Projecting a picture through a window onto a wall?

Question

ok, so recently, i went into my brother's room in his new apartment. and on the wall there is a projection of whatever is going on outside, except it is shown upside down in negative tones. i thought this is a bit weird seeing that most of his window is covered up by a huge blanket, also, how is it that you can have a projection of the oustide onto the wall. and i don't mean there's shadows coming up on his wall, i mean there are detailed objects of cars parked outside and trees and people walking by the house. i'm just wondering how this is possible with just a window being covered up? and i know that with the old pinhole cameras they would show something upside down, but how can it be possible to project something outside into a room?

Answer 1

There's probably a small hole in the blanket and he has the equivalent of a pin hole camera. Walk back to the blanket and if you run your hand over it, the picture will blank out and you'll find the hole.

Answer 2

i think Philip H already answered your question,yes its a form

of camera obscura

Answer 3

Wow, thats pretty cool.

Its not unrealistic. The sun is acting like a lamp in a film projector and pores in the blanket are acting like the lens of a pin hole camera. Its a little like watching the solar eclipse with a peice of cardboard with a little hole in it.

Im not sure why it is coming through in negative, this might be a question for someone who knows more physics.