Sorry to spoil everyone's fun
but here is your explanation for 'ghosts'

en.wikipedia.org/wiki/Infrasound

Infrasonic 17 Hz tone experiment

On 31 May 2003, a team of UK researchers held a mass experiment where they exposed some 700 people to music laced with soft 17 Hz sine waves played at a level described as "near the edge of hearing", produced by an extra-long-stroke subwoofer mounted two-thirds of the way from the end of a seven-meter-long plastic sewer pipe. The experimental concert (entitled Infrasonic) took place in the Purcell Room over the course of two performances, each consisting of four musical pieces. Two of the pieces in each concert had 17 Hz tones played underneath. In the second concert, the pieces that were to carry a 17 Hz undertone were swapped so that test results would not focus on any specific musical piece. The participants were not told which pieces included the low-level 17 Hz near-infrasonic tone. The presence of the tone resulted in a significant number (22%) of respondents reporting anxiety, uneasiness, extreme sorrow, nervous feelings of revulsion or fear, chills down the spine and feelings of pressure on the chest.[30][31] In presenting the evidence to British Association for the Advancement of Science, Professor Richard Wiseman said, "These results suggest that low frequency sound can cause people to have unusual experiences even though they cannot consciously detect infrasound. Some scientists have suggested that this level of sound may be present at some allegedly haunted sites and so cause people to have odd sensations that they attribute to a ghost—our findings support these ideas."[29]
Suggested relationship to ghost sightings

Research by Vic Tandy, a lecturer at Coventry University, suggested that an infrasonic signal of 19 Hz might be responsible for some ghost sightings. Tandy was working late one night alone in a supposedly haunted laboratory at Warwick, when he felt very anxious and could detect a grey blob out of the corner of his eye. When Tandy turned to face the grey blob, there was nothing.

The following day, Tandy was working on his fencing foil, with the handle held in a vise. Although there was nothing touching it, the blade started to vibrate wildly. Further investigation led Tandy to discover that the extractor fan in the lab was emitting a frequency of 18.98 Hz, very close to the resonant frequency of the eye given as 18 Hz by NASA.[32] This was why Tandy had seen a ghostly figure—it was an optical illusion caused by his eyeballs resonating. The room was exactly half a wavelength in length, and the desk was in the centre, thus causing a standing wave which caused the vibration of the foil.[33]


Cheers
(TheManWithThePlan cussed your mum on, Fri 14 Sep 2012, 12:41, 13 replies)

Needs more aliens.

( stuj (^(^;;^)^) GO TEAM SPIDERS!(^(^;;^)^), Fri 14 Sep 2012, 13:25, closed)

Needs more ninjas.

( Je suis un vagabond is an unfunny, up your own arse middle class knob, Fri 14 Sep 2012, 13:39, closed)

Friend of mine who does movie soundtracks and stuff like that
Had a bassline out of synch with another bassline - or something like that, I'm not terribly technical when it comes to music - and discovered that where the two wavelengths overlapped he was creating infrasound. Said it scared the bejeezus out of him, working in his studio alone, until he worked out what was happening.
( emvee cruor deo cruoris, Fri 14 Sep 2012, 13:43, closed)

Think I read somewhere that the soundtrack to the opening of Irreversible
was supposed to work like that.
( monster munch person, man, woman... camera... TV?, Fri 14 Sep 2012, 13:56, closed)

Never watched it, never will
Rapey films really aren't my thing
( emvee cruor deo cruoris, Fri 14 Sep 2012, 14:29, closed)

BORING.

( Je suis un vagabond is an unfunny, up your own arse middle class knob, Fri 14 Sep 2012, 14:40, closed)

I got invited to the premiere of one the other day - rape revenge movies seem to be quite big at the moment
It was really weird, watching these girls tied to beds, covered in blood and vomit, getting raped all the time and then going to the afterparty where the same girls were looking all pretty and lovely in party frocks with their hair done.

When they said, "So, did you enjoy the film?" it was quite difficult to know what to say.
( emvee cruor deo cruoris, Fri 14 Sep 2012, 14:53, closed)

"Yes can I have a go now please?"

( Je suis un vagabond is an unfunny, up your own arse middle class knob, Fri 14 Sep 2012, 15:06, closed)

what was it called?

(TheManWithThePlan cussed your mum on, Fri 14 Sep 2012, 16:59, closed)

You aren't missing much.
The beginning (technically the end, I suppose) is probably the highlight, if watching a man have his head flattened is your thing.
( monster munch person, man, woman... camera... TV?, Fri 14 Sep 2012, 14:52, closed)

you really should give them a try
you don't know what you're missing.
(TheManWithThePlan cussed your mum on, Fri 14 Sep 2012, 16:58, closed)

the beat frequency
where two different frequencies sync at regular intervals to reinforce the amplitude of another intermediate (lower) frequency
( Rotating Wobbly Hat That's not a banana. THIS is a banana., Sat 15 Sep 2012, 1:17, closed)

Like tuning a piano!

( Black Moon Not cracked, I'm all up to be., Mon 17 Sep 2012, 12:27, closed)