Astral projection is an out of body experience (OOBE) technique, sometimes associated with the Occult and the New Age movement, where it is said that the spiritual body is able to move free of the physical body. During astral projections, sometimes the traveler reports being attached to his/her physical body by a silver umbilical cord.
There is discussion as to whether astral projection actually does occur - this behavior could be some form of lucid dreaming, however some astral projectors are said to have described details of the outside world whilst in projection which they could not have known beforehand. For example, Edgar Cayce projected his consciousness to remote locations in order to conduct medical diagnoses (that are well documented).
Pets have been known to react in a frightened manner during the astral projector's experience. There have been recorded instances in which the behavior of the animals coincides with the time the projector claims to have entered the room in astral form. Humans have not always seen a visual representation of a person's spirit during the time she or he claims to be astrally projecting, but those who have describe it as a colored beam or shot or light darting around the room.
Remote viewing, as studied in the Stargate Project and described by practitioners such as Joe McMoneagle, might be similar to astral projection insofar as it might involve the projection of consciousness to remote locations.
Robert Monroe who founded the Monroe Institute published several accounts of his experiences of astral projection including "Far Journeys".