Physics for Entertainment

Update: I’m finally home after a month or so of nonstop events, including several xkcd book fund-raisers/signings.  I met tons of cool people, we raised a lot of money for the EFF and Room to Read, and at one point I signed a book for a robot.  Thank you to everyone who ordered a copy, by the way!  I hope you like it.  They’re shipping out nicely, and we’re about ready to order a second printing.

The events and travel were a huge amount of fun, and I loved getting to talk to (or at) so many of you cool people.  But I’m an introvert at heart, and after doing that much socializing I feel a powerful urge to hide in my room for about a month.  At some point in my travels I seem to have picked up a cold that’s been keeping me down for a couple days, so it’s just as well that I don’t have any more events on the immediate calendar.  There’s no fever, so it’s not swine flu, but it’s keeping me awake at night and I’m going through a lot of tissues and cough medicine.  But it should blow over in a couple days, and then I’ll get to spend a while quietly working on new projects!

While I’m doing that, here’s a bit about a neat book I found recently:

Physics for Entertainment:

Physics for Entertainment was written by Yakov Perelman in the 1920’s (in Russian) and updated periodically through the 1930’s.  There are actually two parts to it, but Volume 1 is long out-of-print (though findable online — more on that later).  The book I have is a 1975 translation of Volume 2. The book is a series of a few hundred examples, no more than one or two pages each, asking a question that illustrates some idea in basic physics.

It’s neat to see what has and hasn’t changed in the last century or so.  Many of the examples he uses seem to be straight out of a modern high school physics textbook, while others were totally new to me.  And some of the answers to the questions he poses seem obvious, but others made me stop and think.  The diagram to the right shows a design for a fountain with no pump — it took me a while to get why it works.  (For an easier-to-build variant, click here.)  Later in the book, he explains the physics of that drinking bird toy.

It’s written in a fun, engaging, conversational style, as if he’s in the room chatting with you about these neat ideas.

There are a lot of diagrams:

And it’s hard not to like the guy:

“If you’ll bear with me for a moment, let’s analyze this fairy tale from a physics standpoint …”  That’s a man after my own heart.

He also spends a lot of time discussing why various perpetual-motion machines won’t work.  it’s interesting to see that there was as thriving a community of free energy people a century ago as there is now, many of their designs based on the same misapplications of physics.

Lastly, when he talks about space travel — from a pre-space-age perspective — he turns starry-eyed and poetic:

I alternate wildly between thinking that it’s totally crazy that we clawed our way up out of the atmosphere and walked on the moon, and thinking that it’s a shame that it turned out to be so boring.  But I really desperately want to see more missions to places like the Jovian moons. If it turns out one of them is teeming with life, we’re gonna feel awfully silly about how long we spent shuffling around in the Martian dust.  Also, Kepler is really exciting, putting us in a much better place to speculate about life in the galaxy.

You can get the printed Volume 2 on Amazon, while Volume 1 was supposedly unavailable for translation or reprint.  However, I mentioned this book at one of the events recently, and reader Matthias Kübel emailed me to let me know Volume 1 is available free online!  I’m looking forward to reading through it.