time, "a continuum moves and swirls..." (the vacuum?), the celestial sphere and life. Talk about big topics! The vacuum is central to Physics and today is still "beyond my inner sight and imagination" ie Physicists still don't understand it at the quantum level although they are getting better. Actually understanding the vacuum has been central to Physics most of our history, see this very interesting painting.
Some of you who work on Sydney Harbour may have noticed that Thor Gitta was docked in White Bay for quite a while (over a month), the mystery why she was there for all this time has been solved: she was waiting for this barge to unload her big load of cable: