中國玄學基礎知識 (二)

地球與太陽的關係

The relationship between the earth and the sun

Chinese Metaphysics Basics 2

（The English version is available below)

 

想了解曆法， 我們可以先從地球與太陽的關係入手。

 

我們都知道地球圍繞太陽運行的同時，地球自己都會自轉。

 

地球自轉一圈就是一天，有太陽照射到地方就是白天，沒有太陽照射的地方就是黑夜。

 

你們可能會有疑問，為什麼白天和黑夜的時間長短不同？

 

地球圍繞太陽運行的軌道(稱黃道) 與地球本身的赤道不是重疊， 而是傾斜約23.5度，這就形成地球上不各個地方都有不同接收日照的時間。

 

再加上地球圍繞太陽運行，不是真正的圓形，而是近似圓形的，橢圓形。這樣有些地方四季分明，而隨著季節變化，會出現「日長夜短」或「日短夜長」 。

 

To understand the calendars, we can start from the relationship between the earth and the sun.

 

We know while the earth orbits the sun, the earth itself revolves on its own axis too!

 

One rotation of the earth is a full day. The half of the earth’s surface facing towards the sun is in day time whereas the other half of the earth’s surface, facing away from the sun is in night time.

 

You may wonder why the lengths of day and night are different?

 

This is because when the earth rotates around the sun, which is called the ecliptic, it does not overlap with the equator of the earth, but inclined by about 23.5 degrees, so it causes different places on the earth receiving sunlight at different time.

 

Moreover, the earth orbits the sun in an oval-shaped called ellipse thus there are four distinctive seasons for some places. The seasons change together with the tilt of the Earth creating "longer days than nights" or "shorter days than nights".