>>12619066Brought to mind:
Some speculation: The entirety of the skin surface acts, in a purposeful way, as a massive EM (inc. mmWave) transceiver array. Similar to how insects navigate by detecting polarization of visible light.
https://www.cia.gov/library/readingroom/docs/CIA-RDP96-00792R000300420003-6.pdfIn this report, children in China were able to determine characters written on folded pieces of paper using their palms, and for one child, the ear. The described how the image would form in their mind (in this report called "extraocular perception"). If the report is accurate as stated, perhaps this works like mmWave airport imaging? Otherwise, there is a voltage difference between the hands, in many ancient systems the right hand "gives" the left "receives" (See "Magnetism and its Effect on the Living System" by Davis and Rawls for body surface voltage measurements), but it doesn't seem to rely on that given that it could be done with a single ear. Perhaps this also relates to the ability to feel when we're being watched, if eyes generate, or contribute, a field of some reliable and relatively specific character, an animal which could detect this would be at a great survival advantage. Similar to how many animals have been found to be very sensitive to specific subsonics in ranges that would be passively created by the relevant predators of the day. The brain already keeps a fine grained map of the body's location in space, via this it could easily infer general direction based on stimulation of the skin. Low infrared (THz waves) could also be at work, as could some other change in the finer structure of water. This ties into "mitogenic radiation" (
https://en.wikipedia.org/wiki/Biophoton) and similar work under many different names, discussed later.
This calls to mind a similar story from ancient Egypt about a challenge from Nubia to read a sealed scroll without opening it.
https://books.google.com/books?id=FfGqNkyjRqQC&pg=PA477 
