Had Newton known about machine learning and had the actual machines to do the learning, then this is how he might have gone about it. First, he could have set up a classification problem with three class labels “down”, “up” and “sideways”. Then he would collect data on the direction of falling apples. He would have noticed his dataset to be highly imbalanced. But, undaunted, he would have marshalled on and trained his classifier. If his classifier were any good it would predict “down” as the direction of fall in most cases.