I found a couple of resources online:
http://www.universal-tao.com/dark_room/DarkRoom.pdf pdf of "Darkness technology", a book about this subject. Does anyone know anything about the universal tao organisation? They organize darkness retreats, i'd prefer to do it on my own though and not for 12 days straight.. supposedly your brain starts making DMT by day 9? I've only skimmed the pdf but it seems pretty out there, pineal gland connected to certain stars illustrated by scientific looking pictures..
http://www.amazon.com/Dawning-Clear-Lig ... 1571743758 a book i could buy on amazon, the reviews are good
picture of a floating tank:
It is also referred to somewhat cynically as the "prisoner's cinema" by wikipedia: http://en.wikipedia.org/wiki/Prisoner's_cinema
The part about truckdrivers is alarming!"The Prisoner's cinema is a phenomenon reported by prisoners confined to dark cells and by others kept in darkness, voluntarily or not, for long periods of time. It has also been reported by truck drivers, pilots, and practitioners of intense meditation. Astronauts and other individuals who have been exposed to certain types of radiation have reported witnessing similar phenomena."
And according to research apparently 15 minutes of sensedeprivation is all it takes: http://www.wired.com/wiredscience/2009/ ... cinations/
"You don’t need psychedelic drugs to start seeing colors and objects that aren’t really there. Just 15 minutes of near-total sensory deprivation can bring on hallucinations in many otherwise sane individuals."