The length of the day is dependent on the inclination of the Earth toward the sun and the observer's latitude. The angle of inclination, relative to the latitude, determines how high the sun rises in the sky, how large an arc it crosses and how long it's in the sky.Continue Reading
During summer in the Northern Hemisphere, the northern half of the Earth is inclined toward the sun and the southern half away from it. This inclination allows sunlight to fall at higher latitudes than it does at other times during the year, and it causes the sun to rise higher in the sky throughout the northern latitudes. With more of the sky to cover in a single day, the sun remains visible in the sky for a longer time between sunrise and sunset, increasing the length of the day.
After the summer solstice, at which point the sun rises as high in the sky as it ever does, and stays out longer than at any other time, Earth's inclination gradually shifts back toward a median point, called the equinox. This progression continues until the next solstice, six months after the preceding one, when the opposite hemisphere experiences its longest possible day.Learn more about Time & Calendars
Earth's seasons are determined by the angle at which the sun passes through the sky each day. During summer, the sun rises higher in the sky and more sunlight reaches the surface, but during winter, the sun passes closer to the horizon, spends less time in the sky and imparts less energy to the ground. The relative angle of the sun is determined by the tilt of the Earth.Full Answer >
Copernicus’ heliocentric model shows how an observer on Earth orbiting the sun would see a planet with a longer orbital period appear to move backward and then forward again. Ptolemy’s model, with the Earth at the center, required complex additional mechanics to explain retrograde motion that never matched the observed motion.Full Answer >
A sundial is a device that tells time using the position of the sun. Most sundials have two primary components: a style, also called a gnomon, and a numbered dial. The sundial uses the sun to cast a shadow from the style over the numbered dial.Full Answer >
The National Oceanic and Atmospheric Administration's website explains that the tilt in the earth's axis means that during different times of the year, different parts of the earth are pointed toward the sun, resulting in longer daylight hours. The earth's axial tilt means that days are longer than nights for half the year, and nights are longer than days for the other half.Full Answer >