this is my perception on the big bang theory. again galaxy UDFJ-39546284(call it

[Jun]

Galaxy A) is where i would? like to start. astronomer believed that Galaxy A is existing 480 million years after the big bang. Lets take a snap shot of the universe during that time to have a bird's eye view of the small and young universe. From the big bang zero seconds, it said to have infinite density with zero volume, so if expansion happens instantly( burst, explosion, or anything similar as the big bang started) one can imagine primeval objects scattered at random in that small sphere of the early universe. So galaxy A and the seed of Milky Way ( if our galaxy in not yet in existence, probably the seed- say SEED A- where it came from probably did) were separating from each other as the theory states that all objects goes with the expansion. At that instance say a light photon left Galaxy A heading to the direction where the seeds of Milky Way going, To satisfy the idea that all stars seems to be going away from each other, lets put the ground zero of the big bang is somewhere in the center of the sphere, and Galaxy A and the Seed A is place each at opposite side of the ground zero, So if Ss is the relative separating speed of Galaxy A and Seed A,. and C the speed of the photon leaving Galaxy A, then the speed of the photon chasing Seed A is: C-Ss. So with that tremendous speed it took the photon to reach earth 13.5 billion years?. And how fast is the universe expanding since when that photon reach earth we see behind us infinite vastness of space?