It's always tomorrow in Australia

I've spent a lot of time reading about Australia to prepare for our move. I've learned some interesting things about Aussie food, sports, taxes, wildlife, and politics. (Well okay, the tax stuff isn't really that interesting- just necessary, but the rest is pretty good.) I'll write about some of these things in the future, but not today.

Today I want to write about something that I find unreasonably fascinating and perplexing about moving to Australia: time. Specifically, some kooky temporal oddities occur when traveling or communicating between the US and Australia.

Time travel via the international date line

My flight leaves Dallas on July 30th and arrives 15 hours later in Brisbane on August 1st. Let's get over that 15-hour flight for a minute, because what I really want to focus on here is this: I will not experience July 31st, 2012. The date will simply not exist for me. It's gone. Poof.

Now I remember learning about the international date line in 6th grade geography and I understand the basic concept that we need an arbitrary line on the planet that divides one day into another if we're going to have a globally coordinated system of time. But still, isn't losing an entire day strange? The upside is that when I fly back to the US and cross the date line in the other direction, I will arrive before I left Australia. That's a pretty neat trick there, and it's nice that the date line will eventually give me a free day to make up for the one that it stole.

Time travel in the 16th century

The same thing happened to the crew of Ferdinand Magellan's circumnavigation of the Earth from 1519-1522, long before the international date line was established. Magellan and his crew sailed west from Spain, around the southern edge of South America, west into the Philippines (where Magellan was killed), west across the Indian Ocean and past Africa, and then north back to Spain. When the crew finally returned to Spain, they discovered that the date had inexplicably moved one day forward. It was September 6th, 1522 in Spain, while the crew thought it was September 5th. Magellan and his officers kept careful daily diaries, but when these diaries were examined, no error was found. The diaries contained daily, successive recordings that accounted for every single day of the journey. Quite literally, the crew had experienced one day fewer than the Spanish public by sailing around the world.

I think that's just kooky.

What time is it in Australia?

Let's say you live in, oh I don't know, Michigan, and you want to call me in Australia. Let's say it's 9 pm in Michigan. Well, the internet says that Sydney is 14 hours ahead of EST, so it's 11 am tomorrow in Sydney. So call me up and I'll tell you about the future. If it's 9 am in Michigan, it's 11 pm in Sydney; please don't call me because I'm lame and I go to bed early.

But wait, how is it possible that it's 9 am in Michigan and 11 pm in Sydney, on the same day, as Michigan and Sydney are separated by the international date line? Don't they have to be different dates? The key is that time zones circle the Earth going from west to east, opposite the rotation of the planet. Your brain needs to mentally travel from Michigan to Sydney the long way around the planet. If you're eating breakfast in Michigan at 9 am, it's lunchtime in Europe, dinner time in the Middle-East, and bed time in Australia. So the title of this post was not entirely correct- I suppose I should have titled it "It's always tomorrow in Australia, except when it's not."




gif animation is from http://en.wikipedia.org/wiki/International_Date_Line