jack: (Default)
[personal profile] jack
In order for life to continue you need a variety of things. You need to severely curtail the number of fusion explosions around. You need oxygen. Need to not be underwater. Not to be constantly struck by lightning.

But funnily enough, for life to come about, you basically need the opposite of all those things.

Date: 2017-06-12 08:57 am (UTC)
kaberett: Overlaid Mars & Venus symbols, with Swiss Army knife tools at other positions around the central circle. (Default)
From: [personal profile] kaberett
I would on the face of it disagree with several of those - see for example extremophiles around ocean vents and The Great Oxygenation Event, which (insofar as mass extinctions actually exist) caused the largest mass extinction in Earth's history. So I think I'm missing or misunderstanding what you're getting at, and would be interested to know more!

Date: 2017-06-12 11:38 am (UTC)
simont: (Default)
From: [personal profile] simont
Out of all the things a living organism needs, the one that always strikes me as the most surreal – from a completely abstract point of view outside our normal preconceptions – is the requirement to be in the right temperature range.

Other requirements make perfect sense from first principles: clearly if you're going to do anything then you need a supply of energy to do it with, mechanical wear and tear (plus of course the need to reproduce in the first place) means you need some raw materials to build and repair your body parts with, and the generalised requirement for the absence of all sorts of phenomena that the organism isn't engineered to withstand is completely understandable (even if a few of the specific phenomena in question might be a bit surprising).

But the thermal requirement, if you discard the high-level concepts of 'heat' and 'temperature' and boil what's really going on back down to the movement of individual particles, sounds utterly weird, because what you end up saying is that in order to survive, an organism requires constant gentle massaging from all the particles in its environment, and moreover, this massage must not only be constant, but must constantly fall within quite narrow limits of intensity – just a hair too much or a smidge too little and the organism takes severe damage or even dies. And yet, somehow, this is seen as perfectly natural, no weirder than the need to eat!