large-scale machinery and engineering
particularly connected to electricity generation.
what makes this a phobia rather than just a fear of being crushed or electrocuted is that such objects seem to be imbued with a deep malevolence, even if they pose no real threat. i cannot even bear to converse with people about them. writing this is hard.
some things that particularly 'set me off' are: generating turbines, wind turbines (but not windmills), cooling towers, nuclear reactors (these trigger a particularly strong reaction, especially the "swimming pool" type), hydroelectric dams, the engine thing in "event horizon", cooling towers (oh god), pylons (they thrum), the place where a suspension bridge's main cables are achored, bells inside belltowers, water wheels, the large hadron collider, and super kamiokande.

oh i'm shaking. *post hurriedly*
( urbane legend i have known the inexorable sadness of pencils, Thu 10 Apr 2008, 19:56, 4 replies)

This may be to do with infrasound.
Infrasound is sound too low in frequency to be heard by the human ear, but we still pick it up and it's known to cause feelings of intense fear, so you are less 'phobic' and simply more sensitive to low sounds than others. The Wikipedia page even mentions wind turbines and other machinery.

The rest is explainable by Hollywood making use of infrasound (for Event Horizon, obviously) and other things you subconsciously expect to make deep sounds.
( Shegetz Chris Kamara's comedy moustache, Thu 10 Apr 2008, 20:10, closed)

Fucking cool!
Damn, I wanna play around with this! How cool would it be to set up a huge sub woofer on Halloween to scare the hell out of the kids?

WOO!
( The Resident Loon Not a demographic. Do not measure., Thu 10 Apr 2008, 20:46, closed)

um, no, that infrasound stuff is pseudoscientific garbage.
utter bilge, my good man; and it fails to account for the fear induced by things i have not experienced anywhere other than photographs. for infrasound to be the cause, it would actually have to be present. sorry.
( urbane legend i have known the inexorable sadness of pencils, Thu 10 Apr 2008, 21:12, closed)

Your brain has the unique ability to 'draw in' what isn't really there.
You may be fearing photographs of machines because you expect there to be infrasound there, sort of like an arachnophobe jumping out of their skin because they've seen a tomato stalk out of the corner of their eye.

I'm not saying "one note of infrasound and you'll be shitting your pants, buddy", but it is know to cause unease, at the very least by the film industry. Wiki cites Irreversible, but I'm willing to bet Event Horizon probably uses it too. I think it exists, and this is b3ta, not /., so there's no point getting into a deep discussion, but I've heard Lustmord (a dark ambient band known for using infrasound to disorientate people) and it works on me.
( Shegetz Chris Kamara's comedy moustache, Fri 11 Apr 2008, 13:12, closed)