Frequently Asked Questions about the Universe by Jorge Cham and Daniel Whiteson

 

"Time as a subject is actually not that well understood in physics. It's so engrained in our theories about how the universe works...we also know that time has a lot of strange properties, none more so than the fact that it doesn't flow at the same rate everywhere. In some places in the universe, time moves faster than in others...The history of scientific discovery reminds us to check our preconceptions because our limited experience isn't always universal...It's possible that time is not a basic permanent fixture, but a special condition, just like the flow of the river."