Is time merely a concept?

Julian Barbour writes:The end of time
Closely related to this work is my study of time. Mach remarked “It is utterly beyond our power to measure the changes of things by time. Quite the contrary, time is an abstraction at which we arrive through the changes of things.” Thus, time as such does not exist but only change. Much of my research has been devoted to the implications of this insight. I have shown how, alongside the relativity of motion, the notion of time as change can be built into the foundations of dynamics. In fact, this idea is contained in a hidden form within general relativity. Its potential consequences for the yet to be found quantum mechanics of the universe are profound. The quantum universe is likely to be static. Motion and the apparent passage of time may be nothing but very well founded illusions. This is the thesis of The End of Time (books), which is aimed both at the general reader and physicists.A Dutch television film, Killing Time, made in 1999, does a remarkably good job of explaining the ideas of the book in a non-technical way. The film is 24 minutes long and requires realplayer; the website is in Dutch.