I've been travelling a bunch recently. Jet lag is a funny beast. I used to let myself adjust slowly, returning east, but now I go cold turkey: Up at 7am every day, from the first day I get back. It makes sure I sleep through the night. Not making concessions to my body throws into relief what my body really wants to do.
When my body wants to go to sleep, the taste of sleep comes on. I get heavy and my head lolls.
During the period I would usually be fast asleep, I'm kinda okay, but it's like walking through treacle. I'm also cold.
Just before my body expects to be waking up - what is, local time, early afternoon - I get that taste in my mouth again, I feel super tired, and my bladder fills up. Give it another hour or so, as I come out of the slump, and my feet get really hot.
What's going on here? I've no idea. But I can guess.
First, my body helps me go to sleep. Even when I'm tired, I'm not necessarily sleepy (I hope you see the distinction). My body must be releasing something to make me sleepy. That lasts an hour or so, enough to knock me out.
That taste in my mouth? While I'm asleep, my body is doing its maintenance tasks. It's dumping out the nasty chemicals, metabolising stuff which it didn't during the day, taking the opportunity to check all my cells and digest the old ones, and whatever. The taste of sleep and crusty eyes, that's my body excreting through my face.
Second, when I'm waking up, that's my body doing its clean-up tasks from the overnight work. There's stuff it kept back because it couldn't excrete them earlier, so when it knows I'll be up and about soon, it flushes liquids to my bladder and the last batch of stuff to my mouth.
My temperature regulation goes to daytime mode last, usually just after I've woken up. My body heats up, and this is felt most in my feet which go cold/hot and clammy (I think this is because my body makes assumptions about whether I'm standing or lying down). I get this same thing if I stay in bed too long on weekends.
What this all feels like gives me a new theory.
I feel like I'm operating my body with levers and buttons, when I get up, I'm jet-lagged, and my body expects to be in deep sleep. I have to operate my legs with levers, and remember to reel my shoulders in, out of the way of door frames. Making breakfast isn't automatic, it's a sequence I have to assemble then follow: Get cereal, get bowl, open cereal, pour cereal into bowl, put down box...
This subjective sensation does not - does not one little bit - correspond with the idea that my body is resting.
What it corresponds with is lag. If I operate my body when it wants to be asleep, my body is thrashing to keep up. I'm overloading it. When I'm asleep, it's because my body is simply too loaded to sustain consciousness.
Those overnight maintenance tasks must be a dog to run. Saving my memory out to long-term storage, running over recent experiences to figure out what to pre-emptively put in the cache, monitoring cell division, allocating resources, doing integrity checks, figuring out how to digest the worst bits of that agro-industry food, shuttling chemicals round my body. That takes work! My body is a busy bee!
Consciousness - being awake - is what my body throws me as a sop when it doesn't need the resources for anything else.
(Apologies for the ugly mind/body division I've been making here. For mind, read 'the self-aware bit of the mind+body me' and for body read 'me.')
Just to get super abstract with the purpose of existence for a moment, the purpose of existence is this: To occupy time and space. In short, things which don't occupy time or space, aren't.
Here are some different ways to occupy time and space: Be big; be multiple; be long lived. Planets are big, so are stars. Grass is multiple. Rocks are long lived. So are trees.
One cheap way to occupy more time and space without being more materially robust is to avoid the termination of the occupation. Animals are smart and get out of the way of being terminated. Movement and intelligence are both good strategies.
Occupation isn't measured in metres or seconds but by witnesses. A dinosaur, being big, occupies space as far as it can be seen. To maximise its witnesses, it moves. There's a kind of persistence of existence which means it occupies a sausage shape in space as it walks along.
I have a theory that dinosaurs were silent, and they were replaced by birds because birds had a technological secret weapon that let them occupy more efficiently: Noise.
Birdsong occupies more space with less meat than dinosaurs.
If this is correct then, on average, birdsong in the late Mesozoic can be heard from a marginally greater distance from that which dinosaurs can be seen.
30 year prediction:
By 2037, China, by virtue of their ability to see and manage environment impact on a larger scale than other countries, will have invented cheap renewables to reduce their dependancy on fossil fuels, and will be working on fixing the atmosphere (perhaps they'll also have genetically engineered rafts of algae on the Pacific, excreting plastics). The West will rely on Chinese innovation to dig us out of our ecological mess.
Just as the West will be a secondary market for Chinese consumer goods, BRIC being central, our prime-time TV entertainment will be dubbed Indian television which will be written and produced better than anything we can make domestically, yet - like our clothes that are always 12 months behind the global styles, and our cooking utensils that aren't really optimised for the kind of food we eat - will leave us feeling strangely culturally decentred.