1. Lecture Five

2. Simultaneity and Synchronization

3. Relativity of Simultaneity

6. Synchronization Stationary observers Relatively moving observers

7. Synchronization for Stationary Observers

8. Synchronization for Relatively Moving Observers

9. Synchronization for Relatively Rest Observers

17. Invariance of Interval

18. meter as unit of time time for light to travel one meter 1 meter of light-travel time in conventional units: c = 299,792,458 meters per second 1 meter of light-travel time = 1 meter/c 1 meter of time = (299792458) -1 sec 1 meter of time  3.3 nanoseconds

19. meter as unit of time “  t = 1 meter (of time)” means c  t = 1 meter

20. geometrization geometrical units natural units

21. Invariance of Interval Event A: the emission of a flash of light Event B: the reception of this flash of light

23. Invariance of Interval in rocket frame: The reception occurs at the same place as the emission.

24. Invariance of Interval in rocket frame: The light flash travels a round-trip path of 2 meters.

25. Invariance of Interval in rocket frame: x ' A = 0, t ' A = 0 x ' B = 0, t ' B = 2 meters  x ' = 0, c  t ' = 2 meters

27. Invariance of Interval in laboratory frame: light flash is received at the distance  x to the right of the origin.

28. Invariance of Interval in laboratory frame: The light flash travels the hypotenuse of two right triangles.

29. Invariance of Interval in laboratory frame: x A = 0, t A = 0 x B =  x, t B =  t c  t = 2 [1+(  x /2) 2 ] 1/2

30. Invariance of Interval in rocket frame: (  x ' ) 2 = 0, ( c  t ' ) 2 = 4 in laboratory frame: (c  t) 2 = 4 [1+(  x /2) 2 ] = 4 + (  x) 2

31. Invariance of Interval 4 = ( c  t ' ) 2 － (  x ' ) 2 = (c  t) 2 － (  x) 2

33. One epitome displays four great ideas 1.Invariance of perpendicular distance 2.Invariance of light speed 3.Dependence of space and time coordinates upon the reference frame 4.Invariance of the interval