Friday, February 21, 2014

Buckminster-Fuller inspires a new classroom demo

One of the challenges in teaching Plate Tectonics to introductory students is that - along with being spread out over a huge scale - most of the maps we use are flat, whereas the plates are actually distributed across a sphere (oblate spheroid, technically).

With most map projections, the polar regions are heavily distorted and much larger in comparison to equatorial regions. So, for instance, if you want to reverse tectonic motions and reassemble the continents into Pangaea, you run in to issues of mis-matched continents. Even worse, students begin to assume that Greenland is really that big and there must be some active tectonic boundaries around such a huge land mass.

A globe tackles the issues of projection and relative scale, but then students can't see what's happening on the back side. After a little digging around, I stumbled upon this graphic on Wikipedia, based on Buckminster Fuller's "Dymaxion" globe - the earth projected onto an icosahedron, but done in a way that minimizes distortion of the land masses.

The next part was deciding how big to make it. I wanted to be able to remove the continents and shuffle them around on the board, so they had to be big enough to be visible from across a classroom. I settled on 20 inches (~500 cm) for the sides of my equilateral triangles (based in part on globe size, but it was also the largest size that would allow for multiple whole triangles from a single piece of black foamcore. I got out my 30/60/90 triangle and meter stick and began cutting. I ended up with about eight half triangles in addition to 16 full triangles.


The finished stack, with reference map/model.

Testing out the fit.

I laid out the panels to form two halves, each pentagonal pyramid half has five triangles dangling below it that would fit between the five from the other half.

I printed out full-size continents (taping many sheets of paper together) to line them up. I flipped the sheets over and traced the outlines in soft pencil. Flipping the sheets back right-side up, I retraced the outlines, transferring some of the soft pencil underneath onto the board.

I went over the outlines with a silver marker and taped up each of the pentagonal pyramids.

Here are the two taped up halves. The "northern hemisphere" is also outlined, but I had yet to ink the other one.

Backsides of the pyramids were color-coded so I knew which edges should line up.

And the whole thing assembled. I lucked out because the narrowest dimension of the icosahedron was about an inch less than the width of our door.

I re-covered the colored tape with black to blend everything together.

Adding latitude/longitude lines in a bronze/copper color. Some of these were transferred using the soft pencil technique for the continent outlines, others were sketched in based on measurements scaled up from a reference print of each triangle.

A "western hemisphere" view of the finished globe.

"Southern hemisphere"

"Northern hemisphere." Incidentally, the pink flamingo in the background is about 22" tall.

A closer view of North America. I really like how the silver stands apart from the bronze and both show up well against the black background.

It is large.

"Atlas, it's done" (pun shamelessly borrowed from a friend).

Thursday, February 20, 2014

So. Much. Snow.

It's been a cold winter up here. And we're in the middle of a pretty impressive snowstorm, too.
I suspect we're going to lose a few branches in the back woods. Which will be good for improving the litter conditions of the woodland floor.

Friday, February 07, 2014

Dispatches from the Dirt Lab, 3rd Edition

It's been cold around here. Very cold. Cold enough that boiling hot water seems to instantly vanish into clouds of steam when thrown into the air. So I did. Just to be clear - do not throw large volumes of boiling water directly into the air over your head. The risk of scalding is real. I used heavy welding gloves to protect my hands and used a squirt bottle to turn the water into small droplets so that any water that would have landed on me would be a small, rapidly cooling droplet. I also aimed the stream of water away from my body.

Dispatches from the Dirt Lab #3: Tea Time and the Polar Vortex from Matt Kuchta on Vimeo.
Where I demonstrate what happens when really hot water meets really cold air.

Although it was only about -14°F (about -26 C), the effect is pretty obvious. Huge billowing clouds of steam. In slow motion it looks pretty freakin' awesome.

Thursday, February 06, 2014

A Get Well TARDIS for Caitlin

Get well cards are cool.

Our friends Michael and Lynn Thomas have a wonderful daughter. Caitlin had surgery recently and it's been a long challenging week for all of them (nine days, actually). I had been kicking around the idea of a get well card that also served as some geek sculpture/puzzle to send to them. It's a chance for me to try crafting something new and it'll give Lynne and Michael something to work on while they're at home with Cait

A blue book. I used a small stylus to emboss the pattern in the front cover.

With various parts. The book is just a few pieces of cardboard, covered in blue craft foam. Another kind of project foam for the "pages" and then shapes cut out of it to hold the TARDIS parts.

Some more parts.

All of the parts removed from the book.

The rolled up note is the center column, the yellow "console" fits around the note.

Most of the TARDIS was cut out of blue craft foam with printed lettering glued on.

The top and bottom fit into the middle.

It's possible there's a wee bit of geekery in this picture.