Via this column from Education Guardian I am apprised of a study claiming to show that the longer a cow has been lying down, the more likely it is to stand up soon, but that the contrary isn't the case - it isn't the case that the longer a cow has been standing up, the more likely it is to lie down soon. From the abstract here you can see how many thousands of lying-down episodes were recorded in arriving at the result, but me, I'm not going to be diverted by mere numbers; I'm looking for an explanation.
At first, it seems obvious. A cow lying down is bound to get up sooner or later because otherwise its limbs would atrophy. You may think that a cow standing up is just as much bound to lie down sooner or later because otherwise it would get exhausted. But you'll have reckoned without the possibility that some cows can have a sleep while standing up, especially if they lean against something, like a fence or a tree. Hence, the greater likelihood of a sooner up-getting for lying-down cows than of a lying-down for standing-up cows.
Or so I thought. Until it dawned on me that some cows that are lying down will never, ever, get up, because they will die lying down. Whereas cows do not die standing up; they fall over as death approaches. Or even if a few cows do maybe die standing up, once dead they instantly fall over and will go into the statistics as standing cows who lay down. (The researchers will only discover they, the cows, are dead once they're down and will have no way of knowing exactly when it was they died relative to the time at which they fell. They, the researchers, will naturally assume that they, the now dead cows, died after they fell and fell because they felt themselves dying.)
So, it's a mystery. Why lying-down cows are likely to get up sooner than standing cows are to lie down has yet to be explained. Even more mysterious is this: why haven't all cows ended up in a standing position if prone cows are getting up sooner than upright cows are lying down? It is questions of just this sort that keep up one's interest in the present election campaign.