Youth reflects the blackness of a fertile ground, filled with life, ready to rise, to vibrate, while the most distant and whiter cloud , in turn, contemplates all the earth and has the function of allowing the light to pass or not to pass.
And also of managing climate,  time, and takes all the force that germinates which is the intelligence of the youth.
 Heaven and earth, youth and understanding cannot be separated. All is nothing more than one.  
The child and the elder are the perpetual circle.