"In terms of the perception of time, many physicists would argue that the perception of time, the flow of time—that the past is no longer real, the present is real, and the future is not yet real—is an illusion, or a mental construct, or something imposed by the brain. And this is the debate between what we call eternalism, or the block universe, and presentism. So under eternalism, the past, present, and future are equally real. And under presentism, only the present is real. And that's how we perceive. And this is the fundamental debate about what's the nature of time. And there's this ongoing debate where the physicists say, "Hey, you neuroscientists figure this out, because obviously time is not flowing. Why does it feel like it's flowing?" And then the neuroscientists say, "Well, you physicists figure this out, because, you know, time is flowing." But the physics is really mostly the interpretation in which, because of relativity, the physics doesn't have a specific point—"you are here" doesn't say there's anything special over here. The equations of physics are time-symmetric, or time-reversible. So that leads to one interpretation: that the past, present, and future are equally real, much like space. You can be anywhere in space; you can be any moment in time.
But I've argued that I think the brain is telling us something true about the physical universe—that it is because we've evolved to survive in a universe governed by the laws of physics, in a mesoscopic part of that universe, not at the micro, not at the cosmo, but at the mesoscopic level, to survive in this world governed by the laws of physics. So I think, and have argued this point, that it is really flowing, and our brain creates this conscious perception of the flow because it's a real part of what we experience, and of the universe."
