Aromatic hydrocarbons! Expected, but still relieving to have evidence. Puts one more tally in the column of "life is probably carbon-based elsewhere, too".
This supports the hypothesis that the early molecules we think are needed to get to life happen elsewhere in the universe.
There are only a few chemistries that could even support life. Carbon is the one we know the most about, and also one that we find the most evidence for getting to that complex of chemistry in the real universe. Nobody knows of course, but odds seem good if there is other life out there is it carbon based. (nobody really can know either - the universe is so far away we can't really detect details very well)
Hydrogen, carbon and oxygen are amongst the most common elements in the universe. So probabilistically life will be carbon based. And it will probably be first formed in water. But it would develop tools on land once opposing thumbs are formed (from climbing trees). So I think there is a high chance aliens with technology will look a lot like us.
Leopards can't begin to approach what a monkey can do [1], since they can't hang safely, since they don't have thumbs. Leopards rely on penetration of their claws, or being on top of the branches, like squirrels. It works for the squirrel because they're small, and the tension forces applied to the bark are negligible, so they can just crawl upside down. You won't see a leopard hanging from anything, in a non-comical way. A leopard does have an advantage of clawing up thick trunks, which is one of the reasons they hunt monkeys that are first on the ground, rather already in the trees.
Yes great at hanging, like a coat hanger. You can only easily pull with a hook. With a thumb, you can push, pull, and easily grip, with much less risk of "unhooking". That's the same risk for a leopard: unhooking. Sloth can't climb a thinner vertical rope, or hang from a thinner branch, because their grip strength is relatively weak, due to the leverage. And, good luck using any sort of tool, like a stick to get terminates, with giant hooked claws!
That logic follows... right up until the leap to arboreal lifeforms with opposable thumbs being an inevitability (or even a prerequisite to tool use!).
Opposable thumbs are not a guarantee. Nor are tree-dwelling lifeforms, nor trees, nor thumbs, nor digits, nor four limbs. For all we know, intelligent life elsewhere might better resemble intelligent octopi using alkaline metals as their first rudimentary energy source as we did with fire.
Why even assume multicelluarity as some kind of inevitability?
Hell, it took 2 billion years to get to single celled eukaryotes on earth. But the earth was teaming with prokaryotes the whole time, two entire separate branches of them, too, and they seem to have sprung into existence almost as soon as the earth cooled enough.
There's still a lot more of them in terms of total weight than animals and protists. A lot.
I was describing the most probable path, not the only path.
I do think that developing more sophisticated tools under water is difficult. Once you have plants on land, taller “trees” are very probable, because they are competing for light. Once you have trees, it’s likely that animals will climb then for safety or food. Once they climb, they will likely develop better gripping, etc…
I guess another way to look at this is that life on Earth is not special (although it is still an insanely amazing occurrence).
I think there are lots of worlds that don’t have dry land. I doubt they would develop advance technology - hard to build fire to melt metals. But perhaps nature will find another way?
Abundant carbon is not the most compelling reason for aliens to be carbon based.
Carbon is one of a few elements to be able to easily bind to other elements including itself and able to form long and complex chains. Silicon is another that can form long, complex chains.
The trace chemicals are even more interesting. Phosphorus while only needed in small amounts has a critical role in life as we know it. Phosphorus also turns out to be extremely rare in the known universe. to the point it is noteworthy to find a star that has it.
I don't think this is an accurate reading of that article. See forex https://arxiv.org/abs/1704.08282 whose abstract reads in part:
> We also found average [P/Si] = 0.02 ± 0.07 and [P/S] = 0.15 ± 0.15 for our sample, showing no significant deviations from the solar ratios for [P/Si] and [P/S] ratios.
Quoting from the introduction I find:
Phosphorus abundances have been derived in planetary nebulae .... and in damped Lyman alpha systems using ionized phosphorus lines
...
Anomalously high phosphorus abundances have been measured using optical phosphorus features in blue horizontal branch stars ....
Molecular forms of phosphorus, such as PO, PN, and CP, have been detected and used to understand phosphorus chemistry in the interstellar medium ...
or example, phosphorus molecules have been detected in the interstellar medium ... and in star forming regions ... Phosphorus molecules have also been found in the circumstellar envelopes of evolved stars (... Finally, the diffuse interstellar medium has been measured using P II lines....
> Other, smaller chunks in the Bennu sample have light-coloured reflective coatings, making them seem brighter than the darker pebbles. But, under a scanning electron microscope, they were found to be covered in a highly brittle layer that broke easily, revealing a dark interior. Chemical analysis showed that this light-coloured surface skin contained magnesium, sodium and phosphate. This combination is rarely if ever seen in meteorites, Lauretta said. “It’s a head-scratcher right now.”
Can anyone expound on which part of this is rare or what would be more expected?
I'm guessing that if most meteorite samples are collected after impact on earth such a brittle crust would be destroyed before observation.
It's rare to find volatile compounds like phosphate and sodium on the surface of a meteorite because they leach out and vaporize. It would make sense on a comet which form in the outer zone of our protoplanetary disk and shed their surface continuously due to all the water, but not a magnesium-rich asteroid that would have formed closer to the center of the solar system where the sun would have boiled volatile compounds off quickly, without a way for replacement compounds to migrate to the surface.
> In October, researchers at the Johnson Space Center in Houston, Texas, discovered that 2 of the 35 screws that fasten the lid of the sample-return canister couldn’t be removed — blocking access to the remainder of the space rocks.
That sounds about like every DIY repair around the house I attempt.
Joking aside, the article goes on to say that "NASA is now making new screwdrivers" to gain access. Does anyone have details on this? Why would NASA need to build something new?
> Joking aside, the article goes on to say that "NASA is now making new screwdrivers" to gain access. Does anyone have details on this? Why would NASA need to build something new?
They have to be qualified for use inside the glove box (read this in a different article), which I assume means sterile and unlikely to flake any material off. NASA is quite worried about being faked out by detecting something added post collection.
Also who knows what the failure mode is, so here is some speculation: Perhaps some distortion in the case, so the screw holes are no longer circular? In which case the tool has to apply more torque than normal (without flaking or snapping) and maybe have a special clamp, and even a strain gauge for measuring torque?
> which I assume means sterile and unlikely to flake any material off.
Yes, as well as being nonreactive, not able to outgas much, etc. They're going to do minute chemical analysis on the samples, so avoiding chemical contamination is essential.
> The screwdrivers that NASA is building to free the remaining rocks and dust will need to be made from materials that won’t contaminate the samples, which are currently inside a nitrogen-filled glovebox.
I'm not sure why the screwdrivers that opened the other screws wouldn't work though, if that's what you're asking.
I bet this new will cost more than the military's infamous $5k ashtray. a) it's very specialized, b) they only need one of them (so better order two), c) the specs are beyond ridiculously strict.
So as we discover that the goods for life are literally everywhere what's the rub? Intelligence is the big jump? Life is everywhere but hiding for some reason?
Could be it's just really hard to pick up life-transmitted signals from all the stellar noise. Obviously one would try to pick a quiet frequency, but transmission across light year distances would still need an awful lot of energy. Or maybe there's a space internet but we're just not aware of it yet.
I think we take it for granted that if your planet simply doesn’t have the right resources available, you’ll never truly have an Industrial Revolution. If there is life, it’s more probable it is stuck in some crude Stone Age state rather than high tech.
For the industrial revolution: after 4B - really ~4.4999995 BY out of ~4.5 BY - arguably it only happened once in a very limited geographical area, and everyone else learned it from them.
I struggle to think of a planet that wouldn't have the necessary ingredients for an industrial revolution. I don't think you need fossil fuels at all; on Earth, even without fossil fuels, we probably could have eventually gone from biofuels to wind/hydro power to solar/nuclear (these requiring a lot of energy for the refinement/processing of raw resources). It would have been a slow and gradual process, but if this process took about ~150 years with fossil fuels, I bet it would have only taken something like 500 years without them - a tiny blip in time, really.
I think any planet capable of hosting carbon-based life would be able to at least produce wind energy, and probably most (assuming a rocky planet with liquid water and an atmosphere containing oxygen) would be able to develop all the energy types I mentioned. Solar and nuclear might be relatively less feasible if certain elements aren't common on that planet, and battery storage might also suffer from lack of resources. But wind and hydro alone are probably sufficient to eventually be able to develop controlled fusion down the line and have most energy-resource issues obviated.
Even if you imagine some exotic form of life not like ours at all, on a planet that doesn't necessarily have water or an atmosphere, the life has to be able to derive energy from some kind of external source, whether it's by facilitating some chemical reaction like our deep sea micro-organisms or photosynthesis. Most likely that energy can be harvested in an automated fashion, and it's probably relatively abundant if life is able to evolve to the point of intelligence. For it to be completely inaccessible due to lack of resources, IMO you'd have to get into truly strange scenarios like intelligent life somehow developing in a nebula or the atmosphere of a gas giant.
I mean, I disagree about fossil fuels. I don't believe we make the necessary advancements without incredibly energy dense fuel. Everything you listed required a base of energy dense fuels for the process in some fashion. It's very hand wavy to say. Well we would've just figured it out. I'm not convinced?
So if we were the first large life to form on the planet, and there weren't any fossil fuels, I think we'd be screwed. I think we would've stalled until something burned us as fuel.
> Everything you listed required a base of energy dense fuels for the process in some fashion
What about wood, or more "advanced" biofuels (idk, some kind of highly productive grass or a refined algae product), prevents us from developing wind and hydro power? Those were both developed before fossil fuels were widely used anyway. They produced mechanical power instead of electrical, but only because electricity was not understood yet.
The more energy you have, the easier it is to scale energy production up, but you have the resources required to initiate that process with just biofuels. And once you have a base of wind and hydro energy, that allows you to begin the feedback loop of using that energy to assist in constructing more power generation in a virtuous cycle.
edit: I'll also add that the industrial revolution came about after there had already been notable advances in mechanization and manufacturing - the introduction of fossil fuels quite literally threw gas on the fire, but people had started developing increasingly sophisticated machinery like the cotton gin (https://en.wikipedia.org/wiki/Cotton_gin) and mechanically-powered loom (https://en.wikipedia.org/wiki/Lancashire_Loom) before fossil fuels started being widely used. And indeed, many of these were hydro-powered.
It's a bit more complicated than this, but one shortcoming is that wood simply doesn't burn hot enough to smelt steel (1100 or so?). Coal was, for us, effectively an essential step.
Advances you mention in your third paragraph don't include the jumps in precision that were predicated on this capability, and indeed necessary for the next steps.
There may of course be some civilisations out there that managed what you're describing - it's a big ol' universe after all - but my gut feel is mitochondria is probably the great filter, rather than an abundance of energy-dense naturally occurring fuel.
This link pops up regularly on HN. It's a spectacularly good read, highly relevant here, in terms of the necessary set of converging prerequisites for an industrial revolution:
Mitochondria are just a hack to integrate efficient oxygen metabolism into archaean cells, and I wish people wouldn't worship them so much. Mitochondria started as free living cells that had that metabolism. There's no reason life on a different world couldn't develop it directly in the same lineage as cells destined for multicellularity.
I appreciate I only have a sample size of one - but then, so does the 'it's no big deal' crowd.
On this planet we have no alternative routes to the same outcome, and no clear evidence that alternative routes a) couldn't have come about, or b) did but were subsequently out-competed.
I suggest everyone with a Fermi-opinion is in the same camp - massively speculative and a single datapoint (unless you count the myriad (in their absence) counter-points).
The original bacteria that were engulfed to become mitochondria are the "alternative route". It's clearly possible for a cell to have oxygen metabolism on its own because that's how we got here. So the question is, is endosymbiosis the only way to integrate that with a large, complex cell? When you phrase it that way, it should be clear which way the odds lie.
But yes, "worship" is not quite the right word for whatever obsession it is that people have with mitochondria.
Sorry I'm a bit late to reply here, but I still think coal isn't strictly necessary. You don't need steel to develop wind and hydropower, and you can electrify with metals that don't require such high temperatures.
Once you have sufficient electrical power, you can heat things in other ways - for example, aluminum smelting requires even higher temperatures than steel and uses electricity https://en.wikipedia.org/wiki/Aluminium_smelting.
The title of the piece is Could we reboot a modern civilisation without fossil fuels?, and is well worth the read.
So, sure, yeah, aluminium melts at about 650 degrees (I considered this fact when looking at aluminium pizza trays for my oven, which can, though rarely does, go beyond 450) and is smelted about 150 more than that.
But in order to smelt it you of course need receptacles that won't melt at that temperature - ie, steel (plus insulation). I was off by a couple of hundred degrees in my earlier comment - steel smelting is around 1300-1500 degrees. So we're back to the original problem.
As to wind and hydro, sure, yes, you can easily generate power from those, as we did for millennia using mostly timber constructs. Though I'm not sure if you're suggesting getting electrical power from those sources is easy, absent some sophisticated technological capabilities (wire-making, for starters).
I don’t think fossil fuels truly come into play until the late 19th century.. Even then to a smallish extent. The great inventors and discoverers did not require them. They are definitely key in manufacturing at scale and globalisation, but I don’t think the development of technology is/was dependent on access to fossil fuels.
It's probably not about the resources, but more about the temperature, atmosphere, pressure, etc. I mean, look at the other planets in our solar system. It's clearly at least very unlikely that a planet can support life.
Under water I always imagine that a biological revolution would be more likely, and technologies that evolve (so to speak) out of organisms that make deposits like coral. So you would have a "limestone age", followed by something harder. At some point metals would come into the picture, but it would likely look very different than our "tech tree"/
Simple life is probably fairly common. But intelligent life that's reached a technological level such that we would notice them is probably pretty rare. It could be that we're the only ones in this galaxy that are currently at this detectable level and the distances to other galaxies is just too far to be able to detect those that might in other galaxies.
Yeah. We've only given off signals detectable in space for 200 years and have only existed for around 200000 years as a species. Less than a blink of an eye from a galactic time perspective.
> dinosaurs were around [...] without developing technology
That's what they want you to think but the historical records of the USS Voyager clearly show that some branches of dinosaurs (haplosurus I believe) did eventually evolve to develop space travelling technology (which is how they survived the Chicxulub event).
Intelligent life may very well be everywhere (on the order of multiple civilizations per galaxy), but its impact is undetectable at such distances, just like someone dropping a pebble in the ocean off the shore of Tokyo is going to be undetectable in LA.
I am not sure why everyone is holding back on using the “L” word. The surface images of Bennu alone should have been enough. You can see the remains of what looks like marine animals (rocks shouldn’t have bilateral symmetry). The samples returned have amino acids which is exactly what proteins structures would decay to over billions of years. So bennu is likely remnants of a planet with life (either debris or an attempted seed packet). So let’s get this conversation moving! We only have 5 billion years left on earth. At the rate we are going we won’t have any of those critters named by then. -Not that anyone asked me but I recommend naming them all versions of either Cthulhu or Gilgamesh.
I’ve wondered sometimes why it is that asteroids are made out of anything as solid as rock, rather than just being big dust bunnies. I would assume that you would need pressure and heat to make rock, and therefore small rocky asteroids are derived from collisions between much larger objects.
In space, if two small dust particles collide, they are probably moving at very high speed in relation to each other, and there's obviously no air to affect the impact. I don't know what that means, but I expect our intuition about how substances accrete is probably way out of whack.
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[ 2.7 ms ] story [ 136 ms ] threadThere are only a few chemistries that could even support life. Carbon is the one we know the most about, and also one that we find the most evidence for getting to that complex of chemistry in the real universe. Nobody knows of course, but odds seem good if there is other life out there is it carbon based. (nobody really can know either - the universe is so far away we can't really detect details very well)
Not a thumb between them.
[1] https://youtu.be/9rdn26Hpdwo?feature=shared&t=118
No thumbs.
Opposable thumbs are not a guarantee. Nor are tree-dwelling lifeforms, nor trees, nor thumbs, nor digits, nor four limbs. For all we know, intelligent life elsewhere might better resemble intelligent octopi using alkaline metals as their first rudimentary energy source as we did with fire.
Hell, it took 2 billion years to get to single celled eukaryotes on earth. But the earth was teaming with prokaryotes the whole time, two entire separate branches of them, too, and they seem to have sprung into existence almost as soon as the earth cooled enough.
There's still a lot more of them in terms of total weight than animals and protists. A lot.
I do think that developing more sophisticated tools under water is difficult. Once you have plants on land, taller “trees” are very probable, because they are competing for light. Once you have trees, it’s likely that animals will climb then for safety or food. Once they climb, they will likely develop better gripping, etc…
I guess another way to look at this is that life on Earth is not special (although it is still an insanely amazing occurrence).
Land mostly requires that your planet doesn't have too much water. Plate tectonics helps, but I'm not sure it's required.
They evolved here. The whole question is how much their existence depends on Earth's specific environment, genetics, etc.
Carbon is one of a few elements to be able to easily bind to other elements including itself and able to form long and complex chains. Silicon is another that can form long, complex chains.
https://www.sciencealert.com/lack-of-phosphorus-in-universe-...
I don't think this is an accurate reading of that article. See forex https://arxiv.org/abs/1704.08282 whose abstract reads in part:
> We also found average [P/Si] = 0.02 ± 0.07 and [P/S] = 0.15 ± 0.15 for our sample, showing no significant deviations from the solar ratios for [P/Si] and [P/S] ratios.
Quoting from the introduction I find:
Phosphorus abundances have been derived in planetary nebulae .... and in damped Lyman alpha systems using ionized phosphorus lines ... Anomalously high phosphorus abundances have been measured using optical phosphorus features in blue horizontal branch stars ....
Molecular forms of phosphorus, such as PO, PN, and CP, have been detected and used to understand phosphorus chemistry in the interstellar medium ...
or example, phosphorus molecules have been detected in the interstellar medium ... and in star forming regions ... Phosphorus molecules have also been found in the circumstellar envelopes of evolved stars (... Finally, the diffuse interstellar medium has been measured using P II lines....
Can anyone expound on which part of this is rare or what would be more expected?
I'm guessing that if most meteorite samples are collected after impact on earth such a brittle crust would be destroyed before observation.
That sounds about like every DIY repair around the house I attempt.
Joking aside, the article goes on to say that "NASA is now making new screwdrivers" to gain access. Does anyone have details on this? Why would NASA need to build something new?
They have to be qualified for use inside the glove box (read this in a different article), which I assume means sterile and unlikely to flake any material off. NASA is quite worried about being faked out by detecting something added post collection.
Also who knows what the failure mode is, so here is some speculation: Perhaps some distortion in the case, so the screw holes are no longer circular? In which case the tool has to apply more torque than normal (without flaking or snapping) and maybe have a special clamp, and even a strain gauge for measuring torque?
Yes, as well as being nonreactive, not able to outgas much, etc. They're going to do minute chemical analysis on the samples, so avoiding chemical contamination is essential.
That way we could cross-check for tool/storage-based contamination or accidental reactions.
> The screwdrivers that NASA is building to free the remaining rocks and dust will need to be made from materials that won’t contaminate the samples, which are currently inside a nitrogen-filled glovebox.
I'm not sure why the screwdrivers that opened the other screws wouldn't work though, if that's what you're asking.
I think any planet capable of hosting carbon-based life would be able to at least produce wind energy, and probably most (assuming a rocky planet with liquid water and an atmosphere containing oxygen) would be able to develop all the energy types I mentioned. Solar and nuclear might be relatively less feasible if certain elements aren't common on that planet, and battery storage might also suffer from lack of resources. But wind and hydro alone are probably sufficient to eventually be able to develop controlled fusion down the line and have most energy-resource issues obviated.
Even if you imagine some exotic form of life not like ours at all, on a planet that doesn't necessarily have water or an atmosphere, the life has to be able to derive energy from some kind of external source, whether it's by facilitating some chemical reaction like our deep sea micro-organisms or photosynthesis. Most likely that energy can be harvested in an automated fashion, and it's probably relatively abundant if life is able to evolve to the point of intelligence. For it to be completely inaccessible due to lack of resources, IMO you'd have to get into truly strange scenarios like intelligent life somehow developing in a nebula or the atmosphere of a gas giant.
So if we were the first large life to form on the planet, and there weren't any fossil fuels, I think we'd be screwed. I think we would've stalled until something burned us as fuel.
What about wood, or more "advanced" biofuels (idk, some kind of highly productive grass or a refined algae product), prevents us from developing wind and hydro power? Those were both developed before fossil fuels were widely used anyway. They produced mechanical power instead of electrical, but only because electricity was not understood yet.
The more energy you have, the easier it is to scale energy production up, but you have the resources required to initiate that process with just biofuels. And once you have a base of wind and hydro energy, that allows you to begin the feedback loop of using that energy to assist in constructing more power generation in a virtuous cycle.
edit: I'll also add that the industrial revolution came about after there had already been notable advances in mechanization and manufacturing - the introduction of fossil fuels quite literally threw gas on the fire, but people had started developing increasingly sophisticated machinery like the cotton gin (https://en.wikipedia.org/wiki/Cotton_gin) and mechanically-powered loom (https://en.wikipedia.org/wiki/Lancashire_Loom) before fossil fuels started being widely used. And indeed, many of these were hydro-powered.
Advances you mention in your third paragraph don't include the jumps in precision that were predicated on this capability, and indeed necessary for the next steps.
There may of course be some civilisations out there that managed what you're describing - it's a big ol' universe after all - but my gut feel is mitochondria is probably the great filter, rather than an abundance of energy-dense naturally occurring fuel.
This link pops up regularly on HN. It's a spectacularly good read, highly relevant here, in terms of the necessary set of converging prerequisites for an industrial revolution:
https://acoup.blog/2022/08/26/collections-why-no-roman-indus...
I appreciate I only have a sample size of one - but then, so does the 'it's no big deal' crowd.
On this planet we have no alternative routes to the same outcome, and no clear evidence that alternative routes a) couldn't have come about, or b) did but were subsequently out-competed.
I suggest everyone with a Fermi-opinion is in the same camp - massively speculative and a single datapoint (unless you count the myriad (in their absence) counter-points).
But yes, "worship" is not quite the right word for whatever obsession it is that people have with mitochondria.
Once you have sufficient electrical power, you can heat things in other ways - for example, aluminum smelting requires even higher temperatures than steel and uses electricity https://en.wikipedia.org/wiki/Aluminium_smelting.
The title of the piece is Could we reboot a modern civilisation without fossil fuels?, and is well worth the read.
So, sure, yeah, aluminium melts at about 650 degrees (I considered this fact when looking at aluminium pizza trays for my oven, which can, though rarely does, go beyond 450) and is smelted about 150 more than that.
But in order to smelt it you of course need receptacles that won't melt at that temperature - ie, steel (plus insulation). I was off by a couple of hundred degrees in my earlier comment - steel smelting is around 1300-1500 degrees. So we're back to the original problem.
As to wind and hydro, sure, yes, you can easily generate power from those, as we did for millennia using mostly timber constructs. Though I'm not sure if you're suggesting getting electrical power from those sources is easy, absent some sophisticated technological capabilities (wire-making, for starters).
Oil may not have been used much before the latter half of the 19th century, but coal certainly was.
That's what they want you to think but the historical records of the USS Voyager clearly show that some branches of dinosaurs (haplosurus I believe) did eventually evolve to develop space travelling technology (which is how they survived the Chicxulub event).