Lightning strikes per session
0
Last lightning
Type:—
Thunder hold:— s
Distance:— km
📐 'Second — Third-Kilometer' Rule
Count seconds between flash and thunder, divide by 3 —
you get approximate distance in km (sound travels ≈343 m/s,
i.e., ≈1 km in 2.9 s ≈ 3 s).
Why do lightning strikes occur?
Inside a thunderstorm cloud, air currents lift and lower water droplets
and ice crystals. They rub against each other, and this results in
electric charge distribution: Light particles in the upper cloud
are predominantly positively charged, heavier ones at the bottom — negatively.
When the potential difference between a cloud and the ground (or between neighboring
clouds) becomes too large, air — usually an insulator — breaking through,
and a short bright discharge channel appears — sparkling... This is the same static electricity as a spark from a doorknob, only a million times more powerful.
Sudden heating of the air along the spark channel (up to ~30000°C) causes
explosive expansion — a shock wave, which we hear as grim 💥.
Light travels to us almost instantaneously, while sound travels at a speed ≈343 m/s,
so the flash always precedes the boom.