Wednesday, February 22, 2012

FTL Neutrinos? Maybe not

Slow down, Einstein slayers. The old man may still stand tall.

It appears there may have been an error in the faster-than-light neutrino findings that set the media world spinning last September. This just in from AAAS' Science Magazine (Science Insider).

Error Undoes Faster-Than-Light Neutrino Results

Hat tip: Shane Trimmer.

Tuesday, February 21, 2012

Scheduled to appear on Global Physics Department

Global Physics Department is a group of high school and college physics educators who meet weekly online to discuss physics, physics learning, and physics teaching. GPD uses Elluminate Live which allows for audio, video, white board, and chat communication.

The live event each week begins at 9:30pm (ET) / 6:30pm (PT) and runs for about an hour.

Moderator/instigator, Andy Rundquist of Hamline University, kindly invited me to present and I've been scheduled for Wednesday, March 21. The recent discussion of Modeling Instruction here at The Blog of Phyz apparently brought me to the attention of a Department member. So we'll talk about that.

Sessions are recorded, so you can entertain yourself running through their archives. I've done that and sat in on a live session. (Live sessions are more fun since they are interactive.) The presentation environment, Elluminate Live, does not suffer from lack of stimuli.

Monday, February 20, 2012

Mirror mirror

Since Apple is shutting down iDisk web hosting ( pages in a few months, I need to move and all the other sites and pages I've created over the past 15 years or so.

I've moved my web baggage to Rage. The mirror site should present a pretty convincing image. Eventually, I'll have pointing to the new space.

Compare for yourself:

CURRENT: (Will not survive past 6/30/12.)

NEW: (Trial status; hoping it will become permanent new home.)

Let me know if you spot any problems!

Modeling workshops 2012 calendar

Jane Jackson recently announced the 2012 calendar for Modeling Instruction summer workshops.

Full details, instructions, and links here.

There's one in Northern California hosted by NCNAAPT's own web weaver, Lee Trampleasure and polished veteran, Don Yost.

Sunday, February 19, 2012

Betrayed again!

An esteemed colleague, LaVerne Gonzales, offered me nuggets of wisdom while I was still very much a rookie. One of them was, "There are two kinds of computer users: those who have lost data, and those who will." I don't assume that the wisdom originated with him, but he was the vessel through which it was passed to me.

He was speaking of the importance of backing up one's computer files. Still a novel idea in the mid- to late-'80s, when personal computing was in its adolescence. I once had a backup regimen involving over 100 floppy disks, and Saturday morning was the scheduled time. Automated backup systems, such as TimeMachine, have since taken the drudgery out of long backup sessions

As a bemusedly graying veteran of computers and teaching, I add a corollary.
There are two kinds of computer users: those who have been betrayed, and those who will be.
My first taste of betrayal was with Silicon Beach Software's SuperPaint. SuperPaint was the initial design software used to develop The Book of Phyz c. 1988. But it seemed to get slower and buggier with each new release. By 1992, I had to jump ship to Deneba's Canvas. Canvas was once a Mac-only application. In 1992, it was tighter and nimbler than SuperPaint.

Back in the bad-old (pre-iPhone) days, software would sometimes originate on the Mac platform, become popular, get ported to Windows, then cease to be developed for Mac. And so it was with Canvas. ACDSee bought Deneba and killed off Canvas for Mac.

They recently introduced a Mac OS product intended to compete with Apple's Aperture and Adobe's Lightroom. I was moved to let them know exactly why no Mac user would knowingly choose to do business with them. The product is alive, but I know of no one who uses it.

But I have tons of curriculum material in Canvas X format with no viable alternative software available. As of Mac OS X 10.7 (Lion), Canvas X is dead. The pain of that harsh reality lies in the near future.

Another betrayal came in the form of a test-generating program called measureUP. By the time I bought into it, it had become LXR•Test. By the time LXR decided that the once Mac-only product would fare better as a PC-only product, I had developed an extensive bank of original test items. There was a long, slow, tedious process converting my old LXR items to ExamView.

ExamView seemed to be all the rage just a few years ago, when we adopting textbooks. But now ExamView is lagging behind on development for Lion.

Indeed, Mac OS X 10.7 Lion is a betrayal all its own. With it, a little internal code-gem known as Rosetta is dead. Rosetta allowed OS X software written in the early days of OS X to work on Intel-chipped Macs. By killing off Rosetta, Apple killed two of the programs central to my teaching: Canvas (also abandoned by ACDSee), and ExamView (Einstruction development status: undetermined).

And finally we have the betrayal which is the genesis of this post. Once upon a time, Apple embraced the growth of online activity. They sold a suite of online applications and services originally known as dotMac (.Mac) then renamed to MobileMe. I bought the product because its iDisk allowed me to host my website as if the directories and pages were mere folders and files on my desktop.

Years later, Apple's new toy is iCloud. In yet another of Apple's ham-fisted moves, everything MobileMe must die: MobileMe bad, iCloud good. So gone is iDisk and website hosting. Poof, as of June 30, 2012. Unlike with the end of the Mayan calendar, the end of this world is real.

I must now move my websites to a new home on the Internet. I own the domain name through 2018 via And I can make point anywhere I like. But I need server space. For now, I'm giving Rage a try. (The name nicely reflects my mood.)

Webpages, PDFs, and other documents are slowly filing (!) into the new space. I keep all the website files on my computer, so uploading everything is a simple, though time-consuming matter.

As of June 30, 2012, all my pages whose URLs include "" will go 404. If Rage pans out, the new URL detritus will be "".

The thing to remember is that and should always work. They'll redirect to new endpoints, but they should always get you there.

There's going to be much angst, confusion, wailing, and gnashing of teeth along the way. I hope it will be short-lived.

I haven't moved to Lion yet and will hold off on that as long as possible. I'll see if I can avoid use of iCloud, knowing that Apple is likely to wake up some morning and decide to shut it down. I have greater faith in DropBox at this point.

Then again, my track record for picking a long-term winner is not good. There simply aren't very many long-term winners in software to be had.

Saturday, February 18, 2012

Physics fashion: Magnetic nail polish

Yet another item to file under "Applications of elementary physics that somebody cashed in on, just not you."

This can also be filed under "You're such a dude; this stuff is sooo last October!"

Late to the party once again. Nevertheless, here it is: magnetic nail polish.

Sephora/nails inc. video:

Physics Central article: "Magnets: Where Physics Meets High Fashion"

io9 article: "The Physics of Magnetic Nail Polish"

Looks to me like the supplied magnet uses a Halbach Array ("rippled polarity") common to refrigerator magnets. I would say there is potential for add-on enhancements to this product. Who will be the enterprising artist who figures out how to make more interesting magnetic field patterns to freeze into polished nails? Candy stripes are OK, but should that be the end of it? How about neodymium chips set creatively into a ceramic base?

Hat tip: Jennifer Ouellette.

Friday, February 10, 2012

The enduring power of "Powers of Ten"

1. The Scale of the Universe 2" by Cary and Michael Huang. Hat tip to Katie Benvenuti.
This is first on the list because it's the one you probably haven't tried yet. Go ahead and play with it. I'm pretty sure you'll like it!

2. Powers of Ten by Charles and Ray Eames.

3. Cosmic View: The Universe in 40 Jumps by Kees Boeke.

4. Cosmic Voyage by IMAX Film Projects.

5. The Simpson's Powers of Ten Tribute courtesy of Dan Burns.

Thursday, February 09, 2012

The Lemon Battery

We built our lemon batteries in Physics 1 last Tuesday, and the energy was great!

Students are given a synopsis of the western-European development of the electrochemical cell (Galvani and Volta) the night before the activity.

On the day of the Lemon Battery activity, a digital multimeter (DMM) is used to show that the terminal voltage of a battery is independent of the size of the battery. A C-cell, an ignitor battery, and an N-cell are used.

Then each group is given half a lemon, and two galvanized nails on a durable plastic plate. When they achieve a design they think will produce at least 0.5 volts, they call the instructor over and use the DMM to get a reading.

The first design each group tries fails. The knee-jerk reaction is to stick the two nails into the lemon and call it a day. But the DMM reads "00.00" volts. Many designs indicate a fundamental "miss" in terms of knowing what's essential for an electrochemical cell. And a "miss" in terms of understanding the importance of item 3 on the apparatus list ("creativity and resourcefulness"). As groups continue to fail to get 0.5 V, spies are everywhere: My student teacher is working with the group of students to the right in the photo below. Notice the student on the left sneaking a peek.

Initial frustration is followed by eventual creativity and grade-school-like excitement when the half volt is attained.

Then clues and additional resources (paper towel, pennies, and aluminum foil) are made available so that groups can try to beat the the school record of 7.29 V set in 1999.

Not all the designs attempted are successful. But my students enjoy the activity! (And rings ARE fair game.)

The post-0.5 V "what now?" section of this activity is where I need to improve it. I think it's natural for groups to have a cursory grasp of the voltaic pile and make "lemon soup." That is, they stick everything they can think of into the lemon half. Which again leads to frustration and disappointment.

Groups that fully grasp the essential design elements of the pile are able to generate 1.0 V or more. Most don't get past the lemon soup phase before time expires.

This year's highest voltage was achieved by Group 3A, whose voltaic pile scored an impressive 2.40 volts on the DMM.

More pics in the 2012 00 Rio Phyz album.

Wednesday, February 08, 2012

Connecting wire continuity test?

There are seven lab activities we complete in our exploration of current and circuits. All of them require connecting wires. And we continue using connecting wires in our study of electromagnetism.

I'm fond of connecting wires ("alligator cords," "jumper leads") that have alligator clips on both ends. I'm also fond of miniature bulbs (flashlight bulbs) in miniature sockets. We put three flavors (2.5-V, 6.3-V, and 14.4-V) of mini-bulbs to good use.

But getting back to the wires. The alligator clip connecting wires that we've been using for many years (Radio Shack and Sargent Welch) are more about "cheap low-cost" than they are about "durable." Many go bad every year. When they do, they lose continuity; a gap suddenly exists, usually between the copper wire and the clamped-on alligator clip.

A wire can fail at any time. When it does, it's not obvious to physics learners that the wire has failed. This can lead to frustration. I scurry about as best I can, troubleshooting circuits as students ask for assistance.

If I suspect a bad wire, what's the best/quickest way to check it for continuity while the lab is in progress and other groups may be waiting for help? I'm not sure. Here's what I've been doing:

I connect the suspect wire to a Genecon and crank. A good wire will offer noticeable mechanical resistance. A bad wire will offer no more mechanical resistance than would occur if the Genecon's leads weren't connected to anything.

I've found that you have to "bounce" the wire a bit while cranking the Genecon to find pesky intermittent failures. It's fairly quick and painless, and doesn't require a meter of any sort. Better still, it garners quizzical, "What the heck is he doing?" looks from students. Later, they will use the Genecons, too. Then I'll be able to ask them how my continuity check worked.

Still though, I'd be willing to pay double (or more) for alligator cords/jumper leads that were built to last.

In any case, what's your preferred method of continuity testing during a lab?

And so it begins: ExploratoRio 2012

Rio's Open House is two months away, but our preparations for ExploratoRio 2012 began this week. ExploratoRio is the annual homage to San Francisco's Exploratorium Science Museum that I orchestrate. (You can find more posts on ExploratoRio by clicking the tag off in the column on the right.)

Two of the eight weeks between now and Open House are school vacations, and there is a sequence to this process that requires time. One thought that never strikes my mind when we're setting up on ExploratoRio Eve is, "we should start preparing for this thing LATER next year."

Too many ExploratoRio resources can be accessed via my ExploratoRio Page.

Step 1: The Posting of the Snacks (and Staff Positions, beyond the frame of this pic)

The snacks are taped over the student minibios that grace the back of the room all year. More on those in another post. (If I remember.)

Monday, February 06, 2012

Get your Scientist Valentines here!

It's that time of year again. Time to celebrate love and science for Valentines Day. My contributions can be found in my collection of Scientist Valentines.

There are 24 in all. "Collect 'em and trade 'em with friends!"

The story of these valentines can be found here and here.

Scientist Valentines