Just read this. WHile it's quite convincing evidence that life developed off world, I'm unsure that the conclusion of the paper, that life is common across the universe, is warranted.
https://www.sciencedaily.com/releases/2 ... 154925.htm
A theory that has been gaining credence over the last few years involves low temperature development of the prebiotic basis for life, even life, in comets, where the freezing action effectively reduces the water in the equation and drives surprisingly fast processes at high concentration and low temperature. The idea is that, as the comets circle you have long periods of frozen dormancy and shorter periods of 'goldilocks' activity. This could allow for an extended period of evolution before hitting Earth and seeding the oceans with life or advanced precursors of life.
While this is still pretty fanciful at this stage, it's still has more parsimony than proposing life is common in the cosmos.
-
- Information on this archive. See IIDB.org
-
-
Please join us on IIDB (iidb.org)
This is the archived Seculare Cafe forum. It is read only. If you would like to respond or otherwise revive a post or topic, please join us on the active forum: IIDB.
-
New paper suggests life arrived from elsewhere!
-
subsymbolic
- Posts: 13371
- Joined: Wed Oct 26, 2011 6:29 pm
- Location: under the gnomon
-
Koyaanisqatsi
- Posts: 8403
- Joined: Fri Feb 19, 2010 5:23 pm
-
subsymbolic
- Posts: 13371
- Joined: Wed Oct 26, 2011 6:29 pm
- Location: under the gnomon
[quote=""lpetrich""]I think that it's an unwarranted jump, from the possibility of extraterrestrial origin to concluding that that's how it happened. Much of what they describe could also happen in icy environments on our planet.[/quote]
Actually, I misread it. The point was more that the incredibly rapid spread of very advanced features, like photosynthesis, suggests that life develops faster, and more robustly, than previously thought. The core idea is that biology will naturally, and spontaneously outperform chemistry whenever that is possible. What is really happening here is the development of testable models. Right now, there are rather a lot of places running prebiotic origin of life experiments. Personally, I think it really is just a matter of time before one of these pays off.
However, to be clear, all it will offer is an existence proof of something that is largely uncontreversial: life can just happen.
Actually, I misread it. The point was more that the incredibly rapid spread of very advanced features, like photosynthesis, suggests that life develops faster, and more robustly, than previously thought. The core idea is that biology will naturally, and spontaneously outperform chemistry whenever that is possible. What is really happening here is the development of testable models. Right now, there are rather a lot of places running prebiotic origin of life experiments. Personally, I think it really is just a matter of time before one of these pays off.
However, to be clear, all it will offer is an existence proof of something that is largely uncontreversial: life can just happen.
I've long been of the opinion that life is common in the universe; given liquid water, basic minerals, some form of energy flow, and time, I think it's likely that chance will ensure the formation of simple life. Evolution will then act to increase its complexity.
However, I'm also of the opinion that intelligent, technological life is bloody rare. No little green (or gray) men buzzing the Earth in their flying saucers. If there was some star-faring species within some thousands of light years, I suspect we'd be able to see the effects of their machines; at the extreme, we'd see stars being occluded as they built Dyson spheres. Even if they only got around on reaction drives, it takes a great huge lot of energy to travel from star to star; and we've seen nothing that looks like the wake of a starship, AFAIK.
However, I'm also of the opinion that intelligent, technological life is bloody rare. No little green (or gray) men buzzing the Earth in their flying saucers. If there was some star-faring species within some thousands of light years, I suspect we'd be able to see the effects of their machines; at the extreme, we'd see stars being occluded as they built Dyson spheres. Even if they only got around on reaction drives, it takes a great huge lot of energy to travel from star to star; and we've seen nothing that looks like the wake of a starship, AFAIK.
-
subsymbolic
- Posts: 13371
- Joined: Wed Oct 26, 2011 6:29 pm
- Location: under the gnomon
-
Koyaanisqatsi
- Posts: 8403
- Joined: Fri Feb 19, 2010 5:23 pm
[quote=""Jobar""]I've long been of the opinion that life is common in the universe; given liquid water, basic minerals, some form of energy flow, and time, I think it's likely that chance will ensure the formation of simple life. Evolution will then act to increase its complexity.
However, I'm also of the opinion that intelligent, technological life is bloody rare. No little green (or gray) men buzzing the Earth in their flying saucers. If there was some star-faring species within some thousands of light years, I suspect we'd be able to see the effects of their machines; at the extreme, we'd see stars being occluded as they built Dyson spheres. Even if they only got around on reaction drives, it takes a great huge lot of energy to travel from star to star; and we've seen nothing that looks like the wake of a starship, AFAIK.[/quote]
NYT: 2 Navy Airmen and an Object That Accelerated Like Nothing Ive Ever Seen
However, I'm also of the opinion that intelligent, technological life is bloody rare. No little green (or gray) men buzzing the Earth in their flying saucers. If there was some star-faring species within some thousands of light years, I suspect we'd be able to see the effects of their machines; at the extreme, we'd see stars being occluded as they built Dyson spheres. Even if they only got around on reaction drives, it takes a great huge lot of energy to travel from star to star; and we've seen nothing that looks like the wake of a starship, AFAIK.[/quote]
NYT: 2 Navy Airmen and an Object That Accelerated Like Nothing Ive Ever Seen
Stupidity is not intellen
Some time ago, the Nontheist Nexus was essentially abandoned, but not before its content was moved to a blog, NexusZine | The webzine of the Nontheist Nexus. I've been blogging in it, and my latest posts there are on the Fermi Paradox.
I've discussed a range of hypotheses:
I've discussed a range of hypotheses:
- The ET’s are rare, if not absent.
- The ET’s are common, but it is difficult or impossible to make contact.
- The ET’s are common, and they choose to hide from us and/or to not make contact with us.
Some years ago Scientific American had a very good article called, "Are Aliens Among Us?"
The idea is this: We can trace all forms of life to a single primordial cell. Could another and entirely different form of life exist on earth? We wouldn't know because we don't know where to start looking. Of course, we are talking about microscopic life; not little green men!
We know that all forms of life are based on amino-acids and those need water as a solvent. This is why, incidentally, we start looking for water in the space, in order to hope to find life.
Then there is, of course, the Drake Equation that is questioned by the Fermi Paradox.
The idea is this: We can trace all forms of life to a single primordial cell. Could another and entirely different form of life exist on earth? We wouldn't know because we don't know where to start looking. Of course, we are talking about microscopic life; not little green men!
We know that all forms of life are based on amino-acids and those need water as a solvent. This is why, incidentally, we start looking for water in the space, in order to hope to find life.
Then there is, of course, the Drake Equation that is questioned by the Fermi Paradox.
-
dancer_rnb
- Posts: 5241
- Joined: Sun Mar 08, 2009 3:38 pm
[quote=""lpetrich""]Some time ago, the Nontheist Nexus was essentially abandoned, but not before its content was moved to a blog, NexusZine | The webzine of the Nontheist Nexus. I've been blogging in it, and my latest posts there are on the Fermi Paradox.
I've discussed a range of hypotheses:
The variant on 3 I've heard is they are not hiding from US (earthlife).
I've discussed a range of hypotheses:
- The ETs are rare, if not absent.
- The ETs are common, but it is difficult or impossible to make contact.
- The ETs are common, and they choose to hide from us and/or to not make contact with us.
The variant on 3 I've heard is they are not hiding from US (earthlife).
There is no such thing as "politically correct." It's code for liberalism. The whole idea of "political correctness" was a brief academic flash-in-the-pan in the early 1990's, but has been a good conservative bugaboo ever since.
[quote=""Michel""]Some years ago Scientific American had a very good article called, "Are Aliens Among Us?"
The idea is this: We can trace all forms of life to a single primordial cell. Could another and entirely different form of life exist on earth? We wouldn't know because we don't know where to start looking. Of course, we are talking about microscopic life; not little green men![/quote]
Here is what might be evidence.
Some cellular organism with no detectable DNA or RNA. Successfully demonstrating the absence of nucleic acids would be a BIG breakthrough, but after the "arsenic bug" debacle, lots of biochemists and molecular biologists will likely be VERY skeptical.
It would also help if it had proteins, but proteins made from a different set of amino acids than what Earth organisms use. The smaller ones are likely shared, because they are likely prebiotic, but the larger ones are likely historical accidents.
The idea is this: We can trace all forms of life to a single primordial cell. Could another and entirely different form of life exist on earth? We wouldn't know because we don't know where to start looking. Of course, we are talking about microscopic life; not little green men![/quote]
Here is what might be evidence.
Some cellular organism with no detectable DNA or RNA. Successfully demonstrating the absence of nucleic acids would be a BIG breakthrough, but after the "arsenic bug" debacle, lots of biochemists and molecular biologists will likely be VERY skeptical.
It would also help if it had proteins, but proteins made from a different set of amino acids than what Earth organisms use. The smaller ones are likely shared, because they are likely prebiotic, but the larger ones are likely historical accidents.
I suppose that looking for non-amino acid life would require tracking energy flows, and seeing if something is using those flows to organize in some repeatable and regular way. Not just crystal formation, but something ongoing, moving.
I've read lots of science fiction about living processes arising in stars, or the hearts of planets. But AFAIK there's no physical system which can maintain the sorts of organization life requires, which could withstand the temperatures in places like those.
I've read lots of science fiction about living processes arising in stars, or the hearts of planets. But AFAIK there's no physical system which can maintain the sorts of organization life requires, which could withstand the temperatures in places like those.
[quote=""Jobar""]I suppose that looking for non-amino acid life would require tracking energy flows, and seeing if something is using those flows to organize in some repeatable and regular way. Not just crystal formation, but something ongoing, moving.[/quote]
Or as I'd posted, finding something like some microbe. Microscopic organisms had been observed long before anyone had a good understanding of what they are, and the same could happen here. As I'd posted, here is how the discovery might go.
Searches for genes with Polymerase Chain Reaction primer: all failed.
Direct searches for DNA in the organisms: failed.
Direct searches for RNA in the organisms: failed.
The organisms have what seem like proteins, and breaking apart those putative proteins reveals amino acids. But some of the amino acids are very odd by Earth standards.
It would be very convincing if all the asymmetric ones had the opposite asymmetry from Earth-protein ones.
The organisms' cell-membrane and cell-wall materials turn out to be different from any Earth organism's.
Some labs start searching for its molecule of heredity, and they finally discover it. It works by a template mechanism, much like our nucleic acids, but it is chemically different enough to be incompatible.
Once biologists work out how to search for this material, they start looking for it in environmental samples.
Or as I'd posted, finding something like some microbe. Microscopic organisms had been observed long before anyone had a good understanding of what they are, and the same could happen here. As I'd posted, here is how the discovery might go.
Searches for genes with Polymerase Chain Reaction primer: all failed.
Direct searches for DNA in the organisms: failed.
Direct searches for RNA in the organisms: failed.
The organisms have what seem like proteins, and breaking apart those putative proteins reveals amino acids. But some of the amino acids are very odd by Earth standards.
It would be very convincing if all the asymmetric ones had the opposite asymmetry from Earth-protein ones.
The organisms' cell-membrane and cell-wall materials turn out to be different from any Earth organism's.
Some labs start searching for its molecule of heredity, and they finally discover it. It works by a template mechanism, much like our nucleic acids, but it is chemically different enough to be incompatible.
Once biologists work out how to search for this material, they start looking for it in environmental samples.
Here it is: Fermi Paradox | NexusZine
[quote=""lpetrich""]Here it is: Fermi Paradox | NexusZine[/quote]
Ah, the Fermi paradox that answers Drake Equation's parameter Fi; the chances that an extraterrestrial life would develop an intelligence similar to ours. It is set, arbitrary to one percent.
But ... why? And what is "our intelligence?" Perhaps the ultimate intelligence is to just have fun around, like the dolphins of the Hitchhiker's Guide to the Galaxy, that British hilarious radio play.
Perhaps the Drake's parameter Fi should be ... 0.000000000000000000001 percent!
By the way, happy winter solstice, everyone!
Ah, the Fermi paradox that answers Drake Equation's parameter Fi; the chances that an extraterrestrial life would develop an intelligence similar to ours. It is set, arbitrary to one percent.
But ... why? And what is "our intelligence?" Perhaps the ultimate intelligence is to just have fun around, like the dolphins of the Hitchhiker's Guide to the Galaxy, that British hilarious radio play.
Perhaps the Drake's parameter Fi should be ... 0.000000000000000000001 percent!
By the way, happy winter solstice, everyone!
[quote=""Hermit""]
Ah! Well, when I came to live in Norway, 40 years ago, my Norwegian wife told me that the winter starts with the first snow.
... then I started teaching meteorology to aviators and came to this:
The winter starts at the winter solstice that is the 21st or 22nd of December - everywhere on earth! But, if you want, you can call the winter for the austral summer. So I will rephrase myself:
Please accept with no obligation, implied or otherwise, my best wishes for an environmentally conscious, socially responsible, low stress, non addictive, gender neutral celebration of the winter or austral solstice holiday practiced with the most enjoyable traditions of religious persuasion or secular practices of your choice, with respect for the religious/secular persuasions and/or traditions of others, or their choice not to practice religious or secular traditions at all.
Yup, and celebrating our first 40+°C day of the season yesterday..[/QUOTE]lpetrich;682310 wrote:Is it summer solstice for you?
Ah! Well, when I came to live in Norway, 40 years ago, my Norwegian wife told me that the winter starts with the first snow.
... then I started teaching meteorology to aviators and came to this:
The winter starts at the winter solstice that is the 21st or 22nd of December - everywhere on earth! But, if you want, you can call the winter for the austral summer. So I will rephrase myself:
Please accept with no obligation, implied or otherwise, my best wishes for an environmentally conscious, socially responsible, low stress, non addictive, gender neutral celebration of the winter or austral solstice holiday practiced with the most enjoyable traditions of religious persuasion or secular practices of your choice, with respect for the religious/secular persuasions and/or traditions of others, or their choice not to practice religious or secular traditions at all.
[quote=""Michel""]
... then I started teaching meteorology to aviators and came to this:
The winter starts at the winter solstice that is the 21st or 22nd of December - everywhere on earth! But, if you want, you can call the winter for the austral summer. So I will rephrase myself:
Please accept with no obligation, implied or otherwise, my best wishes for an environmentally conscious, socially responsible, low stress, non addictive, gender neutral celebration of the winter or austral solstice holiday practiced with the most enjoyable traditions of religious persuasion or secular practices of your choice, with respect for the religious/secular persuasions and/or traditions of others, or their choice not to practice religious or secular traditions at all.[/QUOTE]
And a happy solstice to you too.
I am pleased to see that my faked peevishness provoked such creative and amusing verbosity.
Ah! Well, when I came to live in Norway, 40 years ago, my Norwegian wife told me that the winter starts with the first snow.Hermit;682311 wrote:Yup, and celebrating our first 40+°C day of the season yesterday..lpetrich;682310 wrote:Is it summer solstice for you?
... then I started teaching meteorology to aviators and came to this:
The winter starts at the winter solstice that is the 21st or 22nd of December - everywhere on earth! But, if you want, you can call the winter for the austral summer. So I will rephrase myself:
Please accept with no obligation, implied or otherwise, my best wishes for an environmentally conscious, socially responsible, low stress, non addictive, gender neutral celebration of the winter or austral solstice holiday practiced with the most enjoyable traditions of religious persuasion or secular practices of your choice, with respect for the religious/secular persuasions and/or traditions of others, or their choice not to practice religious or secular traditions at all.[/QUOTE]
And a happy solstice to you too.
I am pleased to see that my faked peevishness provoked such creative and amusing verbosity.
[quote=""subsymbolic""]Just read this. WHile it's quite convincing evidence that life developed off world, I'm unsure that the conclusion of the paper, that life is common across the universe, is warranted.
https://www.sciencedaily.com/releases/2 ... 154925.htm
[/quote]
I read the link but I don't think it actually supports any claim that life on earth developed off world. It only indicates that life developed very early on earth. That doesn't imply an extraterrestrial origin.
Given the abundance of life on earth and the lack of evidence of life anywhere else, it is most parsimonious to assume life on earth started on earth.
I don't think we can assume anything about the abundance of life in the universe given a current sample size of 1.
https://www.sciencedaily.com/releases/2 ... 154925.htm
[/quote]
I read the link but I don't think it actually supports any claim that life on earth developed off world. It only indicates that life developed very early on earth. That doesn't imply an extraterrestrial origin.
Given the abundance of life on earth and the lack of evidence of life anywhere else, it is most parsimonious to assume life on earth started on earth.
I don't think we can assume anything about the abundance of life in the universe given a current sample size of 1.