I am dumb. I do not understand the math behind physicists' study of time. But from a common sense, naively intuitive standpoint, time simply seems to be the measurement of movement in the universe. Therefore, if you had truly empty space there would be no time. But, since empty space is not really empty but is full of virtual particles popping in and out of existence, time seems to be an inherent property of the universe, which is why we have the term space-time. Even if we or any other intelligence were not around to observe and measure it, time would still exist. Am I missing something?