The title will only mean something to British folk of a certain age, and mostly men. Moving on. Actually, and on a serious note, I want to discuss the hypothesis of Panspermia. This hypothesis concerns the origin of life on Earth and proposes that perhaps our planet was 'seeded' by life from elsewhere in the universe. In its simplest form, imagine a wandering piece of rock out in the void of space. Imagine that the lump contains some form of simple life or proto-life. Somehow these life forms survive and remain viable in the inimical conditions of deep space- is it that farfetched? We know, for instance, that many species of bacteria are able to form spores. Bacterial spores are extremely hardy and able to survive in the harshest of terrestrial environments awaiting reanimation thousands of years hence- or even longer. Experiments on the International Space Station have demonstrated that Tardigrades, a segmented micro-animal, can survive the cold and intense radiation of space, without a space suit.
I have never liked the Panspermia hypothesis due to the 'Cop-out Factor'. Panspermia avoids the difficult problem of how life actually came about from inanimate matter. Life just occurs elsewhere and then arrives on our planet to take hold and prosper. But maybe I have been a little hasty in my disdain for the hypothesis, and maybe it deserves a little more personal respect now I have thought about the problem more deeply.
At least the hypothesis tackles the most difficult problem there is in modern biology: How did life occur on Earth in such a short time frame? The latest fossil evidence suggests that some form of life existed within just a few hundred million years after the earth cooled down sufficiently to support life. It is known that the Earth coalesced 4.5 billion years ago and that by 4.3 billion years, the planet had cooled to a condition where life could form and evolve. The oldest known fossils have been found in Australian rocks just 600 million years later. Life would have existed before then, perhaps many millions of years prior. And this is troublesome. How could life occur in just a short geological time span considering the complexity of the problem? Let us not underestimate the issue of complexity involved. For proto-life to occur, we require two complex chemical systems to form and interact in complex ways. I have discussed this elsewhere in more detail; go seek. I will not reiterate here. The fact that these highly complex processes could and did happen within the time frame available is nearly miraculous. And as my regular readership will have gathered, I have no truck with miracles. There has to be a rational explanation.
There are several variants of the Panspermia hypothesis. The variant that intrigues me the most promotes the possibility that life began to coalesce early in the universe at large. The age of the universe has been estimated, using extrapolation, to be in the order of 13.8 billion years. However, recent evidence from the James Webb telescope suggests that the universe may be much older. Let us wait and see what follows. The data is raw and recent and therefore requires further examination and analysis. Regardless, it is important to acknowledge that the universe is a lot older than the Earth. Immediately after the 'Big Bang', the universe was extremely hot and raw. However, just a billion years later, the cosmos reached a balmy/barmy -253.15 C. It is reasonable to surmise that during the interlude between the Big Bang and 1 billion years, there would be a time when temperatures on random pieces of matter would be conducive to the development of life. A solvent would also be required to sustain the reactions. We immediately think of water, but there are other solvents that could serve the process, at least initially. Methane liquifies at a much lower temperature than water (-182 to -161C), thus providing a suitable sustaining environment in a frigid uncaring universe. There are other possible candidates, such as ethane. I'm perhaps erring on the flippant side, but the concept is solid, unlike the solvent. The point to be made, is that there would be innumerable 'domains' (mayhap infinite?) available for this illimitable cosmic experiment. The time available for this to occur is open to speculation, but at least 12 billion years would be accessible. This highly speculative model allows a vast theatre of time and space for the formation of life to occur. Under such conditions, life could come forth from multiple points, over multiple eons.
Imagine a simple, basic life form transformed into a hardy spore buried deep within the rocky envelope of an asteroid. It wanders the cosmos for an indeterminable time until it meets the gravitational field of our home. It roars through the primitive atmosphere to arrive blackened and seared and finally quenched within a vast ocean. There the spore awakens and develops anew in a foreign environment/experiment. It would take but one 'seed' to set the process of reproduction and natural selection to progress. The rest is just the history of life on Earth.
The advantage of this particular flavour of Panspermia is that the factor of time and space is not limited to a small sphere of rock containing dihydrogen oxide put together a mere 4.5 billion years ago. The whole universe becomes the infinite, moist, progenitor vat enshrined within the web of spacetime.
Anyway, back to the title. Pans People: the wet dream of British adolescents circa 1971. Take it away, girls. There is no doubt that the choreography was shit, but we didn't care, probably because we had too much testosterone coursing through our veins and didn't know the meaning of choreography. Arse.
Enjoy.
Looking back on Pans People I am struck by how tastes have changed. I remember that the BBC directed the cameramen to stop filming up the audience girls' skirts when they were dancing on a raised platform.
ReplyDeleteAnd so we come around to the present day when men are cautioned about the oppressive male gaze yet women can get away with displaying (and it is a display) almost everything on the catwalk, or beach, or awards red carpet.
Ordinary life continues though.
What did people know/believe about cosmological stuff 500 years ago?
ReplyDeleteWhat will people know about it in 500 years? Hope, not the same again than anno 1500. Seen comedy-pic "Idiocracy"? Good idea but frightening close to actual tendencies.
p.s. Who needs choreography as long as the chicks are cute?
p.p.s. Hippie-girls were hard to beat - and still they are (mumbles gramps)
As far as panspermia is concerned I think your initial, instinctive (?) reaction – basically a cop out – is valid.
ReplyDeleteAbiogenisis: Life has to start – arise from the inanimate – somewhere. Is this a literally in 10 to the 22 (the number of stars in the observable universe) miracle, or is far more common?
There simply is no testable model as yet, so the origins of life can’t properly be speculated on but making the whole universe in effect a potential petri dish does improve the odds.
Or does it?
The spores or whatever, still have to get here. Life, in some remote part of the universe, could develop into a space faring civilization and do it directly, but failing that it would have to be ejected from its planet of origin (and if that was an early Mars or Venus, a decent sized asteroid impact would do) or, if somehow originating off a world, gain impetus to cross the interstellar and perhaps intergalactic gulfs.
Are these “spores” some sort of universal baseline – is all life basically of the same pattern (likely carbon based as that seems to be easiest to maintain, but there are all sorts of alternative chemistries that might work), able to take root on any world, or would there have to be some degree of compatibility between point of origin and wherever it happens to land.
What sort of leg up does this give anyway
Even the most basic single cell organism able to be described as life is an incredibly complex thing likely requiring a significant evolution to get to this stage. Or is it the basic building blocks – the chemicals, amino acids etc – which develop off a world and drift until they find one?
Etc, etc
It’s such a fascinating subject but it’s also incredibly frustrating precisely because there is no real baseline to begin to properly evaluate.
Pan’s people, ah fond memories. Must say, pleasing rear aspect there as an estate agent would say.
In fact, the whole issue is not even a scientific question. Our data set is 1- we, as yet, have no instance of life occurring elsewhere in the universe. We can't test the hypothesis because there is no data to work with. Therefore, it becomes a philosophical issue rather than a scientific one.
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