Author: Lensyl Urbano

Rules for Group Work

The List: How you should act while doing group work.

It would be nice if the only rule in the classroom had to be something like, “Respect each other,” or alternatively, “Be excellent to each other,” but sometimes you have to go into the details to figure out what exactly that means.

During the last interim I had my middle school class come up with a list of rules about how to act while doing group work. There’s often someone who wants to slack off, and there are other times when people want to work but the other members of the group think they could do the work better without them. So we came up with these rules that try to balance the responsibility of the individual to actively participate, and the rest of the group to let them participate.

The List:

  • Actively work to find work,
  • Actively allow people to work,
  • Should be willing to work productively,
  • Include yourself in the group,
  • Work with others while respecting personal space,
  • Work without distracting the group,
  • Be focused on the specific project,
  • Invite other people to work.

Together with the house cup, the middle school groups are working well together for the moment.

The History of Pharmaceutical Penicillin

For ten years after discovering penicillin, Fleming and his contemporaries could not get the penicillium mold to grow fast enough for mass production. Finally, in 1942, scientists isolated a strain of the mold from a piece of moldy cantaloupe in a garbage can.

Penicillium mold on mandarin oranges. Image by Wikimedia User:Bios.

Gravel Bar in the Creek

A wavelike bar of loose gravel in the creek.

In addition to clearing out the leaves, the fast flow in the creek created some interesting fluvial features. Example number one is this curious gravel bar that was not there a week ago. The gravel is quite coarse — 2-4 cm in diameter — but it’s extremely loose, which is typically of recently deposited sediment.

It seems likely that the sediment comes from beneath the fallen tree that cuts across the creek just upstream of the gravel bar. The tree restricts the stream flow, forcing the water to speed up, and when the water found it’s way through by cutting under the tree, it had enough energy to excavate a hole under the tree and deposit the resulting sediment just a meter or so away.

Constriction of the stream by the fallen tree focused flow beneath it, digging out sediment and depositing just downstream on the gravel bar.

It’s a neat piece of fluvial geomorphology.

Wandering Through the Creek

Inspecting the creek.

The rapid, snow-melt driven, flow in the creek has receded a little, but it managed to clear out most of the dead leaves that have carpeted the stream bed since the fall. Now that the rocky bottom is exposed, hopefully, we’ll be able to see some more of the benthic fauna that’s been invisible for the last few months.

Washing out the dead leaves has exposed the rocks and rapids.

Coronal Rain: Learning Physics with the Sun

NASA’s Heliophysics (physics of the sun) website has an excellent collection of videos that would link quite nicely with physics discussions of the physics of light (electromagnetism) and the Earth’s magnetic field (as well as the action of charged particles in a magnetic field.

They also have awesome solar videos, like this one of coronal rain.

Natural phenomena like this are great for students to analyze because they require the integration of multiple concepts to explain.

Ice on the Creek

Clear ice in January, 2013: Ice thick enough to support a person’s weight, but clear enough to see through. Creating this beautiful shock pattern took a lot of time and concerted effort.

In January, the creek froze over after a few days of below zero (Celcius) temperatures. However, we’d missed the snow that usually accompanies a drop in temperature (it had hit to the south of us), so the ice froze clear and firm. Since they’re used to seeing the whiter ice — on lakes and ice rinks, for example — my students wondered why the ice was so clear.

In February, we got both the snow and cold, which incorporated air bubbles into the ice, resulting in a very different, cloudier ice.

Snow incorporated into the ice makes it cloudier and, I think, somewhat ethereal. Note the same fallen walnut tree trunk as in the picture above.

It was quite neat to see the contrast, and made me wonder about the ecological impact. After all, clear ice lets sunlight through much more efficiently than cloudy ice.