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A Six-Hour Tour. (A Six-Hour Tour)

July 14th, 2008 · 2 Comments

Well. I had planned to write the story of my weekend in Atlanta watching a wedding, but a whopping six hour delay at the Hartsfield-Jackson Atlanta International Airport meant I didn’t get back home in time to write up much here to make the Monday morning post. With any luck I should have that written up for you by Tuesday morning. Suffice it to say that there was lots of delicious wedding food, Mr. W and Miss S became Mr. and Mrs. W, and since Mr. W and his father are petroleum engineers and many of their friends are engineers as well, there was plenty of good sciency conversation even though most of the crowd wasn’t particularly science-inclined.

And even though the six hour delay at the airport was extremely frustrating and nerve wracking (did I mention the flight was oversold and I ended up on standby?), I at least had plenty of time to read some of M. Scully’s excellent Quantum Optics textbook.  There’s a particularly interesting discussion on whether the photon has a wavefunction, which explores some interesting territory and consequences that I haven’t read much about previously.  The short answer is “not really”, but it’s a more subtle point than you might initially expect.

So as you read this, I’m probably off teaching the undergrads about Faraday’s law.  And I have a doozy of a quiz for them.  Here’s hoping they pay attention!

And finally, andy.s gets 10 bonus points (1:1 exchange rate with Whose Line Is It Anyway points) for correctly solving the other quiz problem a few posts down.  Good job!  He also makes me feel guilty for not having spent the time to figure out how to put LaTeX on this server despite it having been on my list of things to do for several weeks now.  I promise I’ll get around to it eventually!

Tags: Miscellaneous

2 responses so far ↓

  • 1 Carl Brannen // Jul 14, 2008 at 3:07 pm

    Regarding the photon wave function, the argument has been going on for years. You might like my version of what Hawton’s photon operator has to do with the Consistent Histories version of QM.

  • 2 CCPhysicist // Jul 15, 2008 at 6:29 pm

    You are lucky you got out of there, but the USAir hub in Charlotte (?) is worse.

    As for that quiz problem, solving it is only part of the story. You didn’t tell me how many included a free-body diagram in the solution (something I mark off if they omit it).

    By the way, since it is probably not obvious, the questions I asked about typical errors are an example of the kinds of things I research these days. Have they learned to transfer knowledge from Physics 1 (free-body on an incline) to Physics 2? I like the problem you assigned because it has a lot in common with another type (wire swinging out at an angle) that also mirrors a standard statics problem from Physics 1.

    Matt replies: There were two main errors I noticed. The first was people messing up the trig for the forces. Sine where there should have been cosine, things like that. I more or less expected there would be some of that. The second wasn’t expected; people knew there was a cross product involving L cross B where L is the direction of current flow. Since the answer involves the sine of the angle between them, some people just used the only angle explicitly given in the problem - the angle of the incline. But clearly this is not the angle between L and B, which is 90 degrees.

    I would have been asking the petro engineer exactly which parts of physics and chemistry are used on a regular basis so I can transfer that to my teaching and that of my chem colleagues.

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