Request for help re light speed, emission of light, and time

I was wondering if I could ask some of our resident scientists to talk me through something which is causing me some confusion.I have seen it explained in the past, on this site (although finding this will take more time than I have, so sorry there's no link), that whilst from, say, our perspective, it takes a photon of light 8 minutes to travel from the sun to the earth, from the perspective of the photon, it takes no time at all. It is travelling spatially at the speed of light, and therefore from its perspective its movement through the dimension of time is zero (since spatial velocity plus velocity in time cannot exceed C). (In fact, it is always equal to C, for everything).(I am no scientist, so apologies for any awful expressions here).What I find confusing therefore, is that in certain circumstances, light can be seen to act as a wave. This indicates to my simple way of thinking that a photon of light travelling in direction x spatially, will during that journey alternate between travelling in a positive and then a negative and then a positive y direction, and so on.If its y direction during its journey alternates between positive and negative, does this not mean that the photon of light is undergoing a number of changes in state during its journey ?And if this is the case, how is that reconciled with (from the perspective of the photon) no time passing during its journey ? In order for its state to change, does this not necessarily mean that time is passing from its perspective ? A change in state requires time to pass, doesn't it ?Can somebody please tell me where I am going wrong ?Many thanks.vimeseyEdited by vimesey, : Had another thought

Thanks guys - I think you've shown me where I'm going wrong - I'm thinking in Newtonian/Euclidian terms, in a quantum environment.Next job - to get my mind around the quantum analysis ! :-)