From fairest creatures we desire increase,
That thereby beauty's rose might never die,
But as the riper should by time decease,
His tender heir might bear his memory:
But thou contracted to thine own bright eyes,
Feed'st thy light's flame with self-substantial fuel,
Making a famine where abundance lies,
Thy self thy foe, to thy sweet self too cruel:
Thou that art now the world's fresh ornament,
And only herald to the gaudy spring,
Within thine own bud buriest thy content,
And, tender churl, mak'st waste in niggarding:
This  hyperbolic  line is characteristic of the poetic writing at the time, where knowledge of the cosmos was fresh and new, hence the reference to “the world”.  This is reminiscent of John Donne and the  Metaphysical Poets , who drew outlandish comparisons like this one. 
 It could be that this forms the  volta , though it isn’t clear where the break is. The speaker, though, does move from focus on the young man’s internal musings to the outward-looking “world’s fresh ornament”. This is a matter of interpretation and readers might view it differently. For example, the volta could be at the end of line twelve, preceeding the last couplet.
Sonnet 1