For those of us used to SI units - thatâs about -13 degrees.
Whenever the search for extraterrestrial life is discussed it irks me when people say âlife may be out there but not in a form we recognizeâ. If something doesnât show at least some of the qualities of what we consider life, such as growth or reproduction, I donât think we can call it life.
I think the article makes a good point, though, that organisms like psychrophiles can be hard to study because the typical lab conditions arenât conducive to growing them. Itâs not so much that we wouldnât recognize them as life. They just depend on conditions that are so different from what weâre used to that they can be overlooked.
Iâm willing to cut them more or less slack depending on what they are commenting on:
If itâs some fairly narrrow concern (eg. âThe chemistry test suite on Viking 1 and 2 could miss âlifeâ based on substantially different chemistry than what we would expectâ), there are points to be made. Even terrestrial extremophiles have some pretty unexpected tricks of metabolism and the like, and they might as well be our siblings by the standards of any actual aliens. Something yet more unexpected might be recognizably âlifeâ, while being odd enough to throw off a lot of the indirect tests that are small and automated enough to cram into a probe.
If itâs some pseudo-vitalist âwhat if the ice crystals on Ganymede are, like, sentient, man?â thing, then thatâs a waste of time.
As the SI also uses Kelvin (260.15 degrees in that other scale), the temperature of -8 in Farenheit equals approximately -13 degrees CELSIUS.
Good catch.
Now, if thereâs life hanging out in some 260 C lake, that would be truly mind-blowing.
But - counter-nitpick: -13 C is +8 F, not -8 F.
There arenât going to be many 260 C lakes (at atmospheric pressure) for long; but apparently, at pressures deep enough that this doesnât cause boiling, the present contender survives and reproduces at 122 C.
No word on whether it also chews nails and spits napalm; but I wouldnât doubt it.
My chronic disuse of the Farenheit scale has made me misplace a dash before the number.
As an aside, I always wondered why some of my parents of the older generation used the expression âYou make me go 212â when angry, until I learned that 212 was the boiling point in Farenheit scale. Which meant I made their blood boil. Figuratively. And sometimes intentionally.
Yeah, Iâm definitely thinking about the latter types. The same ones who will engage in lively debates about whether trees dream.
I do think organisms like psychrophiles are fascinating, though, because, even though theyâre obviously recognizable as life they still push our ideas of where life can be found. I grew up hearing that Earth was the only habitable place in our solar system. I know Europa and even Mars are a long way from Antarctica but I still feel slightly vindicated for not accepting that as incontrovertible.
I dont know how maggiekb has the cheek to call herself a âscience editorâ when she doesnt even use SI.
260 Kelvin. Kelvin temperatures are not referred to as âdegreesâ
Whether or not such things are realistically evolvable, I do think you could engineer a sentient plant or a sentient crystal. Isnât the latter what AI research is aiming for?
I hadnât thought of it that way, but, yeah. If AI ever reaches the point where we develop machines that are self-aware itâs going to raise some interesting philosophical issues, and probably force a rethinking of how we define life.
I suspect that you could do so; but not one that escapes (detectable) requirements for structural complexity, energy use, and various other âlife-likeâ properties. With enough bodging, you probably could get some sort of complex neural network into a plant. Iâm not sure how fast you could run it, given the metabolic demands of a high-end nervous system; but even if it were a very slow sentience, it would presumably qualify. Such a plant, though, would raise serious eyebrows on anatomical inspection.
Similarly, mostly-silicon crystals with complex doping patterns and metal layers look almost nothing like silicon crystals with stochastically scattered impurities, except in bulk. Even if they werenât sentient, if we discover that the crystals of Ganymede show complex internal dopant patterns and electrical activity, and have surfaces that promote deposition of materials from the environment to expand the crystal, theyâd definitely have a good shot at being âlifeâ or at least ânot life, because something; but a very, very interesting phenomenon indeedâ; but that sort of thing would also be detectable, with the right instrument package.
I should probably have clarified this orginially; but itâs the âWhat if something weâve examined up and down for interesting functional structures, with no luck, is capable of those functions anyway, because vitalism!â school that irks me, not the suggestion that quite novel chemical/structural substrates might be more than capable of doing chemistry-akin-to-life. To the best of my knowledge, weâve had very limited luck prototyping or theorizing such things in any detail; but itâd hardly be the first time that evolutionary brute force has shown us a solution more elegant than we would ever have expected.
At the risk of rambling, Iâd give the example of Mycorrhizal networks(a subject near to my heart, if fungi had those). I suspect that, until fairly recently, people wouldnât have expected âjust plantsâ of communication; but it is experimentally demonstrable that they do communicate, albeit about a fairly limited range of things(pests, mostly). Once demonstrated, time to go hunting for the method. And, once we started hunting, we found at least a few, the fungal networks being one, and I think some amount of quasi-olfactory sensitivity to chemicals released by a plant under attack by plants nearby.
The point is not to dismiss the capabilities of everything that doesnât âlookâ like it should be capable of something; but to keep in mind that âlifeâ, âcommunicationâ, âsentienceâ, etc. can be accomplished by a variety of fascinatingly clever techniques, some almost certainly too subtle or unexpected to be detected by relatively primitive fixed-function chemistry sets on robots; but that all those things do impose certain requirements: can your âlife-but-not-as-we-know-itâ shovel entropy into the world and energy out of the world fast enough to keep itself together? Your âcommunicationâ candidate (even if we donât know what itâs saying, or how it works yet) needs some sort of signal channels, electrical, chemical, acoustic, optical, magnetic, something, that should show up with suitable sensors. In the absence of channels, or if all we see is silence and thermal noise on all the channels, I doubt communication. âSentienceâ seems overwhelmingly likely to require considerable connectivity across a relatively complex set of structures, the details might be a surprise; but neither communication nor complexity should be able to hide, even if we donât have a damn clue about how âsentienceâ works even in our own brain-meat.
That makes perfect sense, and I agree completely.
Of course weâre glossing over the size of the possible instrument suite needed to conduct sufficiently thorough analyses, esp. assuming we donât have a human or human-level AI present on Ganymede and every other body combing all the plausible candidate crystals so see what looks interesting; think of how long it is taking 7 billion earthlings to study where life is found on our own planet where we do know what kinds of structures to look for. Looking at each rock for impurity distributions isnât at all like a rover taking soil samples and some videos/pictures.
A human brain runs on about 20 watts. For a typical tree, that would be between 2 and 10 square meters of leaf area. A huge biochemical investment (and I have no idea how it would evolve), but not totally implausible for larger species or clonal colonies (and if the information processing structures resided in buried roots that are already heavily networked and energy use is spread out over acres, the anatomical inspection eyebrows would be much harder to raise). Or, a theoretical mostly-solid-state organism might be able to hibernate for centuries and run its mind only as needed using stored energy.
Short of vitalism, I also think there could be entirely ordinary physical organisms we do not yet have instruments to detect, but whose existence is so unlikely theyâre not worth worrying about at this time. Like coherent collections of gravitational waves, or electrical fields in solar plasma, or strong force based neutron star dwellers. The timescales and energy rates involved may be orders of magnitude off from anything we expect and look for, even if such things are in principle identifiable.
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