"Sustainable" in a poem

As I have mentioned previously, April is National Poetry Month and also Mathematics Awareness Month -- and the mathematical focus is "Mathematics of Sustainability."  To try to connect these April celebrations, I went to the website  www.Poets.org  and searched for a poem containing the word "sustainability."  There I found  "Patience" by Kay Ryan which contains these lines:

       Who would
       have guessed
       it possible
       that waiting
       is sustainable —
       a place with
       its own harvests.    

Please go here to Poets.org to read Ryan's entire poem.

Summing thin slices

This poem by recent (2008-2010) poet laureate Kay Ryan at first made me think of calculus, of integration, summing all the thin slices to find the area under a curve.  And then the poem moved me on.