Chapman emphasizes on his website
that this is "real-time, as-it-happened footage," and "not the usual time-lapse." That becomes clear during the clip, since the stars don't move in the background and people walk by in the foreground at normal speed.
Time-lapse photography is popular for aurora videos because the lights tend to move slowly, at a pace that would test the attention spans of many Internet viewers. But while it's often stunning, time-lapse footage can also create a sense of detachment from reality, since it depicts nature as the naked eye doesn't see it. By filming relatively fast northern lights in real time, Chapman helps convey their ethereal vibe without exaggerating it. And since that added realism may spur questions about what exactly we're seeing, Phil Plait of Bad Astronomy
offers this explanation:
"[T]he movement you're seeing isn't a physical motion. It's not like solid curtains of material are flapping. The lights are caused by atoms in the upper atmosphere getting hit by subatomic particles blasted out by the Sun, caught by our Earth's magnetic field, and funneled down into our air. These particles dump energy into the atoms, moving the electrons up in energy (called excitation). The electrons then jump back down, emitting light in the process (de-excitation)."
Chapman got this shot by traveling to Tromsø, Norway — located more than 200 miles inside the Arctic Circle — and he promises to upload a higher-quality version when he returns home Feb. 2. That will certainly be worth looking out for, but even as amazing as Chapman's footage is, it may just be a hint of what's to come in the near future.
Solar-storm activity rises and falls based on an 11-year cycle, and the sun is currently ramping up toward its next peak, which is expected sometime in 2013
. That should give Chapman and photographers around the world plenty of chances to capture even more impressive aurora videos — both in time-lapse and real-time.
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