Dancing in the Rain

Jack Dikian

November 2010

After a long day at one of our clinics – I realized I’d left my phone in the car and found myself running back to the car in order to retrieve. After all, how would I cope without my phone, what if that special person was to call me…Ignoring that the rain was also cold, in that instant – it occurred to me that running to the car may not necessarily mean I’ll keep dryer.

That is, does running from one point to another help reduce the amount of rain we are likely to collect.

At first blush, I’m guessing that like others, intuition tells us that the longer we remain in falling rain the wetter we are going to get. But what of the logic that by running we will be covering more of an area in a unit of time than if walking, therefore we will be hitting more rain as we run.

Like all things, the devil really is in the detail. Thinking about this a little more it seems there are numerous variables that can affect this question. The presence of wind, is rain falling at a constant speed, whether we walk and/or run with our shoulders straight and our backs upright, etc.

The problem can be divided into two parts:

1. The rain that hits the front of us while we are moving forward. This will be the same amount of rain, but occurring at a faster rate. The amount of rain can therefore be determined by rain per cubic meter multiplied by square of the surface area of our front multiplied by the distance traveled.

2. Wetness as a variable of rain falling from above is entirely a function of time. This amount is determined by how much rain per cubic meter per second multiplied by square of the surface area of our top multiplied by time.

So, when traveling from point A to point B, we should expect to get less wet the quicker we move. However, if wetness is measured by time, and if we are waiting (standing) in the rain - we would become less wet if we are to stand still rather than move around.