# Follow-up on specialized topics mentioned in the book

## Our friend, the skinny triangle: How skinny does it have to be?

Starting on page 20 of the book, we use a simple way to find the angle subtended by an object. We divide the height (or width or diameter) of the object by the distance to it. For our purposes, that works just fine. But if the object is very large or very close, we may have to visualize the situation in a different way. Click here for a page about that (in a new window).

## Paths of Earth and Moon as they orbit the Sun

On page 102 of the book, you'll see this picture of our planet and our moon as they travel around the Sun. Click here for a page (in a new window) explaining how this picture was made from a spreadsheet.

## The Oxford Comma

Why did I call the book *Sky to Space: Astronomy Beyond the Basics with Comparisons, Ratios and Proportions* rather than inserting a so-called Oxford comma to make it *Sky to Space: Astronomy Beyond the Basics with Comparisons, Ratios, and Proportions*? It was a judgment call. I decided to choose in favor of fewer marks to make a cleaner appearance. And handwritten commas, unless tended to carefully, can look like mysterious tiny insects. Reasonable people can differ. Here is a recent *New York Times* article on the famous case of an Oxford comma and overtime pay.