According to general relativity time runs slowly near a massive body. So, I have a question bothering me from some time, that if time for every body/object in universe runs at a different rate, then how can we determine the age of universe? i.e. 13.82 billion years?
Near a blackhole as time runs slowly, which implies that the age of universe would be much much less. In fact, ever body/object in universe would have different age of universe according to it. And if we really want to calculate universe present age, we should put an upper limit to its age, by determining the time passed in empty space from big bang, which is away from gravitational source (as time passes the fastest here) and a lower limit by the oldest and massive blackhole in universe, as time there would have passed the least (i.e) the age of universe from its point of view would be even less than 0.5 billion years. Am I right?