I would like to understand interference using 2 illustrations:
1) Bulbs send out light in all directions, right? If so, at a particular instant of time, shouldn't all the light waves coming out from the bulb interfere and thus gives us light in only direction at that particular instant?
If the above is correct, then we see the bulb emitting light in all directions because at each (infinitesimal) instant, the direction of the resultant wave changes. Is my understanding correct?
2) Below is an image of Bragg's Experiment from Wikipedia -
If the (parallel) light waves getting scattered by the atoms in the solid interfere, then why are the 2 incident light waves shown separately? Shouldn't they interfere and appear as 1 single wave?
Somehow, I can't shake off the feeling that there is something fundamentally wrong about the way I think about light waves and their interference.
Thanks in advance!