Intuition is defined for the purposes of this analysis as: the appearance in the mind of accurate information about the external world, which can be shown to have come not through the five senses, nor through a rearrangement of stored memory contents. Forms of intuition obeying this definition have been explored scientifically under such labels as telepathy, precognition, presentiment, and remote viewing. This paper summarizes those scientific findings, and presents a few theories which have been hypothesized to explain them. Those theories are largely based in theoretical physics, including quantum non-locality, holography, and complex space-time. Related biological theories are also cited, which propose to explain how information might move from the subatomic level up into waking consciousness, for example through DNA structures or neuronal microtubules.