The Native American Cree tribe called the Northern Lights the "Dance of the Spirits," and medieval Europeans debated whether the heavenly light show was a sign from God.
Today, we know the Aurora Borealis (and its cousin in the Southern Hemisphere, Aurora Australis) as a scientific phenomenon, a collision of charged particles high in the atmosphere that you can see best as you get nearer the Earth's poles.
The light can be a fluorescent-green glow or a fainter red. Auroras can make magnetic field lines visible or form "curtains" of light, which can change shape quickly or linger in a static form for hours.
Tourism officials in nations that offer the best show are eager to capitalize on the potential. Helsinki is the latest to toot its aurora horn, and about 400,000 people have checked out the video that Visit Finland has posted of its view of the Northern Lights.
That raised the dander of neighboring Norway.
"We cannot stand by and watch the Finns try to grab a bigger share [of the Northern Lights]," says Per-Arne Tuftin, representative of that country's state-owned tourism company. "We will not give up," he told local media. "The Northern Lights will be ours."
Reporting on the tug-of-war over particles high in the stratosphere, Der Spiegel notes that Tuftin's Norwegian company, Innovation Norway, tried to brand the lights as a Norwegian phenomenon back in 2009.
The Finns concede that the lights are often more easily seen in Norway (90 percent compared to Finland's 75 percent), but they say that margin isn't enough to diminish their light show. A Finnish spokesman shrugs at Norway's reaction of "alarm and emotion," and promises more promotion of the Northern Lights experience in Finland.
Finland has ruffled down-parka feathers around the Arctic Circle before: The Finns, after all, claim Santa Claus as their own, flaunting an elaborate Santa Village where the jolly old soul lives as simple proof.
This notion raises eyebrows in Canada and the US as well as Scandinavia (I've seen Santa in his slippers at his North Pole village in Alaska with my own eyes), but this is probably a case too big for the International Court.
The good news: When the spring equinox rolls around in March, a prime viewing time for the lights fantastic, there are quite a few places tourists can go to sit in a sauna and enjoy the show.