where did light as a feather stiff as a board come from
Light as a feather, stiff as a board The oldest known account of levitation play comes from the diary of Samuel Pepys (1633-1703), a British naval administrator. Pepys’s account of levitation play comes from a conversation with a friend of his, Mr. Brisband, who claimed to have seen four little girls playing light as a feather, stiff as a board in Bourdeaux, France. Pepys’s account of Mr. Brisband’s experience reads:
Speed of light Early Islamic philosophers initially agreed with the Aristotelian view that light had no speed of travel. In 1021, Alhazen (Ibn al-Haytham) published the Book of Optics, in which he presented a series of arguments dismissing the emission theory of vision in favour of the now accepted intromission theory, in which light moves from an object into the eye.[123] This led Alhazen to propose that light must have a finite speed,[122][124][125] and that the speed of light is variable, decreasing in denser bodies.[125][126] He argued that light is substantial matter, the propagation of which requires time, even if this is hidden from our senses.[127] Also in the 11th century, Abū Rayhān al-Bīrūnī agreed that light has a finite speed, and observed that the speed of light is much faster than the speed of sound.[128]