1. We revolve around the sun.
REVOLUTION

2. What about r tation?
Earth rotates at 15o / hour.

3. What about r tation? Earth rotates at 15o / hour.
Different latitudes rotate at different speeds (higher latitudes have slower rotation)

4. What about r tation? Earth rotates at 15o / hour.
Different latitudes rotate at different speeds (higher latitudes have slower rotation)
Causes: day and night, time zones, and celestial objects moving across sky (EW).

5. What about r tation? Earth rotates at 15o / hour.
Different latitudes rotate at different speeds (higher latitudes have slower rotation)
Causes: day and night, time zones, and celestial objects moving across sky (EW).

6. What about r tation? Earth rotates at 15o / hour.
Different latitudes rotate at different speeds (higher latitudes have slower rotation)
Causes: day and night, time zones, and celestial objects moving across sky (EW).

7. What about r tation? Earth rotates at 15o / hour.
Different latitudes rotate at different speeds (higher latitudes have slower rotation)
Causes: day and night, time zones, and celestial objects moving across sky (EW).
How long is an Earth rotation according to the reference tables?

8. It seems 3 min and
56 sec is missing!
It is explained by the fact that the Earth REVOLVES as it ROTATES…

9. One day (slightly more than 360o) is 24h.
You are on the Earth facing the Sun. When the Earth completes a rotation you are NO LONGER FACING the Sun! The Earth requires about 4 more minutes for you to face the Sun again.
One rotation (360o) is 23h 56m 4s.
One day (slightly more than 360o) is 24h.

10. The reason a solar day lasts over 4 minutes longer than the Earth’s actual rotation is
(1) Earth revolves while it rotates
(2) Clocks measure differently in different
locations
(3) Earth rotates at different speeds at
different latitudes
(4) A year lasts longer than a day like on Mars

11. Or…how to ACCURATELY kill lots of people
Foucault’s pendulum
Or…how to ACCURATELY kill lots of people

12. Pendulum appears to change direction. Earth is rotating beneath it!

13. A Foucault pendulum appears to change its direction of swing over a period of several hours because of Earth’s
(1) rotation
(2) tilted axis
(3) revolution
(4) gravity