Why we're the only intelligent life in our galaxy
- Thread starter KimB
- Start date
- Status
zidane1strife
Banned
Chalnoth said:
At worst, if they decide they're gonna start colonizing, I say they expand in all directions and begin assimilating all available mass/energy resources in all directions at the fastest speed that's physically viable(maybe lightspeed if they manage that or faster than that, remember this is worse case scenario, imho.). It's likely they are capable of harnessing molecular machinery to do their dirty work.
My belief is simple:
#1First
They're rare, look we've got giant jupiter our good old fashioned giant meteor vacuum cleaner, we've got the moon, which stabilizes the earth's wobbling and allows for a favorable stable environment for the evolution of more complex life, we're at the apt. distance from the sun, with a planet full of water(universal solvent, thermal stability due to high specific heat, less dense while frozen, and helps increase the chem. stability of isolated dna bases.) and thankfully it appears we were lucky enough to not've evolved shortly before a mass extinction lvl event, with ample time to dev. and acquire lots of knowledge... On top of that we got the ample fossil fuel supply(ok, maybe something else could've been used.), we were also lucky not to have annihilated when the insignificant power of the atom was discovered. All those factors add up(exotic non-biological life could probably have developed but I'd guess it'd probably require a semi-stablish environment, wherever it may be, to develop. Life based on chemistry however would probably more than likely make use of similar atom compositions as that here on earth, smallest strongest bonds and most stable, carbon is also quite special, and thus chemistry should not diverge too much.).
#2Second
For those that dev. intelligent life, most self-destructed or were destroyed by acts of nature/God. The others said goodbye to the seemingly sinking ship universe and left for more fertile ground to live as god-like beings, a few may have even stayed to subtly guide/save the other civilizations that may be unlucky enough to appear in this seemingly sinking ship.
Oh I've given a pretty interesting holistic hypothesis dealing with that. In essence the "secret/key to immortality"
The exponential increase in colonization argument has its flaws. For instance the premise that you can send out a colony ship to colonize 'some random' nearby star's planets. Well the most probably situation is that you very well have no idea which star has habitable planets, much less have one that is reasonably close to your nearby home star. Its not inconceivable that civilizations have perished searching for a new home.
Its also not clear why and how such civilizations would be given a massive headstart over say the earth (the timescale argument), since older stars have a much less favorable habitat profiles. In fact if you look at the odds properly, its much more probable that you find a civilization that is still in their unicellular phase of evolution, much less one that has the need to depart from its home star (where they might conceivably be able to survive for ~2-3billion years on avg)
Theres also the obvious 'is colonization even possible' argument. The raw materials and physics necessary for interstellar travel is by no means guarenteed to be possible.
Anyway I for one think its quite possible we are the only ones in this galaxy at least, but its by no means obvious.
Its also not clear why and how such civilizations would be given a massive headstart over say the earth (the timescale argument), since older stars have a much less favorable habitat profiles. In fact if you look at the odds properly, its much more probable that you find a civilization that is still in their unicellular phase of evolution, much less one that has the need to depart from its home star (where they might conceivably be able to survive for ~2-3billion years on avg)
Theres also the obvious 'is colonization even possible' argument. The raw materials and physics necessary for interstellar travel is by no means guarenteed to be possible.
Anyway I for one think its quite possible we are the only ones in this galaxy at least, but its by no means obvious.
Considering we expect to be able to detect habitable planets within a few years, I find this supposition rather hard to accept.Fred said:
Well, my point is that they cannot have, or we wouldn't be here. What I'm saying is that another civilization needs only a miniscule head start to have gotten here by now, if another exists. That headstart is, at most, around a million years. This is a miniscule number because it is small compared to geologic time.
zidane1strife
Banned
Fred said:
As long as there is matter and energy resources that can be extracted there won't be a problem. No need for habitable planets, the asteroid belt and/or whatever planets there are will be disassembled and reassembled into apt structures at apt distances.
Given how difficult very long term space exploration is going to be for us, it surely must be a safe assumption that a more "advanced" civilisation isn't going to randomly explore system to system, hoping that they find a planet to live on. In other words, they're going to examine such systems in detail far in advance of ever going anywhere near them; if they can build deep-space, generation spacecraft then they can surely construct massive enough telescopes and techniques to pick out individual rocky planets and their emissions. Essentially what I'm getting at is there's a very good chance of an intelligence powerful enough to travel the galaxy of already knowing what the planet is going to be like before going there.
Therefore any civilisation is going to have various views of what is Earth would be like to visit and explore, depending on the location of their starting system with reference to our own. Anything within, say, 100ly could potentially already guess that Earth is inhabited - in which case the argument then moves to whether they would wish to say "hello" or not. Beyond this distance, between 100 to 500ly evidence of prior occupation would be much harder to detect but still possible - and again, the argument changes. But let's say that they're over 5,000ly away and they have the technology and means to observe Earth and decide that it's going to be on of their stop-over points during their mission.
As they get closer and closer, one would presume that they would continue to monitor each planet in turn - if they could travel at near-light speed, then the earliest they could set off before noticing Earth was already inhabited would something like 5000 years ago. But what if they can't; what if they can barely reach 1% (and that in itself would be an amazing achievement)? They would have to set off even further ago but this then raises other problems. The Earth has, of course, not remained constant over time and 50,000 years ago it would have appeared quite inhospitable.
So then - if we trivialise all of the many issues involved with long-term space travel and assume that they can and have been resolved by other intelligences, I think it's reasonable to argue that the apparent lack of evidence to counter Chalnoth's point (about how we're the only intelligence in this galaxy) is due to questions over whether colonisation of a given planet was possible at that time of "arrival", as so to speak. To be honest though, I do not think one can simply debate the "only-intelligence" notion without considering the social and philosophical issues that would face any lifeforms exploring the galaxy.
How quickly would they tire of doing it? Why would they wish to colonise the whole galaxy in a constant manner? Would they chart everything in the galaxy first or blindly travel through it regardless? How would they prevent changes in views of the mission - in other words, would they still be so focused on doing it over thousands of years?
Therefore any civilisation is going to have various views of what is Earth would be like to visit and explore, depending on the location of their starting system with reference to our own. Anything within, say, 100ly could potentially already guess that Earth is inhabited - in which case the argument then moves to whether they would wish to say "hello" or not. Beyond this distance, between 100 to 500ly evidence of prior occupation would be much harder to detect but still possible - and again, the argument changes. But let's say that they're over 5,000ly away and they have the technology and means to observe Earth and decide that it's going to be on of their stop-over points during their mission.
As they get closer and closer, one would presume that they would continue to monitor each planet in turn - if they could travel at near-light speed, then the earliest they could set off before noticing Earth was already inhabited would something like 5000 years ago. But what if they can't; what if they can barely reach 1% (and that in itself would be an amazing achievement)? They would have to set off even further ago but this then raises other problems. The Earth has, of course, not remained constant over time and 50,000 years ago it would have appeared quite inhospitable.
So then - if we trivialise all of the many issues involved with long-term space travel and assume that they can and have been resolved by other intelligences, I think it's reasonable to argue that the apparent lack of evidence to counter Chalnoth's point (about how we're the only intelligence in this galaxy) is due to questions over whether colonisation of a given planet was possible at that time of "arrival", as so to speak. To be honest though, I do not think one can simply debate the "only-intelligence" notion without considering the social and philosophical issues that would face any lifeforms exploring the galaxy.
How quickly would they tire of doing it? Why would they wish to colonise the whole galaxy in a constant manner? Would they chart everything in the galaxy first or blindly travel through it regardless? How would they prevent changes in views of the mission - in other words, would they still be so focused on doing it over thousands of years?
50,000 years ago the Earth would have appeared exactly the same as it would appear today from an observer far away. The Earth would have appeared to be habitable for at least the past few hundred million years. For example, we now believe that the first land plants evolved about 700 million years ago. It may possibly have taken at least land plants to really change the Earth's atmosphere, or it may have happened earlier just from algae in the ocean. But either way, by 500 million years ago, the Earth would have very likely appeared just as habitable as it does today.Neeyik said:
If they take a random walk through the galaxy, the timescales increase significantly, moreover its not clear to me that we would be able to detect habitable planets precisely. At best you can infer planets or moons of the right mass range, and presumably detect the presence of certain key elements (like oxygen), but beyond that theres still a lot of room. For instance, habitable day night cycles require the right planetary precession and orbital tilt, and I very much doubt you can infer that from distant observation conclusively. (I seem to recall you also can only infer the mass of binary planets/stars when they are in precise occlusion relative to our line of sight, so called occluding binaries)
There is also the question of whether it even makes sense to colonize. After all interstellar travel at say 1% of C for a longterm space voyage of a suitably large colonization force is an unimaginably large undertaking with requisite energies that are collosal. One wonders if it wouldn't be more efficient to simply use that energy range to say, change your planets orbit as the local stellar conditions change.
There is also the question of whether it even makes sense to colonize. After all interstellar travel at say 1% of C for a longterm space voyage of a suitably large colonization force is an unimaginably large undertaking with requisite energies that are collosal. One wonders if it wouldn't be more efficient to simply use that energy range to say, change your planets orbit as the local stellar conditions change.
Bear in mind that it's still an exponential expansion: once one planet is colonized, it will want to colonize other planets, and so on. Given this simple fact, it's not going to change the timescales that greatly.Fred said:
As far as us, we are currently expecting to be capable of detecting habitable planets within a few years. Even if these first attempts fail, it's not going to be that far out before we are able to detect them. The primary factor is the existence of liquid water. Detect that, and many scientists believe, you will have detected life.
A better question is does it make sense not to colonize? If we don't colonize other planets, we are going to die out at some point. Colonization is the only way for us to survive in the (very) long run.
I don't want to get too heavily involved in this thread, but Chalnoth your assumption that other life would seek conscious guaranteed survival is based soley on the experience of the human race.
You make the assumption that 'once a planet is colonized' said life would want to colonize other planets, but the logic used to go from a to b is based in large part on the idea that they actually have some interest in spreading and multiplying their numbers. They may not.
We could be the only intelligent life - but to me the 'odds' just seem stacked in favor of us not being the sole intelligent life in this galaxy. So many planets, so many stars, just so much opportunity for random chance alone to repeat the experiment.
But I'll tell you, it doesn't much matter to me either - we just have to continue doing our 'thing' as a race. We can't count on contact or detection. If there were an alien race developing completely parallel to our own on another arm of the Milky Way, it could take ~25,000 years or more for whatever signals to make their way over here. If there are past civilizations we should ostensibly be able to detect their remnants, but honestly science as we know it has made some incredible strides in the last hundred years, and I think there is plenty more to go. So although they 'say' they'll be up to the task of detection soon, I'd say chances are some more spanners get thrown into our understanding of the physical universe in the coming centuries.
Anyway whatever; unfortunately neither you nor I will likely be able to 'prove' our cases within our lifetimes.
You make the assumption that 'once a planet is colonized' said life would want to colonize other planets, but the logic used to go from a to b is based in large part on the idea that they actually have some interest in spreading and multiplying their numbers. They may not.
We could be the only intelligent life - but to me the 'odds' just seem stacked in favor of us not being the sole intelligent life in this galaxy. So many planets, so many stars, just so much opportunity for random chance alone to repeat the experiment.
But I'll tell you, it doesn't much matter to me either - we just have to continue doing our 'thing' as a race. We can't count on contact or detection. If there were an alien race developing completely parallel to our own on another arm of the Milky Way, it could take ~25,000 years or more for whatever signals to make their way over here. If there are past civilizations we should ostensibly be able to detect their remnants, but honestly science as we know it has made some incredible strides in the last hundred years, and I think there is plenty more to go. So although they 'say' they'll be up to the task of detection soon, I'd say chances are some more spanners get thrown into our understanding of the physical universe in the coming centuries.
Anyway whatever; unfortunately neither you nor I will likely be able to 'prove' our cases within our lifetimes.
OpenGL guy
Veteran
That's a narrow view, but is probably correct. If you look at probabilities, then it's unlikely that another intelligient species is currently colonizing the galaxy but hasn't yet reached Earth. Also, it's unlikely that another intelligient species has yet developed space travel. But, one thing that you haven't considered is the possibility of another intelligient species having gone extinct before colonizing the galaxy. The galaxy is roughly 15 billion years old. If we make the assumption that life can only develop in the remains of a supernova (for the creation of heavier elements) then it seems possible that another intelligent species could have evolved in that time, as the large stars that likely formed initially would have consumed their fuel very fast.Chalnoth said:
Given how easy it would be for humans to make ourselves extinct, it's possible other life forms have already done so.
zidane1strife
Banned
Fred said:
energy takes on a different meaning for civilizations with advanced molecular machinery and advanced ais. A probe can easily assemble and accumulate the necessary resources on its own from some materials in such a solar system, travel the interstellar medium and transform all the usable mass of nearby stars and generate further probes expanding in all directions at max possible speed, probably even without any intervention.
Last edited by a moderator:
The desire to spread is entirely a cultural one. And it is only natural that those cultures that want to spread themselves are going to become the ones that come to prominence. Any full planet is bound to have many diverse cultures.xbdestroya said:
A colony is similar. Though it may have a somewhat more uniform culture than a home planet, it was born from a culture that wanted to spread, and thus it is exceedingly likely that one of the child cultures will want to spread as well.
- Status
