What is counted in the Flash-to-Bang Method to estimate distance?

The Flash-to-Bang method is a practical technique used to estimate the distance to an explosion or gunfire based on the speed of sound. The principle relies on the time difference between seeing the flash (the visual cue) and hearing the sound of the explosion or discharge (the auditory cue). When a flash is observed, there is a delay before the sound reaches the observer due to the finite speed of sound. This method helps determine how far away the event occurred.

When using this method, the time measured between seeing the flash and hearing the weapon discharge allows one to calculate the distance. The speed of sound in air is approximately 1,125 feet per second, and this measurement can be correlated to distance traveled in that time period. This makes the method highly practical for the immediate context of estimating danger from potential enemy fire or explosions.

The other options do not correctly align with the principles of the Flash-to-Bang method, as they either refer to different timeframes or events unrelated to the method for estimating distance from a flash and its corresponding sound.