The same way you accurately measure anything... with a lot of hard work and attention to detail. The best physics professor I ever had assigned a fuckload of h

The same way you accurately measure anything... with a lot of hard work and attention to detail. The best physics professor I ever had assigned a fuckload of homework every single day of class and graded it all himself. He probably worked 65+ hours a week, minimum. But you got feedback on all homework and that gave you an understanding of how well you were grasping concepts and on what you needed to work.