Can we talk about ghosts? In the US alone, 1 in 5 people claim to have had paranormal experiences
there are no measurements to back up any paranormal claim BUT if some flavor of paranormal activity exists it's totally plausible that you wouldn't be able to measure it
@majormobius But just the fact that people SEE them means you can measure them. Seeing something is a measurement in itself.
@turi That would be true if the circuitry between light transducers and perception were ironclad reliable, but there seems to be some fuzziness in that arena
@turi Your phrasing here is critical:
True: if a photon hits your eye, then you see something
Not always true: if you see something then a photon hits your eye
Evidence of the latter claim is evident in cases of synesthesia for example but could doubtless come from some other mechanism (i.e spooky spooks)
@majormobius No, they can not come doubtlessly from some other mechanism.
Your brain is physical. So anything that interacts from the outside with it has to have a physical effect. And we can measure physical effects.
Even synesthesia and hallucinations are physical effects, but intrinsic to our brains.
If something you see is real, it has to be physical. There is no way around it.
@turi Hallucinations are not real
@majormobius What hallucinations show is not real (like, for example, ghosts). That is right.
@majormobius But the fact is: you see something if a photon interacts with your eye. So a photon has to exist first, which is something you can measure.
The same goes for any other form of perception we have.