Simple, single-celled life forms were the only life on Earth for 3.5 billion years. We don't know why life jumped from simple, single-celled forms to multiple-celled critters. The Cambrian explosion was sudden and there's not much evidence available that can clue us in to why it happened, though it's an area of intense research. It's entirely possible that a planet could be inhabited by bacteria for tens of billions of years without any more complex life forming, particularly because we don't yet understand how it happened here.
Quote from: M.E.T. on 01/08/2018 08:35 pmQuote from: Star One on 01/08/2018 07:31 pmNow this is an intriguing theory.Are Alien Civilizations Technologically Advanced?QuoteBased on our own experience, we expect that civilizations much older than ours will be scientifically savvy and hence technologically advanced. But it is also possible that a simpler lifestyle rather than scientific prosperity has dominated the political landscape on other planets, leading to old civilizations that are nevertheless technologically primitive.https://blogs.scientificamerican.com/observations/are-alien-civilizations-technologically-advanced/#From my reading, this suffers from the same flaw that hampers so many attempted answers to the Fermi paradox. Namely that while this theory might apply to some alien civilizations, you only need one civilization that is aggressively expansionist to populate the entire galaxy with Von Neuman probes or some such scenario.The latter seems unlikely even for an advanced civilisation due to the vast distances involved.
Quote from: Star One on 01/08/2018 07:31 pmNow this is an intriguing theory.Are Alien Civilizations Technologically Advanced?QuoteBased on our own experience, we expect that civilizations much older than ours will be scientifically savvy and hence technologically advanced. But it is also possible that a simpler lifestyle rather than scientific prosperity has dominated the political landscape on other planets, leading to old civilizations that are nevertheless technologically primitive.https://blogs.scientificamerican.com/observations/are-alien-civilizations-technologically-advanced/#From my reading, this suffers from the same flaw that hampers so many attempted answers to the Fermi paradox. Namely that while this theory might apply to some alien civilizations, you only need one civilization that is aggressively expansionist to populate the entire galaxy with Von Neuman probes or some such scenario.
Now this is an intriguing theory.Are Alien Civilizations Technologically Advanced?QuoteBased on our own experience, we expect that civilizations much older than ours will be scientifically savvy and hence technologically advanced. But it is also possible that a simpler lifestyle rather than scientific prosperity has dominated the political landscape on other planets, leading to old civilizations that are nevertheless technologically primitive.https://blogs.scientificamerican.com/observations/are-alien-civilizations-technologically-advanced/#
Based on our own experience, we expect that civilizations much older than ours will be scientifically savvy and hence technologically advanced. But it is also possible that a simpler lifestyle rather than scientific prosperity has dominated the political landscape on other planets, leading to old civilizations that are nevertheless technologically primitive.
Another possibility, though remote, is that the FRB is a high-powered signal from an advanced civilization. Hence the interest of Breakthrough Listen, which looks for signs of intelligent life in the universe, funded by $100 million over 10 years from internet investor Yuri Milner.“Although it’s extremely unlikely that pulses we have detected from FRB 121102 were transmitted by ETs, we would like to test various ET hypotheses for the FRB type transient signals in general,” Gajjar said.Breakthrough Listen has to date recorded data from a dozen FRBs, including FRB 121102, and plans eventually to sample all 30-some known sources of fast radio bursts.“We want a complete sample so that we can conduct our standard SETI analysis in search of modulation patterns or narrow-band signals – any kind of information-bearing signal emitted from their direction that we don’t expect from nature,” he said.
but it’s too late, we’ve already sent out our calling card. Hitler at the 1936 Olympics is already out there. A timestamp of our own history.
For SERENDIP and most other SETI projects to detect a signal from an extraterrestrial civilization, the civilization would have to be beaming a powerful signal directly at us.
Quote from: Johnnyhinbos on 01/09/2018 02:29 ambut it’s too late, we’ve already sent out our calling card. Hitler at the 1936 Olympics is already out there. A timestamp of our own history.That seems unlikely to me. Signal strength is so low to begin with and diminishes rapidly due to the inverse-square law, the signal becomes lost in noise not long after leaving the solar system.Of course, the reverse is true as well. From Wikipedia's article on SETI:QuoteFor SERENDIP and most other SETI projects to detect a signal from an extraterrestrial civilization, the civilization would have to be beaming a powerful signal directly at us.The image this calls to mind is that of a soap bubble. You can touch it while it is expanding and moving, but only for a short time, then it pops (similar to EM radiation becoming too weak to detect).Admittedly, the Intro to CONTACT (the movie starring Jodie Foster) showing successive broadcast signals going out into deep space was very cool
What follows is my submission to the National Academies of Sciences, Engineering, and Medicine ad hoc Committee on Astrobiology Science Strategy for Life in the Universe, 2018. It is available as a PDF here.Please also see Jill Tarter’s companion white paper here.
My bet is that to the universe earth is basically a niche extremophile environment. Think about it, a planet living very close to a hot star. So hot that biology becomes liquid. Water may be one of the most dangerous poisonous liquids in the universe but hey we're made of it so that's what we think life is composed of.The vast majority of the universe may sees us as the extremophiles of the universe. That is because the vast majority of the universe probably lives in in much colder and darker environments where energy is not derived from heat and Photosynthesis is not a thing. Any aliens living in those environments are probably not sending signals to planets close to stars. They could be looking in the space between the stars. The perception of where life in the universe may lie is relative to your perception of what life may be. They probably consider anything that close to a star to be devoid of life. That could be a possible solution to the Fermi Paradox.
<snip>. Water may be one of the most dangerous poisonous liquids in the universe but hey we're made of it so that's what we think life is composed of. </snip>
The perception of where life in the universe may lie is relative to your perception of what life may be.
QuoteThe perception of where life in the universe may lie is relative to your perception of what life may be.Maybe - but the argument of mediocrity (we are much more likely to be typical, rather than atypical) would suggest that this is a low-probability suggestion.
The Kepler dataset shows that The Solar System has an uncommon arrangement of planets compared to most stars. The odds may be long, but sometimes you hit the jackpot, and space gives you trillions of chances to try your odds.
Quote from: Bynaus on 01/17/2018 08:32 amQuoteThe perception of where life in the universe may lie is relative to your perception of what life may be.Maybe - but the argument of mediocrity (we are much more likely to be typical, rather than atypical) would suggest that this is a low-probability suggestion.The Kepler dataset shows that The Solar System has an uncommon arrangement of planets compared to most stars. The odds may be long, but sometimes you hit the jackpot, and space gives you trillions of chances to try your odds.
You weren't claiming that the Earth or the Solar System were rare, you were claiming that life such as ours is extreme compared to life elsewhere in the universe. Those are two different arguments.Simple probability dictates that it is unlikely by chance to happen to find yourself a member of an extreme group, just as it is unlikely to pick out the one red ball in a bag of 9 other black balls, so the default (though not necessarily correct) assumption is that we are unlikely to be that unusual in the context of other life. This of course is rather negated if we are the first example of sentient life so the bag is low on balls.This is a separate question to the rarity of the conditions in which we formed. Think of it like this, you have 5 oases in a 1000 sq km desert. The chances that the first oasis you come across is hosts radically different life to that in the other four is low, but this has no relation to the rarity of the conditions (an oasis in the desert) that allows any of these ecosystems to develop.