Sunday, March 8, 2009

Cloud Chamber

My cloud chamber adventures started with the LHC Rap video on YouTube that a friend at work shared. I forwarded the link to my son's teacher the week before the first parent teacher meeting of the 2008-09 school year. Last year I brought demonstrations of oobleck and sodium acetate for a presentation. She invited me to come back this year. It is a 5th-6th grade class. In science this year they were studying models. The LHC was a perfect fit, trying to find the Higgs Boson and prove the standard model. The video was a good start but I needed to bring some kind of demonstration. I thought of a cloud chamber.

My search for information on cloud chambers started with Instructables.com but there was nothing. I did find some cloud chambers for sale, websites about cloud chambers, and YouTube videos demonstrating traces in cloud chambers. Then I found Holly Batchelor's video. It had step by step instructions. It was just what I needed. I set off to work. I used an aluminum griddle cut down to fit in the foam cooler that I cut down to hold the dry ice. I used the reptile house Holly used and painted parts of it black instead of sewing the drape. Add some alcohol and dry ice and my kids and I were watching sub atomic particle traces in my garage. Very cool. I shot some video and uploaded this one to YouTube. This video has a clear trace at the end that I believe it is an electron initiated by background radiation.

I also was able to produce Alpha particle traces by placing Americum 241 from a smoke detector in the chamber.

I ended up doing two presentations at school one group included my daughter's class and one included my son's. Some of the kids were interested in the LHC and the cloud chamber, and some others were fascinated by the dry ice bubbling in water and the other dry ice I had filling up a large mylar tube. I hope the kids got something out of it, I know I had fun.

Wednesday, September 10, 2008

Summer Vacation 2008

On July 19, 2008 I dropped Edson off at SeaTac airport to fly to Toronto Ontario with one of the local staff from Keewaydin and a handful of other kids. The rest of the family's adventure started after work on Monday August 4, 2008. The trailer was packed and ready to go. We just needed the perishables and ice in the cooler and we were ready to go. With the cooler loaded the family in the truck I hitched up the trailer. Before we pulled out I did the "light check" to make sure I had taillights, turn signals, and brakes. I did not...

I checked the plug at the back of the truck the bulbs to no avail. I turned off the truck sent the family inside and drilled out the rivets on the back of the trailer. With the back off I could find no obvious loose connection. I drove to the auto parts store and picked up a trailer wiring harness, stripped out the wiring under the trailer and installed the new harness. We left about 2 hours later than planned.

We drove from Seattle East on I90 and I94 through North Dakota and the twin cities to Waupaca Wisconsin to visit Grandmother Stephens. She is not a blood relative, but a very close family friend. From there we drove north through Michigan and crossed in to Canada at Sault Ste Marie. We drove across the border past midnight. My favorite question at the border was "Do you have any live meat?". That one confused me...I had no live animals, so all the meat was dead. I answered that I had some bacon... We were allowed into Canada anyway. That was 3 long days and one Monday evening of driving. It took toll 4pm the following day to get to the dock on Lake Temagami and ride out to Devil's Island and arrive at Keewaydin.

The ride out in the evening was beautiful. The food at Objibway was wonderful. Objibway is the lodge at the north end of Devil's Island for adults. Mostly parents, but anyone can stay there. We stayed on Paul's Island (less than 100 yards from Devil's Island). Our cabin was a rustic log cabin with gas-lights and a wood stove for heat. For water there was a convenient lake surrounding the island and a pitcher on the table. The toilet on Paul's Island is a two seat outhouse with a great view.

We had the option of using the classic wood canvas Keewaydin canoes to get across, but with my mother and two kids we opted for the motor boat. We slept well and were glad to not be on the road. The rain started that night. We motored over for breakfast Saturday morning in the morning in the rain. After breakfast we walked to the South end of the island to watch sections paddle in. The video to the right is from Edson's section (Mattawa) paddle in.

After paddle in we had a chance to catch up with Edson. He went back to our cabin for awhile and we all went back for the Outpost campfire stories. After some great stories we had to walk in the rain and dark back to the north end of the island and motor back to Paul's Island in the wind and chop and complete darkness. I have very little boating experience, but we made it.

The next day included a race around the island and guncanoe competition where the older campers show off their skills tumping, loading, and maneuvering their canoes. We had dinner with the kids and the evening ended with some awards and campfire stories in the rain. We left for Paul's Island a little earlier in the evening and we used the boat to get back and forth from the North and South ends of the island.

We headed out the next morning. I left with my mom and dropped her off at the train station in Temagami. I returned to the dock to pick up the rest of the family and start the second part of vacation. We stopped in North Bay to eat at Tim Hortons. We were curious since all the comedians on CBC (Canadian TV channel we get in Seattle) make fun of Tim Hortons. It was OK but nothing too special. With that I may not be let back into Canada.

We drove through the small town of Mattawa and visited their museum. They had lots of great artifacts and information about Grey Owl. We stayed the night at in Canada and passed into Vermont the next day.

Wednesday, May 14, 2008

Make Faire San Mateo 2008

The whole family drove south to the Bay Area to attend the Make Faire this year. We were hoping for a chance to compete in the king of fling competition, but they did not hold the competition this year. We visited the Exploratorium on Friday before the Faire. An amazing place to visit and an outstanding gift and book shop.

Check out the Make Blog for a good overview video of the Faire. The highlights of the two days included motorized cupcakes, popping acetylene soap bubbles, SparkFun booth, Evil Mad Scientist Booth, mousetrap, Steam punk stem buggy, Adam Savage's Presentation, Home Chem Lab Presentation, 5 Dangerous Things you should let your kids do, the Chumby booth (I purchased one for my 8 year old daughter, really it was for her), and the maker store.

Tuesday, May 13, 2008

Sodium Acetate

My son's 5th grade class studied Solutions in science. At the beginning of the year for open house the teacher mentioned the topic I had recently seen the PopSci post and a Make post about a super saturated Sodium Acetate solutions and was looking for an excuse to play. The teacher was interested but when I offered to prepare the supplies for her to demonstrate she suggested I come in and give the demo. I accepted.

I ordered my crystallized sodium acetate from United Nuclear. Look for reruns of Wired Science to see a story about them. I later realized making the crystals from Baking Soda and Vinegar at home is very simple and much cheaper.

For the class presentation after I did the demonstration showing the clear super saturated solution turning into a solid as I poured it out I shared what was occurring and the chemicals involved. Asking who had made sodium acetate at home resulted in silence and blank stares. I followed that with the recipe of mixing sodium bicarbonate and acetic acid. Again blank stares. I said let me demonstrate. As soon as I poured the vinegar into the baking soda they all knew exactly what it was.

4 in 1 Chain Maille

My son (10 years old) was a knight for Halloween. He was not impressed with the authenticity of his costume. He asked the night before Halloween if we could make some real chain maille. I said of course but not tonight.

The following Thanksgiving I was visiting my in-laws with the whole family. My father in law has a shop and I needed something to do. I looked up chain maille on Instrucables.com and headed to Home Depot to pick up supplies. For a madrel I used a bolt. I cut a slot in the end to "clamp" the wire. For wire I used drop ceiling suspension wire (straight). This yielded very stiff rings with a tight weave.Two and a half days later we had a coif head piece that fit my son.

This inspired him to do a research paper on William the Conquer er. The research paper ended with a "Night of the Notables" where each student is required to stand in front of a display about their chosen "Notable" subject in costume and talk to the student's and parents about their chosen "Notable" person. When my kids do papers like this I learn so much in the proofing process.

The Chain Maille Coif was a big hit. It got heavy on his head so my son took it off and used it as a "hook" to engage parents. He would hold it out to passing parents and ask "Do you want to feel how heavy medieval armour is?" I watched as one mother dragged her husband over to feel the armour.

Oobleck

With the sodium acetate demonstration for the 5th/6th grade class I also built a rig to demonstrate the properties of oobleck. I took the sub woofer out of a powered speaker system for the computer. I built a cone using resin and fleece fabric (I have seen that done on Pimp My Ride for speaker cases). I also built a 4 inch high flanged ring. To the bottom of the ring I affixed model airplane wing covering. For the sound I found MP3 files at various frequencies.

Oobleck is a mixture of corn starch and water. In the right mixture it crumbles under stress but flows when not stressed. On top of the 60Hz frequency it stands up and dances. There are various videos on Youtube of dancing Oobleck.

To start the demonstration I had three volunteers from the class mix three white powders with water. The first was flour and water, pancake batter. The next was powdered sugar and water, icing. The last was the corn starch and water and everyone could see it was acting differently. Especially when it is held upside down for a short time over a child's head.

Next I loaded it in the machine and showed standing waves at lower frequencies, but the fun really starts at 60Hz.

I had fun making the rig. The kids all had fun watching the oobleck dance and making a sample of oobleck to take home. I didn't hear from any parents who were uhappy about the mystery substance that the kids came home with.

Trebuchet

One of my first adventures in making was a trebuchet. The inspiration came from the Nova episode where they built and tested a trebuchet. I watched that with my two older children (10 and 8) My son (10) asked about a month later if we could build one. I said of course. We started with some internet searches to see what others had done. I found some diagrams that looked good but were a little small. We built ours a little bigger (about 3 foot high pivot point).

My wife was not so excited about building a weapon. When she suggested we use it as a science fair project, I agreed and all was ok. A few good days in the shop and we had an operational weapon, I mean science fair project.

The first firing threw a baseball about 60 feet. We quickly lost the baseball in the forest and switched over to rocks. We had some great throws into the forest. Then we discovered really light rocks land right in front of the machine and really big rocks can go straight up. A rock flying straight up 60 feet takes a while to land. That is a confusing few moments followed by a few moments of terror. Except for the science fair experiment we stuck to launching watter balloons after the short experiment with rocks.

For the science fair part I drilled holes in a dozen tennis balls and filled them with varying amounts of silicone caulk. The science was charting the different ranges from the different masses.

Shortly after we built the trebuchet I took the two kids to the Make Faire in San Mateo (2007). They announced the King of Fling competition but we already had plane tickets and the trebuchet was much too large and heavy to check as luggage, but we had a great time watching the other catapults. We drove to the Faire this year (2008) but alas no king of fling competition was held.