I'm reminded that we still don't know conclusively what purpose sleep serves[1]. We know about things unimaginably distant in scale or time -- like quarks and the Big Bang -- but we don't know the answer to something seemingly pedestrian.

[1] https://en.wikipedia.org/wiki/Sleep#Functions

I looks like they're referencing this paper[1] which suggests that like dolphins, birds can sleep 1 brain hemisphere at a time. That's pretty interesting.

[1]http://www.nature.com/nature/journal/v397/n6718/full/397397a...

> On land, birds can switch from sleeping with both hemispheres simultaneously to sleeping with one hemisphere at a time in response to changing ecological demands17,18. During such unihemispheric slow wave sleep (USWS) birds keep the eye connected to the awake hemisphere open and directed toward potential threats.

This reminds me of the low-power sleep states of PCI (L0s, L1, etc.) or a multicore CPU

We really need to figure out what sleep is for. It seems important.

I'm currently reading Where Song Began[1] which discusses this, and is super-interesting besides. Has an anecdote of WW1 pilots encountering flocks of dozing swallows at night.

1. https://www.amazon.com.au/Where-Song-Began-Australias-Change...

Just me or the fact that they managed to record the brain activity of birds in flight seems more interesting than the fact that birds sleep in flight?

I mean, the reason I clicked the link is because I wanted to learn HOW they recorded the brain activity.

I just never imagined EEG sensor + logger can be miniaturized to such a degree.

Is it possible for a human(for example a meditator) to learn to sleep with one eye open ?

Kind of OT, but does anyone happen to know if a person with a severed corpus callosum can sleep with one hemisphere at a time?

It would make sense that birds do fall asleep while flying, as they are sometimes prone to fly into buildings or windows that were obviously visible.

wow, birds can auto-pilot.

if two halves of the brain can work independently, wouldn't there be a sync problem! I wonder how the brain handles it.

Sometimes I can hear myself lightly snoring while asleep. Its kind of weird

I wonder if they have that "I'm falling" dream and then wake up.

Personally, I always have trouble sleeping while flying.