3 ms·

I absolutely don't know much, so question here: Why is it assumed that a "star faring society" must originate from a place of significant gravity? I can under

I absolutely don't know much, so question here: Why is it assumed that a "star faring society" must originate from a place of significant gravity? I can understand heat and some way to gather the required chemicals (primordial ooze) together is required. But does it require much gravity really?

zdragnar 6y ago
Well, life as we know it relies on carbon (energy storage), oxygen (energy activation) and liquid water (oxygen and chemical transfer). Setting aside the quandary of sufficient mass to support life evolution and development from 0 => faster-than-light (or some other interstellar) travel, there's the problem of liquid water. The lower the pressure it is under, the more quickly it will evaporate or even boil. Not only that, but dissolved gasses within the water will also boil out. So, we're left with either imagining some means of having a large quantity and volume of mass configured in a way that maintains pressure without gravity, OR identifying an alternative set of chemicals for the properties that carbon, oxygen and water currently fulfill. Water is especially useful due to being a dipole, and there are several other known compounds that are as well, but they are significantly more complex. I'm definitely not super informed in this area, but my understanding is there really aren't other options that are readily found in nature in regular quantities.
- CarbyAu 6y ago
  Oh! Thank you so much for that, my mind figuratively went Ding! While I mentioned "primordial ooze" I was thinking of ooze as a random assortment of elements we may or may not know much about as my "keep your mind open to possibilities" attitude left it vague. But by defining the Ooze(especially with probabilities of elements in the universe) you define the requirements - mainly liquid water. And then conditions by which you have to keep a blob of water together and liquid in the harshness of space are more apparent. As you say, in theory you could come up with weird physical structures to keep water liquid and together; or some other chemistry to fulfill the same roles. But in practice, probability says "Liquid Water + Gravity".
- ajuc 6y ago
  I've read a sci-fi story set on a cold planet where methane was fulfilling the role of water. There were methane rivers, seas, it was falling in rain, and it was the basis for all the chemistry. It sounded reasonable, but I'm not good enough with science to know if it was legit.
  - zdragnar 6y ago
    One thing i overlooked earlier is water's propensity to form acids and bases, which support all sorts of useful biological functions. Methane's hydrogen atoms are tightly bound and methane itself is has no dipole moment- meaning it may have the same physical phases as water, but I am skeptical that it could fully support life as a substitute. ...not to mention that you also have to do away with an oxygen rich atmosphere as well...
BurningFrog 6y ago
Places without gravity don't have matter, which makes forming life hard to imagine. Places with low gravity, such as Io, could easily form life just like Earth did, and would have an easier time to get spaceward if evolution ever got that far.

zdragnar 6y ago

Well, life as we know it relies on carbon (energy storage), oxygen (energy activation) and liquid water (oxygen and chemical transfer). Setting aside the quandary of sufficient mass to support life evolution and development from 0 => faster-than-light (or some other interstellar) travel, there's the problem of liquid water. The lower the pressure it is under, the more quickly it will evaporate or even boil. Not only that, but dissolved gasses within the water will also boil out. So, we're left with either imagining some means of having a large quantity and volume of mass configured in a way that maintains pressure without gravity, OR identifying an alternative set of chemicals for the properties that carbon, oxygen and water currently fulfill. Water is especially useful due to being a dipole, and there are several other known compounds that are as well, but they are significantly more complex. I'm definitely not super informed in this area, but my understanding is there really aren't other options that are readily found in nature in regular quantities.

CarbyAu 6y ago
Oh! Thank you so much for that, my mind figuratively went Ding! While I mentioned "primordial ooze" I was thinking of ooze as a random assortment of elements we may or may not know much about as my "keep your mind open to possibilities" attitude left it vague. But by defining the Ooze(especially with probabilities of elements in the universe) you define the requirements - mainly liquid water. And then conditions by which you have to keep a blob of water together and liquid in the harshness of space are more apparent. As you say, in theory you could come up with weird physical structures to keep water liquid and together; or some other chemistry to fulfill the same roles. But in practice, probability says "Liquid Water + Gravity".
ajuc 6y ago
I've read a sci-fi story set on a cold planet where methane was fulfilling the role of water. There were methane rivers, seas, it was falling in rain, and it was the basis for all the chemistry. It sounded reasonable, but I'm not good enough with science to know if it was legit.
- zdragnar 6y ago
  One thing i overlooked earlier is water's propensity to form acids and bases, which support all sorts of useful biological functions. Methane's hydrogen atoms are tightly bound and methane itself is has no dipole moment- meaning it may have the same physical phases as water, but I am skeptical that it could fully support life as a substitute. ...not to mention that you also have to do away with an oxygen rich atmosphere as well...

BurningFrog 6y ago

Places without gravity don't have matter, which makes forming life hard to imagine. Places with low gravity, such as Io, could easily form life just like Earth did, and would have an easier time to get spaceward if evolution ever got that far.