Object Permanence: https://en.wikipedia.org/wiki/Object_permanence

Unless it's being observed externally it is in a state of quantum uncertainty, I think.

have to ask the Maintainer of Time

https://twilightzone.fandom.com/wiki/A_Matter_of_Minutes

The old philosophical question remains, "If a tree falls in a forest and no one is around to hear it, does it make a sound?" [1]

[1] https://en.wikipedia.org/wiki/If_a_tree_falls_in_a_forest_an...