UFO Sighting in Butterwick, on July 21st 2014 – dim round light changing direction as if bouncing of invisible walls

me and my mate was on the library roof messing around and we stopped sat down talking then out the corner of my eye I noticed this dim light because it was daylight but it was still very noticeable we observed it for a few minutes. when we first saw it we thought it could of been a searchlight from the town but that only goes on rarely once a month and always after dark never during the day it was as if it was bouncing in an invisible like box it was changing direction so quick defying the laws of physics then eventually after changing direction for its last time it shot off so quick we lost it me and my mate was so amazed on what we just saw and thought we cant tell anyone because they would think we where wackjobs it was like it was to real for it to be true if that makes sense.