This is something that I have trouble understanding. Maybe someone can explain it to me.

If I am flying from, say, California to Australia, and everytime I cross a time zone I go back one hour in time, then why, when I get to Australia, is it tomorrow?

In reverse, if I was flying from Australia to California, if I leave today, do I arrive yesterday?

Terry

Hey Terry - I got the Lotto results!!

Quick buy a ticket, you're a day and half behind over there!

No really, all I can say is there has to be SOME advantage to living this far away from Italy.

OK, Terry. This may not be a scientific explanation, but it gets me out of a lot of trouble. It is the sentiment from a Peanuts birthday card for a belated birthday:

"In some parts of the world, tomorrow is already today and today is yesterday. In other parts of the world, today is yesterday and tomorrow will be today . . . So who's to say I missed your birthday?"



Earline

Hope this helps!

Here's a quote from the World Atlas site.

"The planet is divided into 24 time zones and there must be a place where a day begins, thus the International Date Line. Travel west across it (gain a day), travel east across it (lose a day)."

Basically flying west, when you lose an hour until you reach it then you gain a day (24 hours) when you cross it. Coming back it is just the opposite you will gain an hour until you cross it and then you lose a full day (24 hours)

We're flying to Sydney in September. We will leave here in Seattle at 9am Saturday morning in Seattle and we will arrive in Sydney at 7pm Sunday night. It is an almost direct flight through Honolulu of 15 hours but yet it seems to take over a day and half to get there because of crossing the date line. In reality, only 17 hours with a plane change.

Coming back, we'll leave Sydney at 9pm on Sunday and arrive in Honolulu 10 am Sunday. Yep. It will seem as if we've gone back in time and should have bought those Lotto tickets Leslie told me about.

The reason there is an international dateline is to account for the "Circumnavigator's Paradox". The 18 survivors of Magellan's expedition around the world (1519-22) were the first to present this dilemma for the bewilderment of Europe. After three years sailing west, they first made contact with European civilization again on Wednesday 9 July, 1522 by ship's log. But in Europe it was already Thursday, July 10th! Antonio Pigafetta (an Italian explorer from Vincenza and one of the 18 surviors) wrote about it from first hand experience then, although middle eastern and European astronomers and geographers had previously discussed the paradox theoretically in the 13th and 14th centuries.
Now if Magellen had sailed eastward the crew would have returned to find the day would be Tuesday July 8th.
Thoroughly confused yet??
To avoid confusion an international date line exists. It is 180 degrees of longitude from the prime meridian (Greenwich - England - Mean Time) and divides the world into the western hemisphere (west of Greenwich to 180) and Eastern Hemisphere (east of Greenwich to 180). Fortunately it falls over the Pacific Ocean where there is sparse population. It also zigs and zags to keep political entities in the same day. Thus all of Alaska is on the same day as the rest of the US.
The date line resolves the potential circumnavigation difficulty, but leads to other paradoxes such as yours, a traveler on a long trip from the Oz arriving in the United States several hours before leaving your point of departure.
The Date Line has changed from time to time to reflect geo-politics. It used to be that the Philippines was also in the Western time zone when it was a Spanish colony. Imagine that zag! Also Alaska was in the Eastern Hemisphere time zone when it was a Russian possession.

quote:

Fortunately it falls over the Pacific Ocean where there is sparse population.

My understanding is that it was set up as it is for exactly that reason. The fortunate coincidence was that the already established Prime Meridian just coincidently happened to have this huge empty ocean opposite it. Taking that "opposite line" as the beginning/ending of the official 24-hour standard "day" meant that no large area of population had to straddle (be divided by) the date change. It's not a terrifically big deal to go from one place to another far away, and have a bit of "day" confusion on arrival. We can get accustomed to resetting our watches for time zones, right? But imagine living in a city whose two sides were having different days!

Another famous traveler who came across the date change conundrum was the eccentric millionaire Phileas_Fogg.

I always find it complicated, but think of it as an artificial solution to an artificial problem of time zones and dates.

I was quite interested to find out that before rapid transport became widespread (i.e the Railways), all time in UK was local - so noon was the time when the sun was at it's peak. This meant that Bristol was 8 minutes behind London which caused chaos for rail timetables.

Thanks for the explanations. Don't you think a great way to celebrate a birthday in a big way would be to make it a 2 day marathon, on each side of the dateline?

Terry

Dear Teaberry,
Sure, but you'd have to either charter a pretty large yacht to accomodate the party, and sail back over it for day two, or fly the party from one inhabited place to another. Let's see, I think it would work if you began in Fiji, then popped over to Hawaii to "repeat" the day? http://worldatlas.com/aatlas/infopage/dateline.htm

That would be the experience of a lifetime, eh?

quote:

Originally posted by BuckyE:
That would be the experience of a lifetime, eh?

Yes it would, Bucky, but it would do nothing in trying to help you "slow down"

Terry