Is the past real?
The past is real, and nothing outside the world deletes it. It is the set of commits that have been made, each one a repair of a disagreement, tied to the others by certified reads, where a later commit shows that it read what an earlier one wrote. Its content is fixed, because rewriting it would need information the commits destroyed. The everyday picture has a present sweeping forward and leaving the past behind. That sweep would need a clock outside the history to advance it, and there is none, so nothing outside erases what lies behind. Inside the history, events are ordered wherever dependencies connect them, records form and local states change. What happens to a particular record is a matter for the dynamics inside. A repair can overwrite it, and a copy can keep it somewhere else.
Also in Chapter 16: Why Does Time Run, and Only One Way?, Chapter 7: Why Is There No Such Thing As Now?.
This answer comes from OPH, Observer Patch Holography. OPH is a rigorous, consistent and complete description of the unified, self-creating computational Universe we inhabit. Its consistency is machine-checked: the fixed point at its core is constructed explicitly, and a theory with a model contains no contradiction.
To understand OPH and check every step yourself, start with the free book Reverse Engineering Reality. It builds the theory from the ground up, and the OPH Notebook answers your questions while you read.
read the free bookask the notebookor ask sage:read epilogue: The Last Rungwatch a universe make its own particles