Monday, May 28, 2007

Which constants should students memorize?

High school physics students, specifically.

Some might argue for none. I can see some reason in that. Many think of memorization of any kind as a burdensome task that kills all joy for miles around. Such absolute aversion may be an overreaction to bad instructional experiences from one's own past.

At the moment, I can see some value in having high school physics students internalize five constants:

Gravitational acceleration at the surface of the earth: g = 9.8 m/s^2
Elementary charge: e = 1.6 x 10^-19 C
Speed of light in free space: c = 3 x 10^8 m/s
Universal gravitation constant: G = 6.67 x 10^-11 kg m^2/kg^2
Coulomb constant: k = 9 x 10^9 N m^2/C^2

High school physics teachers all tend to think alike and readily agree on all maters pedagogical. So I'm guessing that if these are the values I think should be memorized, the rest of you agree by default. Am I right?

Sunday, May 20, 2007

Why the sky is blue

Here is my lesson on why the sky is blue. It's a combination "springboard"/presentation. That means students get a sheet with questions to be answered through class discussion during the presentation. The presentation includes images and animations to illustrate what's going on. Read over the student worksheet (and especially the teacher's edition with answers) and step through the interactive presentation before trying this one in class. This is no autopilot-style lesson. The teacher must teach this one and you need to know some details to flesh the whole thing out.

Student Springboard (worksheet)
Teacher's Edition (answer key)
Presentation (zipped interactive QuickTime: 39MB)

QuickTime (free)
Means to project the presentation (not free)
Resonant tuning forks
PTSOS visible optics "skinny fish" tank
Scattering agent (Mop-N-Glo or equivalent)
Flashlight (mini maglite or equivalent)

As always, I'm eager to hear your comments.

Tuesday, May 15, 2007

What's up with PhysicsBowl 2007?

I ask because I've been checking the official unofficial website at

and I'm not getting this year's results. I can see this year's test and answers, but not the results of the competition. If you know something I don't let me know.

You know what would be good in a situation like this? An online physics educator forum (see the post below).

UPDATE 1: Wednesday has come and gone; still no results. I posted a query to Richard Olenick, current head honcho/fearless leader of the AAPT Examinations Editorial Board; I'll let you know if I hear anything. In the meantime, it's fun to watch the page counter spin. When I started checking the page mentioned above, the counter was under 6000. At the moment of this update, it's pushing 9000. Yeah, I need to get out more.

UPDATE 2: The results are in. The Division 2 average was 17 out of 40 (typical of this challenging competition exam). In the California/Hawaii Region, first place went to Mission San Jose in Fremont, CA. Second place went to Mira Loma right here in Sacramento! The top scoring student in our Region/Division was Henry Tung of Torrey Pines in Santee, CA. Second place student was Erik Chen of Mira Loma! Congratulations to this year's winners. For complete results, click the link posted above.

Listservs are sooo 1995

Ah, institutional inertia. We physics educators might pride ourselves in innovative techniques and strategies, but in the end, we're likely as bad as anyone else.

So it is with listservs. When email was an emerging technology, the listserv provided a means by which people with similar interests could broadcast emails to each other. Responses were similarly broadcast, and conversations took place. Listservs were good. At least they were in 1995. The physics teaching community weighed in strong with the Physhare and Phys-L listservs, not to mention the AP Physics listserv.

Time and technology march on, though. So these days, people with similar interests typically communicate via online forums. These are webpages that fill with threads comments from individuals. Not strings of email to clutter up your email storage space. Webpages that occupy their own webspace. Brilliant! And de rigeur for online communities since about 2000.

Examples: The DPReview Forum (for digital camera enthusiasts) and the JREF Forum (for skeptics).

So here it is 2007. Physhare and Phys-L continue apace. But where are the true online fora for physics educators? If I had the skills, I'd set one up myself. Clearly, there are physics educators out there with the skills. It takes time, talent, and energy just to keep the listservs afloat. But listservs are yesteryear's news. Reminds me of ye olde BBSs: great in their day, but their day has passed.

If they're out there and I'm too dim a bulb to find them, please light my way! And if you can tell me why a listserv is better than a true online forum, please do. I'm clearly ranting here, but I'm open to education.

Sunday, May 13, 2007

Science PhD gender gap narrowing?

It could be that I lack the proper optimism, but the trend didn't appear as earth-shattering to me as it did to the author of the article. Especially the most recent data points! When the top bar on the graph is at 50%, I'll breathe a little easier. Until then, there is work to be done. Click the graph to get the full story from the Sacramento Bee.

Among the best lines from the article: "[Suzanne} Barber, a fourth-year doctoral student, is one engineer who hopes the phenomenon leads teenage girls to discover the sciences and reject frivolous media portrayals of young women. 'This idea -- be like Paris Hilton or Mandy Moore. I think it's important to show a different side of what a woman can be,' said Barber, who is studying materials science engineering.

Bonus blogpoints if you can identify what's wrong with the graph. Comment away!

Saturday, May 12, 2007

Watch carefully to figure out the trick

Skeptical trickster Richard Wiseman is at it again. This time with "The Amazing Colour Changing Card Trick."
Props to The Bad Astronomer.

Tuesday, May 08, 2007

We are the champions, my friends

Quizmaster Chris, Christy, Kelly, Billy, Gary, and Dean. Weapons of Mass Instruction Win TriviaBowl V. Photo by Todd Freund.

It started as a lark on a "Veterans' Eve" Thursday. A group of teachers entered the weekly trivia contest at Sacramento Brewing Company. Six of us huddled around an answer sheet as the Quizmaster bellowed questions from the bar area of the brewpub. We fiddled and fussed over our answers and cheered for each correct answer during the post-quiz answer revelations. We won on that very first outing in 2005, beating over a dozen other teams. Since then, our cast of characters has varied a bit, as has our Thursday night trivia success.

Tonight though, we won the Big Kielbasa.

To make things more interesting, team scores from each Thursday quiz accumulate to quarterly totals. This sum determines a quarterly champion. Our team, comprised almost exclusively of Rio Americano High School teachers, finishes in the top five each quarter. But last Thursday, we broke through and finished at the top of the heap. Team Rio was the quarterly champion at last! (The $100 cash prize paid for that evening's comestibles and libations.)

The top five teams (and a few wildcards) from two brewpubs then go at it at the quarterly TriviaBowl. You can see how serious this stuff gets! As Sac Brew quarterly champions, we went to the rival bar to represent our home pub and our school pride. We've been to these competitions before. As Sacramento trivia competition goes, this is The Bigs. We enjoy the contest, but we just don't take our trivia very seriously. So we usually finish in the middle of the pack.

The questions in tonight's TriviaBowl were brutal and we were short one player, but we stepped up and took top honors. The prizes included giant magna of Sac Brew's "Pickled Brains" Tonic (see photo above), limited-edition T-shirts, and the addition of a signed team vegetable to the "pickled brains" jar. And wow, what an aroma that thing unleashes when opened! I feared for my eyebrows.

As the member who contributed least to the win, it fell upon me to tell the story and spread the word. That and I was the guy with a camera and a blog. There is no history unless you record it.

Sunday, May 06, 2007

Updated: Web Video for the Classroom

The Northern California and Nevada section of the American Association of Physics Teachers (NCNAAPT) met Friday and Saturday at Stanford, I presented a talk on the Web Video for the Classroom page I maintain. Pretty groovy to see these clips on a huge screen in a Stanford lecture hall, and those in the audience seemed to enjoy the show. I added a few clips to the collection, so I thought I should jot a quick post.

No doubt there are other physics video treasures out there. Let me know so I can add them to my page.

Oh, some attendees of the meeting asked about the skeptics group and conference I referred to when showing the firewalking clip. The group is the James Randi Educational Foundation and the annual meeting in Las Vegas is The Amaz!ng Meeting.

Friday, May 04, 2007

Peppermint party

As Rio Americano headed into the second week of STAR testing, a new test-preparation strategy was brought to bear. The tradition of providing snacks for student test-takers was continued as it had been practiced since the implementation of STAR testing lo those many years ago. But with a twist. Classroom snacks distributed for this week's tests included carefully counted and bagged peppermint candies.

The prescription, provided by the school's administration was to "hand one peppermint to each of your STAR testing students prior to taking the test." Why give students mint-flavored candy before a state-mandated assessment? The directive from the administration explained, "It is a proven fact that peppermint has been known to stimulate the human brain."

I was unaware of this "proven fact." My skeptical hackles were raised. I reflexively "reply to all-ed" with a request for evidence and some light-hearted criticism of the idea. Then I looked for the evidence (or lack thereof) on the web. There were some popular press items about peppermint aroma and cognitive tasks. But they seemed sketchy. There were also dismissals of those studies.

From the "Ask a scientist" column at Cornell Center for Materials Research, "Will eating peppermint candy help you to do better on a test? Probably not; there is no solid scientific evidence that peppermint will boost test performance."

From, "...on the basis of [a] newspaper article, some teachers are giving their students peppermint candy because 'research proves that candy improves memory.' Is it any wonder that some neuroscientists are beginning to accuse educators of engaging in pseudoscience or worse, becoming "snake-oil salesmen" for products and programs that have no real scientific foundation?"

I broadcast links to the dismissals to my colleagues, and the results were somewhat predictable. Though I took measures to couch the "bad news" in humor and good cheer, I was criticized for being such a curmudgeon. This wasn't my first rodeo, so I anticipated that result. Most people who have confronted woo among friends, family, or co-workers quickly learn that in polite company, woo is supposed to be given a free pass. Given the ironic twist that the peppermint strategy was deployed for the STAR tests in science, I couldn't just stand by.

I launched the topic as a thread on the James Randi Educational Foundation's Education Forum. The resulting banter was more enlightening than what occurred at school. Still though, you can always count on JREF forums for contrarians. And one did due diligence in an attempt to bolster the peppermint story. He fell short in my estimation, but not for lack of effort.

In the end, there's just no experi-mint-al evidence for this odoriferous claim. I made a funny!

ADDENDUM: JREF Forum member Suggestologist sent me the link to the NPR story on peppermint. They hasten to confess a lack of scientific support. But the story was just too tasty not to air. I'll be here all week; don't forget to tip the wait staff.