Which page? Give a link.
Again: we cannot discuss out of context quotes from an unknown source. Either give a specific link to the actual discussion you're asking about or this thread will be closed.
Coordinate time is a coordinate label that you put on events in spacetime (more precisely, one of four coordinate labels that you put on each event, assuming you are using appropriate coordinates).
Proper time is the time elapsed on a clock between two events on the clock's worldline.
Proper time is the "distance" along a timelike worldline. If you arrange a set of parallel inertial (i.e. straight) timelike worldlines, this is one direction of a grid. If you agree a zero on all of the lines (preferably so that the zeros form a line orthogonal to each timelike line) then you have coordinate time.
It's exactly like the distinction between the length of any old line and the length along a set of parallel straight lines (which you'd call a y-coordinate) in Euclidean geometry.
My reading is that he's showing that clock measurements emerge from quite simple quantum systems. Einstein said time is what clocks measure - the paper is a (partial?) explanation of why that is so.So what is this guy I quoted in OP explaining? Is he correct or incorrect?
Not coordinate time or proper time. So if you were hoping to get information about what those are, that StackExchange thread is not the way to do it--nor is the paper linked to there.
In quantum mechanics (more precisely, non-relativistic QM), the time ##t## is a parameter; the state of the overall quantum system is a function of this parameter, but the parameter is just imposed by the theory, it has nothing to do with anything that's measured or anything physical.
"Measured time" in the paper is the change in the correlations between the subsystems of the overall quantum system as measurements are made on them, interpreted as evidence of "time flowing", as part of a proposal made by the authors of the paper on how we, as individual subsystems in the universe, could perceive time to be flowing (or, to put it another way, things to be changing), when, if you try to apply non-relativistic QM to the whole universe and assign the whole universe a quantum state, the Hamiltonian you get out of it says the state of the whole universe never changes at all as a function of the parameter ##t##.
As above, none of this has anything to do with either coordinate time or proper time as those concepts are used in relativity. A discussion of the paper and the StackExchange thread really belongs in the QM forum, not here, if that's what you want to ask about. But such a discussion has nothing to do with coordinate time or proper time.
Clock measurements can emerge from entanglement. Clock measurements are not time.Does time emerge from entanglement?
But the experiment states that from an external observer, the universe would be static, as the observer is not entangled with the photons, only when an internal observer entangles with the photon pair, time can be measured. Thus time itself emerges from entanglement.Clock measurements can emerge from entanglement. Clock measurements are not time.
(See disclaimer in my previous post)
how could the universe be static to an external observer
the experiment states that from an external observer, the universe would be static