Yes i think the sarcophagus was used an sensory deprivation tank to induce lucid dreaming. Its makes the skin jump alright when think of what the
implications and motives for that was, and where only skiming the surface still.
What an amazing movie, this is what started my interest in Isolation/Floatation Tanks too. I was going to reference it but decided to read through the
thread first just in case someone else had! You beat me to it! Also made me a William Hurt fan!