The first week we did hands on experiments in food science as part of the Farm to Table theme.
We
started our discussions about food talking about what it is made of. I
wanted to see what the students think about the contents of food so I
knew what to talk about.
What the students said varied depending
on their age but the one universally surprising thing was how strongly
their lists seemed to be influenced by advertizing. Iron and Vitamin D
were surprisingly high on the list.
I started to refine my
question by asking what they thought made up most of the weight of the food
that they eat. They are Summers-Knoll kids so of course they are
clever and they mentioned water. True but not what I was looking for. Such are the perils of playing guess what the teacher wants. We did get lots of ideas and terms flowing.
I indicated that minerals,
vitamins and micro-nutrients are important out of proportion to the
amount of space and weight that they contribute and that there are three
types of molecules that are critical to life that make up most of the
non-water weight of food. The molecules of life, protein, fats(lipids) and carbohydrates. Enough talk, on to the hands on stuff!
The
kindergarteners, and first and second graders took a first stab at
three tests for food content. We tested for glucose (table sugar and a small carbohydrate) , carbohydrates in general and
fats/oils. For glucose they used DiaStick test strips that turn from
green to brown. For carbohydrates the students prepared the sample and
the teachers or I dripped iodine onto it. Iodine changes from
brown/red to dark purple) in the presence of carbohydrates. For fats and oils they smeared or smashed the food
samples onto pieces brown paper grocery bags. Stains that don't dry
indicate fats and oils.
For the kindergarteners I prepared all
of the materials so that they only had to stir and dip. For the first
and second graders I gave instructions and they had to follow, collect their materials and samples from the front of class follow the procedure and evaluate the results.
After
a similar discussion with the third and fourth graders about content
they split into groups and followed multistage directions (recipes) to
separate the proteins from whole milk and soy milk.
Their were
three groups one using vinegar to coagulate whole milk, one using rennet
to coagulate whole milk and the third using Epsom salt (magnesium
sulfate) to coagulate soy milk. Vinegar made a cheese sort of like ricotta(not a really ricotta though). The rennet made something like mozzerella. If we have any cheese making experts in the community I would love to learn more. The reading I have done about cheese making chemistry has done little more than point out the depth of my ignorance.
For many of the students reading through the instructions
and understanding them before they started was a challenge. This is an important skill because it uses one of the most
amazing capabilities of the human brain, the ability to model and
predict the future.
The oldest students covered the molecules of
life, "what is in food?" discussion and continued on to address the
topic of calories in much more detail. I had them break up into small
groups and look up the definition of a calorie on the internet. (I give
them one computer for 3 or 4 students. This was inspired by a great TED
talk by Sugata Mitra called Child Driven Education. The
experiment was in part the inspiration for the movie "Slum dog
Millionaire."
They found that their is both a physical calorie and a dietary calorie or kcal. The definition of a dietary calorie the the amount of heat that is needed to raise the temperature of one kilogram of water by one degree Celsius, at one atmosphere. The high point was an attempt to measure the calories in a dorito chip. We put 100gm of water into a pop can and lit the dorito on fire under the can. By measuring the increase in the temperature of the water we were able to calculate a lower estimate of the amount of kcals in the dorito.
Wednesday, September 12, 2012
Monday, June 4, 2012
Things that would be good to have when looking for the balloon. If you have any of these it would be great if we could borrow them. Better if you want to come and can bring them
Better yet is there a parent how can volunteer to coordinate equipment?
If several parents want to come it would also be good to have someone to coordinate communication.
Long step ladder.
Long extension ladder
Pruning saw that attaches to a long pole
Bathing suit and towel
Waders ( I have a pair)
A surf board works great to float out on a muddy farm pond.
It looks like we will plan on an early morning launch on Wednesday or Thursday. I'm looking for a few people to get up very early in the morning and drive to the launch site (TBD by winds) and get things ready (2-3 hours) so that Chris and B can drive the students out in the buses. They would could leave as early as 9:00 AM. Assuming that their drive is about an hour. We can attempt tp launch at 10:00. The flight time will be less than 2 hours. That gives us all afternoon and if needed evening to find the payload.
Launch delayed
There is a problem with one of the radios. I have an engineer working on it.
When we lauch it will be as early in the morning as we can make it. The location will be determined by the high altitude winds.
Keep watching here and on Facebook for updates.
Near Space Balloon
The third and fourth graders in Chris Swinko’s class at Summers-Knoll School aren’t just studying space, they are going there. Well, sort of. They are sending a balloon to near space - hopefully over 100,000 ft. up into the air to take video of the earth and the stars. Their science teacher, George Albercook Ph.D. (A.K.A. Dr. G), is a former faculty member of the college of Engineering and used to work with Scientists and Engineers at the Space Physics Research Laboratory at the University of Michigan. With the support of several local businesses, Huron Scuba, Orino Auto and Rocks and Robots Summer camp, the class is not only sending their payload 25 miles high, they will track it by GPS in real time and attempt to recover it.
This is not all the student are looking forward to. Recent studies have reported several new bacteria were discovered in the Earth’s stratosphere. Amazingly, they survive in a vacuum, 40 degrees below zero while being bombarded with Ultraviolet (sterilizing) radiation. Once the students are confident that they can launch and recover a payload, Dr. G. plans to collect a few samples in hopes that they will discover more unidentified bacteria.
The balloon the Summers-Knoll students are using is a giant weather balloon 14 feet high and 12 feet across. Attached to the balloon is a parachute and two independent telemetry systems. One uses an amateur radio transmitter connected to a GPS that sends the current coordinates to a worldwide network of repeater stations and on to the internet. The other use a low power wireless internet style transmitter to send GPS coordinate directly to a receiver on the ground tracking the balloon. Dr. G. says that the two systems are redundant the use independent batteries, GPS receivers, and radio transmitters. In addition to the telemetry systems, the payload has four video cameras. Two are HD high end cameras. The other two are amazingly capable keychain video cameras that cost as little as $14. Dr. G. hopes to promote amateur space science as a hobby and bring the cost down to allow more people to participate.
The launch is planned (weather permitting) for June 3rd, the day after the Ann Arbor Mini Maker Faire. Dr. G. and some of his students will be at the Fair on June 2nd. with the balloon payload explaining how it will all work. You can follow their results in real time. Details at the facebook page http://www.facebook.com/AlbercookScientific
Thursday, May 17, 2012
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