Show me how life can evolve without coherent atoms and I'll accept that there can be life on a star.
We agree 100% that organic life can't and by extension that any molecular life can't (unless they are molecules I never heard of). As you say later, what I'm getting at is that so long as our definition of "life" is basically "life as we know it (Jim)", we may be looking in a very small subset of the right places. I don't think stars are any likelier than you do. I just don't KNOW.
Bovine excrament. There is NO circularity there. Many field paleontologists get cross-trained in archaeological resources identification. It's a job hazard--juvenile paleos and archaeos, at least in the USA, often spend time monitoring construction sites, and we tend to work together a lot. I myself have been an archaeological resources monitor and have collected a number of artifacts. My boss has done a great deal more of that (he actually can identify fire-cracked rock, something I'm deeply impressed by when I'm not thinking he's pulling my leg). I am fully capable of seeing tools in rock. They're pretty obvious to the trained eye--stone flakes have a unique appearance, based on the mechanism by which they must be formed.
That's good to know. It wasn't part of my education, in the 1970s. I also studied basic archaeology, but that was just chance.
let me repeat though that all training in archaeology is, by default, in
human archaeology, because there ain't any other kind - and that's the assumption I'm pointing out.
I grant all you say about the mechanics of stone tools, but nobody wastes his time deciding whether a flaked flint is natural or artificial unless it's both possible
and probable that it could be an artifact.
Take an absurd example- there were beetles in the Miocene who established a global empire based on 1mm long flint sickles, shaped by the radula(e)? of trained boring bivalves. Who, in his right mind, is looking for tools amongst 1mm long flint flakes? Nobody . (I hope). But would anyone, cross trained or not, be likely to recognise a 40 million year old,
non-human flint tool?
Sure, once it's under the microscope, the hallmarks of manufacture may be there (corrected for scale)- but is anyone going to look in the first place?
Bone I'd grant you might be easier to recognise, but decent preservation of tool marks on fossilised bone of that age?
If we know what to look for, we can identify tools. All I'm suggesting is that what we know to look for is based on experience of human tools- and while all tools, I do agree, will show some properties in common, the differences may be so big that we never even consider the possibility.
The presence of cross-trained paleontologists in field sites such as the one I'm currently directing serves as the test for tools in the formations we examine. (In the formation I'm working in right now it'd be obvious--it's well-indurated and has been since the Pliocene, so anything we find during excavations below the surface is necessarily Pliocene in age at minimum.) This means that, as I said, we don't see tools prior to humans because they do not exist.
I think what you're trying to get at--in a very round-about and back-handed way--is that we need to develop a better understanding of what life is in order to look for life. I whole-heartedly agree with that. I've seen arguments that liquid methane, which has been found on at least one moon in our solar system, can produce biochemistry, for example. We aren't looking for liquid methane, which is a serious error in my opinion.
However, I understand why SETI is doing what they're doing. They're starting off looking for life similar to our own. Once we find it, we can start exploring weirder types of life. There are enough planets that, assuming life is common, we should be able to use what we learn from other planets to find other life that's even more different from Earth life. The issue is that we need to start somewhere, and looking for what we know we can identify is as good a place as anywhere.
I concur, but starting with life like ours is exactly what I'm suggesting too. We know tool use has developed among several species right here. If fate had not dropped a rock when it did, tool use among dinosaurs may have been only a matter of time. We know some made nests. Did they have the sort of ritual displays modern bower birds do too? Far from impossible. We've all seen crows do some pretty complicated things. I do wonder if some of the Chinese sites might not embody "cultural activity" at a high (animal) level, if we knew what to look for. (Again, to stress- I'm thinking "likely" in the context of SETI findings being " likely", not in terms of "We are 'likely' to find Roman remains if we dig up any street in southern England. Orders of magnitude different.
[P]aleontologists like myself are fully capable of identifying stone tools, and even fragments thereof, in Eocene rock. If you disagree, please say exactly why. And I mean EXACTLY why--what SPECIFIC features do you think I'm missing? Remember, the form of stone tools will be dictated by the rock used.
Yes, they would- but to some extent they will also be dictated by the design of the creatures using them. But you miss my point. I don't doubt that if you found what looked like a flint core, surrounded by flakes, showing a pattern of percussion cones, conchoidal fractures , reworked edges and the like, complete with the flake-free backside space of the critter who made them you would at least sit up and scratch your head, but that would require a fossil erosion surface (assuming terrestrial animals).
Trying to think like an alien intelligence is tricksy, to say the least- but say you're examining a maiasaur nest. There are shell fragments on the ground.
Are they in random patterns, or are they arranged in any way? If they are, by comparison with modern seabirds, I would say they were likely pushed there by a chick grabbing its territorial space after hatching, or by a parent , "tidying" the nest, perhaps removing the organic shell lining to keep vermin away from the chick. It would not occur to me that
the pattern of fragments itself had any significance. Perhaps it would occur to a modern cross trained palaeontologist, I don't know.
Bad example perhaps, but what I'm trying to get at is that it's precisely the things we never think of that are the things we could be missing.Does that make sense?
Which do you find more probable: a 1:1,000,000,000 event or a 1:5,000,000,000 event? At a certain point, the question becomes meaningless from any practical standpoint.
Fair enough, but this IS a pretty speculative thread.
I can say with a fair degree of certainty--because I myself have tested the idea, and am currently testing it--that organisms prior to humans haven't developed stone tools, beyond the rocks otters use to smash shells open. I can't say anything about life in the galaxy, so I'd say that it's probably more likely that there stoneare other intelligent life forms elsewhere in the galaxy--merely because I've been part of the demonstration that the other option isn't true.
Just one point- you (understandably) stress
stone as do I, because over the time spans involved, not much else survives, unless fossilised. Tool
effects might be another thing to look for. Butchery with a bronze axe does leave bones in different shape from butchery with teeth, but the chances of discriminating between butchery with a flint knife and teeth on a skeleton millions of years old...well, do you think it would be feasible? And if feasible, how many people would be convinced?
Let's face it, even if people were seriously looking for this sort of evidence, the chances of finding it are pretty small.
Still. Any time I wander along the basal unconformity between the Silurian and Old Red, I keep hoping I'll find a Betelgeusian Army Gazongo, casually dropped by a giant ant from a survey ship back in the day. (I'll keep you posted).
ps Doing this on a small laptop screen. Somewhere in there is a half sentence that went missing. I can't find it, but if you find a line that makes absolutely no grammatical sense (leave the content issue to one side for now) that may be it.
