Longitude and Time. Imagine clocks did not exist…..what would you base time on?
-
Upload
alisha-preston -
Category
Documents
-
view
214 -
download
1
Transcript of Longitude and Time. Imagine clocks did not exist…..what would you base time on?
Longitude and Time
Imagine clocks did not exist…..what would you base
time on?
Solar Time – Solar Noon –
Sunrise
Solar Noon
Sunset
What did the early clocks look like?
Sundial
Review Longitude Lines
Do students in California get up when you get up for school?
Time = Longitude!!
Earth’s Rotation
• Earth Rotates ___o
in 24 hours
• 360o/24hrs = __o per
hour
Standard Time Zones
What is the amount of time difference between each time zone?–1 hour–Every 15o longitude is a new time
zone.–How many time zones are there? –24 hours in one day… there are 24
time zones!
Map of 24 Hour Time Zones
•
Determining Longitude
1st: -
A chronometer is a clock set to the
local time at Greenwich, just
outside of London.
2nd: - Local time best found at Solar Noon (12
noon)
Sextant
3rd: Multiply by -0/hr
4th: -
• If GMT is later in the day compared to local time – you are west
• If GMT is earlier in the day compared to local time - you are east
Prime Meridian
East sees daylight first!
West last to see daylight!
Example 1• GMT = 2 pm • Local Time = 12 noon• What is your longitude?
2 hours*15° = 30°2pm is later in the day than 12 noon -
30°W
Prime Meridian
The Prime Meridian is later in the day than local time.
2pm
12pm
• GMT = 8 am• Local Time = 12 noon • What is your Longitude?
Final Question
• GMT = 10 pm• Local Time = 12 noon • What is your Longitude? http://www.polleverywhere.com/multiple_choice_polls/NTc3NDc4NTY1/web
Final Question
• GMT = 10 pm• Local Time = 12 noon • What is your Longitude?
-* -° = -°-