willy its all about perspective, as you approach the speed of light quite a few things start to happen, your mass increases and time slows down. once you are at the speed of light, anything that has mass will be infinity heavy, (thus the speed of light travel is reserved for stuff without mass) and time stops.
thus from the photons perspective it traveled the 4 billion light years in no time at all, less than a second. for the rest of us it took 4 billion years to get from A to B.
if you think about it from the photos perspective everything happens instantaneously its creation, destruction and everything between.
regarding the universe and the concepts of big and small. these horizon programs are worth watching
http://www.dailymotion.com/video/xz3...erse-720p_news
http://vdownload.eu/watch/2470089-ho...-universe.html