6 ms·
The Cosmos Teems with Complex Organic Molecules
- MrMcCall 2y agoOnly human-level organisms can contemplate the grandeur of this vast, vast universe and its Unfathomable Creator. We Earthlings required billions of years of cellular evolution on our planet before we were even possible, so, yeah, the seeds of life are naturally produced by relatively basic chemistry. "There are no accidents." --Master Shifu
- cmiller1 2y agoThe seeds of life, but the next step, their germination so to speak, is the hard part. All life on Earth is part of one grand tree, so out of those billions of years the step from complex organic molecules to life only was completed successfully once as far as we can tell.
- conjectures 2y agoGenuine question: how would we tell/know if it was more than once? Doesn't other life-2 floating around in the primordial soup look like food to life-1? Or wouldn't it be co-opted mitochondria style?
- cmiller1 2y agoThere's a whole wikipedia page answering exactly this question: https://en.wikipedia.org/wiki/Evidence_of_common_descent https://en.wikipedia.org/wiki/Evidence_of_common_descent From biochemical similarities, the chirality of certain sugars and amino acids, dna similarities, etc. the evidence for a single common ancestor of all life on Earth is fairly strong; however we don't really have evidence that there never were other lifes that simply were outcompeted at their very early stages.
- vlovich123 2y agoOr the environment of Earth is hospitable to only one structure for life. Or all life we’d find anywhere has the same structure. We don’t yet know enough about the phase change transition from inorganic chemistry to biology.
- MrMcCall 2y agoThe speed of light has put a severe limit on what we can "know" about life in the other 1+ trillion (?) galaxies, or even in the other hundreds of billions (?) of stars in our own Milky Way. And it was all apparently very difficult, from our point of view, but that aspect of creation -- and more specifically, its Creator -- are beyond the ken of creatures such as ourselves, even with our vastly superior talents and abilities. Very few of us reach the pinnacle of our ability to commune with the vast information system that is the universe around us. "It is so wonderful, now that I am in in a constant conversation with You." --Rumi (my paraphrase from memory) "The Way goes in." --Rumi
- vlovich123 2y agoAs best we know single called life formed about 600M years after the earth (at least the earliest evidence we have for such life). And we don’t actually have evidence as to how many times it occurred. Our mathematical models for defining life and making predictions are just starting to take shape.
- m3kw9 2y agoIf life can happen here it can happen in another part of the universe from similar conditions and that’s only for the conditions we know of. People go down to the ocean where we didn’t think life can exist, and found out it can, and that’s just on earth
- spacemark 2y agoRight, but life down there didn't independently spark from raw organic molecules. Or, rather, there is no evidence for that, whereas there is quite a bit of evidence to suggest all such life on earth is migratory to new ecosystems and shares one common ancestor. That leap from organic molecules to "life" is still a bit of a mystery. And how often it occurs is still up for debate. Look at Earth's history - trees existed for 60 million years before some chance bacterial mutation stumbled on efficiently breaking down lignin. And then boom, trees everywhere - every continent on earth - immediately (in geologic timescales) were decomposed. The fact that it took 60 million years for extant bacteria to allow for that should give pause to any sweeping statements about the certainty of life and especially complex life.
- octopoc 2y agoDoesn’t this essentially prove that if there is life outside earth, almost all of it will be carbon based? As opposed to silicon based.
- CuriouslyC 2y agoSulfur and phosphorus can also form complex molecules in addition to silicone. Carbon forms complex molecules in a larger array of chemical environments though. Ultimately everything hinges on how you define life.
- Mistletoe 2y agoSilicon based never really made much sense to me anyway. The bonds it forms are too stable and hard to break apart. https://www.the-ies.org/analysis/does-silicon-based-life-exist https://www.the-ies.org/analysis/does-silicon-based-life-exi...
- alwayslikethis 2y agoGiven the abundance of elements, Carbon-based life with water as liquid is probably the most likely.
- roughly 2y agoRoughly, life is carbon based because carbon has interesting properties for biochemistry and is the cheapest way to make a range of complex molecules. If life somewhere were not to be carbon based, there’d need to be some reason why carbon based life didn’t take off instead.
- dr_dshiv 2y agoSilicon-based life seems pretty likely in the near future
- asah 2y agoDoes this affect the Sagan equation?
- bongodongobob 2y agoNo because we don't actually know any of the coefficients. It's not supposed to be a real measure, it's just a fun thought exercise. Guessing at a many variables is still just guessing.
- arethuza 2y agoDo you mean the Drake equation?
- 082349872349872 2y agowhat about chirality?
- gus_massa 2y agoThey have 50% and 50%. Also, "complex" is very small, like 20-30 atoms. I think someone found small polymers with 100. A lot for not-live stuff, but tiny in comparison to the molecules inside a cell.
- roughly 2y agoDo you have a source for the 50/50 chirality?
- deleted 2y ago[deleted]
- gus_massa 2y ago:( I assumed it because they are inorganic reactions. One way to detect a different ratio is using https://en.wikipedia.org/wiki/Polarimetry#Measuring_optical_rotation https://en.wikipedia.org/wiki/Polarimetry#Measuring_optical_... I searched in Google for a while, I found some polarized astronomical source but not mention about rotation.