This is Nancy, me, and our friend James in front of a large Sequoia tree. All of that wood did not just appear out of nowhere. Where does the matter for making a tree come from?
Trees are mostly made up of a substance called cellulose, which is a type of chemical called a polysaccharide. That means that it is made up of a chain of hundreds or thousands of sugar molecules, all hooked together. So where does the sugar come from? Plants produce sugar through the process of photosynthesis, using the energy of sunlight to combine water and carbon dioxide into sugar. So the matter the makes up the tree is mostly composed of water (from rain) and carbon dioxide (from the air.) So you could say that matter for the tree's growth really does just appear out of thin air.