Month: October 2012

Seeing Functions at the City Museum

The slide on the third floor of the City Museum. A co-ordinate system is overlayed, and points showing the curve of the slide are selected.
Elegant curves.

I asked my students to take pictures of the curves they found while on our field trip to the scrap metal playground that is the City Museum. The plan is to see if we can determine what functions best fit the curves. To do so, we need to transfer the curves from the images to a co-ordinate system. Since I’m primarily interested in what type of functions might best fit the data, the scale of the co-ordinates does not matter that much.

Feet, inches, meters, centimeters, pixels, or any other units can be used. In fact, I use a purely arbitrary set of coordinates in the image above. All I require is that the grid be evenly spaced (although the vertical and horizontal spacing don’t have to be the same, it’s more straightforward if they are).

Now we take a set of points that lie on our shape and try to match them to some sort of curve using a spreadsheet, and, if we’re able, least squares regression.

There were lots of shapes to choose from.

There were lots of shapes to choose from, including the nice sinusoid in the background.

Shrimps are not for Wimps

Shrimps are not for Wimps
by Abby Reynolds

One day I walked into the science class,
I was preoccupied as I looked into the looking glass.
For Dr. Urbano had cooked up a surprise,
And after I wished I was at the car rental Enterprise.
Then I would be able to drive away,
From the disgusting horrors I saw that day.
It started with a metal tray,
With icky rubber a sickly gray.
He brought the probe and scalpel too,
My o my, Sydney turned blue!
Then a smelly smell filled the room,
Making us cough and gag all too soon.
When I saw the shrimp my stomach did flip-flop,
For the color was like that of a caramel lollipop.
I inhaled through my mouth to calm my brain,
Trying not to think how the shrimp was slain.
It helped somewhat until I saw Sydney,
Who was slicing and dicing at a kidney.
She looked up and grinned a big grin,
A smear of blood dripping down her chin.
I will kindly spare you the rest of the story,
For I fear that it gets MUCH too gory!

And there I was thinking that the shrimp dissection had gone rather well.

Following the Technology

Following the arrow.

Our middle and high school students tried their hands at geocaching on our visit to the Audubon Center at the confluence of the Mississippi and Missouri Rivers.

They got their GPS units and instructions on how to use them: basically just choose the right waypoint and follow the arrow. They were told that they wouldn’t need to walk through the prairie.

But the arrow pointed toward the prairie.

Following the GPS.
(These guys were actually on a trail). The Mississippi River is in the background.

The results were scratched legs and quite a number of boarders.

Seedpod boarders.

Afterwards, our guide pointed out that they could have found all the caches by using the paths.

Melting Permafrost and a Warming Climate: Another not-so-Positive Feedback

There’s a lot of organic matter frozen into the arctic permafrost. As the arctic has been warming much faster than the rest of the planet, the permafrost soils are thawing out quite quickly. As they unfreeze, they set up a positive-feedback loop. The warming organic matter starts to decay releasing carbon dioxide into the atmosphere, exacerbating the warming.

To generate the estimates, scientists studied how permafrost-affected soils, known as Gelisols, thaw under various climate scenarios. They found that all Gelisols are not alike: some Gelisols have soil materials that are very peaty, with lots of decaying organic matter that burns easily – these will impart newly thawed nitrogen into the ecosystem and atmosphere. Other Gelisols have materials that are very nutrient rich – these will impart a lot of nitrogen into the ecosystem. All Gelisols will contribute carbon dioxide and likely some methane into the atmosphere as a result of decomposition once the permafrost thaws – and these gases will contribute to warming. What was frozen for thousands of years will enter our ecosystems and atmosphere as a new contributor.

— Harden and Lausten (2012): Not-So-Permanent Permafrost via USGS Newsroom.

Caving

Looking into the narrow passageway that our guides called the "Birth Canal".

They took us into a sculpted, limestone cavern they called “Twins Cave”. The entrance was large, but, for those with the predilection, there were narrower passageways that required crawling, wiggling, and a definite lack of claustrophobia.

Apart from the wonderful speleotherms, the cave was home to some charismatic fauna.

An owl sits amid the stalactite formations near the roof of the cave.
A salamander wanders the floor, picking its way through the limestone debris.

Though I did not capture any pictures of bats, they flew around us, and we found evidence of their presence just under the cloying red mud that covered most of the cave floor.

Much of the cave was floored with a sticky, red, residual clay, which, in places, covered deposits of bat guano.

The limestone precipitated cave formations were quite beautiful: fluted, cathedral-organ-like stalactites;

Fluted stalactites reminiscent of Gaudi.

thin, precise straws hanging from the ceiling:

Looking up at the crystal encrusted straws hanging from the ceiling.

The juxtaposition of the beauty above us and the mess beneath our feet brought into focus the idea that happiness is not an absolute thing, but rather comes from the difference between misery and joy.

(Eminence Immersion)

Authentic Teambuilding

Figuring out how to work a canoe.

Observing my students figuring out how to canoe on the river this last outdoor education trip has reinforced my belief in the effectiveness of authentic team-building experiences over simulations and co-operative games.

Each morning, I assigned different pairs of students to each canoe. One of the main objectives of the outdoor ed trip is to help integrate the 7th and 8th graders, and the new 8th graders into a cohesive group. Good relationships among the students are necessary to achieve the benefits of the multi-age classroom.

Figuring out which way is upstream and which way is downstream.

It took them a while (sometimes up to an hour on the water), but they eventually figured out how to work together.

And when one of the canoes tipped over — more from overconfidence than from anything else — everyone pitched in to help recover the canoe.

Recovering the tipped canoe.

Then, when the storms came, they pulled together and all the practice paid off.

Paddling through the storm.

No simulation could have matched the experience.

Forging a team out of cold water, thunder, and lightening.

From our Eminence Immersion.

Evidence of Wild Horses

From horses?

Out along the Current River, we found evidence of large, vegetarian animals (see above). When we described the feces to our guide, he suspected that they might be from one of the small herds of wild horses that roam the area.

The story goes, that when the government acquired the lands for the Current River Conservation Area and changed the rules about what could be done in the area, horses were released in protest by the local farmers.

(From our Eminence Immersion)