Generalized coordinates, trajectories, lagrangians, and action

I just spent 3 hours watching Leonard Susskind [Wikipedia page] deliver two lectures on Classical Mechanics via iTunesU. I started this over Winter Break (I watched 4 lectures), but I stopped because I didn’t have the proper time to devote. Once you stop, and enough time passes, you have to start all over [1]. Plus I hadn’t bought a pretty $15 notebook from Paris to take notes in.

But I started over, notebook in hand.

The end result of this is: I’m inspired. I love love love learning about trajectories, generalized coordinates, lagrangians, and principles of least action. Plus, there are some pretty neat digressions or mini-lectures I could use for my multivariable calc class next year.

I highly recommend it. You just need calculus (and some basic multivariable can’t hurt). It’s a bit hard to find on iTunes, but this link might take you to the first lecture. It’s his Stanford PHY 25 course taught in 2007 (October – December).

[1] It reminds me of borrowing the 1st season of LOST from my friend, who had the last seventh disc out on loan to a different friend. Once I finished the first six discs, I was hungry for the last. But still, the other friend refused to return it. And to this day, I have not seen the entire first season of LOST. Now, since so much time has lapsed, I will have to start the season all over again. (Double sigh.)

And the blogosphere keeps marching on…

When I was away in Paris for Spring Break, people didn’t stop blogging. I spent a good number of hours catching up, while I’m sick and not in the mood to do anything really active. (When am I ever really in the mood to do active things, though?) So I logged into netvibes and buckled down… carnivals… posts… links…
picture-1.png

There’s a lot of good stuff out there. Here’s some that I want to highlight:

  1. A primer on the zeta function: you know this person knows how to break something down and present it in a clear way. It builds up, from smaller simple examples to build intuition, to a grand finish.
  2. An analysis of whitespace — physical, and metaphorical: “I like to talk. I really wish I could just and listen to myself, because the information that I spew out is just awesome stuff. My students might disagree, though. If I reduce the amount of noise that I make, my students will be more likely to hear the important things I tell them. As a side note, I find that the misbehaviors in my class seem to happen when I am talking or the students are otherwise disengaged. So the less I talk and the more I work, the better! “
  3. A funny (but insightful) take on parent teacher conferences, which I had to pass along to a number of my teacher friends. To whet your appetite: “I also feel I must apologize. I am sorry that I sent your child to the nurse the other day when he complained of a toothache. I don’t know where my head was. Thank you for the quick analysis of my motives via email that afternoon. Had you not pointed it out, I would have never picked up on my underlying desire to lessen the number of students in my class by sending them to the nurse for innocuous ailments. I got your message loud and clear though. Your use of 18 point font, bold print, all caps text really aids in the reading process. From now on, I will not send him to the nurse for toothaches.”
  4. I struggle with homework, and it’s nice to know others do too. Good ideas for other forms of assessment are in the comments after the post. Huzzah!
  5. A small, silly, cutsie way to get students engaged when dealing with coordinate points.
  6. Carl Sagan on Flatland (from Science After Sunclipse)… Amazing expository. Good teaching. I was hooked and I know all this.

Pi Day, Reprise

On Pi Day…
In my seventh grade class, I had to forge forward with the curriculum, but I came up with something great to punctuate the class work with. We have been working with areas of geometric shapes (specifically circles), radicals, and the pythagorean theorem. One day, a few days before Pi Day, I drew The Perfect Circle on the whiteboard. They were impressed. I was lucky — but I didn’t play it off as luck, but practice and skill. I rehearse, I told them.

That night, I sent them this video over email:

And again, they were impressed. So I decided that in honor of Pi Day, I would hold a freehand circle drawing contest. They came to class psyched. One said he had practiced drawing circles in the air so much that his arm hurt, and another used a whiteboard marker on a mirror. We forged forward, and as we worked, we punctuated the class with the competition (3 students at the board at a time; the winner of each round got to compete in the final championship round).

The winner of the contest got to create — with me — the bonus problem for the next test.

Pi Day, Pi Day!

 
3 point

14159265358979323846264338327950288419716939937510

58209749445923078164062862089986280348253421170679

82148086513282306647093844609550582231725359408128

48111745028410270193852110555964462294895493038196

44288109756659334461284756482337867831652712019091

45648566923460348610454326648213393607260249141273

72458700660631558817488152092096282925409171536436

78925903600113305305488204665213841469519415116094

33057270365759591953092186117381932611793105118548

07446237996274956735188575272489122793818301194912

98336733624406566430860213949463952247371907021798

60943702770539217176293176752384674818467669405132

00056812714526356082778577134275778960917363717872

14684409012249534301465495853710507922796892589235

42019956112129021960864034418159813629774771309960

51870721134999999837297804995105973173281609631859

50244594553469083026425223082533446850352619311881

71010003137838752886587533208381420617177669147303

59825349042875546873115956286388235378759375195778

18577805321712268066130019278766111959092164201989

38095257201065485863278865936153381827968230301952

03530185296899577362259941389124972177528347913151

55748572424541506959508295331168617278558890750983

81754637464939319255060400927701671139009848824012

85836160356370766010471018194295559619894676783744

94482553797747268471040475346462080466842590694912

93313677028989152104752162056966024058038150193511

25338243003558764024749647326391419927260426992279

67823547816360093417216412199245863150302861829745

55706749838505494588586926995690927210797509302955

32116534498720275596023648066549911988183479775356

63698074265425278625518184175746728909777727938000

81647060016145249192173217214772350141441973568548

16136115735255213347574184946843852332390739414333

and so on and so forth…

Paris, or bust

I’m going to be heading off to Paris on Sunday, taking a much-needed break from the daily grind. I might post something before I leave, but I’ll be gone until March 26th.There’s a good chance I’ll be bringing my lappy toppy with me, so you might get an update or two from the French capital, but in case you don’t hear from me, I’m (probably) a-okay

Yahoo! for teachers

Update: Bill Fitzgerald and Dan Meyer are now on a similar quest.

Yahoo has started a new web 2.0 site for helping teachers create, manage, and share “projects.” I’ve dreamed of a site where teachers collaborate (as well as beg, borrow, and steal) online in a massive community. Yeah, bloggers read and comment, but that’s not what I dream of. I want a huge archive and discussions on projects.

This could be that, if we’re speaking with all the idealism and naivety of a ten year old. But for a site like this to work, people have to use it. Without having played with it, my initial spidey sense is telling me that instead of the website being adaptable to us, instead we’re going to have to adapt to it. Constrained by what the website constitutes a “project,” teachers are likely to think this site isn’t as natural as it could be. Instead of technology adapting to our needs, we might reconfigure our needs to adapt to this technology. And I’d like to have some… not promise… but strong indicator that it’s worth it before heading off into the technological blue.

It’s unclear to me how useful this is going to be (if at all), but I’m going to keep an open mind. One thing I’ve often noted is how hard it is to find smartboard presentations online. I create mine from scratch, but I also imagine that others would find them useful, as I would find looking at (and stealing parts of) their presentation of the same material useful. I secretly have a hope that one day I will be the facilitator to this giant city wide project which will get teachers who actually make lessons (smartboard, handwritten, typed, group projects, etc.) to upload them to some site to share.

In any case, the website is still in beta form: http://beta.teachers.yahoo.com/

I signed up for an invite forever ago, and just got invited to join today, but maybe anyone can get one now that they’ve opened it up for testing.