How do you use an optical plummet?

wait for dark, if you can get away from street lights and lit houses, even better. aim it at something interesting in the sky look through it.

Apart from pretty lighting effects - they can be used to send Huge ammounts of data, quickly

An optical pyrometer is used to measure the temperature of a surface without making contact. (If you can't reach it or can't touch it without harming yourself).

optical fibres work on the principle of total internal reflection.that is a long concept but easily available.because of this T.I.R the light transmitted through the wires is very small.so it can...

Scientists and kids for their work