Technology

hideshow 4 child comments

parent

[–] merc@sh.itjust.works 10 points 4 months ago (3 children)

Ok, that's a paper that attempts to explain the feeling that a building might be haunted. There's nothing in there about causing people to hallucinate. They talk about the supposed "resonant frequency of the eye", but then they say:

The resonant frequency is the natural frequency of an object, the one at which it needs the minimum input of energy to vibrate. As you can see from above, any frequency above 8 Hz will have an effect and some sources quote 40Hz

If the values are that vague, then there is no resonant frequency. There may be frequencies that transmit vibrations to the eye, but with a big enough speaker you can cause anything to vibrate.

The closest the get to hallucinations is to say that "the eyeball would be vibrating which would cause a serious "smearing"of vision. It would not seem unreasonable to see dark shadowy forms caused by something as innocent as the corner of V.T.’s spectacles." So, no hallucinations, just some blurry vision that might vaguely count as an excuse for seeing a ghost if your eye is vibrating significantly. Notice that that's all just speculation, saying "this seems like it could be possible" rather than actually testing for that hypothesis.

hideshow 3 child comments

parent

[–] fiat_lux@lemmy.zip 2 points 4 months ago (2 children)

We had slightly different readings.

As he was writing he became aware that he was being watched, and a figure slowly emerged to his left. It was indistinct and on the periphery of his vision but it moved as V.T. would expect a person to. The apparition was grey and made no sound... V.T. was unable to see any detail and finally built up the courage to turn and face the thing. As he turned the apparition faded and disappeared.

He experienced a visual disturbance in his periphery manifesting as the false perception of a person. Even without it being interpreted as a person, that's a textbook mild hallucination.

Once V.T. knew this he calculated the frequency of the standing sound wave ... 18.97Hz ... plus or minus 10%

Table IV on page 212 of this book shows frequencies causing disturbance to the eyes and vision to be within the band 12 to 27 Hz.

Most interestingly, a NASA technical report mentions a resonant frequency for the eye as 18 Hz (NASA Technical Report 19770013810).

He cited two sources inline with ranges narrower than 8-40Hz which indicate that vision can be affected at the same frequencies he measured in the lab. He even noted that everyone would have slightly different resonant frequencies.

No, it's not a full research paper, but it is the citation you requested.

hideshow 2 child comments

parent

[–] merc@sh.itjust.works 2 points 4 months ago* (1 child)

He experienced a visual disturbance in his periphery manifesting as the false perception of a person

Which can't be explained by an unfocused eye. They do a lot of speculating to come up with a reason why he could possibly see something out of the corner of his eye. But, that's only the physical part of it. It doesn't explain why he might think that whatever he was seeing was "a figure" and moved like a person.

That's like saying that ghosts can be explained by wearing glasses with dirty lenses, then going into detail about how dirty lenses can cause someone to see something that isn't there, while ignoring the ~~elephant~~ ghost in the room. Except it's even worse because a smudge on your glasses causing you to "see something that isn't there" is really easy to test and barely needs an experiment to confirm it's true. But, low frequency waves causing someone to see something that isn't there isn't something that has been tested. It's pure speculation.

So, pure speculation that low frequency waves can cause someone's eyes to blur in such a way that the corner of their glasses is mistaken as something that isn't there. No proof that has happened or can happen, just speculation.

Then ignoring the elephant in the room that just because someone might not see clearly if their eye is vibrating, that is somehow magically interpreted as a figure moving like a person, which they interpret as a ghost.

There's a humongous jump there from "a certain frequency might cause the eyes to wiggle" to "and therefore that's why he saw a ghost".

parent

hideshow 1 child comment

[–] fiat_lux@lemmy.zip 1 point 4 months ago

I'm not sure I understand. Peripheral hallucinations are a recognized type of hallucination, and hallucinations can involve anything from shadows or flashes of light through to full vivid imagery. It only requires perceiving anything that isn't really there and but it feels real. The patterns or colors you see when you close your eyes are considered hallucinations too.