Timeless Scientific Follies, Courtesy of 1906

I record public domain audiobooks of works that are out of copyright for the website Librivox. My most recent project is a section of John Phin’s The Seven Follies of Science, a collection of bogus inventions, ideas, etc. based on seven impossible “scientific” ideas. Although Phin is most famous as a theist, this book shows that he was very well versed in science and mathematics. For something written in 1906, the modern scientist will find it quite readable.

My section in particular deals with perpetual motion machines. Phin divides these up in a section on “absurd” devices into a few core classes:

I. “Directed Momentum” Machines
These machines use weights placed at strategic positions, either in channels or attached via rope or rigid rods, around a central spinning wheel. The (fallacious) idea is that the weights will counterbalance one another perfectly to prevent the wheel from slowing down or stopping. See below for a few examples from the book.

II. “Hydraulic” Machines
The idea of these machines is that the weight of water in a large container has the ability to push a smaller, deeper quantity of water through a connected tube and back into the top of the container. This is physically impossible because the water in the large container can only exert enough force to push deeper water to its own level—no higher.

Hydraulics gone wrong!

III. Liquid Conveyors
The most interesting of these uses an Archimedean screw to convey water upwards, which falls back down to power the screw. It’s not tough to see that the force of the falling water will not be sufficient to turn the screw, despite the drawing below. Phin debunks a similar idea that employed mercury in place of water (because, you know, mercury doesn’t stick to stuff).

A miller's dream (but physically impossible!)

IV. Capillary Action Machines
Interesting idea here—can capillary action result in perpetual motion? Unfortunately the answer is decidedly no; however, Sir William Congreve of Congreve rocket fame did his damnedest to build such a machine (and before Congreve, even Robert Boyle speculated about the possibility of such a machine). The machine looks creepily like tank treads!

A machine for perpetual motion via capillary action

V. Magnetic Machines
It’s invisible, it’s funky…and a lot of people believed it could facilitate perpetual motion. However, machines incorporating magnets, such as the one below, are also shown bogus.

Perpetual motion via magnetism?!

The chapter contains all kinds of other ridiculous stories, and several additional classes of “perpetual motion machines.” A good read! Here’s a link to my audiobook chapter.

Chemical Education Roundup, 6-12-2011

This week has been an interesting one in chemical education. I know I promised interactive concept mapping on the web like two weeks ago, but things have gotten a little crazy as I’ve gotten stuff together for a publication (and realized the massive amount of work I have to do to make the publication complete). I’m going to go ahead and stamp it with a “Coming Soon” label.

At any rate, the Journal of Chemical Education was abuzz this week with a debate about the role of the rate-limiting step assumption in enzyme kinetics. Definitely worth a read if you’re a biology-leaning chemist with an interest in Michaelis-Menten kinetics.

In Science, experimental philosophy in the social sciences came under the gun this week, as Shaun Nichols and David Carmel debate the role of surveys in social-science experiments. In education, the value of triangulation has been recognized for a long time as a means to support survey data. Student performance data, qualitative observations, student interviews, focus groups, and a loooong list of assessment techniques (including, but not limited to, surveys) may all be used to judge the effectiveness of a classroom intervention or change. In fact, when such data are missing, raised eyebrows are the norm. Personally, I learned this lesson the hard way on my first publication… 😛

Speaking of classroom assessment, this JCE paper outlines a qualitative approach to assessing “inquiry-based” teaching methods, which involve open-ended problems that demand application of the scientific method to reach a reasonable solution. The authors argue that most current assessment techniques are inappropriate for inquiry-based activities (IBAs), advancing the “mental models” framework as a theoretical basis for assessment of IBAs. Critically, the goal is to shift the focus of assessment toward the learner and away from content exposure (and other irrelevant measuring sticks).