Category Archives: technology

From Digital Junk Drawer to Online Exploration for Students

I’m not sure how many people will be interested in this post describing the tools and process I use to transform the bits in my digital junk drawer into online explorations for my students. However, I notice more and more educators using Macs, and, for those who don’t, they may be able to generalize these ideas using their own tools.

I create a topic page in [Schoology]( for every unit:

Topic page

This topic page contains a bunch of links at least somewhat related to the unit. Each topic page has categories for simulations, articles, videos, and projects to make. This topic page is from the first unit which is somewhat less focused than the others and, therefore, has subcategories as well. While some of this material will be referenced in class, most of it is just for students to explore and enjoy. When I introduce topic pages, I tell students that when they are procrastinating, they should click on these links rather than randomly browse the web.

Creating these topic pages takes very little effort because of the tools that I use.

Every time I encounter something that may be somewhat related to physics, or at least science, or maybe just education, I drop it in my digital junk drawer which is [Yojimbo]( To be more precise, I tag it as I drop it in Yojimbo. This is as simple as a clicking a button or hitting a keystroke in Safari or NetNewsWire and typing the tags. My tags are organized around the units that I teach, the main concepts that are covered, and the types of activities I perform as an educator. I keep a list of my tags in a text document that I can reference if I can’t remember which ones to use. My Yojimbo window looks like this:


Yes, I have over 4000 items in Yojimbo and most of them are related to education. Most of the time, I just keep tagging and adding items to Yojimbo. When we’re ready to start a new unit and its time to create or update the topic page, I use Yojimbo’s collections to organize the links that I want to feature:


It is easy to filter by tags in Yojimbo and sort by date. I review the new items that I’ve added since I last updated the topic page and drag them into these temporary collections corresponding to the topic page categories (the lessons/labs are for items that I want to incorporate into class rather than the topic page). Once I’ve reviewed all of the new items, I highlight all of the items in a category and use [FastScripts]( to run an AppleScript that generates HTML for all the items:

tell application "Yojimbo"
	set urlList to "<ul>
	set selectedItems to the selection
	repeat with bookmarkItem in selectedItems
		if the class of bookmarkItem is bookmark item then
			set urlList to urlList & "	<li><a href=\"" & (location of bookmarkItem) & "\">" & (name of bookmarkItem) & "</a></li>
		end if
	end repeat
	set urlList to urlList & "</ul>"
	set the clipboard to urlList
end tell

The script copies the HTML to the clipboard so all I have to do is paste it into the page editor in Schoology.

While I’ve focused on using Yojimbo to make it easy to create these topic pages, this is just one example. When I or another teacher vaguely remembers something, I can usually find it in Yojimbo in a matter of seconds. While I love [1Password](, Yojimbo keeps an encrypted record of all my passwords and serial numbers. I also encrypt weekly backups of my web-based grade book since I certainly don’t trust its security. Yojimbo can handle more than just bookmarks, I give it images, PDFs, and text notes referencing journal articles or books which aren’t available online.

And yes, if you are familiar with [Now, Discover Your Strengths]( and are wondering, Input is one of mine.

Near-Space Balloon

The Physics Club at my school recently completed our second-annual near-space balloon launch and recovery. Our goal was to launch the balloon payload to over 100,000 feet. We planned to record pressure, temperature, and radiation data; test the effects of altitude on biological samples; capture photos and video; and, ideally, recover the payload! While we didn’t achieve every goal, the launch and recovery was a resounding success.

An alumni of the Physics Club worked with Ken Walczak from the [Far Horizons project]( at [Adler Planetarium]( last summer and suggested that we contact Ken. The students contacted and met with Ken on their own, set the goals for the project, and designed and constructed almost every element of the balloon. (Ken provided the pressure and radiation sensors, while I provided the Arduino and temperature data logger.)

This project was a good excuse for me to buy a new Arduio Uno and the [Data Logger shield from Adafruit]( The data logger shield was easy to assemble, simple to interface with via the Arduino, and convenient to retrieve the data due to the SD card storage.

Armed with our supplies, we met up with Ken in El Paso, Illinois (selected due to its launch-friendly park and sufficient distance from Lake Michigan). With his experience, Ken provided many tips as well as the 1000-gram balloon!

We inflated the balloon:

IMG 5196

… assembled the payload and connected it to the parachute and balloon:

IMG 5201

.. and the president of Physics Club let go! (That process took over two hours!)

100 0316

The camera captured a great arial view of El Paso, Illinois:

IMG 1477

… and quickly rose above the clouds:

IMG 1567

While not definitive, based on our data, we estimate that the payload reached at least 105,000 feet:

IMG 2109

… before the balloon popped and the payload fell to earth:

IMG 2325

We used a cell phone that sent GPS coordinate to a web site to track the balloon. Unfortunately, the cell phone stopped sending coordinates immediately after launch. As a result, we had no idea where the balloon was until the payload landed back on the ground, two hours and forty minutes after launch. Fortunately, it landed in a vacant lot in a subdivision relatively close to the predicated location. We were able to retrieve the payload, recover all the data, and be home for dinner.

We had some issues with the data logging. The pressure data wasn’t valid (we were having issues before even launching; so, we weren’t too surprised). Also, the Arduino got too cold when falling and some of our temperature data may be suspect. Regardless, the graphs of temperature vs. time correlated with radiation counts will provide some authentic data for our freshman earth science class next year:


Next year, we plan on replacing our cell phone-GPS tracking system with a GPS receiver connected to a APRS transmitter. We don’t like losing contact with the payload during launch. We also hope to invite our district’s middle schools to design experiments to include in the payload. The students also expressed interest in adding a camera facing upward to capture a new perspective.

If you are interested in launching your own near-space balloon, feel free to contact me and, while limited, I’ll share our experiences!

How My iPad Replaced My Laptop

I started the fall semester with the intention to see if my iPad could replace my laptop during the school day. In short, it has. How was this possible? Before I elaborate, I want to be clear that I have an iMac at home that I use all the time and there are days that I use my school-issued tablet due to limitations of the iPad.

Key Features

I’ve been surprised by several of the features that I most appreciate about the iPad.

The best is that it turns on instantly. It takes my school-issued tablet several minutes to boot. Even if I wake it from sleep, it fails to connect the the wireless as often as not and requires at least a reboot. While this is an appreciated feature for me, I’ve recently realized that this is a killer feature for iPads in the classroom. When a student pulls a laptop out of the cart, boots it, logs in, and then later, shuts it down, a substantial fraction of class is spent with these worthless tasks.

The iPad battery is fantastic. I never charge it at school; I just plug it in every night. My bag is light and now there’s more room for lab reports.

VGA output is a critical feature. I need to display a variety of media via an LCD projector in my classroom. VGA output is not a universal feature; it has to be supported by individual applications. I’m surprised by how many people are unaware that an iPad can project slides via an LCD projector.

Key Applications

I rely on a number of important applications on the iPad in order for it to replace my laptop. Just as importantly, I rely on a number of applications on my Mac that interface with my iPad.


My life is manageable because of Omnifocus. I’ve followed the Getting Things Done methodology or something similar for years and Omnifocus; which is synchronized between my Mac, iPhone, and iPad; is the best implementation of it. Without Omnifocus, the iPad wouldn’t even be an option.


Yojimbo is my digital junk drawer. All of my bookmarks, notes, receipts, etc. are stored and tagged in Yojimbo. I don’t often need to create new items on my iPad but I definitely need to search and access them.


I often have slides to display in class. I’ve used Keynote on my Mac for years. Keynote on the iPad pretty much displays whatever I create on my Mac. The latest version of Keynote supports the display of presenter notes on the iPad while displaying slides via the LCD. This is a key feature for me as it allows me to scroll through my lesson plans while a slide is being displayed.


I used to copy Keynote files between my Mac and my iPad via iTunes. This is a huge pain. I now use [Dropbox]( to have practically all of my files accessible from my iPad. I wish the iWord apps on the iPad would integrate seamlessly with Dropbox. No, I don’t want to use


Each of my logins is unique and relatively secure. I rely on 1Password on my Mac to manage this and it syncs with 1Password on my iPad. The 1Password iPad browser doesn’t work as well as Safari for some sights, but it works well enough for me to take attendance without having to type my log in information in every period.

Other Apps

PCalc: I teach physics, PCalc is the best calculator.

iBooks: I don’t read many books on my iPad, but I reference a ton of PDFs.

YouTube and Videos: These apps support VGA output so I can share videos with my classes.


I still use my school-issued tablet when I want to demonstrate how to solve physics problems. I was given an Acase iPad stylus for Christmas. It works better for writing equations than the Pogo Sketch, but I wish it had a finer point. The best note taking application that I’ve found so far that supports VGA output is PenUltimate. However, I plan to try Note Taker HD soon. If you have any recommendations for another stylus or app that would be well suited for writing equations as well as drawing diagrams, please let me know!

There are many excellent physics simulations available ([PhET]( and [OpenSource Physics]( However, they require either Flash or Java. I’m tempted to compile my own Java interpreter so I can at least run some of the simulations but I really have better things to do. Hopefully, someone figures out a solution that is compatible with Apple’s application requirements regarding interpreters.

I occasionally wish I could display something via an LCD projector in an app that doesn’t suport VGA output. It would be great if the iPad supported universal VGA output (without jailbreaking it). It would be even better if it supported wireless LCD projectors (like the Epson one in my room).


Overall, I’m quite pleased with my iPad at school. I find that the benefits outweigh the limitations and I can go find my school-issued tablet when needed. Rather than replacing my first generation Intel-based MacBook Pro this winter, I bought a 27″ iMac instead. The price of my iPad plus an iMac is less than a new MacBook Pro. In case you are wondering, I really like the 27″ screen.