If You See a Bright Flash, Duck!


by Carol Deppe


About 1200 people were injured by the February 15 explosion of a meteor over Russia. Many of the injuries were from broken glass; news programs were full of pictures of people with cut up faces. I think many of these injuries could have been prevented.

Some of the videos of the event showed people inside offices and open areas of buildings initially going about their businesses. Then they see a bright flash from a window, and respond by looking toward and moving toward the windows. Next comes the shock wave, and the windows shatter inward right into those maximally vulnerable upturned faces.

Looking toward or moving toward a bright flash is understandable given human curiosity. It's the same impulse that leads people, unless they know better, to run toward instead of away from the suddenly receding ocean when a tsunami is on the way. Many people these days have learned that they should not run toward that drastically receding ocean, no matter how fascinating the exposed beach is or however many trapped fish flop enticingly. We have learned that drastically receding oceans are dangerous. I suggest it's time to learn that bright unexplained flashes are also often dangerous.

When things explode, the light produced by the explosion travels much faster than the shock wave. If the explosion is close to you, the light and shock wave will arrive almost simultaneously. However, if the explosion is some distance off, the bright flash arrives first. This means you may have some warning of the shock wave to come. In one particular video of people inside a building, the bright flash appeared to arrive roughly four seconds before the shock wave. Everyone was looking toward and walking toward the window when it exploded inward, spraying them with glass. There was plenty of time for everyone to have instead run or dived for cover.

I suggest this general rule: If there is a bright unexplained flash in the sky, assume a shock wave is coming and dive under a desk or run for cover. If you are indoors near windows, put as much cover as possible between yourself and the windows. If you are driving, pull over to the side of the road and hunch down to keep your face and eyes as protected from the windshield and windows as possible.

A blinding flash of light might not be a meteor, comet, or asteroid. It could be a chemical or power plant or gas line exploding. It could even be an atom bomb. Any of these could really ruin your day. Looking right at and moving right toward any of them is just not the optimal strategy.

I once thought the old cold war rule of "duck and cover" for protection against atom bombs was ridiculous. On further consideration, I now realize that it is more sensible than it seemed. If an atom bomb falls right on you and incinerates your building, ducking and covering won't help. However, the zone of damage from the shock wave is much larger than the zone of incineration. The zone of massive destruction from the shock wave is smaller than the zone of milder, potentially survivable destruction. This is true of all explosions, whatever their origin. If you are some distance from ground zero, you might be in the outer area of damage from the shock wave, the area where taking cover could make a difference.

In summary: If you see a bright flash, duck.

Carol Deppe is author of The Resilient Gardener: Food Production and Self-reliance in Uncertain Times. She is a freelance plant breeder and author who focuses on developing varieties and methods for sustainable agriculture.