When the question of life elsewhere in the universe comes up, we always consider the odds that it exists based on how many worlds similar to Earth are out there. We consider the odds based on how many star systems can support a planet with the same properties as ours, such as water, oxygen, protection from cosmic rays, adequate temperature, etc. Why? Because these are the conditions under which life thrives… life based on DNA.
But what is DNA? Isn’t it just an extremely complex molecule capable of functioning as a storage unit for genetic information? Why should we assume this molecule is only kind that can carry out this sort of function? Isn’t it possible that molecules based on other groups of elements come together into equally complex forms and act as storage for information. Why should there be any limit on what kind of molecular structures can do this?
Suppose there as such an alternate molecule elsewhere in the universe. It’s entirely possible that the kind of environment it requires to thrive and replicate itself is completely different from Earth. It might require things like high levels of CO2, or oceans of acid, or toxic fumes, or anything else that would be leathal to life on Earth.
I’m in full agreement. I’ve thought of that many times. DNA is something that nature can readily accidentally develop and work with. But can’t there be complex proteins developed within particles smaller than neutrons? Some physicists say yes.
Our heads a little less in the clouds and more in current day - we may soon see a time when we don’t simply engineer a genome to make an animal. We may engineer a molecule to make a genome!
It is possible that the development of an alien race could be interpreted rather easily by the makeup of its genome. Like the rings of a tree, the “second” type of genome shows that it’s advanced enough to recreate its own structure, like a “second” ring showing that the tree is more than a year old.
No reason at all, in fact there are life forms on earth that exist in very high temperatures and toxic fumes around volcanic vents in the ocean, and they have DNA.
I’m not sure that we assume that. The problem is that we must recognise life in order to find it. For all we know, stars are alive and possess consciousness. For all we know, the sun worshippers have got it right.
^^ They are alive. You know what they’re thinking?
“God damn it’s hot! Someone put me the hell out! Damnit! Someone grab a fire extinguisher or some baking soda or something! Ow ow ow ow OW!”
Seriously though, I know what you mean.
SETI tries to confirm life on a planet by aiming radio telescopes toward the vicinity and looking for interesting radio waves. I think scientists are banking on life forms complicated enough to make radio transmitters being carbon-based. They have their reasons, but that’s not to say some fantastic circumstance didn’t create a titanium animal somewhere. Carbon-based life forms are certainly as fantasticly circumstantial.
Why intelligence? I don’t know; I suppose because the word “intelligence” is most closely associated, in my mind, with complex and survival perserving behavior.
Anayways, I believe life can survive in the strangest of places. I do however, think that a relatively warm climate is essential for life. A planet that is frozen probably can’t create life because nothing moves.
Another way to look at the subject is to think of what elements are vital to our processors and our industrial machinery. Almost everyone agrees that water is crucial to almost everything. It’s an acid with minimum PH, which makes it kind of the least volatile catalyst for any process.
Silicone or carbon seem to be another important element. There are theories toward a silicone based organism. I think that’s about all science can assume right now - environments where silicone or carbon, and water, can flourish are probably the prime candidates for intelligence