Do sleep times add up?

[threeright]

Lets say I sleep at 12:00 AM...

Then, I wake up at 3:00 AM,

Go surf the web for an hour,

Then go back to sleep at 4 til 8:00 AM

 

is this equilivalent to sleeping at 12:00 AM, then waking up at 7:00 AM?

[CaptainPanic]

Yes, they add up (somewhat). But I think it is a little too simplistic to say that the two sleeps of 3 and 4 hours are the equivalent of 7 hours. It's not maths, it's sleep... and because there are different stages of sleep, all of which are important to how you feel when you wake up, the equation is probably more complicated than you suggest.

 

But there is a lot of evidence that such a sleep was very common. In the middle ages, it seems it was very common to wake up in the middle of the night.

The BBC have an article about it, which I think it fascinating.