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"Lightning never strikes the same place twice." One building in New York takes about twenty-five hits a year, and a single flash usually strikes three times before you have finished blinking.
People say it to mean don't worry, it won't happen again.
As a piece of comfort it's fine. As a fact about lightning it is completely made up, and the thing that disproves it is one of the most photographed buildings on Earth.
It is tall, it is metal, and it is on its own above everything around it. The National Weather Service puts the number of times it gets hit at around twenty-three a year — some years fewer, some years many more.
That is not bad luck. It is the same building being the easiest target every single time, because lightning has no memory of yesterday and no interest in fairness. It takes the shortest route it can find, and if the shortest route was that spire in June it is still that spire in July.
And here is the part that finishes the saying off. What you see as one flash is usually three or four separate strokes, one after another down the very same channel, inside about half a second. That flickering you sometimes notice is the strokes arriving. Lightning frequently strikes the same place twice before you have registered that it struck at all.
Lightning goes wherever the path is shortest and easiest. Being struck once does nothing to change that — which is why tall, isolated, well-connected things get hit again and again.
For most of human history lightning was simply the sky doing something. Put these in the order they happened — the gap between the first two and the last two is the whole story.
Tap whichever you think happened next
Two and a half centuries between guessing and watching from space — and the rod Franklin sketched before anyone knew what lightning was is still on roofs today, doing exactly what he said it would.
Rub a balloon on your hair and stick it to a wall. You have just moved a small amount of electric charge from one thing to another, and the balloon now clings to a wall it has no business clinging to.
A thundercloud does that, on a scale that is hard to hold in your head.
Inside a storm cloud, air is hurtling upward. It is full of ice — tiny light ice crystals, and heavier soft hail called graupel. They smash into each other constantly, millions of collisions, and every collision scrapes a little charge across.
The light crystals get carried to the top of the cloud. The heavy graupel sinks. So the charge gets sorted by weight: mostly positive up high, mostly negative down at the cloud's base.
Now the cloud base is sitting there, enormously negative, a couple of kilometres over your head.
That pushes negative charge in the ground away and leaves the ground under the storm positive. The cloud wants to reach the ground. The ground wants to reach the cloud. Between them is air, which is a genuinely excellent insulator — normally nothing gets across.
But the push keeps building. And eventually the air gives up.
All of this takes under a second, most of it under a thousandth of one. Press through it and watch which direction things actually travel — this is where nearly everyone is surprised.
A radio mast on a hilltop was struck last summer. Somebody says it is now the safest mast in the country, because lightning won't come back. What is missing from that?
That channel of air gets heated to somewhere around 50,000°F — roughly five times hotter than the surface of the Sun. Not a typo, and not for long: a fraction of a second.
Air that hot does not warm up gently. It explodes outward. That explosion is a shock wave in every direction, and the shock wave reaching your ears is thunder. Same event, twice: once as light, once as sound.
Which gives you a free instrument. Light arrives essentially instantly. Sound takes about five seconds to travel a mile — about three seconds per kilometre. So count from the flash to the rumble and divide.
You see a flash. You count steadily and reach fifteen seconds before the thunder arrives. Roughly how far away did that flash happen?
The whole of it fits in one line that forecasters have been repeating for years: when thunder roars, go indoors.
If you can hear thunder, the storm is close enough to matter, and the response is simply to go into a building with walls and wiring, or into a car with a hard metal roof. Then carry on with your day. That's it.
A few extra details, each of which has a reason:
None of that requires being frightened of a thunderstorm. It requires going inside, which most people were going to do anyway.
You are halfway across a wide open playing field when you hear thunder. There is one big tree in the middle of the field, and a sports pavilion at the far edge. What does everything in this episode point to?
You’re previewing as a parent — nothing here is recorded.
"Lightning never strikes the same place twice" is listed by the National Weather Service as a myth: lightning often strikes the same place repeatedly, especially tall, pointy, isolated objects, and the Empire State Building is hit an average of about 23 times a year. (NWS Lightning Safety, 'Lightning Myths and Facts', weather.gov/safety/lightning-myths.) A single cloud-to-ground flash typically contains three to four separate return strokes down the same channel, which is the visible flicker. (NWS/NOAA, 'Understanding Lightning: Lightning Flashes and Strokes'.) Charge separation: collisions between small ice crystals and larger graupel in a storm's updraft transfer charge; crystals carried aloft leave the upper cloud positive and the lower cloud predominantly negative. A stepped leader descends from the cloud, upward streamers rise from objects on the ground, and when they connect the return stroke travels upward along the channel. (NOAA/NSSL Severe Weather 101, 'Lightning Basics'; NWS 'Understanding Lightning'.) A typical cloud-to-ground flash carries on the order of 300 million volts and about 30,000 amps, and the United States sees roughly 25 million cloud-to-ground flashes a year. (NWS Lightning Safety; NOAA/NSSL.) The lightning channel is heated to around 50,000°F, roughly five times hotter than the surface of the Sun; the rapid heating and expansion of the air produces the shock wave heard as thunder. (NWS/NOAA, 'Thunder'.) Sound travels about one mile in five seconds (about three seconds per kilometre), which is the basis of the flash-to-bang count. (NWS.) Safety, all from NWS Lightning Safety: 'When thunder roars, go indoors' — move to a substantial building or a hard-topped metal vehicle; indoors, stay off corded phones and away from plumbing, wiring and windows; avoid open fields, hilltops, isolated tall trees and bodies of water; wait 30 minutes after the last thunder before resuming outdoor activity. NWS explicitly withdrew the old 'lightning crouch' advice. Lightning can strike more than 10 miles from the area of rainfall — the 'bolt from the blue'. (weather.gov/safety/lightning.) Timeline dates: Franklin described a pointed iron rod for buildings in a 1750 letter to Peter Collinson in London; Thomas-Francois Dalibard drew sparks from a tall rod at Marly-la-Ville in May 1752, with Franklin's kite experiment the same year; the Empire State Building opened in 1931 and became a long-running lightning research site; the first photograph of a sprite above a thunderstorm was captured by University of Minnesota researchers in 1989; the GOES-16 satellite, carrying the Geostationary Lightning Mapper, launched in November 2016. (Franklin Papers; NOAA; NASA/NOAA GOES-R programme.) Safety guidance in this episode is a plain-English restatement of published NWS advice. It is not a substitute for a parent's judgement or local warnings.