Children's Art Has Its Own Logic

Even simple scribbles are meaningful. While it was once thought that kids only scribbled to experience the physical sensation of moving their arm along the page, “now it’s been shown that when children are scribbling … they’re representing through action, not through pictures,” said Boston College’s Winner. “For example, a child might draw a truck by making a line fast across the page and going ‘zoom, zoom,’ and so it doesn’t look like a truck when the child is done, but i...

 Back-of-the-Envelope Calculation

It was from Kuiper that I first got a feeling for what is called a back-of-the-envelope calculation: a possible explanation to a problem occurs to you, you pull out an old envelope, appeal to your knowledge of fundamental physics, scribble a few approximate equations on the envelope, substitute in likely numerical values, and see if your answer comes anywhere near explaining your problem. If not, you look for a different explanation. It cut through nonsense like a knife through butter.