I've found the answer!
It all has to do with probability!
Why didn't someone just tell me to look up Huygens-Fresnel principle!?
Thank's for an interesting discussion every-one!
Thankyou very much,
do you know of any websites/books etc from which i can learn this second half of the wave theory? half-understanding is frustrating!
Now, I've asked about this on some other forums: and it seems all people are able to to is repeat what happens at refraction, but not actually to answer the question:
[PLAIN]http://ryansuchocki.co.uk/media/tmp.jpg
From the above image, why does the first sittuation occur rather than the...