Thanks . Lots of useful points and concepts here in a general discussion on sleep for (lots of humour plus Professor of Circadian Neuroscience at Oxford and Prof Psychology at Hertfordshire)
And segmented sleep contesting the myth of the 8 hour sleep:
“For most of evolution we slept a certain way,” says sleep psychologist Gregg Jacobs. “Waking up during the night is part of normal human physiology.”
And more: