A wave is never found alone, but is mingled with as many other waves as there are uneven places in the object where the said wave is produced.
Leonardo da Vinci... we might say that the earth has a spirit of growth; that its flesh is the soil, its bones the arrangement and connection of the rocks of which the mountains are composed, its cartilage the tufa, and its blood the springs of water.
Leonardo da VinciA good memory, which nature has endowed us with, causes things long past to seem present.
Leonardo da Vinci