[hn3333]

Probably it's just how the math works out. The atoms emit in all directions, however the waves traveling in all the other non-correct (according to reflections and refraction laws) directions cancel each other out, and only the ones with the new correct direction are still there / visible.

[wizzwizz4]

WikiBooks really does have everything: https://en.wikibooks.org/wiki/A-level_Physics_%28Advancing_P...

This example is wrong, but useful, and it's (probably) less wrong than what you've been talking about so far. At the very least, it's more useful.

[hn3333]

Thanks for correcting me and thanks for the link. But what have I been talking about so far? I don't understand. Also I just watched this video I'd recommend that explains the idea: https://www.youtube.com/watch?v=NumSE2LvSmQ

[wizzwizz4]

Sorry, by “you” I meant the people way up thread.