I'm trying to understand Young's experiment and have been unable to find a clear, precise, historically accurate description of what Young actually did.
Specifically, discussion in Young's double slit experiment with a single photon does not make it clear Young used monochromatic light or sunlight. It also cites Tony Rothman's book Everything's Relative and Other Fables from Science and Technology (which I haven't read) which, according to what is currently footnote a, Rothman claims that there is no historical evidence that Young actually conducted his experiment.
I find it hard to believe that Young didn't actually conduct his experiment. Presumably, an answer to my question will also answer Rothman.
The reason that I want this precise description is that Young would have had to assume that either all of the light coming form his source was a single wave, or else that all of the different light emitters in his source somehow produced waves that were phase aligned. Otherwise, the light from different waves would cancel out, would they not?
I'd like to ask Young what was going through his mind, but it's currently not possible to do so...