I was reading about the reason why we think neutrinos have mass, and it said that because they evolve over time, they must have mass because they feel the flow of time. But don't photons also evolve over time? They get red shifted, isn't that evolution over time?
they must have mass because they feel the flow of time
This is a badly designed sentence to describe a specific mathematically explained behavior of neutrinos.
Neutrinos with a specific energy and momentum vector ( whose length gives the invariant mass of the particle) as they travel change type of neutrino in an observation called neutrino oscillation.. This observation is dependent on time. There are three kinds of neutrinos whereas there is only one type of photon, so this effect cannot happen to photons.