time. all measurements of time are based directly on the apparent movements of the sun
TRANSCRIPT
Time
All measurements of time are based directly on the
apparent movements of the sun.
Solar noon: when the sun is centered at its highest point in the sky on that
day.
Solar Day: the time from one noon to
the next noon
(midnight to midnight actually measures one day)
•For convenience we have adjusted the day to 24 hours,
although it is a little less
The Basis of the Time Zone: • The Earth like all circles is 360˚ around
• The Earth spins 360˚ in one day (24 hours)
• If we divide 360˚ by 24 hours in a day, we get 15˚ for every hour
The basis of Time Zones• Since the Earth moves 15˚every hour, Earth is
divided into 24 time zones that are 15˚ of longitude apart.
Time Zones• For convenience sake, states and countries do
not always divide the time zones directly along the lines of longitude
Think about this…
• Earth Rotates counterclockwise (so that means it rotates West to East)
• This means that the EAST experiences the day first…
• Time zones to the east are later in the day then time zones in the west
Time Zone Problems!!
1. If the time was 12:15 am in Los Angeles, California what time would it be in Bow, New Hampshire? 2. If it was 9:00 p.m. in New Hampshire, what time would it be in Miami, Florida? 3. About how many time zones would you pass through if you traveled 190 degrees around the earth?