Entries Categorized as 'Experiential'

Building a Guitar

June 9, 2014

Guitar bodies.

Guitar bodies.

This week I’m learning how to build an electric guitar–from scratch (or almost). Tom Singer, a professor in design and manufacturing at Sinclair Community College in Dayton, Ohio, is the lead on an NSF funded project to bring guitar building into schools.

I may have a tin ear when it comes to music, but there is quite the interest in guitar playing at the Fulton School at the moment–all the way from the elementary kids to the high schoolers–so I thought it would be a good catch-the-imagination mechanism for use in math and science.


A guitar body, ready to become MY guitar.

A guitar body, ready to become MY guitar.

First we got to choose a guitar body. The guitarbuilding team had a fair collection of guitar shapes for the group in the workshop to choose from. The shapes are cut from 1.75 inch thick woo. To get the elegant layered patterns you see above, they laminate about half a dozen different types of wood. This may make for beautiful guitars, but the different densities and hardnesses of the wood have to be considered when working with them. The darker colored woods in the guitar body above were much harder to shave and sand than the lighter colored material.

Note to self: Indeed, if I remember to get hold of some scrap pieces of the different woods, I can probably make up a nice density measuring project. Indeed, it would be nice to have students graph the relationship between density and hardness. Wood hardness is measured on the Janka scale. I suspect there is a positive relationship, but I’d like to see if we could determine the shape of the curve.

Not all of the guitar bodies are beautiful laminates, however. Some, of a single type of wood, are the best candidates for painting. Others are hollowed out, and can be played acoustically as well as plugged in.

Neck and Fretboard

Today I learned what a fretboard is. Apparently it’s a separate piece with the gradational markings that’s attached to the neck.

Bodies, fretboards and necks.

Bodies, fretboards and necks.

The necks were all of maple, if I remember correctly, but the fretboards were made of different types of wood. Each was a single piece of wood, but the wood’s hardness and affects the “brightness” of the sound produced by the guitar.

So now it’s time to sculpt and sand the body, and put all the pieces together.

Citing this post: Urbano, L., 2014. Building a Guitar, Retrieved April 22nd, 2018, from Montessori Muddle: http://MontessoriMuddle.org/ .
Attribution (Curator's Code ): Via: Montessori Muddle; Hat tip: Montessori Muddle.


November 2, 2013

Identifying the culprits using blood testing.

Identifying the culprits using blood testing.

At the suggestion of Mr. Elder, I put together a Crime Scene Investigation (CSI) simulation for one of our afternoon interim activities. Sixteen students were challenged to solve a murder/mystery using simulated blood tests, fingerprinting, hair analyses, and chemical tests for drugs. And the assailants and the victims were members of the group.

Knife at the crime scene.

Knife at the crime scene.

I set up the crime scene with four different lines of evidence — fingerprints, hair, blood, and drugs — and forensic methods, so I could break my students up into four groups. The students were all told that they were competing to solve the mystery; to find out what happened and who did what to whom. Without any coaxing, the groups each claimed proprietary rights one type of evidence and set about trying to solve the mystery on their own. Since none of the lines of evidence could explain everything from the crime scene they ended up having to combine what they all found.

A blood soaked murder weapon (also with fingerprints and hair sample).

A blood soaked murder weapon (also with fingerprints and hair sample).

The Crime Scene

There were two weapons lying on the floor: a bloody knife and a bloody rolling pin with a hair stuck to it. On the table above the weapons were a few lines of white powder. There seemed to have been originally four lines, but one and one half of them had been used. There were fingerprints and a strand of hair next to the powder lines.

Also on the table, close to the powder, were a deck of cards (with fingerprints), a set of poker chips, a scale, and another stray hair.

Fortunately for our detectives, the fingerprints and hair had already been pulled and tagged.

The crime scene setup.

The crime scene setup.

Acquiring the Evidence

It took quite a bit of effort to acquire and plant the evidence. Some of it, like the blood, was simulated, but I had to get the hair and fingerprints from the students themselves. Since the individuals who chose this activity were a self-selected fraction of the middle and high-schoolers, I wandered around the building at lunchtime at the breaks between classes trying to find one or two students who were by themselves or were in a group with others who had not chosen the CSI activity.

The crime scene setup really only requires evidence of two people, but to keep it a little more mysterious I used a little misdirection. I got five students to contribute fingerprints and hair, but told them all that they’d be the murderer. I also got one person who was not in the class to contribute as well so we’d have a set of completely mysterious evidence.


I pulled fingerprints by having students rub their fingers on a black spot I’d created using a basic number 2 pencil. The student would get the black graphite on their fingers and then touch their fingertips to the sticky part of some clear tape. The fingerprints turned out quite clearly that way.

Since I did not have time to figure out how to transfer the fingerprints to the surfaces I wanted them on, I just stuck the pieces of clear tape where I wanted them in the crime scene, which also saved the detectives a bit of time and effort.

Once I told them how to get the fingerprints from their peers, the students did not need any other guidance about how to analyze the fingerprints. They took the imprinted sticky tape and stuck them to a sheet of white paper, where the black prints showed up quite nicely. Then they fingerprinted everyone in the classroom and compared, looking for whirls and swirls primarily, but also basing their conclusions on the size of the prints which they took to be indicative of gender.

Comparing fingerprints.

Comparing fingerprints.

Of the four sets of prints, they were able to accurately identify the two people who were holding the knife and the rolling pin. The misidentified the one set that was from a person not in the class, and could not find the match for the last set.

Interestingly, of the four students in the group, two did most of the work while the other two wondered off to join other groups.


Hair was easy enough to collect since the students were quite happy to donate one or two for the cause. One hair per student would have been sufficient, but I kept loosing them until I just decided I’d stick them onto a piece of clear sticky tape and leave the sticky tape with hair attached at the scene of the crime.

Examining hairs under the microscope.

Examining hairs under the microscope.

With only a little nudging, the group working on the hair realized that they could get out one of the compound microscopes to examine their specimens, and compare them to the students in the class.

One major indicator that helped with the hair identification was the length. Two of the hair samples were from girls with long hair, while one was from a fairly short haired boy. I did consider just leaving pieces of the hair as evidence, instead of whole strands, but it’s a good thing I did not since, for one reason or another, the hair group had a difficult time identifying the owners of their samples (lack of effort might have been one part of it). It did help a bit that the two major perpetrators of the crime were members of that group.


My idea here was to simulate a drug (cocaine) deal gone bad because of a contaminated/cut product. I laid out three lines of corn starch to simulate the cocaine and one line powdered glucose in between the last two cocaine lines to represent the adulterated drug. I removed the last cocaine line and half of the glucose line to make it look like someone had been ingesting the lines and stopped part-way through.

The lines of powdered substance (cocaine) were severely disrupted by student's sampling, but you can still see the two full lines to the right and the half line that the spatula is touching.

The lines of powdered substance (cocaine) were severely disrupted by student’s sampling, but you can still see the two full lines to the right and the half line that the spatula is touching.

Since we’ve been testing for simple and complex carbohydrates in biology and chemistry classes I told the group testing the drugs that the test for cocaine was the same as the iodine test for starch: if you add a drop of potassium iodine to a starch solution then it turns black.

If the students had examined the drugs on the table closely enough they should have been able to see that the glucose line was different from the others; it was not as powdered (so the crystals were small but visible), and it did not clump as much as the corn starch. However, they did not, and I had to hint that they should perhaps test all the lines of powder instead of just the first sample they took.

When they discovered that one of the powder lines did not react with the potassium iodine, I told them that a common adulterant was sugar so they should perhaps test for that. One of the students remembered the Benedicts solution test, which they were able to easily conduct since I’d already had the hot water bath set up for them.

Testing for glucose.

Testing for glucose.

Looking through the United Nations Office on Drugs and Crime’s Recommended Methods for the Identification and Analysis of Cocaine in Seized Materials, it seems that a common test for cocaine (the Scott test) turns a solution blue when the drug is present, so the next time I try this I may have to find some tests that produce a similar color change.

Blood/DNA testing

Simulating the blood testing was one of the trickier parts of the procedure for my part since I had to keep things very organized when students started being sent to me to be blood tested.

The blood was actually a few drops of food coloring diluted into 10 ml of water. I used three drops of red in each case to try to at least get it to a somewhat blood-like color, but then in mixed in one or two other colors to get five unique blood types.

The number of drops of food coloring mixed with 10 ml of water to get the 5 blood types.

  • Type 1: 3 red + 1 blue
  • Type 2: 3 red + 1 green
  • Type 3: 3 red + 1 yellow
  • Type 4: 3 red + 1 green + 1 yellow
  • Type 5: 3 red + 1 blue + 1 yellow

To match everything up with the crime scene, I assigned Suspect A to have Blood Type 2, and Suspect B to have Blood Type 4. So a sample of Blood Type 4 went on the knife, and a sample of Type 2 went on the rolling pin.

As a result, when the blood type testing group wanted to blood test everyone in the classroom, I had them send the students to me one at a time and I handed each student a small cup with a random sample of one of the Blood Types, except for the two students whose blood were on in the crime scene. With 16 students, we ended up with three or four students with each blood type.

Blood type testing using chromatography.

Blood type testing using chromatography. The little containers of food coloring can be seen to the upper left.

This blood sample -- from the rolling pin -- is beginning to separate into its constituent colors (red, yellow and blue).

This blood sample — from the rolling pin — is beginning to separate into its constituent colors (red, yellow and blue).

The students took their blood samples back to the testers who I’d shown a simple chromatography method. They’d cut out thin (< 1cm wide) strips of coffee filter, put a drop of the blood sample on the middle of the strip, and then taped it down to a sheet of clear overhead transparency film. Although any clear glass or plastic would have worked, the transparency film was nice because you could tape five coffee filter strips to one sheet and then loosely roll the sheet up and put one end into a partially filled beaker of water (see Figure above). Capillary action sucked the water up the strips and smeared out the blood samples so you could see its constituent colors. The method worked pretty well, and the students were able to compare the blood at the crime scene to their test results to identify the small group of people who shared the suspect blood types. It was a lot of work, and it would have taken much longer if the group doing it were not amazingly organized and worked extremely well together.

This method is more akin to blood type testing than DNA testing, which I’d have liked to simulate better, however I did not have the time to work on my chromatography method.

In Conclusion

It took a little coaxing to get them to the right conclusion in the end, but I and the student had a lot of fun solving the mystery.

Citing this post: Urbano, L., 2013. CSI: TFS, Retrieved April 22nd, 2018, from Montessori Muddle: http://MontessoriMuddle.org/ .
Attribution (Curator's Code ): Via: Montessori Muddle; Hat tip: Montessori Muddle.

24¢ per hour

October 9, 2011

Picking green beans at the Heifer International Ranch.

We worked in the fields this afternoon: picking beans and planting garlic. Clear skies with a cool, early October breeze; warm, but not hot.

It was enjoyable work. The fields were small and there were a lot of us. Lots of conversation.

We picked somewhere close to 64 lbs of green beans, which, according to our guide, sells for somewhere around six dollars per pound (organic beans). Three hundred and eighty four dollars. Took us about an hour.

Earlier in the morning, we’d had a discussion about Community Supported Agriculture (CSA). Heifer ranch is a CSA. People from the surrounding towns buy shares in the annual crop, and the ranch brings them a basket of produce every week for the season. CSA’s are great: fresh local produce, for about the same price as in the store. You tend to get a broad enough variety that it helps expand your cooking repertoire. And you avoid all the externailties from long distance transportation and factory farming.

Finding out how much workers make in CSAs vs industrial agriculture.

They (our guides) had compared CSAs to the “typical” industrial agricultural system. Students read out notecards as they went through the all the jobs of the people who get your tomatoes to you. One student, who represented the energy going into the system, had to do a lot of jumping-jacks and pushups – situps too. There are eleven different jobs in the industrial system, with the people actually picking the crops – migrant workers – getting one cent for every dollar you pay at the store. They are three jobs within the CSA, and the farmer gets 80% of the sale price.

The presentation was a little problematic, unfortunately. Heifer is a CSA after all. Trouble started with our facilitator’s terminal question, “So which one do you think is better?” The first response was, “Well with the economy these days, won’t you loose a lot of jobs with the CSA?”

Fair point. But it might be argued that the industrial system might take one big farm and 11 jobs to bring 1200 tomatoes to market, it might take 4 CSAs, and about the same number of jobs (12), to do the same. Although the each person in the CSA system gets a little less, the money is more equitably distributed.

The second question, cut to the crux of the problem, “But what are the notecards leaving out?” Cynical? Perhaps. However, I’d like to think of it as healthy skepticism.

So now our guide was stuck. How could she, an obvious advocate for CSAs, convince the skeptical? Not easy, perhaps not even possible. By being too strong of an advocate for her side, she’d have a hard time convincing even the impartial.

It’s not easy making an argument that you’re passionate about. Not at all.

Snapping green beans. Students agree that beans you pick yourself taste better.

I made sure I had a small discussion with the more skeptical students, to make sure they realized that even if you distrust the credibility of someone, you can often learn something useful. In fact, that’s why you should always look for multiple sources of information. Also, while CSAs are great for some things, local farms in Arkansas or Missouri aren’t going to be producing a lot of tomatoes in January.

That’s why I’m glad we picked the beans later in the day. And it was important that we did the accounting.

It took sixteen of us one hour to pick $384 worth of beans. That works out to 24 bucks per person per hour. Since the migrant workers only make 1% of the final cost, we would have made about 24¢.

24¢ for an enjoyable hour of gardening on a pleasant day. But what do you do when you’re hot and miserable in the middle of the summer, and hour after hour after hour of the same work is what you need to feed your family. And you’re missing school to do it.

Planting garlic.

I’m not sure that students will intuit the difference between what we did and what migrant farm workers do; neither the time we put in, nor the effort we expended were anywhere near equivalent.

I think making that distinction is important. Recognizing what migrant workers do, many who are the same age as my students, might make the point of what organizations like Heifer and Human Rights Watch are trying to do better than just talking about it, or simulating it, in the classroom.

I think it might make a big difference to hear the voices of these workers.

So I’ll show the HRW video advocating for the CARE Act to reduce child labor among teen migrant workers, and see if it has an impact.

Citing this post: Urbano, L., 2011. 24¢ per hour, Retrieved April 22nd, 2018, from Montessori Muddle: http://MontessoriMuddle.org/ .
Attribution (Curator's Code ): Via: Montessori Muddle; Hat tip: Montessori Muddle.

Live from 1500 Meters Deep

August 22, 2011

Link to live video feed from the ROV ROPOS surveying a cable on the ocean floor at the Juan de Fuca midocean ridge.

Live science. The remotly operated submersible ROV ROPOS is surveying an undersea cable recently laid across the the Juan de Fuca midocean ridge.

This scientific expedition will be going on until the end of August, and there’ll be live feeds every time the rover is deployed (which depends a bit on the weather at the surface).

If you have questions, they’re also answering your tweets.

Right now, the rover’s heading toward the caldera of the axial seamount volcano. It should get there some time tonight (if they don’t have to stop for anything). So far, we’ve seen dumbo octopuses, crabs, weird fish, brainless worms, sponges, deep sea corals, starfish and lots of pillow basalt. The basalts are unsurprising because these are the rocks produced when volcanos erupt under water.

Dumbo octopus (from the ROV ROPOS seafloor gallery at Interactive Oceans).

Citing this post: Urbano, L., 2011. Live from 1500 Meters Deep, Retrieved April 22nd, 2018, from Montessori Muddle: http://MontessoriMuddle.org/ .
Attribution (Curator's Code ): Via: Montessori Muddle; Hat tip: Montessori Muddle.

Thinking Like a Cartoonist

July 25, 2011

The Guardian website has some very interesting glimpses into the mind of the artist, with a series of videos where Paul Trevillion describes his thought process as he draws different players for his You are the Ref strip.

Citing this post: Urbano, L., 2011. Thinking Like a Cartoonist, Retrieved April 22nd, 2018, from Montessori Muddle: http://MontessoriMuddle.org/ .
Attribution (Curator's Code ): Via: Montessori Muddle; Hat tip: Montessori Muddle.

Molly Backes on How to Be a Writer

July 21, 2011

Molly Backes, an author of young adult fiction, considers the question from a mother about her teenager, “She wants to be a writer. What should we be doing?”

Her first answer was, “You really do have to write a lot. I mean, that’s mostly it. You write a lot.”

But then she thought about it, and that’s where it gets really interesting:

First of all, let her be bored. …

Let her be lonely. Let her believe that no one in the world truly understands her. …

Let her have secrets. …

Let her fail. Let her write pages and pages of painful poetry and terrible prose. …

Let her make mistakes.

Let her find her own voice, even if she has to try on the voices of a hundred others first to do so. …

Keep her safe but not too safe, comfortable but not too comfortable, happy but not too happy.

Above all else, love and support her. …

— Bakes (2011): How to Be a Writer

At the end she posts a picture of her collection of forty-two writer’s notebooks.

It’s a wonderfully written and well considered post that I’d recommend to anyone trying to teach writing and language, particularly if you take the apprentice writer approach. And, I’ve always been a great believer in the power of boredom.

Backes’ advice more-or-less summarizes my interpretation of the Montessori approach: create a safe environment and give students the opportunity to explore and learn, even if it means a certain amount of struggle and failure.

Jungle play area at the Skudeneshavn Primary School in Karmøy on the west coast of Norway is another great example of creating an environment that offers students the opportunity to explore.

It’s also interesting to note how differently writers and other experts think, yet how much their practices overlap. Mathematician Kevin Houston also recommends writing a lot when he explains how to think like a mathematician, but his objective is to use full, rigorous sentences to clarify hard logic, and less to explore the beauty of the language or discover something profound about shared humanity.

Citing this post: Urbano, L., 2011. Molly Backes on How to Be a Writer, Retrieved April 22nd, 2018, from Montessori Muddle: http://MontessoriMuddle.org/ .
Attribution (Curator's Code ): Via: Montessori Muddle; Hat tip: Montessori Muddle.

What’s Needed for a Nation’s Peace

June 23, 2011

The Fund for Peace has been doing a lot of thinking about what it takes for a country to be considered peaceful, and what it takes for a state to fail. For the last seven years they’ve been putting together maps of the world with an index of how stable different countries are.

Finland - the most sustainable state, at least according to the Failed State Index.

While it’s pretty in-depth and makes for rather sobering reading, it’s worth taking a look at the criteria they’ve come up with to determine a country’s stability. It may be useful to include some of this information in the cycle where we focus on peace.

Their criteria for instability include:

  • Demographic pressure (such as having too many young adults, as we’ve seen in Egypt)
  • Amount of refugees and internally displaced peoples (refugees are people who’ve crossed international borders). Both leaving or entering refugees can undermine stability.
  • Historical Injustice – communities can have an understandably hard time forgetting the past, just look at Isreal/Palestine.
  • Brain Drain – when countries start to fail, the first to leave are the ones who can afford to. Yet these intellectuals and professionals, with their college degree are vital for creating a stable and prosperous country.
  • Inequality – especially when driven by active discrimination (wealth inequality is something to watch out for).
  • Economic decline – pushes trade into the black market and increases criminality and corruption.
  • Illegitimacy of the state – if people don’t believe the people in government have everyone in the country’s best interests at heart, and are only looking out for themselves and their friends, then there’s probably going to be trouble.
  • Public Services go kaput – It’s a really bad sign when the government can meet people’s basic needs – like picking up the garbage.
  • The Rule of Law goes kaput – when you’re ruled by the caprice of men, and your rights under the law are not respected, you may begin to consider and agitate for other options for government.
  • Personal Armies – forces that are tied to individual leaders, like private militias or super-secret police for example, are very damaging to a country’s cohesion.
  • Fighting elites – healthy countries need robust arguments in their political class – think checks and balances – but it can go too far and lead to things like extreme nationalism and ethnic cleansing.
  • Invasion – both overt invasion and covert meddling in the affairs of a country are unhealthy for that state’s stability.

It’s also very nice that you can download their index data as a MS Excel spreadsheet, which you can let students analyze to answer their own research questions. For example, I was wondering what was the difference between the best, the worst and the USA, so I plotted this graph.

Comparing the best (Finland), worst (Somalia) and the USA using the Fund for Peace's Failed State Indicies.

The USA is much closer to Finland than Somalia, thank goodness, but should probably watch out for that Uneven Development (wealth inequality).

I think something like this would make a good experiential exercise for the science of geography.

Citing this post: Urbano, L., 2011. What's Needed for a Nation's Peace, Retrieved April 22nd, 2018, from Montessori Muddle: http://MontessoriMuddle.org/ .
Attribution (Curator's Code ): Via: Montessori Muddle; Hat tip: Montessori Muddle.

Coon Creek Immersion: Visiting the Cretaceous

April 1, 2011

70 million year old shell and its imprint collected at the Coon Creek Science Center.

Just got back from our immersion trip to collect Cretaceous fossils at the Coon Creek Science Center, and hiking in Natchez Trace State Park.

It was an excellent trip. Despite the cold, Pat Broadbent did her usual, excellent job explaining the geology of Coon Creek and showing us how to collect and preserve some wonderful specimens. Back at the cabins, we looked at some of the microfossils from the Coon Creek sediments (and some other microscopic crystals); similar fossils can tell us a lot about the Earth’s past climate.

Back at the Park, we traced a streamline from the watershed divide to its marshy estuary, and cooked an excellent seafood dinner as we learned about the major organ systems.

Dinner was delicious.

Our trip was not without difficulties, however. The group learned a bit more about self-regulation, governance and the balance of powers, as a consequence of “The Great Brownie Incident,” and the, “P.E. Fiasco.”

We were also fairly well cut off from the “cloud”: no internet, and you could only get cell reception if you were standing in the middle of the road in just the right spot in front of Cabin #3.

But more on these later. I have some sleep to catch up on.

View Coon Creek Immersion in a larger map

Citing this post: Urbano, L., 2011. Coon Creek Immersion: Visiting the Cretaceous, Retrieved April 22nd, 2018, from Montessori Muddle: http://MontessoriMuddle.org/ .
Attribution (Curator's Code ): Via: Montessori Muddle; Hat tip: Montessori Muddle.

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