Post by Charles1952 on Nov 29, 2015 20:51:16 GMT -6
This thread is inspired by a comment Mystic Wanderer made in her thread on "Life and death on Mars." She kindly allowed me to explain and explore this "paradox."
io9.com/the-7-least-plausible-solutions-to-the-fermi-paradox-1688525196
Fermi's work has been made more mathematical by the Drake equation. While "Equation" sounds very precise and mathematical, it is just a series of estimates, some of which are pure guesswork, in mathematical form. Drake wrote the formula as a way of raising issues to be discussed at a scientific meeting, realizing that any result would be very speculative, if not pure guesswork.
He said that the number of active, communicating civilizations in the Milky way Galaxy could be found by:
N = R* x fp x ne x fe x fix fc x L
R* = The average rate of star formation in our Galaxy
fp = Fraction of those stars that have planets
ne = Average number of planets per star having planets that might support life
fe = Fraction of those planets that go on to develop life
fi = Fraction of those planets that develop intelligent life
fc = Fraction of the planets with intelligent life that communicate their presence by sending signals into space
L = Lifetime of civilizations sending signals into space
Note that this describes the possible number of signalling civilizations, not necessarily space traveling ones.
Using the lowest estimates proposed by some scientists and the highest values proposed, the Drake equation gives us between 0 and 34,000,000 planets with communicating civilizations. The original meeting at which this was proposed came up with a value of between 1,000 and 100,000,000 such civilizations. There are other factors which have been introduced, but I'll leave them out of this discussion.
The Fermi paradox, again, asks where are these civilizations, why haven't we heard from them? This is where it gets fun. There are possible explanations all over the place, it seems like you can pick the one you like.
There re two general answers to the Fermi paradox. Type 1 answers are based on the idea that we don't hear from higher civilizations because there aren't any higher civilizations. Their position is that if there are all these millions of civilizations out there, at least one would have broken all rules and appeared to us. If the math says there must be thousands of them in our galaxy there must be something screwing things up. That something is called "The Great Filter."
The Great Filter is a evolutionary event which life just can't seem to easily get past. For example, the fact that life arose on Earth. It took the earth a billion years to get to that stage, and scientists have been unable to recreate it. It may be that intelligent life may have arisen only on Earth, and there is no intelligent, or any kind of life out there at all.
The Great Filter could be the jump from the simple prokaryote cell to the complex eukaryote cell. After prokaryotes came into being, they remained that way for almost two billion years before making the evolutionary jump to being complex and having a nucleus. If this is The Great Filter, it would mean the universe is teeming with simple prokaryote cells and almost nothing beyond that.
Now if the Great Filter is not behind us, we can hope that we are one of many species on our way to super intelligence. Some space catastrophes, such as gamma ray bursts may be hindering other civilizations from developing much ahead of us.
Finally, if the Great Filter is still to come, we're in deep trouble. The Filter may erase our civilization.
Philosophers have said that the worst possible news would be the discovery of complex life forms, even fossilized, on Mars. That would indicate that the Great Filter is ahead of us and not behind us, and that our doom is approaching.
But if you don't accept the Great Filter approach, other ideas have been suggested to explain the absence of contact.
1.) They visited before we were here.
2.) The galaxy has been colonized, but we're out in the boondocks where nobody cares to explore.
3.) A truly advanced civilization may have no interest in other planets, with all of the energy and technology at their disposal, they've created their Utopia.
4.) There are hostile civilizations and everybody else knows better than to broadcast their location.
5.) There is an intelligent, hostile civilization which ensures its safety by destroying any civilization which rises sufficiently to be a threat.
6.) There is a lot of signalling going on, but we're listening for the wrong things with equipment that can't pick it up.
7.) Higher civilizations are here, all around us, but we're so far below them that they don't register to us. Do we try to communicate with cockroaches?
8.) We may be part of a computer simulation made by a higher civilization which didn't bother to program in other civilizations.
9.) Civilizations are aware of us and observing us, but they don't contact us because of a non-interference rule.
These are just some of the possible explanations for Fermi's paradox. I hope it stimulates some thought. Thanks again to Mystic Wanderer for giving me permission to do this thread.
waitbutwhy.com/2014/05/fermi-paradox.html
en.wikipedia.org/wiki/Fermi_paradox
en.wikipedia.org/wiki/Drake_equation
Fermi's paradox is driven by three rather powerful premises: 1) our galaxy has been around for a very, very long time — about 13.2 billion years (or 13,200 million years), 2) intelligent life was capable of emerging when the galaxy was still very young, and thus, 3) aliens have had plenty of time to visit, colonize, and reshape every portion of the Milky Way. Yet it doesn't appear that any civilization has done so.
io9.com/the-7-least-plausible-solutions-to-the-fermi-paradox-1688525196
Fermi's work has been made more mathematical by the Drake equation. While "Equation" sounds very precise and mathematical, it is just a series of estimates, some of which are pure guesswork, in mathematical form. Drake wrote the formula as a way of raising issues to be discussed at a scientific meeting, realizing that any result would be very speculative, if not pure guesswork.
He said that the number of active, communicating civilizations in the Milky way Galaxy could be found by:
N = R* x fp x ne x fe x fix fc x L
R* = The average rate of star formation in our Galaxy
fp = Fraction of those stars that have planets
ne = Average number of planets per star having planets that might support life
fe = Fraction of those planets that go on to develop life
fi = Fraction of those planets that develop intelligent life
fc = Fraction of the planets with intelligent life that communicate their presence by sending signals into space
L = Lifetime of civilizations sending signals into space
Note that this describes the possible number of signalling civilizations, not necessarily space traveling ones.
Using the lowest estimates proposed by some scientists and the highest values proposed, the Drake equation gives us between 0 and 34,000,000 planets with communicating civilizations. The original meeting at which this was proposed came up with a value of between 1,000 and 100,000,000 such civilizations. There are other factors which have been introduced, but I'll leave them out of this discussion.
The Fermi paradox, again, asks where are these civilizations, why haven't we heard from them? This is where it gets fun. There are possible explanations all over the place, it seems like you can pick the one you like.
There re two general answers to the Fermi paradox. Type 1 answers are based on the idea that we don't hear from higher civilizations because there aren't any higher civilizations. Their position is that if there are all these millions of civilizations out there, at least one would have broken all rules and appeared to us. If the math says there must be thousands of them in our galaxy there must be something screwing things up. That something is called "The Great Filter."
The Great Filter is a evolutionary event which life just can't seem to easily get past. For example, the fact that life arose on Earth. It took the earth a billion years to get to that stage, and scientists have been unable to recreate it. It may be that intelligent life may have arisen only on Earth, and there is no intelligent, or any kind of life out there at all.
The Great Filter could be the jump from the simple prokaryote cell to the complex eukaryote cell. After prokaryotes came into being, they remained that way for almost two billion years before making the evolutionary jump to being complex and having a nucleus. If this is The Great Filter, it would mean the universe is teeming with simple prokaryote cells and almost nothing beyond that.
Now if the Great Filter is not behind us, we can hope that we are one of many species on our way to super intelligence. Some space catastrophes, such as gamma ray bursts may be hindering other civilizations from developing much ahead of us.
Finally, if the Great Filter is still to come, we're in deep trouble. The Filter may erase our civilization.
Philosophers have said that the worst possible news would be the discovery of complex life forms, even fossilized, on Mars. That would indicate that the Great Filter is ahead of us and not behind us, and that our doom is approaching.
But if you don't accept the Great Filter approach, other ideas have been suggested to explain the absence of contact.
1.) They visited before we were here.
2.) The galaxy has been colonized, but we're out in the boondocks where nobody cares to explore.
3.) A truly advanced civilization may have no interest in other planets, with all of the energy and technology at their disposal, they've created their Utopia.
4.) There are hostile civilizations and everybody else knows better than to broadcast their location.
5.) There is an intelligent, hostile civilization which ensures its safety by destroying any civilization which rises sufficiently to be a threat.
6.) There is a lot of signalling going on, but we're listening for the wrong things with equipment that can't pick it up.
7.) Higher civilizations are here, all around us, but we're so far below them that they don't register to us. Do we try to communicate with cockroaches?
8.) We may be part of a computer simulation made by a higher civilization which didn't bother to program in other civilizations.
9.) Civilizations are aware of us and observing us, but they don't contact us because of a non-interference rule.
These are just some of the possible explanations for Fermi's paradox. I hope it stimulates some thought. Thanks again to Mystic Wanderer for giving me permission to do this thread.
waitbutwhy.com/2014/05/fermi-paradox.html
en.wikipedia.org/wiki/Fermi_paradox
en.wikipedia.org/wiki/Drake_equation