Slaves of the Slave System Plantation agriculture was wasteful, largely because King Cotton and his money-hungry subjects despoiled the good earth; quick profits led to excessive cultivation, or âland butchery,â which in turn caused a heavy leakage of population to the West and NW.
It means that since most adults need 8-9 hours of sleep, they will need about 1.6-1.8 hours of deep sleep to feel fully functional next day. However, the time of deep sleep is changed and that's mainly due to the change in the sleep need of different group of people. For instance: Age Group.
You need to sleep eight to 10 hours continuously to cycle through these stages three to four times. Every time you cycle the length of the REM sleep increases while the deep NREM decreases until you have a good 30 minutes in dream sleep without any deep sleep occurring, that is considered healthy sleep.