So here's the deal, if you stand when you use the toilet, pee splashes back on you, on your shoes, and on your clothes. And if you share a bathroom with someone who stands when they pee, a fine layer of pee covers your entire bathroom.
When at home, 7 in 10 men said they usually pee standing rather than sitting. In fact, only 17% usually sit down to urinate. These figures come from a survey of British and American people, which included 680 men.
How do we know this? Well, we aren't psychic, and we haven't been prowling around in your bathroom, but we are scientists - and few people understand the science behind peeing like we do.
When liquids fall through the air, they break into smaller droplets, as the surface tension of the liquid pulls them apart. The technical term for this is Plateau-Rayleigh instability. The further the urine stream has to travel through the air, the more likely the stream is to be pulled apart into hundreds of tiny droplets. Imagine standing and peeing from the top of the Empire State building, and what that urine stream would look like when it hits the sidewalk below. Even on the calmest of days, it would not resemble a stream in any way, but would land more like a light rain shower on the pedestrians below. (If the thought of that made you smile, your sense of humor is as bad as ours.)
Usually, pee drips and splashes are only noticed by the man who’s peeing or the person who uses the bathroom after him if large droplets happen to fly onto the seat or floor, but by using ultraviolet light and fluorescent liquid, we exposed droplets of every size and exactly where they flew.