Nearly every living being (whether human or lion or bacteria or ant) is aware of the fact that What Season Is? In fact, even if we just talk about humans only, a human being can divide one year up to four seasons such that: Summer, Fall (Autumn), Winter, and, Spring.
Moreover, we can divide seasons in so many different ways. In India, according to Hindu Calendar, a year is divided into six seasons or (Ritu) such that each season has a fixed 2-month time span of the 12-Month Hindu Calendar.
According to the Hindu Calendar, the six seasons or Ritu are Vasanta (spring), Greeshma (summer), Varsha (monsoon), Sharad (spring), Hemanta (early winter), and Shishira (prevernal or late winter).
Reason For Season On Earth
In a modern world, everyone is quite aware of the scientific fact that earth revolves around the sun in an elliptical orbit, of course, according to Johannes Kepler Heliocentric Model.
Therefore, as a result, one might assume that our planet’s changing distance from the sun could be the reason for season on earth. But, sadly, it is not the correct explanation for the reason for change in the seasons.
Not to mention, it has some effects on different seasons on earth. But, could not be the effective or sole reason for the justification for the reason for season on Earth.
Highly recommended, December Solstice: First Day of Winter in Northern Hemisphere
Now the question arises that in actuality, what causes seasons on earth?
Earth’s Tilt – Reason For Season On Earth
Well, the actual reason for season on earth is Earth’s Axial tilt, relative to its orbital plane while traveling in an elliptical loop around the Sun. The angle of Earth’s Tilt is approximately 23.4 degrees.
In the astronomical world, the angle at which the earth is tilted is known as “Obliquity“. Well, you can say that the change in seasons and the tilt of the Earth are practically related.
In fact, if you want to, you can also summarize that elliptical orbit and axial tilt are the reason for the season on earth.
Why Is The Earth Tilted?
The correct reason behind the Earth’s Tilt is still a puzzle to solve. In fact, there are so many controversial and hypothetical theories related to the Earth’s Axial Tilt, but, none of them is satisfactory.
One theory suggests that during the early age of the solar system when young-earth collided with some early heavenly body – a body which later became the natural satellite of planet Earth.
Therefore, as a result of that collision, there is an axial tilt on earth of 23.4 degrees. On the other hand, some scientists suggest that planet earth may have tilted itself to gain its ecological balance.
Related, Why Moon Is Moving Away From Earth?
In my view, one mindful person can regard that both of the above theories are just theoretical. Because when that happened we were not there. Therefore, All we can do is argue!!
Who Discovered The Earth Was Tilted?
The axial tilt of the earth is surprisingly known for a very long time. I mean, according to the historical scientific writings; the earth’s tilt had been logically calculated in Ancient India and China around 1100 BC.
Later, in 1437, Ulugh Beg of Samarkand, Uzbekistan who was an Astronomer, a mathematician as well as the Sultan confirmed the earth’s Obliquity as 23°30′17″ (23.5047°).
Moreover, later in the modern world, the first accurate calculation of the earth’s tilt was calculated by a Danish Astronomer Tycho Brahe.
How The Seasons Are Formed?
It is a world-recognized fact that is if we divide our sphere (planet earth) what we get is two hemispheres. These are commonly known as The Northern Hemisphere and The Southern Hemisphere.
Due to the cyclic rotation of the earth around the sun, the hemisphere tilted toward or away from the changes simultaneously.
Therefore, because of the earth’s tilt, when it is summer in the northern hemisphere, it is winter in the southern hemisphere.
In other words, when the northern hemisphere is tilted toward the sun, it experiences a harsh summer. Meaning, longer days shorter night.
On the other hand, at the same time, the southern hemisphere is experiencing winters. Meaning, shorter days longer nights.
During the month of May, June, and July; the Northern Hemisphere experiences summer. And during the month of November, December, and January; the Southern Hemisphere experiences summer.
We can conclude that due to the Earth’s Tilt, “northern hemisphere’s summer solstice = southern hemisphere’s winter solstice”.
As far as the equator is concerned; there is no change in the season. Because each day sunlight strikes the equator at the same angle. In other words; every day of the year, the equator receives 12 hours of sunlight.