Niu Alani Crosses the Date Line
On April 25th at roughly 6pm Hawaii time, Niu Alani crossed the International Date Line (IDL) and demonstrated that time travel is in fact possible. Ok, not really, but let’s think about what just happened and discuss what is so special about 180 degrees longitude.
First, we need some background.
As you know, the world is broken up into time zones, a convenience that means you’ll typically eat lunch at 12pm and the sun will be at its highest point in the sky as the Earth rotates. The Prime Meridian, at longitude 0, goes through Greenwich, England and provides the baseline time for which all other locations are compared. This is referred to as Greenwich Mean Time (GMT), Coordinated Universal Time (UTC), or Zulu Time. Honolulu is at GMT – 10, which means that whatever time it is in Greenwich, Honolulu is 10 hours earlier. So, if it’s 11pm in England, it is 1pm in Hawaii’s local time.
As Niu Alani left Hawaii and went west, its local time zone changed, which means its difference in hours from UTC changed. As it approached the IDL, it was 12 hours behind UTC and two hours behind Honolulu. Just before it crossed the IDL, its local time was around 4:00pm on April 25, 2009. The next moment, it was instantly transported a day into the future and its new local time was 4:00pm on April 26, 2009.
Wow, so Niu Alani never experienced the evening of 4/25 and most of 4/26 (did anything cool happen?). Crazy to think about, but the same thing happens to you every time you fly west to Asia or Australia. Even weirder, when you fly east to the United States, you jump one day backwards and often land at your destination before you ever left. So, don’t ask, “Are we there yet?” on the flight, or your answer might be, “We’ll be there yesterday.”
As you might guess, the International Date Line (and time zones in general) can cause lots of problems for people traveling on airplanes or making phone calls internationally, but it’s hardly a new problem. In fact, the first “victim” of the IDL was Ferdinand Magellan, the first person to circumnavigate the Earth. When he arrived in Spain for a stopover, his ship’s logs were a day off. The same thing happened to Phileas Fogg in Jules Verne’s book “Around the World in Eighty Days”.
Of course, since we aren’t traveling with Niu Alani, our time zone hasn’t changed and there is no skipping or losing a day. That is fortunate for us, but here’s something to think about: What happens to people who live right near the IDL? Or right near a time zone line? Hint: the IDL and time zone lines are not straight along the same longitude.
And then there’s Daylight Savings Time, but we won’t go there!!!
