The foldscope has created a new excitement among the students. some of them are bringing things at school so we can view them under the fodscope. I am not abe to capture a of them as we are not allowed to use mobile phones in the classroom. But I try to bring few samples home and write a post about.
This is about the color changing hologram sticker which we find on books and other products which makes them secure from others copying it.It changes colors as we view them from different angles.
but how do they work? asked one of the student who brought it. Even i was curious to know the phenomena so we put it under the foldscope
In the pictures we can see that, there are many tiny holes.But what for?
Physics behind it: when Light rays are incident on them the tiny holes scatter light. when the light is scattered all the colors in the white light are separated and these colors can be view at different angles. For more on scattering of light visit http://en.wikipedia.org/wiki/Light_scattering .
THIS IS THE HOLOGRAM STICKER WE EXAMINED:-
THIS IS THE SLIDE:-
HOLOGRAM UNDER THE 140x LENS:-