Introduction About the author As a long-time woodworker, I enjoy being able to tell one wood from another. In the process of learning how to do that, I’ve developed some knowledge of wood anatomy that I think will interest both biology students and woodworkers. There is an enormous variety of wood-anatomy characteristics; this article discusses…
Overview of “What If” Questions We receive many “what if” questions here on Physics Forums. This article explores three common types and offers suggestions for students whose questions may fall into one of those types. “What if” questions that contradict physics as we know it. “What if” questions that are themselves self-contradictory. “What if” questions…
Introduction In this Insights Guide, the focus is entirely on types of languages, how they relate to what computers do, and how they are used by people. It is a general discussion and intended to be reasonably brief, so there is very little focus on specific languages. Please keep in mind that for just about…
The Balloon Analogy is a straightforward way to illustrate — without being complete — two important points of modern cosmology that many people find counterintuitive: that the universe expands roughly uniformly and that it has no center or edge (in the sense relevant to the analogy). The analogy is unpopular with many professional physicists because…