Will you get less wet if you walk in the rain or run in the rain. On the walk side, you would be going slower and spend more time in the rain. On the run side, you would be moving through more raindrops on your journey (or would you?)
I know Mythbusters covered this and their results were inconclusive.
It seems to me that the problem could be solved mathematically. My small brain cannot compute such a complex idea. Is there anyone out there with the skills to do this?
Or is there a logical solution to this puzzle?
Mythbusters revisited the myth, and on the revisit confirmed what Cecil reported. It’s better to run.
Assuming that the rain rate is constant, you’ll move through the same number of raindrops no matter how fast you go: It’s just the number density of drops times your cross-sectional area times the distance you travel. However, the number which fall on your top surface (head, shoulders, etc.) depends on the time you spend in the rain. So you’ll get the same number of chest drops and more head drops if you walk.
Furthermore, the assumption of constant rain density usually isn’t a good one. In a real rainstorm, it’s sometimes raining more, and sometimes less. If you run, then you can time your run to coincide with a lull in the rain, but if you walk, you’re likely to still be out in it when the lull ends.
In 2002 I did a detailed analysis of this question for anyone who wants to get into the math of the problem. I also used Peterson & Wallis (cited by Cecil) as a starting point for my research.
That article was my first introduction to the Dope. Back in the late '90’s I was searching for something and stumbled upon it, and I thought wow- this guy is thorough. Several years of lurking ensued.
This is a classic example of careful calculations that lead carefully to the wrong answer. If the question is simply “should you walk or run in the rain” (without specifying that the objective is to try to avoid the raindrops), the answer is that you should walk - because running makes you look like an idiotic sissy.
If there’s some very good reason why you must reduce the number of raindrops with which you will interact, then Chronos’ summary is correct and by all means run, but in nearly every real-world case, it doesn’t make a practical difference whether you run or walk - you’re going to get wet anyway, and the small number of raindrops you avoid by running just isn’t worth the effort (particularly when you risk slipping up turning a corner and planting your arse in a big muddy puddle).