LECTURE- International Date Line!

SO this posting may say MARCH 29th BUT we did not have a March 29th this year. We went right from Saturday March 28 to Monday March 30th (which was difficult for all of us, in particular those that were recognizing Palm Sunday, which did not happen this year aboard our ship). That is what happens when you cross the International Date Line in the East to West direction. Of course in 2023, we went the other day and celebrated our friends Tim & Krista’s anniversary, 6/28, twice. Read about why we have an International Date Line, and how the Earth was carved up to map/navigate it and with the rotation on its axis every 24 hours and how our traveling time zones we had to gain or lose a day in order for everyplace to have day/night.

The Longitude Conundrum started the question as to where should the dateline be located. “Somewhere” between the American Samoa and Samoa (in the mere 40 mile stretch) is that “imaginary line” where the date changes and magically you gain or as in our case lose a day, depending on which direction you are going.

Longitude: the question as to how the Earth is divided and is very important for explorers as well as for cartographers that were trying to map the countries of the world. The sextant was the only solution but not easy to use and required extreme accuracy. Of course, finally in the last 30 years it has been replaced with GPS.

Latitude: was relatively easy to figure out because the widest part of the Earth is the equator (we have crossed it about 7 times) and every 10 degrees for 90 degrees north and 90 degrees south of the equator and you can draw a line to get the latitude. As a starting point, early explorers found the Tropic of Cancer (northern) and the Tropic of Capricorn (southern), where they can measure the angle of the sun at its highest point and it tells you where you are (latitude) relative to when the sun is directly overhead.

Columbus used this when he sailed the “blue line” (see photo) to the Canary Islands and then followed the line of latitude to find the Caribbean and found America and this allowed him to follow a straight line to get back and to find other places on subsequent voyages. These East/West routes became very important discoveries in the spice routes around the world. As for moving off these “lines”, explorers could only use “instinct” and “luck”.

The next major improvement for explorers for determining your location when on a ship was “dead reckoning”, calculating the current position of a ship by using a previously determined positions and estimates of speed, direction and elapsed time.

BUT Longitude calculations were more difficult and need to be more accurate or you could be way off as was clear for those that use a sextant. For example, a 1707 flotilla of the Royal Navy from Gibraltar to Portsmouth lost 2,000 sailors when the fleet struck the rocks of the Isles of Scilly 4 (of the 20) ships. This disaster led to the Longitude Act of 1714, which offering a large prize to anyone who could develop a reliable method for determining longitude at sea. Astronomers had some potential solutions. Clocks were required and it would be impossible to have accurate pendulums clocks at sea, so that didn’t work either and clocks don’t work well at sea conditions. Finally, John Harrison, an English carpenter and clockmaker invented the marine chronometer, after developing 5 timepieces over 30 years (in 1776) with a 5”, 3lb watch that could be carried on a ship. Cartographers were able to redrew many maps after this event. The first journey, the HMS Beagles, to map Cape Horn and where Darwin came to fame carried 22 of these devices.

This finally led to an International Committee (in 1884) to set the Prime Meridian (Greenwich mean time) at 0 degrees longitude in a place where no one lived, all water, so it would affect the fewest people. We now could place NULL ISLAND at 0,0. (a fictional island located where the Prime Meridian meets the Equator). Now 24 time zones could be calculated from this reference point. Of course, some countries make their own arbitrary decisions on time zone (like all of China in one zone).

The problem was when this Prime Meridian is drawn around the Earth it is mostly in water and ends up in the Pacific. Kiribati is in the central Pacific Ocean, roughly halfway between Hawaii and Australia It is the only country in the world with territory in all four hemispheres -Northern, Southern, Eastern, and Western.

So, a long way to say the date changes at this line when you follow this line around the Earth right near Samoa (where most of their business is with Australia and New Zealand and they want to be on the same day as these countries) and American Samoa (where most of their interaction is with the US , who wants to be on the same day as the US). ALL THIS RESULTS IN THE DAY CHANGE IN THIS SMALL 40 MILE STRETCH.

Is there a line to see? NOPE
Does the water color change when you cross? NOPE
Is there a Ceremony when you cross this line, line the. Equator one? NOPE, just confusion.
SO we lost a day, that we will get back very slowly one zone at a time over the next 3 months. (or if you fly back to the US when we get to Sydney)

In the infamous movie Around the World in 80 Days, Phileas Fogg thinks he missed the deadline by 5 minutes BUT since he was going East, Tokyo to SF, he got the day back and therefore he was a day early and he WON. AhhhhhRead more