A while back I posted an item from Steve Spangler’s Science site that demonstrated how to make lava lamps. I decided to go ahead and try it and I filmed it. The materials that are required for the demo are shown below. As the video shows the peanut butter jar is filled with 3/4 vegetable oil and 1/4 colored water. Place an 1/8 of an Alka-Seltzer tablet into the jar. The Alka-Seltzer reacts with the water to form carbon dioxide gas bubbles. The gas is less dense than the water or oil. The carbon dioxide gas bubble attach themselves to the colored water, causing them to rise to the surface. When the gas breaks through to the surface the higher density colored water droplets sink back down into the jar. The second part of the video shows the same demonstration, this time in a large test tube.
We're now into three weeks of summer vacation and I've fully surrended to it. I figured I'd better make a list before summer is over, so here it is.
- Naps. A summer day is incomplete without a nap.
- Low stress. What is there to worry about? Not much.
- Lack of constant recurring "Mr. Fix" questions, requests, or complaints from middle schoolers. When I see a middle schooler out and about, it's very comforting to know that I don't have to worry about their behavior.
- Weekdays are just like weekend days. What day is it today? I don't know. Sundays are like Tuesdays. Saturdays are like Mondays. There is nothing more satisfying than going to a late movie Sunday night and not worrying about going to work the next day. You almost feel sorry for those saps that have to go into work Mondays. Almost.
- No parent emails. I don't have to cringe when I check my work email (why would I check my work email?) and see those helicopter parents' names in the inbox.
- Running errands during the day. It's not enjoyable to do errands, but it is more pleasant to go into a store at 10am on a weekday when stores are less crowded.
- Exercise. I can do any kind of exercise, any time during the day, then of course take the required nap after.
- Trips. I can take that hiking trip, biking trip, trip to the lake, etc.
- Chores. Not fun, but I have time to do them, and time to procrastinate.
- Read. I don't have to feel guilty reading instead of correcting papers, lesson planning, etc.
- Summer still has a special place in my life. Most adults don't get to enjoy summers anymore. It was a special time only during childhood. I glad I don't have to give that up.
- Recharge my brain. When summer ends (shudder), I will be more than ready to take on the new school year with fresh new ideas.
My only complaint about summer break? It's way too short.
I know what you are thinking. How can an iPhone be of any educational value in the science classroom? You are right. As of this moment it’s not quite ready to improve your students’ learning, but there are some tantalizing possibilities in the near future. What features does an iPhone have that can be used in the classroom?
1. An accelerometer. You have seen commercials showing the iPhone’s screen changing when the unit’s position is changed. How does it do that? It has a built in accelerometer that detects change in position in the x, y and z axis, as well as a change in speed. Speed and direction together is velocity, and a change in velocity is acceleration. What are some apps that take advantage of the accelerometer?
Roller Coaster Physics (Silver Mana Software) This app measures vertical g-forces. Press the start button and it will plot the vertical g-forces on the y axis and time on the x axis. This is ideally meant for a person to keep the iPhone in a pocket while riding a roller coaster. The best feature is emailing the data to yourself. The data is in comma separated value form and can easily be imported into Excel for analysis.
G-Meter Lite (Silverview Consulting Inc.) This app measures “steering” (left/right) g forces and accelerating/braking g forces. It plots the data points on a four quadrant graph. Unfortunately this app doesn’t save the data for use later analysis. It is merely a visual representation of real time forces, and thus it really isn’t useful for data analysis. G FORCE and G-Force are also apps that do this very same thing.
2. A microphone. The iPhone obviously has a microphone or else it couldn’t be used as a phone. What app can possibley be used in a science class that takes advantage of the microphone?
ioscilloscope (Gabe Jacobs Productions) This app shows the amplitude and wavelength of sound waves. Have a student bring in an instrument (or use prerecorded tones), like a trumpet or a sax and have the student play a single note at different volume levels to show the differences in amplitude. Then have the student play a series of higher pitched notes to show the different wavelengths (or frequencies).
3. A clock Don’t all cell phones have a clock? Yes, so the iPhone isn’t so special on this feature. Each year our science department buys 15+ stopwatches at about $6 each minimum. These are cheap stopwatches and their quality is also cheap. They don’t last more than 10-20 uses because either the battery goes dead or the buttons break. Since they don’t last more than a year they are considered consumables. This year I decided to end this cycle of spending. Most students now have cell phones and most of these cell phones have a stopwatch (timer) feature that measures to the nearest 0.01 seconds. Now when we need to measure time for learning activities I ask volunteers to use their own cell phones and the science department doesn’t have to spend any more money.
Summary It’s a little too soon to utilize a few of these iPhone apps to enhance learning in the science classroom. What is encouraging though is in probably 5 years most cell phones will be like the iPhone–a minicomputer that can collect all types of data. Today many physics and chemistry classes use expensive specialized probeware (like from Vernier and Pasco) to collect and upload data to computers. Students might bring their own data collection devices via their cell phones.
Educational Innovations’ website teachersource.com sells tons of unique science related items. One of those items is the handboiler. When you wrap your hand around the base the colored liquid (probably alcohol) heats up and moves up to the top where it eventually bubbles. My guess is that the molecules of the liquid speed up causing them to move up. When you let go the liquid eventually cools and goes back down via gravity. You can make the liquid go down faster by grabbing the top with your hand. I do this demo with student volunteers. We make observations and they hypothesize what is causing it. We also record who is able to send the liquid up the fastest.
Precautions: Don’t squeeze the handboiler. It can break easily.