polyphasic sleep and dream hacking

I just discovered an interesting stuff on the web called polyphasic sleep :O a way that allows you to shrink your sleep duration to 2h or more, by reducing or eliminating the NREM sleep because it's "useless" and doesn't have any effect or advantage on body and mind, sleep effects only happen in REM-sleep... But there are many contradictory information and opinions about it... does anybody know anything about it? is it true that deep sleep stages are useless?

And, it's something related to "brain hacking"... does anybody know what is "brain hacking" about? :?

idk, but I want that.

Can you link the website?

Thats not true cause think of it, no matter WHAT stage of sleep you are in, you are still getting rest... even if your not sleeping and your just laying there with your eyes closed, you are still getting rest

I do what I call efficient sleeping. I work physically hard and in heat of 90F. But sleep I truly hate as life is too short. So I sleep about 4 hours everyday. When I lay down I drop into a deep sleep immediately and 4 hours is enough. I never used to be like this. Before, I needed 10 hours of sleep.

All the states are natural and needed. Hacking them works but at cost and be very careful. Point being if you mismanage this one you may find yourself instantly asleep while driving or some such thing.