Sunday, August 17, 2014

How the Sun Sees You

I found this video to be totally captivating. The message is an important one. But the soundtrack is also nice. And then… how did they record this? See for yourself.

I love the "Oh My God!" moments. The appearance of the sunscreen didn't surprise me. We try to incorporate the opacity of sunscreen in our ExploratoRio Purple Haze exhibit. What I came away really wanting to know was… how can I set up a similar rig to capture live video in UV? Cameras with glass optics and glass filters and glass over their sensors are well protected against ultraviolet light.

The Exploratorium's Paul Doherty shared this informative Photonics article.

Ultraviolet Reflectance Imaging

The article mentions fused silica optics. Paul recalled grinding sodium chloride lenses for use in UV imaging. Fused silica and salt lenses? My ignorance is so vast, sometimes it hurts.

Here's a video tutorial on getting a DSLR modified and configured to shoot in the UV range. It's, well, a nontrivial affair.

Saturday, August 02, 2014

Planning the year: NGSS, AP1, and AP2 - Part 1: The broad strokes

My assignment for the 2014-15 academic year includes Physics, AP Physics 1, and AP Physics 2. The Physics course should be aligned to Next Generation Science Standards. Our students are years from facing NGSS assessments; right now school officials of nearly every stripe are focused on Common Core State Standards nearly to the exclusion of any other academic concern.

Last year marked my first attempt to let go of the past decade+ focus on California's now-abandoned academic content standards in physics.

Advanced Placement Physics 1 and Advanced Placement Physics 2 debut this year, and Rio has enrollments in both. Now that AP Physics B is dead and gone, The College Board is laying the AP1 and AP2 cards on the table. My friend, Chicagoland physics teacher extraordinaire, Martha Lietz, pointed me to her AP Physics resource page. And I have been poking around in the links!

This post will give a general direction of how I plan to implement the three courses at my school.

Physics remains a first-year course with an Algebra 1 prerequisite. It needs to fulfill the needs of NGSS as well as provide a suitable foundation for students who might elect to move onto AP Physics 2. It is not feasible to allow Rio's pipeline to AP2 be restricted exclusively to AP1 "alumni".

AP Physics 1 is a first-year course for highly-motivated students who have passed Algebra 2. It must cover the AP Physics 1 syllabus provided by the College Board. But it must also cover the expectations of NGSS.

AP Physics 2 is a second-year course for highly-motivated students who have passed Algebra 2 and a first-year physics course (Physics or AP Physics 1). It must cover the AP Physics 2 syllabus provided by The College Board.

In any case, here's my plan so far. Click to embiggen. Subject to change!

And yes, I'm willing to try the current fashion of energy before momentum. Wide ties/narrow ties. It seems that among the cognizanti, teaching momentum before energy is on par with wearing a wristwatch or typing two spaces after a period as far as age indicators go. I know there are strongly-held beliefs, arguments, and preferences here. Sometimes I think we get too exercised about such things.

In good company

The American Association of Physics Teachers formally unveiled its Fellows program at the Awards session of its Summer 2014 meeting at The University of Minnesota in Minneapolis.

Generally speaking, previous AAPT award winners were inducted as the Inaugural Cohort. I was a recipient of their Distinguished Service Citation in 2008. And that's how I came to be included on a list of physics-teaching heavyweights. It's true, I have an ego the size of Montana, but I'm also grounded enough to know I'm dwarfed by the giants on this list.

AAPT's Fellows Announcement Page
A List of the Inaugural Cohort

Thursday, July 31, 2014

AAPT SM14: Physics Force selected moments in high speed

The Physics Force provided the demo show for AAPT's Summer Meeting 2014 at the University of Minnesota in Minneapolis. I caught a few moments at 120 fps in HD and posted the compilation to YouTube.

Physics Force AAPT SM14

Sunday, July 27, 2014

My AAPT SM14 photo album begins

Most images are from Sunday's High School Share-a-thon at The American Association of Physics Teachers Summer Meeting 2014 (AAPT SM14) so far.

Monday, July 14, 2014

Yellowstone lightning strike caught on video

The lightning grounded through a tree and the voltage remained high through the conductive root structure. The heating of the surrounding (less conductive) earth was rapid and intense, resulting in what look like explosive pop of soil.

Click to link to the video
(Oh Yahoo News, why must you annoy me so?)

Lightning strike caught on camera at Yellowstone National Park - Lonewolf Sager

Enjoy the curious stat about lightning strike "gender bias". Oh, the original item mentioned that more men than women are struck by lightning. I'm guessing that male golfers are overrepresented among lightning strike victims.

Friday, July 04, 2014

I was bound to do this

So there I was at Victoria Falls, on the border between Zimbabwe and Zambia. The Victoria Falls Bridge spans a gorge through which the Zambezi river runs, post falls. We are told the deck of the bridge is 135 meters above the water.

At the midpoint of the bridge there is a low-slung hut through which bungee jumpers are fitted with harnesses and pushed over a precipice. We are told the bungee jumpers plummet 111 meters, though it seems the mileage would vary from one jumper to the next, depending on weight.

I'm much too bashful to reveal my weight, but the bungee operators wrote 111 on my arm after having me stand on a scale. Oh yeah, I signed up for this jump. I teach physics! I was bound to do this.

They harness you quite thoroughly, and cinch your lower calves to each other and attach them to the bungee cord with five carabiners. I was bound to do this.

They help you waddle out over the lip of the diving platform. Then it's "5-4-3-2-1-BUNGEE!" and off you go, into the gorge. But enough jibber-jabber. Let's roll the film.

Victoria Phyz Falls

Was I ever really in danger? As it turns out, yes I was. This very jump dropped an Australian woman into the Zambezi a few years back.

Aussie Tourist's Bungee Cord Snaps

I really only put myself at risk like this so that Dan Burns could generate some nice, personalized physics problems, if he is so inclined. If you think of some, leave them in the comments or email them to me.

Did I mention that I jumped off a bridge?

My African media shoeboxes

The month-long African safari is in progress!

Lightly-processed safari photos are accumulating on Flickr:

Accommodations and other random shots are accumulating here:

Videos are accumulating here:

The blog at Outdoor Safari Photographers. I was/am with them June 16-20 (Machaba), June 28-July 2 (Chobe/Pangolin), and July 5-9 (Elephant Plains).

Further details when I return.