Trees Grow Out of the Air

Richard Feynman is a renowned physicist, known for his lectures and interviews, and known in the physics world for his contributions to quantum mechanics and particle physics. In his interviews he often enjoyed talking about everyday objects or occurrences that are “fun to imagine” on the atomic level. There is a “Fun to Imagine” series of Feynman clips on YouTube, and I’d like to share one in particular that blew my mind. In the beginning of the 5-minute video, he speaks of how fire works, then he goes on to explain how a tree works. It’s the tree segment that I will paraphrase:

People think that trees grow out of the ground. In actuality, trees grow out of the air. The substance of a tree is mostly carbon, which comes from the air in the form of carbon dioxide. Carbon dioxide goes into the tree, and the tree changes it, kicking out the oxygen, and uses the carbon as the base of all the new material it creates. The tree also uses water from the ground, but that water rained from the sky. There’s a little from the ground, some minerals and such, but most of the actual substance of a tree comes from the air.

We mentioned that carbon dioxide is changed by the tree to retrieve just the carbon. How is the tree so smart as to manage to separate the carbon from carbon dioxide? Ah, life! Life has some mysterious way! No - the sun is shining, and it’s the sunlight that comes down and knocks the carbon free. So it takes sunlight to get the plant to work.

What an amazing world we live in. As Feynman himself said, “nature’s imagination is so much greater than man’s, it’s never gonna let him relax!” My explanation can’t give the video justice, you’ll just have to watch it yourself!

- Evan