Many people like to ask whether the future is determined. This has relevance to issues like free will, for example.
I would like to address the reverse question: Is the *past* determined?
In other words, is the past fixed once we pass it?
Another interpretation of the problem, possibly a different spin: Given the state of the universe *now* (and I am flexible about what this means), is the entirety of the past determined? Can every event of the past be *theoretically* deduced from the information of the present?
When framed in this way, I have to say that it seems unlikely. For example, it seems quite unlikely that the weight of Casar's last drink is fixed from anything available in the universe today. It seems unlikely that the question 'was there a T-Rex standing in this spot 68 million years ago exactly' actually has an answer that is determined by the state of the universe now.
So, to what extent is the past determined? If it is NOT determined, how does that affect your views of the past? if it *is* determined, in what sense is it so?
If I had a video of the event with a timestamp, would that count?
Law enforcement would say yes, but I know you're a physicist so * Shrug *.