It took centuries to discover why plants are (usually) green and how they grow and create food from thin air. I was watching a programme about botany last night and there was a long explanation about the science of it.
First people experimented by weighing a plant before and after tending it for five years and finding that although it gained weight it did not affect the soil. Then they tried growing plants but without light, which meant they would not thrive. They realised that they created starch in their leaves, but took time realising they absorbed carbon dioxide and gave out oxygen as a byproduct.
The whole programme was very informative but I wasn’t taking notes. But the idea that humans could understand it and may be able to use the process artificially is amazing. The ability to turn sunlight into fuel would be something that could help humankind.