AIUI, the booting process is essentially the computer, run by its BIOS, loading OS files from the disk into memory to make them available for execution.
When I wake up, I’ll often have a brief moment when I’m uncertain where I am, especially when I’ve been travelling. It takes a few seconds or fractions of a second for me to realise this and to become aware of whatever issue was on my mind when I went to bed the night before. Is it a viable analogy to compare this process to booting a computer, with my brain obtaining relevant information from wherever it is stored and moving it somewhere else where it’s more immediately accessible?
I think you could call it an analogy - waking up for me includes a certain amount of checking which bits are working, where I am and what I need to do next, waiting for my various faculties to start working.
I’d say a computer does it much more strictly and methodically than a human.
I wouldn’t say there is much in common at all.
The biggest reason is that the brain is a fundamentally different system to a conventional computer.
When a computer boots, the first thing that happens is that you initialise everything into a know basic state. And assume that the dynamic state you didn’t initialise, is basically random.
The entire idea of bootstrapping is embodied in the name. It comes from the idea of lifting yourself up by your own bootstraps. (Which is intrinsically impossible, so the name itself contains something of an in joke.) But it becomes the question of how to start with only the tiniest sliver of state and then from there claw ones way up to a next level of state, that has enough capability to claw up to another state.
So:
- power on, hardware goes into reset state,
- jump to known address in ROM,
- initialise some more state, able to read basic configuration from persistent memory,
- use that to read initial bootstrap program from known bit of disk into a known bit of memory,
- call newly loaded code in memory,
- that initialises another layer of system, usually including enough filesystem code to read arbitrary files off disk, and loads the desired OS kernel into memory,
- call into newly loaded kernel,
- that initialises another slab of system, including setting up all the device drivers, initialises the memory system, network, and runs the various initialisation jobs. (Traditionally, Unix creates the process init, which then handles the rest of the system startup.)
- The system processes responsible for general running initialise themselves, and your computer is ready for you so start surfing for porn again.
- Nowadays, individual applications will try to remember a bit of state about what they were up to. So what files were open, what you were roughly doing. So they might also be restarted and try to reconstruct what was happening before they were shut down. So your bowser will try to open all the tabs you had open last time. But these are not resuming what the process was doing before. They are newly created processes.
Brains don’t work like this at all. At least not as we know it. The best counter example to the idea is that we dream when asleep. Computers don’t dream when they are powered off. Not even HAL.
Our brains are doing stuff when we are asleep. Critically, we know that memory processing is occurring. Sleep deprivation causes significant and sometimes long lasting damage. We know the clock still runs when we are asleep.
Moreover, we are alert to some things even when asleep.
Years ago a friend of mine told the story of finding himself locked out of the house late at night. He couldn’t rouse his wife by shouting. Then he had an inspiration. He called out in a pitiful voice “Mummy, mummy!” Bang - the lights were on and the bedroom window shot up.
When you put a computer to sleep, it may save a good fraction of active state to disk, and it pauses most processes, but keeps alive a basic set of activities that monitor the environment. If you hit a key, open a laptop lid, or send the machine a packet over the network, it resumes some processes, and it decides it is wakeup time or not. If it is wakeup time, saved state is resorted back into memory, and paused processes run. This is a lot closer to being asleep. If we were to add permission for the computer to continue with background activities - such as backups - but not if they take too much energy - we would be closer to human sleep.
I’d say it’s more like reopening your awake app.
Your computer booted a long time ago, probably in your mother’s womb on a BIOS level, and took many years to load all the subroutines of the YouOS.
Yeah, waking up is really more like if your computer is running a heavyweight screensaver like Electric Sheep, and you jiggle the mouse and wake it up. Everything freezes for a couple of seconds while it unloads those resources, then it loads your normal working desktop view.
It was always a fully booted computer that’s actively running a program, it’s just task-switching.
A more interesting question is what happens in hard-down situations like when someone’s been in ice water for 40 minutes. In that case the brain is totally switched off, no activity at all. Even in that case it’s really not like a computer cold boot. Your brain never unloaded memory, it just stopped processing. This is also like how computers wake up from hibernate. It doesn’t go through the step-by-step process of loading bigger and bigger routines and data into memory. All of their current state is saved somewhere, and when the computer wakes up, it’s restored as it was. Same with waking up from a deep-freeze or coma. Some data might be lost or damaged in that process, but your mind/body isn’t waking up from zero and learning how to breathe, see, hear.
Good to see another Electric Sheep fan 
I think going to sleep would be closer than waking up
A slightly more apt analogy would be, not with booting a computer, but with waking one from sleep or hibernation, where the full context of the pre-sleep state is preserved. Booting a computer is more closely analogous to being resurrected from death, with a new state being created from external information. For instance, if you shut down a computer, and swap out the boot drive with a suitably configured different one, at reboot you might have, in effect, logically a completely different computer, maybe even with a completely different OS.
No. Even when I am in deep sleep I am never really out of it. The slightest, unexpected, noise and I am awake. Maybe not instantly, but I am awake.
Ever have children?
I have low blood pressure issues and sometimes blackout as a result.
Coming round from a blackout is fascinating and totally different to waking up from a normal sleep. You start off being aware of your own thoughts, but having no sensual input. Your senses then come back online one at a time. Hearing first, followed by touch, smell and taste. Vision always seems to be the last one to start working. So I’m usually lying on the ground, which I can feel, and I can hear concerned people, but can’t see them.
The most disconcerting thing is that I usually have no memory of the blacking out and this part is the most computer like. It’s as if the last 15 seconds or so of consciousness was in volatile cache and never written to disk. That break in continuity really leaves me feeling weird and not entirely sure if I’m the same person. Please don’t ever make me use a Star Trek transporter!
I like the analogy well enough to use it occasionally. Though, the temptation is to extend it further than it deserves. If you’re explaining computers to somebody completely unfamiliar with them, it’d be great. If you’re trying to figure out something about your brain or about your computer, it’d be more trouble than it’s worth.
Old school approach: I think it’s more like turning a rheostat up on your rational mind/consciousness. You turn it down at night to save the batteries.