The Green Ray (in French: Le Rayon vert) was a novel written by Jules Verne in 1882. It is named after the optical phenomenon that sometimes occurs right after sunset or right before sunrise. When the conditions are right, a green spot is visible above the upper rim of the disk of the sun.
In the novel, two people are trying to view the phenomenon in Scotland. They try multiple times, however multiple obstacles block their view of the sun, including clouds, flocks of birds, and a distant boat on the horizon. When the conditions are right and the green ray is visible, they don't pay attention to it, as they have found love in each other.
Shortly after her parents Daniel and Martha had passed away, Clara Clayton was reading The Green Ray. She began to imagine her life outside of New Jersey, and decided to head west. In 1885, she took a teaching position in Hill Valley, California. She hoped to find adventure and love, as her parents did 45 years earlier on the Oregon Trail. She found both when she met Emmett Brown.