In a general physics class, one of the things we are studying is light waves. Optics is my biggest struggle within physics anyway, and now my book is explaining what happens when a laser is pointed through a barrier with holes on it. It includes some trigonometric formulas for...I don't even get what the formulas are for. I'm very lost on this part, so I was hoping someone could point me to a website, or maybe even a book I can get at the library that explains this phenomenon. I think part of the problem is just that I need a good illustration. The illustrations in my textbook are clunky and cluttered and I can't really see what is going on. I tried googling, but I can't really find anything, probably in part because I'm not sure what exactly to google. The section heading is just called "Interference," but that applies to all sorts of stuff with waves. I appreciate any help!