As a sort of palate-cleanser after the quantum chicanery discussed in the previous post, let me recommend Donald Simanek's Museum of Unworkable Devices, a wonderful collection of failed ideas for perpetual motion machines, including explanations of why they don't work.
I'm tempted to turn a couple of these into exam questions, the next time I teach mechanics...
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I suppose I really ought to say something about the "demonstration" of Steorn's perpetual motion machine that's supposed to start today, but, really, I don't have much to say. I mean, if they were claiming that their device extracted free energy from extra dimensions thanks to their revolutionary…
The folks at Harvard University Press were nice enough to send me an advance copy of Ken Ford's new book, 101 Quantum Questions: What You Need to Know About the World You Can't See a few months ago. I've been too busy working on my own book to read any other physics books, though, so the actual…
I'm giving an exam this morning (magnetic fields, circuits, magnetic forces on charges), which is always a carnival of boredom-- happily, I have papers to grade during the test, which will keep me busy. Sadly, this is not a final exam, as Female Science Professor and others are making or grading…
So, why math?
The short version of the answer is remarkably simple: math provides
a tool where you can, without ambiguity, prove that something is true or false.
I'll get back to that - but first, I'm going to make a quick diversion, to help you understand my basic viewpoint on things.
This…
Earlier today I saw on TV news a new service that's come out, where they use nitrogen rather than air to inflate tires.
The explanation for how this was supposed to work was that nitrogen molecules are larger and thus would not leak out.
I wrote that down as the guy was saying it, so that's not from memory.
Naturally, the news program has no fact checkers.
These people have no idea what they're talking about. They really ought to try nitrous oxide instead. It's a gas....
Here is the straight dope on nitrogen:
http://www.straightdope.com/columns/070216.html