Monthly Archives: April 2011

Words, Episode 6: “… 2000 times as small …”

I’ve been reading the very fine book Superconductivity: A Very Short Introduction, by Stephen Blundell, about which I’ll have more to say in a subsequent post. The book is very well written, with only a very few editorial infelicities in … Continue reading

Posted in Mathematics, Physics, Words | Tagged , , | Leave a comment

Why Does A Propane Torch Get Cold When Used? Updated, With Refrigerators

I was fixing a leaky water pipe in my garage yesterday, and so I had occasion to use a propane torch to heat up the pipe and melt the solder into the joint. It’s not something I do often, but … Continue reading

Posted in Physics, Physics puzzles, Thinking puzzles | Tagged , , , , , , , , , , , , , , | 9 Comments

A Practical Use For Logarithms, Part 2: How We Multiplied Large Numbers 40 Years Ago, And How Integral Transforms Use The Same Basic Idea

(Click here for Part 1.) A common argument for the use of technology is that it frees students from doing boring, tedious calculations, and they can focus attention on more interesting and stimulating conceptual matters. This is wrong. Mastering “tedious” … Continue reading

Posted in Mathematics | Tagged , , , , , , , , , | 19 Comments

Teaching Critical Thinking: An Example From Electricity And Magnetism

As I discussed in this post the other day, I believe that an excellent way to teach critical thinking is to present students with statements that are muddled, garbled, confused, poorly written, or just plain wrong, and instruct them to … Continue reading

Posted in Physics | Tagged , , , , , , , , , , , , , , , , , , | 3 Comments

Sense And Nonsense In Elementary Electricity And Magnetism

Today my students wrote the final exam in the first-year university course in electricity and magnetism (+ a two-week introduction to quantum physics at the end of the course) that I taught this past semester. I reproduce the first question … Continue reading

Posted in Physics | Tagged , , , , , , , | Leave a comment

A Practical Use For Logarithms

What can you do when you have to describe phenomena that extend over many orders of magnitude? One option is to use different units; this is what we typically do in every-day life: We use centimetres or inches to describe … Continue reading

Posted in Mathematics | Tagged , , , , , , | 11 Comments

Everyone Complains About Taxes, But Who Knows Where They Go?

David Olive writes about an American initiative to help inform citizens about how tax money is spent. By providing freely available information, one hopes that there will be a more sensible discussion about the perilous financial straits in which the … Continue reading

Posted in Economics | Tagged , , , , , , , | Leave a comment