with.

Some aliens would be reasonably "humanoid" in their behaviour (but not Star Trek rubber faces) because that is the intelligent, tool-building solution that exists for their environment. Others would just be utterly alien. It's entirely likely some reasonably advanced alien civilisation is eyeballing our planet with a baseline interferometry the size of their Oort Cloud with mirrors kilometres across and seeing water vapour, nitrogen, oxygen, chlorophyll. Perhaps the shape of our continents. Maybe in a few hundred years they'll notice increased carbon dioxide levels, pick up radio waves. Because we can do it, logically so must they (if there are some in the neighbourhood).

Exciting times.

[Captain Zim]

Water is the only element it's solid floats in its liquid.

Hydrogen and oxygen are rather common too. Plus dihydrogen oxide is an important solvent and reactant in many biological and geological processes.

EDIT: Ahhh, I forgot who I was replying to here. Anyhoo...

Liquid gallium, bismuth, acetic acid and couple others have solids less dense than their liquids. But I doubt we'll see oceans and icebergs of liquid gallium. Acetic acid of course will eventually break down to CO2 and H20 anyway. The odds of vinegar-based life however...

Edited March 13, 2014 by Captain Zim

[danielost]

Hydrogen and oxygen are rather common too. Plus dihydrogen oxide is an important solvent and reactant in many biological and geological processes.

EDIT: Ahhh, I forgot who I was replying to here. Anyhoo...

Liquid gallium, bismuth, acetic acid and couple others have solids less dense than their liquids. But I doubt we'll see oceans and icebergs of liquid gallium. Acetic acid of course will eventually break down to CO2 and H20 anyway. The odds of vinegar-based life however...

Sorry I should have said naturally occurringelement. Bismuth only occurs in a smelter.