suza

I heard the astronauts are using a binaural beat technology to reduce their need for sleep. They said it quickly creates Theta brainwaves, which cause chemical changes that refresh the brain. Rather than taking 8 hours it can occur in about 30 minutes. I did a search and found this http://www.brain.web-us.com/thescience.htm. Here I found it is also used for creating altered states, deep meditation, and visions, has anyone tried this and does it work ? Is it safe ?