When reading of Fermi paradox, that outstanding question "why do we seem to be alone in the universe?" I've encountered many observations about the uniqueness of Earth.
"Were it not for Earth's protective magnetic field life would be impossible."
"Were it not for Earth's unusually large moon..."
etc.
The answer to the paradox these answers claim is that Earth is much more unique than it appears and life far more fragile.
@futurebird Fermi paradox is overrated. Space is mind bogglingly ginormous, relativity utterly rules out any kind of causal relationships with feedback between distant worlds much less unified interplanetary civilizations, and there's no reason we should expect to see signs of far away intelligent life on the scales that it could exist at.
frankly, any mission where we send anybody to another planet in our solar system is going to end up being a one-way trip, even Mars. the moon was barely doable with 1960s/1970s technology. we would need to devise a spaceship that can house multiple human beings for years; those human beings would need to be able to live almost literally in each other's laps with zero ability to get away from each other, except for EVAs, the entire time. and if anything goes wrong, there is literally nothing we would be able to do about it unless it happened while the ship was near Earth. in short, any mission is going to have to be 100% self-sufficient and capable of solving problems on its own.
in order for that to change, we would need new propulsion systems capable of significant thrust in a short amount of time, in space, with minimal fuel requirements that can be manufactured from resources on Earth. ideally we'd be able to capture an asteroid or comet and process it so that fuel can be generated in space, which would help a lot, but the technology for all of that also doesn't exist yet.
and even assuming we can solve all of those problems, we'd still need to solve the problem of maintaining life in space without supplies from Earth before any sustained habitation could happen.
and that's all challenges we have to overcome if we want to expand within the solar system.
Have you heard about that laser sail project to photograph and exoplanet ... up close?
If we had our act together we could see such photos in our lifetime even... if we cared about things that mattered, you know ... like getting to SEE a photo of the surface of a planet in another solar system!
That would be so amazing... but I don't think it will happen... the way things are going. Maybe some of the kids I teach will get to see such a photo.
@futurebird@VulpineAmethyst@dalias
is this a project backed by any organization with actual access to space, or is it just a bunch of spacefans who read Roche World too many times?
@VulpineAmethyst@dalias@futurebird Sad thing is, quite possibly our best real way to truly gain a foothold towards any of this ever being reasonable is to start by building a base on the Moon. But apparently the Moon is suddenly boring or something because everyone has decided that Mars is the only future even worth thinking about. A base on the Moon would be far more reachable, has gravity, and later would provide facilities for, could provide facilities for later missions, etc etc
@futurebird@VulpineAmethyst@dalias I didn't word that well perhaps. Part of a kneejerk/irritation in general at the way everyone suddenly became basically interested only in Mars.
As they say, you should learn to walk before trying to run. But then a lot of famous people like Musk decided running was all that mattered and it feels like humanity just sort of went along.
I feel like a Moon base is the next step and would help any other steps along the way in addition, but no one is trying.
@futurebird I was never very impressed with the Fermi paradox, TBH. It seems to assume extraterrestrial life must exist, which strikes me as more an article of faith than a scientific observation.
"But statistically--!"
Statistically, a planet has a 1/n chance of having life, where n is the number of planets we've explored thoroughly enough to say for certain whether or not it has life. And, okay, that's P=1, but our sample size isn't exactly great.
@futurebird I think there are a lot of issues with Fermi's paradox. It makes a LOT of assumptions. It really is fair to say that our setup here is somewhat more unique. Don't forget also Jupiter acting as a cosmic vaccuum so we get fewer major asteroid strike event (and what we do get is at more regular intervals.) There are a LOT of unique factors. I think intelligent life is much rarer. We also have barely scanned 1% of our view of the universe. And we don't know what to look for...
@futurebird We think we know what to look for of course. Obvious stuff. More heat than can be accounted for on a planet. Major changes in atmosphere that could only be life. Radio signals. What if they use laser communications (won't be visible outside a straight line...) Maybe they find a way to use quantum entanglement. And we won't be able to see a dyson sphere or stuff built around it at all probably...
Still ... I can't help but find it all these kinds of explanations a little "Just So"
Of course life on Earth is adapted and shaped by the peculiarities of Earth.
But, life, that which arises by accident but then evolves, is hopefully not so limited.
But then, in mathematics we have unique complex objects, like the Monster Group-- that seem as if they ought to be one of many, but instead represent some limitation of the rules it's impossible to directly intuit.
@futurebird When you look at the history of atmospheric conditions, it seems likely that a bacteria bloom can simply render the biosphere uninhabitable.
It's not that likely that a completely uncontrolled process should always be self-sustaining.
Though, absent other instances of planet-spanning life, we simply lack the data to establish probabilities.
@futurebird
Like for example: earth biochemistry happens in water. And any time a proton needs to get added or subtracted, you just grab one from or give one to a passing water molecule. But moving electrons around is A Whole Thing. Tons of biochemistry is centered on electron transport.
And the cofactors (vitamins, really, in people) used for this are these kind of aromatic small molecules, little mostly carbon rings with some other atoms and some double bonds. …
@futurebird
EXACTLY the kind of molecule that's probably all over the place in, e.g., the ethane pools on Titan. So I just imagine the possibility of a COMPLETELY different biochemistry in which, say, energy is managed by elaborate mechanisms for moving protons around. What would it look like? What sort of biomarkers would it present that we could detect? I don't know and I'm not sure anybody else does either!
@futurebird One way I think of this is maybe from the pov of “the universe” we are just one snowflake that happened to have a particular arrangement of conditions and atoms… but it’s no more special or important than any other unique snowflake. It just seems that way to us because we are in it.
What “life” is, is our idea — not something intrinsic to the universe.
@futurebird I don’t think people think about how daunting interstellar travel is with our current understanding. Einstein ruled out faster than light travel and the rocket equation is even more restrictive than that.
@norgralin@futurebird a good rule of thumb used in the scenarios is we could maybe get to a tenth of light speed and not have anything too weird happen to our bodies. At that speed the closest star is still four decades away. So basically a one way trip, maybe there and back if you are lucky. Basically anything else would have to be generational ships.
@futurebird@ReverendMoose not really. The reference frames that matter are in relation to us and where we want to go. And in comparison to the speed of light, we’re effectively not moving. Or to put it another way, any reference frame where we’re moving that fast our destination will also have that velocity offset. Just like following another car on the highway.
@futurebird Earth had single celled life for far longer than it had multicellular life. Maybe something on the level of microbes is common but more complex living things are much rarer.