Tell me more ×
Physics Stack Exchange is a question and answer site for active researchers, academics and students of physics. It's 100% free, no registration required.
up vote 0 down vote favorite

An acquaintance of mine, while being home alone, saw that the light bulb in the room which was hanging from the ceiling with wires having a pendulum motion which was more than noticeable. He says that that was a ghost but i know better than that.

I just can't find an explanation. Maybe you can help.

The light bulb was ON at the time. Some windows in the flat could have been open but the person said he was in the room at that time and there was no draft.

share|improve this question
It is a mechanical resonance. This question should be closed. – Ron Maimon Oct 7 '11 at 19:48
1  
Long pendulums with small amplitude can be in noticeable motion for a long time -- speed and cross section is small and so is friction. IMO this is may be a reason of the behavior you observed; make an experiment -- poke this bulb on your own and check how long will it swing. – mbq♦ Oct 8 '11 at 8:13

closed as too localized by Ron Maimon, David Zaslavsky♦ Oct 7 '11 at 20:28

This question is unlikely to help any future visitors; it is only relevant to a small geographic area, a specific moment in time, or an extraordinarily narrow situation that is not generally applicable to the worldwide audience of the internet. For help making this question more broadly applicable, see the FAQ.

1 Answer

up vote 2 down vote

Maybe there was a tiny draft and the person didn't notice. It's not impossible.

Maybe there was a small earthquake, small enough to not be perceived, but big enough to impart a tiny but visible swinging motion to various objects like that. I live in California, and whenever I feel there might have been a tiny earthquake, I look at objects hanging like that - if they are swinging, chances are there was an EQ; if they aren't, chances are there wasn't.

Maybe a large truck passed on the street and caused vibrations.

Maybe someone next door were dancing or jumping and caused vibrations through the building.

There are so many possibilities.

share|improve this answer

Not the answer you're looking for? Browse other questions tagged or ask your own question.