“Without vitamin C,” Anthony writes, “we cannot produce collagen, an essential component of bones, cartilage, tendons and other connective tissues. Collagen binds our wounds, but that binding is replaced continually throughout our lives. Thus in advanced scurvy”—reached when the body has gone too long without vitamin C—“old wounds long thought healed will magically, painfully reappear.”
In a sense, there is no such thing as healing. From paper cuts to surgical scars, our bodies are catalogues of wounds: imperfectly locked doors quietly waiting, sooner or later, to spring back open.
Forest Therapy, also known as “Shinrin-yoku,” refers to the practice of spending time in forested areas for the purpose of enhancing health, wellness, and happiness. The practice follows the general principle that it is beneficial to spend time bathing in the atmosphere of the forest. The Japanese words translate into English as “Forest Bathing.”
These days I am more interested in the reverse case [of Da Vinci's helicopter]: ideas that could have worked many centuries before they actually appeared. The economist Alex Tabarrok calls these “ideas behind their time”
Curious minds want to know why these ideas appeared so late — and whether there might be anything that would prevent delays in future. One explanation is that the ideas aren’t as simple as they appear.
The bicycle is not as straightforward an invention as it seems. To move from ox-hauled cart to human-powered bicycle requires smooth-rolling wheel bearings, which in turn need precisely engineered bearing balls. Modern steel ball bearings were not patented until the late 1700s, and demand from the 19th-century bicycle industry helped to improve their design.