back-projection

[nimsooze]

please help me understand the meaning of underlined words and whole sentence:
it reduces the past to a mere function or back-projection of the present.

[Casiopea]

MULTIPLE-MATERIAL WORLDS WITH SINGLE-MATERIAL GOALS

"When a projection is simple, we can define a kind of inverse for it, which we will call its back-projection."

Source: BINDINGS AND UNIFORM REDUCIBILITY

[nimsooze]

thanks casiopea
but what does exactlymean my example?

[Casiopea]

Simply, the past is a different perspective of the present.