As we march on toward Newton’s birthday, we come to the second of Maxwell’s famous equations, which is Gauss’s Law applied to magnetic fields: For once, this is pretty much as simple as it looks. The divergence of the magnetic field is zero, full stop. As I said yesterday (albeit using the wrong terminology), the… Continue reading The Advent Calendar of Physics: Monopole!
Category: Physics
Simple Answers to Stupid Rhetorical Devices
Over at Scientific American, John Horgan has a blog post titled In Physics, Telling Cranks from Experts Ain’t Easy, which opens with an anecdote any scientist will recognize: A couple of decades ago, I made the mistake of faxing an ironic response to what I thought was an ironic faxed letter. The writer–let’s call him… Continue reading Simple Answers to Stupid Rhetorical Devices
Mandatory Higgs Boson Post
I was planning to let today’s Higgs press conference pass with only a few oblique mentions in posts about other things, but apparently, I would lose my license to blog about physics if I did that. You’d think that, being married to a lawyer, and all, I’d know to read the fine print in these… Continue reading Mandatory Higgs Boson Post
Christmas Physics: How Strong Is One Grinch?
And what happened then? Well, in Who-ville they say That the Grinch’s small heart Grew three sizes that day. And then the true meaning Of Christmas came through And the Grinch found the strength Of ten Grinches, plus two — Dr. Seuss’s How the Grinch Stole Christmas It’s nearly Christmas, so SteelyKid keeps demanding to… Continue reading Christmas Physics: How Strong Is One Grinch?
The Advent Calendar of Physics: Gauss and Maxwell
As the advent calendar moves into the E&M portion of the season, there are a number of possible ways to approach this. I could go with fairly specific formulae for various aspects, but that would take a while and might close out some other areas of physics. In the end, all of classical E&M comes… Continue reading The Advent Calendar of Physics: Gauss and Maxwell
The Advent Calendar of Physics: E and B
Having covered most of what you need to know about classical physics, the traditional next step is to talk about electricity and magnetism, colloquially known as “E&M,” though really, “E and B” would be more appropriate, as the fundamental quantities discussed are the electric field (symbol: E) and the magnetic field (symbol: B), whose effect… Continue reading The Advent Calendar of Physics: E and B
The Advent Calendar of Physics: Newton’s Gravity
We kicked off our countdown to Newton’s birthday with his equations of motion, so it seems fitting to close out the section on classical mechanics with another of Newton’s equations, this time the Law of Universal Gravitation: Like all the other equations to this point, I’m cribbing this from the formula sheet for my just-completed… Continue reading The Advent Calendar of Physics: Newton’s Gravity
The Advent Calendar of Physics: Torque
Today’s advent calendar post was delayed by severe online retail issues last night and child care today, but I didn’t want to let the day pass completely without physics, so here’s the next equation in our countdown to Newton’s birthday: This is the final piece of the story of angular momentum, the undefined symbol from… Continue reading The Advent Calendar of Physics: Torque
Superlative Science Books
Three quick items relating to science in book form: 1) It’s that time of year again when every media outlet of any consequence puts out a “Year’s Best {Noun}” list, and John Dupuis is checking the lists for science books so you don’t have to. It looks like a pretty reasonable year for science in… Continue reading Superlative Science Books
The Advent Calendar of Physics: Using Angular Momentum
Now that we’ve defined angular momentum, the next equation on our countdown to Newton’s birthday tells us what to do with it: This is the Angular Momentum Principle, and as with energy and momentum before it, this relates the time derivative of the angular momentum (that is, how quickly it’s changing its value) to a… Continue reading The Advent Calendar of Physics: Using Angular Momentum