Sir Isaac Newton, renowned for his contributions to physics and mathematics, may have come up with a theory to explain the ascent of water in plants over 200 years before botanists, writes David Beerling in a Comment published online this week in Nature Plants.
How water moves up through plants, against the force of gravity, is explained by the widely accepted cohesion-tension theory, first proposed by botanists in 1895. According to this theory, evaporation at the leaf surface pulls water up through the plant in continuous columns.
Newton recorded his thoughts on the upwards movement of sap in trees in one of his undergraduate notebooks sometime in the early 1660s. In line with the cohesion-tension theory, he appears to describe how energy from the Sun causes sap to continually rise up through trees via ‘pores’ in the stem.
Beerling notes, “It should come as little surprise that Newton’s genius was capable of presciently imagining the germ of an idea explaining the ascent of sap in plants some two centuries before botanists came up with it for themselves.”