Is winter half over?

     Today (February 2) those of us with roots in Pennsylvania join enthusiasts from everywhere as we  look to mythical groundhog Punxsutawney Phil for a forecast concerning prolonged winter or early spring.  This morning Phil's forecast was bleak but not unexpected: we will have six more weeks of winter.
     This news that our winter is only half over has led me to a poem (found in the illustrated anthology Talking to the Sun, edited by Kenneth Koch and Kate Farrell, published in 1985 by the Metropolitan Museum of Art):

      Another Sarah     by Anne Porter (1911-2011)
                 for Christopher Smart
       When winter was half over
       God sent three angels to the apple-tree
       Who said to her
       "Be glad, you little rack
       Of empty sticks,
       Because you have been chosen.

       In May you will become
       A wave of living sweetness
       A nation of white petals
       A dynasty of apples."

Another winter poem by Porter with a bit of mathematics is included in this post for 25 November 2012.

Lincoln and Euclid -- common notions

     This afternoon I enjoyed the recently-released film, Lincoln -- appreciating Sally Fields as Mary Todd, Tommy Lee Jones as Thaddeus Stevens and (especially) Daniel Day-Lewis as Abraham Lincoln. An absorbing drama -- inspiring and also informative.  With a slight mention of mathematics:  in a film conversation with two-young telegraph operators, Lincoln reflected on his study of Euclid and shared with the young men the first of Euclid's common notions:

     Things that are equal to the same thing are equal to each other.