On Whether Time Exists or Not
In response to Normam McDowell's statement that "Time" does not exist "in the sense that we use the word," it has to be pointed out that we use the word "time" in a number of different senses. There is the scientific use of the word "time," and the ordinary use of the word "time." In some uses of the word, the focus is on our perception of time and the way we experience it (for example, in the expression "Time flies.") In other uses of the word, the focus is on time as part of the fabric of the universe (as in "time is the fourth dimension"). Of course time exists!
If it didn't, we wouldn't have a perception of it. But there is no great virtue in pointing out that our perception of time is merely a perception and does not necessarily reflect the reality of time. Everyone knows that—and not just about time but about all our perceptions. We perceive time the way we do because that is how we evolved. If there are sentient beings in other parts of the universe, they may well have evolved to perceive time quite differently. It might be more useful to talk about how our perception of time shapes the way we think about ourselves and the universe that to make muddy (and muddled) statements such as "Time does not exist."