The term "wearable" should summon several thoughts in your mind, right off the bat. "Apple Watch" or "iWatch" is probably one of them, followed by "smartwatch" and on to "another one of those devices ...

What is time? Is it an ever-rolling stream that bears all our dreams away, as the old hymn says? Or is it a railroad track? Maybe it has loops and branches, so you can keep going forward and yet ...