To open this interdisciplinary conference on concepts of time in the sciences, humanities, and arts, I discuss how physicists visualize time geometrically, the differences between time and space, various puzzles that physicists confront when seeking to understand time, and the question of whether time emerges from some deeper concept.

1. The Matter of Time
George Musser
6 June 2009
http://www.cs.adelaide.edu.au/~paulc/physics/picasso.gif

2. 1. How Physicists Visualize Time

3. Basic Model of Nature
The world The world
Laws of
at one a moment
moment physics later

4. Spacetime

5. Spacetime

6. 2. Time Is Special

7. Objectivity of Cause-Effect Relations
B
B A
A
A B A B
A B

8. 3. Our Experience of Time

9. Basic Mystery of Time
There’s a disconnect between
time in physics and time in everyday life.
a. Arrow of time

10. The Arrow of Time
Scientific American,Jun 08

11. The Arrow of Time
Big
Bang

12. Basic Mystery of Time
There’s a disconnect between
time in physics and time in everyday life.
a. Arrow of time
b. Flow of time

13. Flow of Time

14. Basic Mystery of Time
There’s a disconnect between
time in physics and time in everyday life.
a. Arrow of time
b. Flow of time
c. Problem of frozen time

15. Resculpting Spacetime

16. Problem of Frozen Time
Space at Space a
General
one moment
moment relativity later
EQUIVALENT

17. 4. The Emergence of Time

18. The Fine Structure of Spacetime
American Scientist,Nov/Dec 91

19. Relational Time
t

20. 5. Conclusion

21. Where Does Time Come From?
The everyday properties of time
must emerge from physical time …
… which might itself emerge
from deeper, timeless ingredients.

22. http://www.timereverse.com/brochure.asp (top);
http://www.motivatedphotos.com/?id=6545 (bottom)

23. For More

24. For a copy of the slides, visit
www.strings.musser.com

25. Backup Slides

26. Basic Model of Nature
State
space Initial
state
Final
state

27. Space and Time

28. Spacetime
Each of us moves into the future
at his or her own pace.
http://casa.colorado.edu/~ajsh/sr/construction.html#grid

29. The Arrow of Time
Why did
it begin
here?
Fresh Partially Completely
egg broken egg broken egg

30. Where Life Fits In
food oxygen TLC
heat bodily
waste

31. Does Time Matter At All?
Time present and time past
Are both perhaps present in time future,
And time future contained in time past.
If all time is eternally present
All time is unredeemable.
—T. S. Eliot, Four Quartets

32. Emergence of Classical Spacetime
Scientific American,Jul 08

33. The Tree
of
Physics
Mercury Nov/Dec 97

34. But that's a puzzle. The microscopic laws of physics,
governing the behavior of individual objects, are
perfectly reversible – they work equally well running
forwards and backwards in time.
Why is the collective behavior of macroscopic objects
irreversible, while the behavior of the individual
consitutents is perfectly reversible?

35. http://commons.wikimedia.org/wiki/File:Boeing_737-73V_-_EasyJet_Airline_-_G-EZJI_-_LEMD.jpg (top);
http://upload.wikimedia.org/wikipedia/commons/6/60/CandlestickTelephones.jpg (bottom)

36. http://en.wikipedia.org/wiki/File:Arbor_Lake-Aerial.JPG (top);
http://hoboken411.com/wp-content/uploads/2009/03/text-messaging-at-dinner.jpg (bottom)