Antipodean musings

If you dig a hole straight down, where DO you come out?

I was looking at my visitor stats, and I noticed I had a visitor from a very long way away, in this case, Pakistan, more than 7,000 miles away. That got me to thinking, where is the point that is the farthest possible distance from Five O’Clock Somewhere?

That would be the antipode, the point on the Earth exactly opposite. I remember being told as a child that if I dug a hole straight down, I would come out in China – but that’s not true. If you are in North America, a hole straight down will not come out in China, because China is in the northern hemisphere, and a hole dug in the northern hemisphere is going to come out in the southern.

Antipodes are important for cruising sailors. They define when a sailor has truly circumnavigated the Earth – in order to count, the sailor has to pass through at least one pair of points that are directly opposite each other. Otherwise, the sailor could simply sail a short loop around Antarctica (admittedly not easy, but still a much shorter distance).

Calculating the latitude of the antipode is easy – if one is in the northern hemisphere, the latitude is the same, but south instead of north. Since Five O’Clock Somewhere is at about 37 degrees north latitude (actually a few minutes less, but we’re not going for precision at the moment), its antipode will be about 37 degrees south.

The longitude is a little trickier to calculate. Five O’Clock Somewhere is west of the Prime Meridian, and the antipode will be the same amount west of the International Date Line. So I can take 107 degrees west (again, a rough approximation), subtract it from 180 degrees east, and I end up with 73 degrees east.

So what is at 37 degrees south, 73 degrees east? Well, not much. It’s in the Indian Ocean, east of Madagascar and a little bit south. It’s kinda-sorta close to the island of Diego Garcia.

So my best bet for a true antipodean visitor is somebody stationed at Diego Garcia. Of course, these guys are dedicated to their jobs of protecting the United States’ interests in a very volatile part of the world – they support air operations in the Middle East. But when they have time off, I invite them to join the party at Five O’Clock Somewhere.