The Arch & That Medieval Thing

As we investigated the field of archeology and learned about the science behind uncovering ancient ruins, 2nd, 3rd, and 4th graders became very interested in how buildings were constructed thousands of years ago. Our path led us to Rome and in particular, the longevity of the Roman arch bridge design. We briefly covered the history of bridges and students began to identify the basic types of bridges and to understand the forces of gravity, tension, and compression that act on them. Students formed human arches and felt the forces in action! After they tried creating model arches with small stones and a sand/corn starch mixture, many students decided that using a removable frame as a base was key to successfully constructing a model archway.

They found that building an arch is anything but easy. Since the arch is completely unstable until the two sides meet in the middle at the keystone, students realized why engineers for years used wooden forms on each side to hold the structure in place until the two spans met in the middle.

Others were interested in comparing different materials for constructing an arch and they tested arch design using sugar cubes and glue (but said they would rather use thick frosting next time, concluding that the mortar is a most important factor for success!)



In the Kindergarten and 1st grade classroom, our investigators developed a deep interest in castles, knights, and Medieval times. In December, students began noticing the different geometric shapes that can be found in castle architecture. In several classroom-wide hunts, they identified shapes that resembled certain attributes of a castle. We introduced 3D-shape vocabulary and played with handheld models. Students became comfortable counting the faces, vertices, and edges of geometric shapes.

January brought us to an investigation of simple machines as they relate to castles. We provided several materials challenges centered on levers and learned about force, effort, and load. Students tested different shapes that could be used as a fulcrum, and experimented with moving the placement of fulcrum along the arm. They each set up their own mini seesaw, using a 12-inch ruler (the arm), dixie cups (as load and effort containers), a thick marker (fulcrum) and proceeded to investigate how the effort changed depending on the position of the fulcrum from the load. Another time they used a large thick wood board for an arm and a thick cylinder piece for the fulcrum and were able to lift a box of books and a classmate!

Big dig

We’ve started thinking about archaeology!! 2^nd 3^rd and 4^th graders are exploring what types of objects archaeologists search for, where their laboratories are, and what tools they use. In investigations we’ve learned that archaeology involves a whole lot of careful detective work. Archaeologists are scientists who use ancient material as evidence, to infer human behavior and human activity that occurred many years ago. We’ve looked at a tool kit used by archaeologists and discussed the elaborate protocol that is undertaken in setting up a field survey and dig site. We’ve imagined what archaeologists might conclude about our classroom and students if our school itself was a dig site! Students are thinking about what objects get left behind, how scientists catalog artifacts, and how they use technology to date the objects that they find. We are learning how to keep careful records in our notebooks and thinking like budding archaeologists. Students completed an archaeological investigation of a grave site, using diagrams and cataloging techniques. We are realizing that burial sites provide a human connection to the past and reveal the culture of ancient people. We have learned about the original settlers of Lincoln, MA, not only their family names but in many cases, their cause of death, age, hobbies, wealth, ancestry, and history.

We have a professional archaeologist coming to visit in December!

Leaf Book

Kindergarten and 1st graders began creating their leaf book last month!
After some very concentrated illustration sessions, the students helped one another to identify their leaf species using kid-friendly tree guides and the ipad app leafsnap. Here are just a couple snapshots of their work in progress. We plan to use MagCloud photo book for our final document.

Our forest studies

Our Kindergartners and 1st Graders are deciding how to best tell tree species apart. They have been discussing the key features that all trees share and we are learning to notice the attributes that give us clues about which species a given tree might belong.

A typical tree guide requires significant amount of background knowledge; much of which we adults take for granted. Wouldn't it be great to have the students design their own tree guide -- deciding for themselves the features that they deem most important for telling trees apart?



We are working toward that goal. In order to categorize the leaves that they find, students have begun collecting fallen leaves around the school yard and are listing all of the traits and qualities that they notice. K/1's started making Venn Diagrams comparing and contrasting sets of leaves. One of our first comparisons included looking at a white mulberry leaf and a catalpa tree leaf. We are on our way to collecting data for creating a K/1 guide to trees!







Students also spent time outside yesterday, between rain showers, studying an elaborately decorated maple tree. But before they even began depicting coloration to their drawings, students carefully counted the branches and trunk formations; we were surprised to count at least 7 large branches that started very near the base and looked like the tree had multiple trunks.

Nature's Engineers

 We invited members of a silk lab to our school. And oh, wow, were we treated to an amazing presentation today!

I am forever grateful to Principal Investigator Fio Omenetto who came, along with Benedetto, a post-doc, and Alex, a graduate student, to talk to our students about the seriously mind blowing power of silk. I thought I already knew a fair amount about potential applications of biomimicry (imitating elements of nature to solve complex human problems). But today, thanks to the silkworm (and to some really smart biomedical engineers!) I could actually envision a future without our piles of trash accumulating in landfills.

It was inspiring to meet these scientists who are spending their life's work cleaning up our planet; creating everyday products made out of silk.  Fio and his lab members are figuring out how to manufacture electronic gadgets from a renewable, sustainable source.

Could we really hand off a cleaner world to future generations; one without plastic piling up in landfills and in trash heaps?! It's a beautiful vision!

Fio, Ben, and Alex came with beaucoup props: thin sheets that looked like plastic, screws, nuts and bolts, a femur bone, entirely made of melted down silk. And enough cocoons for every student to take one home.

Testable Questions

Recently we spent time brainstorming about possible research projects. Students excitedly offered their ideas about different questions that they would like to test using our silkmoths. 

Shown here (on right), a 4th grader lists her initial questions in her science notebook and illustrates a molting larva:

1. How much do they eat in 10 minutes? 

2. Do they make silk before the cocoon making? 

3. We have silk worms that are different ages but do they care about the younger worms?

After we talked about how scientists go about forming a testable hypothesis, the students decided to try their hand at changing their initial questions into testable statements.

The same 4th grader uses a microscope to enhance her observational drawing and translates her questions into statements (her changes shown here to the right).

Later, as a class, the students listed additional wonderings that they are interested in investigating:

1. Are larvae attracted to light?

2. Does the pupa die in its cocoon if it's too hot or too cold?

3. Do the larvae gain weight at different rates if they have been fed chow vs. fresh leaves?

4. What is the exact number of days from egg to adult moth?

5. What are the different weights at each stage (larvae, pupa, adult) of the life cycle? 

6. How much silk can we get from one cocoon?

7. How long does it take to form a cocoon?

The students will form these questions into testable hypotheses (based in-part on researching primary source material) and then pick one (or two) statements that they will pursue by experimental design. I'm looking forward to seeing how they decide to design a reproducible protocol in order to test their hypothesis!

The power of keeping a science journal!

Our second week of science class was a whirlwind of good things. The students are becoming more comfortable with using their science notebooks. Many of them are developing detailed and methodical observational drawings and some are adding their personal wonderings.

Here a 3rd grader writes, "Can they produce silk at this age?" He decides that he will try his next observation using the microscope; hopeful to spot silky strands.