Elephants, cows, goats and dogs all take roughly 21 seconds to empty their bladders. A “law of urination” now explains the physics behind what happens when you just gotta go.
Scientists filmed rats, dogs, goats, cows and elephants urinating and gathered footage from YouTube of others relieving themselves. Combining this with data on mass, bladder pressure and urethra size, they were able to create a mathematical model of urinary systems to show why mammals take the same time to empty their bladder, despite the difference in bladder size.
And very weird scientific research, learn more here if you really want.