The Secret of Time

What then is time? If no one asks me, I know:
if I wish to explain it to one that asketh, I know not.
Augustinus, Confessiones, 11. Buch, 14. Kapitel
What is it all about?
Origin of this site
To the videos
Physical background
Further reading
[auf deutsch]

Class 8c (2007/08) of the Luitpold-Gymnasium Munich
is showing the results of a video project in Physics: 

Reversible and irreversible processes
The arrow of time