Drivers of any age must take a vision test with each renewal. In 2011, the legislature turned away a proposal to test older driversâ reflex and reaction times starting at age 75, and to require every-six-months renewals for people 90 and older.
What causes the tides? It is the gravitational attraction of the sun and moon that cause waters of the ocean to raise and lower at different parts of the earth. Tides occur in oceans, and to a much smaller extent, tides also occur in large lakes, in the atmosphere, and within the solid crust of the earth.
Ocean tides have 4 causes: 1  The gravitational force difference between the Moon and the Earthâs surface, versus the Moon and Earthâs center of mass. 2  The gravitational force difference between the Sun and the Earthâs surface, versus the Sun and Earthâs center of mass. Centripetal forces on the Earthâs surface, due to itâs orbital motion with respect to the Moon and Sun. The geography of Earth, which amplifies the tides in specific areas (see map below).