Photo: hugo (Flickr)
You may have heard that your car is a safe place to be in a thunderstorm, and this is true. You might not know the reason for this, however. On today’s Moment of Science, we’ll learn exactly what would happen if lightning struck your car.
At first you might think that the rubber tires would keep you safe. After all, the rubber insulation on appliance cords keeps you from getting shocked every time you plug in a lamp.
Unfortunately, the rubber in your tires won’t slow a lightning bolt at all, especially if they’re wet. A lightning bolt has up to a hundred million volts; once it gets going, it won’t slow down for much.
Remember that the lightning already must travel about a mile between cloud and ground and that much air is usually a pretty good insulator.
If the rubber tires won’t keep you safe from a lightning strike, what does? Believe it or not, it’s your car’s metal chassis! Although metal conducts electricity‑‑and might even attract a lightning bolt‑‑you’re protected because of the particular way that electricity moves through metal.
When a rapid pulse of electric current moves along a copper wire, all the current moves across the outer surface of the copper. There isn’t any electrical movement inside the wire itself. The same is true of your car. Although a lightning strike contains a lot of energy, it will all travel along the outer surface of your car, never reaching the interior.
Where You Wanna Be…
The safest place to be in a storm is probably in a house or building with adequate lightning rods, but if a storm happens to catch you while driving, remember this Moment of Science and feel more secure — unless there is a tornado, then you should seek safer shelter.