字幕表 動画を再生する 英語字幕をプリント Canada and the United States share the longest, straightest, possibly boringest border in the world. But, look closer, and there's plenty of bizarreness to be found. While these sister nations get along fairly well, they both want to make it really clear whose side of the continent is whose. And they've done this by carving a 20-foot wide space along the border. All five and a half thousand miles of it. With the exception of the rare New England town that predates national borders or the odd airport that needed extending, this space is the no-touching-zone between the countries and they're super serious about keeping it clear. It matters not if the no-touching-zone runs through hundreds of miles of virtually uninhabited Alaskan / Yukon wilderness. Those border trees, will not stand. Which might make you think this must be the longest, straightest deforested place in the world, but it isn't. Deforested: yes, but straight? Not at all. Sure it looks straight and on a map, and the treaties establishing the line *say* it's straight... but in the real world the official border is 900 lines that zig-zags from the horizontal by as much as several hundred feet. How did this happen? Well, imagine you're back in North America in the 1800s -- The 49th parallel (one of those horizontal lines you see on a globe) has just been set as the national boundary and it's your job to make it real. You're handed a compass and a ball of string and told to carefully mark off the next 2/3rds of a continent. Don't mind that uncharted wilderness in the way: just keep the line straight. Yeah. Good luck. With that. The men who surveyed the land did the best they could and built over 900 monuments. They're in about as straight as you could expect a pre-GPS civilization to make, but it's not the kind of spherical / planar intersection that would bring a mathematician joy. Nonetheless these monuments define the border and the no-touching-zone plays connect-the-dots with them. Oh, and while there are about 900 markers along this section of the border, there are about 8,000 in total that define the shape of the nations. Despite this massive project Canada and the United States still have disputed territory. There is a series of islands in the Atlantic that the United States claims are part of Maine and Canada claims are part of New Brunswick. Canada, assuming the islands are hers built a lighthouse on one of them, and the United States, assuming the islands are hers pretends the lighthouse doesn't exist. It's not a huge problem as the argument is mostly over tourists who want to see puffins and fishermen who want to catch lobsters, but let's hope the disagreement gets resolved before someone finds oil under that lighthouse. Even the non-disputed territory has a few notably weird spots: such as this tick of the border upward into Canada. Zoom in and it gets stranger as the border isn't over solid land but runs through a lake to cut off a bit of Canada before diving back down to the US. This spot is home to about 100 Americans and is a perfect example of how border irregularities are born: Back in 1783 when the victorious Americans were negotiating with the British who controlled what would one day be Canada, they needed a map, and this map was the best available at the time. While the East Coast looks pretty good, the wester it goes the sparser it gets. Under negotiation was the edge of what would one day be Minnesota and Manitoba. But unfortunately, that area was hidden underneath an inset on the map, so the Americans and British were bordering blind. Seriously. They guessed that the border should start from the northwestern part of this lake and go in a horizontal line until it crossed the Mississippi... somewhere. But somewhere, turned out to be nowhere as the mighty Mississippi stops short of that line, which left the border vague until 35 years later when a second round of negotiations established the aforementioned 49th parallel. But there was still a problem as the lake mentioned earlier was both higher, and less circular than first though, putting its northwesterly point here so the existing border had to jump up to meet it and then drop straight down to the 49th, awkwardly cutting off a bit of Canada, before heading west across the remainder of the continent. Turns out you just can't draw a straight(-ish) line for hundreds of miles without causing a few more problems. One of which was luckily spotted in advance: Vancouver Island, which the 49th would have sliced through, but both sides agreed that would be dumb so the border swoops around the island. However, next door to Vancouver Island is Point Roberts which went unnoticed as so today the border blithey cuts across. It's a nice little town, home to over 1,000 Americans, but has only a primary school so its older kids have to cross international borders four times a day to go to school in their own state. In a pleasing symmetry, the East cost has the exact opposite situation with a Canadian Island whose only land route is a bridge to the United States. And these two aren't the only places where each country contains a bit of the other: there are several more, easily spotted in satellite photos by the no-touching zone. Regardless of if the land in question is just an uninhabited strip, in the middle of a lake, in the middle of nowhere, the border between these sister nations must remain clearly marked.