What is "heaven and earth are mysterious and yellow"?

"Mysterious heaven and earth, vast universe"-the concept of the universe was first put forward by China. The so-called universe refers to space, and the universe refers to time. Together, it is the concept of time and space. ("Huainanzi: the universe called by the Quartet has been called the universe since ancient times. In the west, this concept was put forward by Einstein, and now we have seen it in thousands of words, which means that we are stronger than the west for more than two thousand years.

Xuan means black, which is used here to represent the deep blue color in the sky; The birthplace of our Chinese nation is in the Yellow River Basin, and the soil is yellowish, so it is called "mysterious yellow of heaven and earth". As for the formation of the universe, as mentioned above, it was formed1500 million years ago according to the present statement. In ancient times, there were no advanced equipment and instruments for scientific observation and measurement. Only an adjective "Honghuang" could be used to represent that extremely distant era, which was equivalent to the concept of "no beginning" in Buddhism.