The idea that humans can leave their bodies during dream states is an ancient one. Countless people — from New Agers to shamen around the world to 19th-century occult philosopher Madame Blavatsky — believe that it is possible to commune with cosmic intelligence through visions and vivid dreams experienced during astral projection, also known as out-of-body experiences.
Surveys suggest that between 8 and 20 percent of people claim to have had something like an out-of-body experience at some point in their lives — a sensation of the consciousness, spirit, or "astral body" leaving the physical body. While most experiences occur during sleep or under hypnosis, some people claim to do it while merely relaxing. According to one popular theory, the astral body remains connected through a metaphorical silver cord (akin to an umbilical cord) that tethers the roaming consciousness to the physical body.
Though practiced for millennia, these days astral travel can be big business; a man named Mark Pritchard (who goes by the more evocative moniker V.M. Beelzebub) offers an online course and book on how to learn astral travel in eight weeks. As he explains, "the Astral is one of two planes on the fifth dimension; it is where dreams occur, where mystical teachings are given and where the deceased go.... you can meet spiritual beings in the Astral, discover secret knowledge, learn about yourself, see where your spiritual obstacles and inner defects are, learn hidden wisdom about death, the process of awakening, get premonitions of the future, receive guidance, discover the purpose of life, discover what happens with death, and much more.... it is something that really happens to you. You actually find yourself in another dimension, existing outside the physical world. You will be able to fly, go through walls and objects, meet people and travel to distant places. It is a profound experience."
Science and astral projection
It may be a profound experience, but the fundamental problem is that there's really no way to scientifically measure whether or not a person's spirit "leaves" or "enters" the body. The simplest and best explanation for out-of-body experiences is that the person is merely fantasizing and dreaming. Because there is no scientific evidence that the soul exists — or for that matter that consciousness can exist outside of the brain — the premise behind astral projection is rejected by scientists. [Related: Near-Death Experiments are Lucid Dreams, Experiment Finds]
One of the most important scientific principles, Occam's Razor, is that if you have a phenomenon to be explained and several different theories are proposed as solutions, the simplest one (or the one with the fewest assumptions) is likely to be the correct answer. (One common illustration of this is the statement, "When you hear hoof beats, think horses, not unicorns" — or, in this case, "When you have a dreamlike experience while sleeping or resting, think dreaming, not astral projection.")
Practitioners of astral travel insist that it must be real because it seems so vivid, and because some of the experiences are similar, even for people from different cultures. But it's not surprising that many people who try astral projection have similar experiences — after all, that's what the term "guided imagery" is: when an authority (such as a psychologist or astral travel teacher) tells a person what they should expect from the experience. The power of suggestion can be powerful, and a person who is told they will encounter an alien or godlike entity who imparts cosmic wisdom is likely to imagine exactly that.
The problem is that there's no evidence that those people who leave their bodies are actually going anywhere — and certainly not anywhere on Earth. One strong piece of evidence that the "travel" takes place in the mind is that those who return from out-of-body experiences can't give verifiable details or information about the places they've been or what they've seen. If real, astral travel would be incredibly useful. There would be no need to send humans into dangerous conditions — such as the 2011 Fukushima Daiichi nuclear disaster in Japan — to find out what the situation is (or if a meltdown is imminent); instead, engineers should be able to simply visit the site astrally to survey the damage and report back without danger of radiation contamination.
For that matter, if consciousnesses can fly, go through walls, and circle the globe, it should have been a simple matter for astral projection teams to locate Osama bin Laden during his decade of hiding out in Pakistan, and save innocent lives (not to mention collecting the $25 million reward). The disincarnate consciousnesses of bilingual, astral-projecting spies could easily visit top-secret facilities around the world and return with important information about everything from corporate trade secrets to military nuclear codes. If astral bodies truly can visit other planets, then there seems little need for the $2.5 billion spent on the Mars Rovers, since scientists and engineers could simply travel there in astral form during dreams and provide detailed information about the geography, soil composition, ecology, and so on.
According to researcher Susan Blackmore, author of "Beyond the Body: An Investigation of Out-of-the-Body Experiences," people who experience astral travel "have been found to score higher on measures of hypnotizability and, in several surveys, on measures of absorption, [a] measure of a person's ability to pay complete attention to something and to become immersed in it, even if it is not real, like a film, play, or imagined event." Out-of-body experiencers are more imaginative, suggestible, and fantasy-prone than average, though have low levels of drug and alcohol use, and no obvious signs of psychopathology or mental illness. [Related: Out-of-Body Hallucinations Linked to Brain Glitch]
It is also possible that some out-of-body experiences are the result of dreaming during what is called "microsleep" — falling asleep for anywhere from a fraction of a second to half a minute, and not realizing it. This is common when people are tired, relaxing, or doing tedious activities such as long-haul trucking. In some cases the person may believe they have been out of their bodies for minutes or even hours when in fact they simply experienced microsleeps. If a believer in astral projection has a sudden, unexplainable and vivid dream and does not know they were asleep, this could easily be interpreted as an out-of-body experience.
Though astral projection practitioners are convinced their experiences are real and not merely dreams or fantasies,their evidence is all anecdotal — just as a person who takes peyote or LSD may be truly convinced that they interacted with God, dead people, or angels while in their altered state. It is not a coincidence that drug users refer to a psychedelic experience as a "trip."
Astral projection is an entertaining and harmless pastime that can seem profound, and in some cases even life-changing. But there's no evidence that out-of-body-experiences happen outside the body instead of inside the brain.
Benjamin Radford is deputy editor of Skeptical Inquirer science magazine and author of six books including "Scientific Paranormal Investigation: How to Solve Unexplained Mysteries." His website is www.BenjaminRadford.com.