For observers within a couple of degrees of the equator, the period from sunrise to sunset is always several minutes longer than the night. At higher latitudes in the Northern Hemisphere, the date of equal day and night occurs before the March equinox.
Daytime continues to be longer than nighttime until after the September equinox. In the Southern Hemisphere, the dates of equal day and night occur before the September equinox and after the March equinox. The chart shown below shows the dates and times for the equinoxes and solstices through Times listed are in Eastern Time.
Subtract one hour for Central Time. Source: U. Naval Observatory. The answer is YES. However, you can stand an egg on end, with a large amount of patience, on any day of the year.
This idea seems to pop up every year around the equinox. The thought that an egg can only stand on end on the spring equinox due to gravitational forces of the sun being aligned with the earth sounds like science, but it isn't. According to Chinese tradition, an egg can be made to stand on end at the precise moment winter ends and spring begins.
But, the Chinese calendar had this transition occurring at a variable time each year, determined partly by the Chinese lunar month, usually in early February. More recently, this thought became fixed to the time of the spring equinox. The underlying assumption relating to standing eggs on end is that there must exist some special gravitational balance.
There are many forces acting on an egg when you try to stand it on end on a flat surface. Some people think that the gravitational pull of the Sun becomes balanced with that of the Earth to allow for this phenomenon to occur. However, the Moon exerts a much stronger gravitational effect on the Earth than the Sun, dominating the ebb and flow of the ocean tides.
The Moon's effects are different at each of the equinoxes however. The most dominant force of gravity on a standing egg is the one between the Earth and the egg itself. This is determined by the weight of the egg and the force pulling the egg to the counter top. If you want to prove this to yourself, take a fresh, uncooked egg and hold it with the larger end resting on a table or counter top. Wait for the fluid content of the egg to settle, then carefully test the balance.
Be patient as you find the point where you can ever so gently let it go to remain standing on end. A season is a period of the year that is distinguished by special climate conditions. The four seasons—spring, summer , fall, and winter —follow one another regularly.
Each has its own light, temperature , and weather patterns that repeat yearly. In the Northern Hemisphere , winter generally begins on December 21 or This is the winter solstice , the day of the year with the shortest period of daylight. Summer begins on June 20 or 21, the summer solstice , which has the most daylight of any day in the year.
Spring and fall, or autumn, begin on equinoxes, days that have equal amounts of daylight and darkness. The vernal, or spring, equinox falls on March 20 or 21, and the autumnal equinox is on September 22 or The seasons in the Northern Hemisphere are the opposite of those in the Southern Hemisphere.
This means that in Argentina and Australia, winter begins in June. The winter solstice in the Southern Hemisphere is June 20 or 21, while the summer solstice, the longest day of the year, is December 21 or Seasons occur because Earth is tilted on its axis relative to the orbital plane, the invisible, flat disc where most objects in the solar system orbit the sun.
Earth rotates around its axis. This means it gets more hours of daylight. In December, when the Northern Hemisphere is tilted away from the sun, with fewer hours of daylight. Seasons have an enormous influence on vegetation and plant growth. Winter typically has cold weather, little daylight, and limited plant growth. In spring, plants sprout , tree leaves unfurl , and flowers blossom. Summer is the warmest time of the year and has the most daylight, so plants grow quickly.
In autumn, temperatures drop, and many trees lose their leaves. The four-season year is typical only in the mid-latitudes. The mid-latitudes are places that are neither near the poles nor near the Equator. The farther north you go, the bigger the differences in the seasons. Helsinki, Finland, sees In mid-December, however, it is light for less than 6 hours. Athens, Greece, in southern Europe, has a smaller variation.
It has Places near the Equator experience little seasonal variation. They have about the same amount of daylight and darkness throughout the year. These places remain warm year-round. When the Sun is at its mid-point in the sky, we reach the ' autumn equinox ', around 22 September. Day and night are both 12 hours long and its the beginning of autumn. The Earth continues on its path, and our north pole starts moving towards the Sun again.
The Sun moves upwards in our skies and the days continue getting longer. Again, we reach a midpoint when day and night are both 12 hours long. This is called the ' vernal or spring equinox ' and happens around 21 March.
The Earth's movement around the sun causes the seasons, but it does not affect the temperatures during the seasons. Many people believe that the temperature changes because the Earth is closer to the sun in summer and farther from the sun in winter. In fact, the Earth is farthest from the sun in July and is closest to the sun at the beginning of January! During the summer, the sun's rays hit the Earth at a steep angle because the sun is higher in the sky.
The light does not spread out very much, thus increasing the amount of energy hitting any given spot. The long daylight hours during the summer months allow the Earth plenty of time to reach warm temperatures.
This is why the days are hotter in the summer months. Because the sun is higher in the sky our shadows are shorter than they are in the the other three seasons. During the winter, the sun's rays hit the Earth at a shallow angle because the sun is lower in the sky. These rays are more spread out, which minimizes the amount of energy that hits any given spot. The long nights and short days prevent the Earth from warming up.
This is why we have cold winters. Summer is warmer and winter is colder because of the length of our days and nights.
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