<P> The following special cases are depicted: </P> <Ul> <Li> <P> Day arc at 0 ° latitude (equator) The arc passes through the zenith, resulting in almost no shadows at high noon . </P> </Li> <Li> <P> Day arc at 20 ° latitude The Sun culminates at 70 ° altitude and its path at sunrise and sunset occurs at a steep 70 ° angle to the horizon . Twilight still lasts about one hour . </P> </Li> <Li> <P> Day arc at 50 ° latitude Twilight lasts almost two hours . </P> </Li> <Li> <P> Day arc at 70 ° latitude The Sun culminates at no more than 20 ° altitude and its daily path at sunrise and sunset is at a shallow 20 ° angle to the horizon . Twilight lasts for more than four hours . </P> </Li> <Li> <P> Day arc at 90 ° latitude (pole) If it were not for atmospheric refraction, the Sun would be on the horizon all the time . </P> </Li> </Ul> <Li> <P> Day arc at 0 ° latitude (equator) The arc passes through the zenith, resulting in almost no shadows at high noon . </P> </Li> <P> Day arc at 0 ° latitude (equator) The arc passes through the zenith, resulting in almost no shadows at high noon . </P>

When do we have shorter day and longer night