This is a very interesting topic!

My late friend Jack, who, me and him used to enjoy making things together, Like, aircannons and so-on, once tried the same thing, shining an infer-red light into a camera, and found he could see it. He then started collecting controllers, taking out the infer-red LED's, and plaving them in an LED torch Trying to make a night-vision camera. As, believe it or not, night vision works upon infer-red light, too.

I suppose its "logical" that spirits and such exist upon a spectrum invisible to our eyes. I personally believe that spirits are mad eof the same energy that runs through the earth naturally. So, in a way, we are part of the earth, in every shape and form.

Oh! And I will just add, because I can, in thermal imaging, which is, imaging via the collection of infer-red light, which, obviously, is the element in light that creates heat, people are shown much hotter on the insides, even white-hot in places. This is commonly believed to be because the internals of the body are much hotter then the externals, but you never know, could be a bit of spirit in there somewhere.