u/Appropriate_Yak_1468

Not sure if i can explain this well. Given 4 dimensions. I like to think that everything (light, particles with mass) moves with constant speed. What changes is the dimensions through which they move.

So light moves with speed c through space but stands (almost?) still in time.

Particles with mass move through space with speed less than c but with high speed in time.

Is that a good way to think of it?

When we calculate the age of the universe, do we take into account time dilation caused by the enormous mass and density of the universe at the beginning? Not sure if it matters because probably the whole universe was quite uniform and there was nothing else (or maybe there was? ) to have a different frame of reference. Did the small fluctuations that occurred a little later actually have different frames of reference?