#That uncertainty has nothing to do with the time metric of various atoms

[maeamian]

I find "If you follow the time metric of any given atom, it is unknowable and pseudo random" to be an entirely unsatisfying answer to the question of "What day of the year is the anniversary of the big bang?" The answer does not actually answer the question in question but because it contains a lot of big words it looks like it does.

Time metrics of everything vary depending on what sort of gravitational field they're in, something that we have an incredibly successful model of in general relativity. The question of how old the universe is does not depend on questions of "how has a specific atom experienced it" it is a question about how old the universe is, which is much better defined by understanding things like the expansion of spacetime and inflationary cosmology rather than trying to apply general relativity principles to a bunch of quantum particles, those two domains famously do not play well together.

I actually think that the person who said, effectively "Our uncertainty about the exact age of the universe is significantly larger than one year, so there is no reason to believe that the anniversary of that is a known or possibly even knowable quantity." was demonstrating a lot more understanding of the question by asking it than someone who wanted to have Maxwell's demon slap a bunch of clocks on atoms as a way of measuring it.