Episodes 10 and 11 are an inquiry into the nature of time. It is so large a topic that I have split it into two parts. The current episode, 10, discusses aspects of the measurement of time and the use of clocks. It is easier to discuss the measurement of time than to deal with the philosophical question of the nature of time. In the current episode, after having argued that clocks need to rely on precise and regular natural processes, I briefly mention some cultural and scientific conceptions of time.

Then I begin to look at philosophical models of time. In the current episode I introduce idealist views of time, which make the mind the instrument of time (Saint Augustine, Emmanuel Kant). I explain why they are unsatisfactory.

This episode ends with a look at units of time, that is natural, conventional and semi-conventional units of time. Whilst natural units make a reference to natural processes (summer must coincide with the highest position of the sun in the sky), conventional units of time (New Year, the lengths of the calendar months) make no reference to natural events. Episode 11 continues the investigation into the nature of time.

Literature:

You can find a very nice overview of time travel in science and literature in P.J. Nahin, Time Machines (1993). The material for episodes 10 and 11 is drawn from Friedel Weinert, The Scientist as Philosopher: Philosophical Consequences of Great Scientific Discoveries (2004) and The March of Time: Evolving Conceptions of Time in the Light of Scientific Discoveries (2013).