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Lightning Distance Formula:
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The lightning distance calculation estimates how far away a lightning strike is based on the time delay between seeing the flash and hearing the thunder. This method uses the fact that light travels much faster than sound.
The calculator uses the simple formula:
Where:
Explanation: Sound travels at approximately 0.34 km/s. Dividing the time by 3 gives a quick estimate of distance in kilometers (since 1/0.34 ≈ 3).
Details: Estimating lightning distance is crucial for safety during thunderstorms. If the time between flash and thunder is decreasing, the storm is approaching, and you should seek shelter.
Tips: Count the seconds between seeing the lightning flash and hearing the thunder. Enter this time in seconds. The calculator will estimate the distance to the lightning strike in kilometers.
Q1: Why divide by 3 specifically?
A: Sound travels at about 0.34 km per second. Dividing by 3 provides a quick mental calculation that's approximately correct (1/0.34 ≈ 2.94, rounded to 3 for simplicity).
Q2: How accurate is this method?
A: It's reasonably accurate for estimating approximate distance. Temperature, humidity, and wind can affect sound speed slightly, but the calculation is sufficient for safety purposes.
Q3: When should I seek shelter?
A: If the time delay is 30 seconds or less (about 10 km or closer), you should immediately seek shelter in a substantial building or fully enclosed metal vehicle.
Q4: Can I use this for miles instead of kilometers?
A: For miles, divide by 5 instead of 3 (since sound travels about 1 mile in 5 seconds).
Q5: Why is there sometimes no thunder?
A: Lightning can be too far away for thunder to be audible, or atmospheric conditions might prevent sound from reaching you. This is called "heat lightning."