Feb 012013

Week 1: Module1: 2/1/13

What time is it where you are, and what time zone are you in? How about where the JRH is?

How do you know when you enter a new time zone if there isn’t a handy sign on the side of the road telling you? Simple I just look at my cell phone and it does it for me! Well let’s suppose that you are in the middle of the Atlantic Ocean and there isn’t cell service. What then?


Time has always been something that humans have been fascinated with. Throughout human history we have been trying to keep track of time. Over 5000 years ago both the Egyptians and the Sumerians had developed calendars and shortly after that the Egyptians developed the sundial, to keep track of hours and minutes. As we fast forward in history to about 100 years ago a universal standard was implemented, formerly called GMT now called Coordinated Universal Time or UTC. This is the standard that we are all familiar with, which has the prime or zero  meridian as the base for time and longitude. longitudeIn this image you can see that the world, being roundish, is separated into 360 degrees, 180 to the west and 180 to the east of the prime meridian, at which point they meet at the international date line. At this aforementioned conference it was decided that since there are 24 hours in a day and 360 degrees, that these divide nicely and give us 15 degrees for each hour. These boundaries are subject to political and physical barriers, but roughly every 15 degrees equals one hour. Since the earth rotates to the east the time zones to the east are ahead of the prime meridian and those to the west are behind. With this information you can figure out what time it is on the boat by just knowing your time and their longitude. In this way the crew of the boat keeps track of their relative time so that they can keep a consistent schedule of sleeping and waking at the same time. Using their most recent position (found here) can you tell to the minute how far behind or ahead of the Coordinated Universal Time (UTC) the JRH is now?


[suffusion-the-author display='description']

  3 Responses to “Daily Education Update 1.4 Time”

  1. And for a great read about finding a method to keep accurate time at sea (including the dangers of not doing so), read Dava Sobel’s book “Longitude”. A fascinating tale of how a man with no formal education tinkering in his workshop solved one of the problems that the world’s best engineers, scientists and astronomers of the time could not solve.

  2. I am interested in the watch you have pictured above, could you give me information as to where I can purchuse the watch or who the manufacturer is. I would appreciate it alot, Thank you.

  3. Hi Libby! Great question. This was an image that was pulled from the internet for the purposes of the day’s discussion. I did another search but can’t seem to track it down. Try looking here: http://www.etsy.com/search?q=sundial%20watch&view_type=gallery&ship_to=US&ref=auto3.

    Best of luck! –Greg

 Leave a Reply

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <s> <strike> <strong>