CoursesCourse 21
Thinking about time
The hidden logic of science and technology. Every culture has a picture of time, and the picture shapes what it builds: a sundial and a farming calendar, a Greek search for what never changes, a Christian line with a beginning and an end, a clock in the town square, Newton’s absolute time, Einstein’s timeless block, and the arrow that physics found again. This course follows each picture to the people and instruments behind it, and asks what the clock left out.
Start lesson 1Lessons
- 1 What is time?Everyone knows what time is, until asked. The two kinds of time we live by, the sun that taught us the first, and the Greeks who looked for what never changes.
- 2 A line, and a clockA monk who counted the years, a bishop who asked what God was doing before the world, and a machine that made the hour the same for everyone. How a theology of time and a way of counting it made a schedule.
- 3 Time becomes a numberFrom Newton’s private papers to railway time, relativity, and the atomic second, time was turned into a coordinate. Then the second law of thermodynamics brought back its arrow.
- 4 Time as it is livedWhat the clock left out. Nietzsche’s demon, Bergson’s duration, Husserl’s thick present, Heidegger’s death, and the Chinese idea of the right moment.
You’ll be able to
- Explain the two kinds of time experience, timing and flow, and how counting the sun’s motion turned the first into the measured time of days, months, and years.
- Describe how the Greeks and the early Christians pictured time, why the neat contrast “cycle versus line” is a simplification, and what Augustine made of time.
- Trace how a clock became a social machine, from Su Song’s tower and the first European clocks to railway time, the atomic second, and Newton’s and Einstein’s pictures of time.
- Say why the second law of thermodynamics gives time a direction that the basic laws of motion do not, and what Chinese ideas of timeliness add to a world run by clocks.
About this course
This course covers 时间论 (Thinking about time), a philosophical history of how people have understood time and what those ideas did to science and technology. It is the third of four courses in this series that look at the picture of the world as a whole: Cosmology: the starting point of philosophical thinking (Course 19) asked what “the universe” means, and Thinking about the Earth (Course 20) followed the planet. Here the subject is time itself. It draws on The cosmos before Newton (Course 3), Newton’s clockwork universe (Course 4), and Energy, entropy, and order (Course 5), which tell the physics that this course only touches.
The argument and the examples lead, and much of the argument is interpretation, not settled history. Around it we add what is ours: every date and number checked against sources (several popular claims turned out to be wrong in the usual telling, among them what the Council of Nicaea decided, where the first mechanical clock came from, and who first said the present has no length), hands-on activities, background for readers in China and the United States, and an honest “Another view” in each lesson, including on how much of “cyclical time against linear time” is a real difference between the Greeks and the Christians and how much is a modern simplification.