Maybe we need to widen our search for life. Earth is a planet with about 15 degree average temperature and abundant water and oxygen. So that's what live here consumes and where it thrives. But life is all about adaptation. So, father than looking for planets with similar temperatures and resources, shouldn't we be looking for other possible foundations for life? Maybe there's a thriving civilization out there, living happily at 300 degrees, breathing neon and eating sulfur?
“Most promising signs yet” of alien life on a planet beyond our Solar System
181–190 of 365 posts
Re: “Most promising signs yet” of alien life on a planet beyond our Solar System
#182Earlier quoted context omitted.
Dark forest hypothesis explains this in a “dark” way. They exist but are smart enough to hide from hostile hunter/predator life forms. Meanwhile our dumbasses are blasting radio signals into space like a little kid trying to talk to every stranger they see.
Dark Forest depends on the presumption that interstellar travel is worth engaging in (ie it's possible to do faster than light), and that spectacularly devastating weapons are possible. So far we have no reason to believe that either of those assumptions is smart.
Faster than light travel isn't needed (and IIRC doesn't occur in the series the dark forest name comes from). Spectacularly devastating weapons are definitely possible - redirect an asteroid into an inhabited planet and you're likely to kill most of its inhabitants; redirect enough and you can kill almost everything. That's not even getting into things like antimatter, gamma rays, etc. The dark forest hypothesis doesn't need destruction of solar systems to be possible, just severe damage to civilisations.
Re: “Most promising signs yet” of alien life on a planet beyond our Solar System
#183Firstly that is completely badass science. The idea that you can use observations to detect the chemical composition of an exoplanet millions of kilometres away is an absolute triumph of the work of thousands of people over hundreds of years. Really amazing and deeply humbling to me. Secondly, my prior was always that life existed outside of earth. It just seems so unlikely that we are somehow that special. If life d…
If life is very common in the universe, then that is probably bad news for us. It means that civilizations should exist that are millions of years more technologically advanced than us; and should be leaving telltale signatures across the sky that we'd likely have detected by now. And the absence of those signs would be relatively strong evidence that life, while common, isn't long-lived. Suggesting that our demise t…
no matter how advanced the civilization is, proxima centauri will always be 42 trillion kms away. Our civilization in current stage is not even close to 0.1% the speed of light but lets say your advanced civilization goes at 99% the speed of light, still doesnt change the fact they need 4.25 years approx to reach earth. Still doesnt change the fact that unless they have a 1 billion km wide telscope, they cannot reliably tell if earth has life or not. So basically you are asking them to take a shot at coming to the solar system on a 5 yr trip when they have no idea what is found here. Now extrapolate the numbers for the average 100 light year trip between 2 points on our galaxy and you ll quickly realize why we dont have aliens
Re: “Most promising signs yet” of alien life on a planet beyond our Solar System
#184My understanding is that the great filter theory means this is bad news for us humans here on earth. And considering the state of the world right now, it's especially ominous. Fate loves irony.
How so? If great filters exist at all, which is not a given, there could be multiple ones, first of all. They could be somewhere between our level of biological complexity and the kind hypothesised to be responsible for this signal. Endosymbiosis is a very plausible such filter. The evolution of language and the bootstrapping of cultural evolution is another one. Both n=1 on our planet. Probably there are others I can't think of right now.
Re: “Most promising signs yet” of alien life on a planet beyond our Solar System
#185Last time bio signatures where found (I believe on Venus), there was a flurry of papers on arXiv a week later, which all explained the signature by abiotic processes. Of course, if you have more than one explanation, then you really don't have one explanation. So I fully expect the same thing to happen here, and perhaps sometime in a decade or so follow up observations will have ruled out all but one explanation, until then exciting but ultimately it's not over before the fat lady sings.
Re: “Most promising signs yet” of alien life on a planet beyond our Solar System
#186Earlier quoted context omitted.
If life is very common in the universe, then that is probably bad news for us. It means that civilizations should exist that are millions of years more technologically advanced than us; and should be leaving telltale signatures across the sky that we'd likely have detected by now. And the absence of those signs would be relatively strong evidence that life, while common, isn't long-lived. Suggesting that our demise t…
I often wonder if the answer to the Fermi paradox isn't just as extremely banal as "turns out that interstellar exploration just isn't economically viable". I think it's entirely plausible that advanced economies are circular, and that within a circular economy, it's just extremely difficult to justify the massive expenditure of resources that it would take to become interstellar. I mean, think about how many stars h…
I thought it might just be the rocket equation. Bigger planet = very little of the rocket is payload.
If most planets are bigger than Earth, then most civilizations will be like "muh we can do it but what's the point?" and they'll be content with just having a few science experiments in orbit, and that's all.
Re: “Most promising signs yet” of alien life on a planet beyond our Solar System
#187Re: “Most promising signs yet” of alien life on a planet beyond our Solar System
#188Earlier quoted context omitted.
If life is very common in the universe, then that is probably bad news for us. It means that civilizations should exist that are millions of years more technologically advanced than us; and should be leaving telltale signatures across the sky that we'd likely have detected by now. And the absence of those signs would be relatively strong evidence that life, while common, isn't long-lived. Suggesting that our demise t…
no matter how advanced the civilization is, proxima centauri will always be 42 trillion kms away. Our civilization in current stage is not even close to 0.1% the speed of light but lets say your advanced civilization goes at 99% the speed of light, still doesnt change the fact they need 4.25 years approx to reach earth. Still doesnt change the fact that unless they have a 1 billion km wide telscope, they cannot relia…
> Still doesnt change the fact that unless they have a 1 billion km wide telscope, they cannot reliably tell if earth has life or not.
How come we’re making progress on this without a 1bn km telescope?
Re: “Most promising signs yet” of alien life on a planet beyond our Solar System
#189Earlier quoted context omitted.
It is quite plausible that life is abundant, but sentience is not. If we take Earth, it formed 4.5 billions years ago, conditions became suitable to support life like 4B years ago and first known signs of life are dated 3.7B years ago. Now, in just .5B years Earth would likely become uninhabitable due to Sun becoming a red giant. In other words, on Earth life spent 90% of its total available time before sentience eme…
This is now much less plausible. Intelligence, like eyesight, is believed to be a result of convergent evolution[0]. [0] https://www.quantamagazine.org/intelligence-evolved-at-least...
Birds are not remotely as smart as humans.
Re: “Most promising signs yet” of alien life on a planet beyond our Solar System
#190Earlier quoted context omitted.
We'll put a giant sunshade in the Earth-Sun L1 Lagrange point.
Sadly it is still only a stop-gap measure. The sun is for all intents and purposes, dying a slow death.
Long before death it will expand to or almost to Earth's orbit. I doubt humanity could isolate Earth from that.