I just had this image of calculating statistical boundaries in particle physics.
Given size and speed of raindrops, (random?) speed and path and distance from raindrop to head of walker, couldn’t some baseline statistical odds be determined for optimal paths/speeds of the walker to avoid getting wet be calculated?
Perhaps I am phrasing this query incorrectly, or-- not for the first time–am emitting query farts.
Thanks,
Leo
Cecil covered this a while back, concluding that running keeps you drier. However, he measured it over the same distance, when he should have measured it over the same time, which I suspect would give similar results (running might actually make you wetter if the rain is coming straight down since it will be hitting the whole front of your body and not just the head/shoulders, at least until the water starts to run down).
The same distance is the appropriate measure, since the time when the question is relevant is when you have to get from one building to another, or from a building to your car, or the like. It’s not like you’re running around in the rain just because you’re bored.
And assuming constant rainfall and no wind, it’s straightforward: You’ll get the same number of drops hitting your front surface no matter what you do, and the number of drops hitting your top surface is proportional to how long you’re out there. This favors running, since that’ll decrease the time you’re out.
But that’s with those two assumptions, which might not be valid. If there’s a wind, then you can eliminate the front drops by moving at the same velocity as the wind (theoretically, at least, though this is generally very difficult). And if the intensity of the rain is varying, then you probably want to wait a bit for a relative lull before moving, and you want to get where you’re going before the lull ends, thus favoring running.
Here’s a calculator which calculates how wet you will get in the rain; it confirms my guess about running possibly getting you wetter over the same distance (if it means that the angle of raindrops relative to your body increases). As a test, I used the default options which gives 38.38 ml of rain over a 200 meter distance at 1 m/s; if I set the speed to 10 m/s and increase distance to 2000 m (to keep time at 200 s), it calculates 241 ml, which is over 6 times as much water (it would be less over the same distance though, but not as much as you might expect, about 2/3 of the 1 m/s rate). So, it would help to run if it is windy and the wind is blowing in the same direction you are running and at a similar speed (also dependent on how fast the rain is falling), but otherwise you won’t be much drier.