Thanksgiving Day was approaching, and a family had received a Thanksgiving card with a painting of a pilgrim family on its way to church. Grandma showed the card to her small grandchildren, observing, "The pilgrim children liked to go to church with their mothers and fathers."
"Oh, yeah?" her grandson replied, "so why is their dad carrying that rifle?"
Light theoryIn 1827, William Rowan Hamilton presented his Theory of Systems of Rays at the Royal Irish Academy in Dublin. Although he was still an undergraduate, only 21 years old, his work is one of the important works in optics, for it provided a single function that brings together mechanics, optics and mathematics. It led to establishing the wave theory of light, which gives that light is a form of energy that travels in waves. |
){kind=link}