6. Earth's rotation
Earth's rotation is the rotation of the
solid earth around it's own axis. The
earth rotates from the west towards the
east, or from left to right. The earth
rotates ones in about 24 hours with
respect to the sun. The earth's rotation
is the reason for changing day and night.
7. Earth's revolution
The earth travels once around the sun, it is
considered as revolution on earth. A
revolution is quite a bit longer - one year! The
earth orbits the sun( its revolution) ones
every 365 days, 6 hours and 9 minutes. The
extra quarter day creates a 366th calendar
day in leap years.
8. The axis
The axis of rotation is an imaginary
line going from the north pole to
the south pole. The earth turns all
the way around or spins on its axis
one time.
9. Time zones
The world is a sphere. As the sun shines
on different places on the spare, the
other side will be in shadow. This means
that on one side of the world it is noon,
and on the other, it is midnight, creating
24 different 24 time zones with 15
degree of longitude wide.
10. Longitudes
It is an angular measurement, usually
expressed in degrees. Longitude is
defined in terms of meridians, which are
half circles running from pole to pole.
Longitude angles can range up to +180
degrees (180 degree east) and down to -
180 degrees (180 degree west).
11. Latitudes
Latitude is defined with respect to an
equatorial reference plane. This plane
passes through the center of the sphere,
and also contains the great circle
representing the equator. Latitude
angles can range up to +90 degrees (or
90 degrees north) and down to -90
degrees ( or 90 degrees south)
12. Seasonal variations
Earth's revolution is the main reason for the
seasonal variations of the earth. Every place
on earth experiences seasonal variations.
Because of the direction of the tilt changes in
rotation to the sun, the northern and
southern halves of our planet experiences
different seasons like summer, winter,
autumn etc.
