“ Sorrow prepares you for joy. It violently sweeps everything out of your house, so that new joy can find space to enter. It shakes the yellow leaves from the bough of your heart, so that fresh, green leaves can grow in their place. It pulls up the rotten roots, so that new roots hidden beneath have room to grow. Whatever sorrow shakes from your heart, far better things will take their place. ” ― Rumi
The Feynman Lectures on Gravitation are based on notes prepared during a course on gravitational physics that Richard Feynman taught at Caltech during the 1962-63 academic year. For several years prior to these lectures, Feynman thought long and hard abou