Recreational physics is physics that’s pursued for the fun of it, out of pure curiosity, as play, or for entertainment.
It’s analogous to recreational mathematics, which the Oxford English Dictionary defines as “mathematics studied or indulged in for pleasure or amusement, esp. involving mathematical puzzles and games, the mathematical principles underlying certain phenomena, etc.”
Suppose you’re on a boat and someone throws the anchor overboard. You might wonder if that increased or decreased the depth of the water.
That’s a physics question. You could contemplate it for a few minutes or discuss it with your friends. It’s fun to think about and it doesn’t matter if you don’t answer it. The standard answer doesn’t require much technical knowledge and can be figured out without too much effort.
A Basketball Analogy
When a professional basketball player is playing a pro game, it’s a job: focus and technical sophistication are required, and there are consequences to doing badly. The same person can play basketball recreationally with friends on the holidays: those games can include pranks, kidding around, and silly wigs; the point is to have fun.
The same is true of physics. One might do it professionally, recreationally, or both.
The term “recreational physics” is not as common as “recreational mathematics,” a situation which has led some people to conclude that recreational physics doesn’t exist. That’s like saying that the cat roaming the neighborhood doesn’t have a commonly-agreed-upon name, therefore it doesn’t exist!
Firstly, there are many examples of people who have done recreational physics, as I’ve defined it at the top of this page. (One such person was Richard Feynman, who wrote specifically about playing with physics.) The cat exists.
Secondly, I’m not the only person to use the term “recreational physics” in this way. For example, Martin Gardner wrote in his autobiography :
My friend Ron Edge, a retired physicist at the University of South Carolina, made frequent visits to Hendersonville… We always got together to exchange information about recreational physics, a topic of interest to us both. Ron would write up details about new science tricks and toys to build in the periodical [named The] Physics Teacher.
The Physics Teacher is a peer-reviewed journal published by the American Association of Physics Teachers. Here’s a quote from a paper published in that journal (by Juan Miguel Campanario) :
Some popular books on recreational physics and books with questions and answers referring to physics are also useful as a source of amusing and interesting material [for teaching physics].
A Common Misconception
A common misconception is that a specific topic or question can be categorized as being “recreational physics” or “not recreational physics.” It doesn’t work like that. One can pursue a specific topic or question recreationally, professionally, or both.
The same is true of recreational mathematics. For example, Martin Gardner wrote :
No one can deny that paper flexagons [which he wrote about in his recreational mathematics column] … are enormously entertaining toys; yet an analysis of their structure takes one quickly into advanced group theory, and articles on flexagons have appeared in the most technical of mathematical journals.
It’s true that some topics or questions are better-suited to recreational pursuit than others. For example, few people have the time or money to build a linear accelerator in their back yard, so most people won’t be pursuing linear accelerator physics recreationally. In principle, though, a rich person could build (or rent) a linear accelerator for the fun of it.
Types of Recreational Physics
There are many ways to pursue physics recreationally. One way is to do physics questions for the fun of it. I wrote a page about places you can find physics questions well-suited to recreational pursuit. You could also:
- read about physics for enjoyment,
- watch a documentary or video about physics,
- attend a public talk about physics,
- repeat an old physics experiment (or do one of your own design),
- play a trivia game with (trivia) questions about physics,
- play with physics toys (e.g. simple electronics kits),
- watch a physics demonstration at a science center, or
- try the hands-on physics exhibits at a science center.
1. From page 181 of Undiluted Hocus Pocus: The Autobiography of Martin Gardner, published in 2013.
2. From “Using Counterintuitive Problems in Teaching Physics” by Juan Miguel Campanario, published in The Physics Teacher, Vol. 36, Oct. 1998, page 439.
3. From the Introduction in The Scientific American Book of Mathematical Puzzles & Diversions, published in 1959.