“Surely You’re Joking, Mr. Feynman”: Adventures of a Curious Character

“Isn’t it true that you’re supposed to get hallucinations under those circumstances?” I asked, excitedly.

“That is true indeed.”

I had always had this fascination with the images from dreams and other images that come to the mind that haven’t got a direct sensory source, and how it works in the head, and I wanted to see hallucinations. I had once thought to take drugs, but I got kind of scared of that: I love to think, and I don’t want to screw up the machine. But it seemed to me that just lying around in a sense-deprivation tank had no physiological danger, SO I was very anxious to try it.

I quickly accepted the Lillys’ invitation to use the tanks, a very kind invitation on their part, and they came to listen to the lecture with their group.

So the following week I went to try the tanks. Mr. Lilly introduced me to the tanks as he must have done with other people. There were lots of bulbs, like neon lights, with different gases in them. He showed me the Periodic Table and made up a lot of mystic hokey-poke about different kinds of lights that have different kinds of influences. He told me how you get ready to go into the tank by looking at yourself in the mirror with your nose up against it—all kinds of wicky-wack things, all kinds of gorp. I didn’t pay any attention to the gorp, but I did everything because I wanted to get into the tanks, and I also thought that perhaps such preparations might make it easier to have hallucinations. So I went through everything according to the way he said. The only thing that proved difficult was choosing what color light I wanted, especially as the tank was supposed to be dark inside.

A sense-deprivation tank is like a big bathtub, but with a cover that comes down. It’s completely dark inside, and because the cover is thick, there’s no sound. There’s a little pump that pumps air in, but it turns out you don’t need to worry about air because the volume of air is rather large, and you’re only in there for two or three hours, and you don’t really consume a lot of air when you breathe normally. Mr. Lilly said that the pumps were there to put people at ease, so I figured it’s just psychological, and asked him to turn the pump off, because it made a little bit of noise.

The water in the tank has Epsom salts in it to make it denser than normal water, so you float in it rather easily. The temperature is kept at body temperature, or 94, or something—he had it all figured out. There wasn’t supposed to be any light, any sound, any temperature sensation, no nothing! Once in a while you might drift over to the side and bump slightly, or because of condensation on the ceiling of the tank a drop of water might fall, but these slight disturbances were very rare.

I must have gone about a dozen times, each time spending about two and a half hours in the tank. The first time I didn’t get any hallucinations, but after I had been in the tank, the Lillys introduced me to a man billed as a medical doctor, who told me about a drug called ketamine, which was used as an anesthetic. I’ve always been interested in questions related to what happens when you go to sleep, or what happens when you get conked out, so they showed me the papers that came with the medicine and gave me one tenth of the normal dose.

I got this strange kind of feeling which I’ve never been able to figure out whenever I tried to characterize what the effect was. For instance, the drug had quite an effect on my vision; I felt I couldn’t see clearly. But when I’d look hard at something, it would be OK. It was sort of as if you didn’t care to look at things; you’re sloppily doing this and that, feeling kind of woozy, but as soon as you look, and concentrate, everything is, for a moment at least, all right. I took a book they had on organic chemistry and looked at a table full of complicated substances, and to my surprise was able to read them.

I did all kinds of other things, like moving my hands toward each other from a distance to see if my fingers would touch each other, and although I had a feeling of complete disorientation, a feeling of an inability to do practically anything, I never found a specific thing that I couldn’t do.

As I said before, the first time in the tank I didn’t get any hallucinations, and the second time I didn’t get any hallucinations. But the Lillys were very interesting people; I enjoyed them very, very much. They often gave me lunch, and so on, and after a while we discussed things on a different level than the early stuff with the lights. I realized that other people had found the sense-deprivation tank somewhat frightening, but to me it was a pretty interesting invention. I wasn’t afraid because I knew what it was: it was just a tank of Epsom salts.

The third time there was a man visiting—I met many interesting people there—who went by the name Baba Ram Das. He was a fella from Harvard who had gone to India and had written a popular book called Be Here Now. He related how his guru in India told him how to have an “out-of-body experience” (words I had often seen written on the bulletin board): Concentrate on your breath, on how it goes in and out of your nose as you breathe.

I figured I’d try anything to get a hallucination, and went into the tank. At some stage of the game I suddenly realized that—it’s hard to explain—I’m an inch to one side. In other words, where my breath is going, in and out, in and out, is not centered: My ego is off to one side a little bit, by about an inch.

I thought: “Now where is the ego located? I know everybody thinks the seat of thinking is in the brain, but how do they know that?” I knew already from reading things that it wasn’t so obvious to people before a lot of psychological studies were made. The Greeks thought the seat of thinking was in the liver, for instance. I wondered, “Is it possible that where the ego is located is learned by children looking at people putting their hand to their head when they say, ‘Let me think’? Therefore the idea that the ego is located up there, behind the eyes, might be conventional!” I figured that if I could move my ego an inch to one side, I could move it further. This was the beginning of my hallucinations.

I tried and after a while I got my ego to go down through my neck into the middle of my chest. When a drop of water came down and hit me on the shoulder, I felt it “up there,” above where “I” was. Every time a drop came I was startled a little bit, and my ego would jump back up through the neck to the usual place. Then I would have to work my way down again. At first it took a lot of work to go down each time, but gradually it got easier. I was able to get myself all the way down to the loins, to one side, but that was about as far as I could go for quite a while.

It was another time I was in the tank when I decided that if I could move myself to my loins, I should be able to get completely outside of my body. So I was able to “sit to one side.” It’s hard to explain—I’d move my hands and shake the water, and although I couldn’t see them, I knew where they were. But unlike in real life, where the hands are to each side, part way down, they were both to one side! The feeling in my fingers and everything else was exactly the same as normal, only my ego was sitting outside, “observing” all this.

From then on I had hallucinations almost every time, and was able to move further and further outside of my body. It developed that when I would move my hands I would see them as sort of mechanical things that were going up and down—they weren’t flesh; they were mechanical. But I was still able to feel everything. The feelings would be exactly consistent with the motion, but I also had this feeling of “he is that.” “I” even got out of the room, ultimately, and wandered about, going some distance to locations where things happened that I had seen earlier another day.

I had many types of out-of-the-body experiences. One time, for example, I could “see” the back of my head, with my hands resting against it. When I moved my fingers, I saw them move, but between the fingers and the thumb I saw the blue sky. Of course that wasn’t right; it was a hallucination. But the point is that as I moved my fingers, their movement was exactly consistent with the motion that I was imagining that I was seeing. The entire imagery would appear, and be consistent with what you feel and are doing, much like when you slowly wake up in the morning and are touching something (and you don’t know what it is), and suddenly it becomes clear what it is. So the entire imagery would suddenly appear, except it’s unusual, in the sense that you usually would imagine the ego to be located in front of the back of the head, but instead you have it behind the back of the head.

One of the things that perpetually bothered me, psychologically, while I was having a hallucination, was that I might have fallen asleep and would therefore be only dreaming. I had already had some experience with dreams, and I wanted a new experience. It was kind of dopey, because when you’re having hallucinations, and things like that, you’re not very sharp, so you do these dumb things that you set your mind to do, such as checking that you’re not dreaming. So I perpetually was checking that I wasn’t dreaming by—since my hands were often behind my head—rubbing my thumbs together, back and forth, feeling them. Of course I could have been dreaming that, but I wasn’t: I knew it was real.

After the very beginning, when the excitement of having a hallucination made them “jump out,” or stop happening, I was able to relax and have long hallucinations.