How have the silence and emptiness of nature proven fulfilling to Montag after his former life and the pursuit of books in Fahrenheit 451?
Consider the time “needed to think all the things that must be thought” (p.143). He discovers “He was not empty. There was more than enough here to fill him” (p.144).
That is a loaded question, but I will begin to answer it.
Montag's former life was filled with technology. There was so much automation that relationships and the meaning of life suffered. Montag did not have to think, he just had to respond. This is clearly shown in the morning after Mildred's stomach is pumped, because the scene places the two of them being served breakfast by machines. This was just a subtle glimpse of what the technology must have been like.
After meeting Clarisse, Montag knew there was something more to this life, and this began his pursuit of books. He thought there was something real in them.
When he finally arrives in the great expanse of nature, he realizes that there are great details in nature, and they are soothing. He found great licorice smells and weeds that arose "like a child". He found a fire after walking the tracks that drew him in, not because he was a consumed fireman, but because of the warmth that it provided to those sitting around it. The big difference between his life prior to this moment and now is the fact that before his life was fixed and meaningless. Now, his life is rich and purposeful.
The silence and emptiness of nature gave him time to comprehend all that Clarisse had described as beautiful in this world. The moments walking along the tracks let him comprehend the sights and smells since he wasn't flying in a beetle at 200 miles an hour.