Is Susan's class we started out identifying all of the bridges over the Huron River on a map of Ann Arbor. We split into three groups. Each group took one section of the river and compared what the map showed to what was on Google Earth. They found several differences. The paper map omitted several smaller bridges and a railroad track appeared to travel on a very long bridge that was actually a long causeway. Next they combined all of the group's results into one master map.
Next we started building our won bridges with straws and paperclips. I challenged them to build a bridge that could span a gap slightly shorter than a single straw length and hold up an orange. The paper clips can only be used to make joints. No paperclip chains. We already had several successes.
And one group I had to kick out so they would go eat some lunch.
I gave Owen a specific challenge to build a triangle out of three straws.
We had an unexpected visit from Professor Alberdore. He presented a challenge to the 3/4th grade class but anyone in the school is welcome to attempt it.
While studying energy conservation Mr.B's the class got very interested in a material called Aerogel. Aerogel is the lightest solid know and it makes a very good insulator. The problem is that it requires supercritical CO2 at a pressure 74 time that of atmospheric pressure to make it. Besides the safety concerns the price of a machine that can reach those pressures with a substantial volume is cost prohibitive.
Luckily the students found SeaGel a version of Aerogel that is made from Agar Agar (boiled sea weed jello). I tried to make so but my first attempt looked more like jello beef jerky. The trick is to freeze the Agar Agar and pump all the water away before it melts. That is called Freeze drying. When my first attempt melted before it dried I just made dried jello not freeze dried jello.
My second attempt worked much better but the chamber was small and there was only room to make pea sized bits.
Our next attempt was to try to building a freeze dryer (lyophilized) with two chambers. One chamber for the sample and a second chamber to trap the water that leaves the sample. The idea was to be able to independently control the temperature of the two chambers. The sample would be in an ice/salt water bath to hold it at -20 degrees C. While the water trap would be in a bath of rubbing alcohol and dry ice at -80 C. If all went well the water would sublimate from the first chamber and be trapped in the second. Here is a video showing the parts.
Fun with a vacuum pump. I wanted the students to have good understanding of the vacuum pump that we were going to use in making our Aerogel. So we did some experiments.
Now can we understand it?
Now for water. Boiling?
Soldering! Who doesn't love melting metal with fire?
This is a wonderful series from the first LEGO EB with Alex and Lilith. I was asking them about the impact of the relative size of the pulleys in a belt and pulley drive system.
Mr. B's class tackles difficult material with teamwork.
In connection with the human body focus the class will be doing an actual cloning experiment. They will take the gene for Green Fluorescent Protein (GFP) from a jelly fish, make 10's thousands of copies of it with the Polymerase Chain Reaction (PCR) then insert that gene into living bacteria with a plasmid.
Obviously this requires an enormous amount of knowledge that most 5th/6th grade students don't have (like high school and college biology). Even reading the experiment description and student manual was difficult because it is full of terms, concepts and methods that they don't know. I took this as an opportunity to suggest strategies for tackling difficult material including summarizing and outlining.
The entire class is now sharing a google document that they can all edit in real time. Each student took responsibility for a few paragraphs. After reading their section many times they are writing a summary in the co-authored outline on google docs.
Monday, January 9, 2012
In Chris's class we have been studying some electronics. We started out doing simple circuits with flashlight bulbs and batteries. Since they are Summers - Knoll kids they blasted through that in a flash. So we moved on the what I called "Arguably the most important invention of the last 100 years."
It is always fun to see that students say when I ask them what they think is the most important invention of the last 100 years is. Try asking. If you really want to make it interesting see if you can get them to tell you why they think that their choice is so important.
For a few weeks we have been working on some simple transistor circuits. (You guessed it my candidate is the transistor. The entire electronics industry would not be possible without it.) The circuit below is a transistor switch circuit.
Today was very cool. The class was buzzing. When we started this project I told them that it would include some frustrating parts. That I was asking a lot of them but in return they would be masters of the most important invention of the last 100 years. Pretty Epic don't you think.
Today was cool because they really turned the corner on their understanding. In addition, they were eagerly helping each other so all the groups mastered the circuit. Another fun part is that I get to be diabolical by sabotaging the circuits to see if they can troubleshoot them and fix them again.
