Depth 1 · 34 s
The film strip
Mei's grandmother learned to ride a bike sixty years ago. Is that day still somewhere, or just gone? Augustine's puzzle about time, and two answers - only now is real, or every time is real, like pictures on a film strip.
About this video
Mei's grandmother is telling her about the day she learned to ride a bike, sixty years ago, on a dusty road by the river. Mei listens, then asks, "Is that day still somewhere? Or is it just gone?" Her grandmother laughs: she has never been asked that before. What is time, and where are the past and the future?
About 1,600 years ago the North African thinker Augustine wrote: "What then is time? If no one asks me, I know. If I want to explain it to someone who asks, I do not know." We use time all day, yet it is very hard to say what it is. Augustine noticed a puzzle. The past is gone: it doesn't exist any more. The future isn't here yet. And the present is only the moment between them, over as soon as you say "now". So how much of time is real at all?
One answer: only now is real. The past was real and the future will be, but the only things that exist are the things that exist now; the bike ride is gone and tomorrow's breakfast isn't anything yet. This fits how time feels: things come, and pass, and are gone. Its puzzle: it is true that dinosaurs once lived and that the grandmother rode a bike that day - but if the past doesn't exist, what makes those sentences true?
The other answer: every time is real. All of time is like a very long strip of film, every picture on it there, the first as much as the last. "Now" is just the picture you happen to be in, the way "here" is just the place you happen to be: other places are real though you aren't in them, and so are other times. Some scientists think Albert Einstein's physics fits this answer best. Its puzzle: if every time is equally real, why does time seem to pass, and why can we remember the past but not the future? This video goes with the Is Only Now Real? lesson of Metaphysics Level 1 on Knaph.
This video shows depth 1 of Past, present and future.
Learn Past, present and futureTranscript
- 0:00Grandma learned to ride a bike sixty years ago. Is that day still somewhere?
- 0:05What is time? If no one asks me, I know, wrote Augustine.
- 0:11Perhaps only now is real. Then what makes the past true?
- 0:17Or every time is real, like pictures on a film strip. Now is like here.
- 0:23Then why does time pass? And why remember only the past?
- 0:29Is only now real?