Follow Up Experiments

 

After observing our petri dishes for days, we continue to be baffled. Why do we consistently grow more germs in the samples of the washed hands than the unwashed hands? The children created a list with over twenty reasons they THINK we could be getting strange results. They've developed lots of follow- up questions from,  "Did we treat the perti dishes correctly?" to "Does it matter how long you rinse your hands?"

 

Some questions have been answered over time and through other experiments. The children are designing new experiments to answer some of the remaining questions.

 

Today we set into motion the one of the experiments designed to determine how to best grow cultures in a petri dish. They wonder if our lack of knowledge might be affecting our samples.This group is specifically asking, "Do germs grow best in light or dark?" in partnership with another group designing an experiment to test if germs grow best in warm or cold temperatures. 

 

I've struggled a bit with this science investigation because there are SOOOO many variables to control. It is very hard in my adult heart to feel like our results are accurate. But on the other hand, the greatest weakness of this medium has also been its greatest strength because I've never seen a group of children this young become so adept in thinking about all of the subtleties that are affecting our results.

Today as our atelierista, Anna, and I were watching the experiment and listening to the children's conversations, we were both struck by how sophisticated their thinking had become. They were thinking and planning so many subtle details to help control their experiments ... and not just because that's the way their teacher told them to do it. Sure I posed a few questions to help probe for deeper thinking, but all in all they were making their own decisions about how to run their experiments "fairly."


They decided ahead of time who would open the door, turn on the water, push the soap dispenser.
There was a person timing to make the washing more accurate.

We all became "checkers" to be sure the experiment was happening as planned.
Were we labeling the dishes correctly? Swabbing for a fair amount of time on each hand?
 

Swabbing on the dishes for the same amount of time?

 

"We wanted to test the same person for all of the petri dishes so that the germs are the same."
"But we didn't want to swab the same hand because the first time we swab we might remove a lot of the germs. That wouldn't really be fair."
"We're going to have the person rub their hands together before we start to even out the germs on their hands. Then we can swab the right hand for one dish and the left for the other."
"We wanted a clean and dirt hand for both the light and the dark, just to see how each one reacts. It will tell us more information."

A clean and dirty hand sample are in place under the light.

A clean and dirty sample are in place in the darkness of the filing cabinet.
Time will tell!

Time Machine in the Forest

The time machine has reemerged, but this time it is in the forest.
Groups get together to discuss.
"What might this forest have been like in dinosaur times?"
"What might this forest have been like for Native Americans before European settlers?"

 

Germ Comics

As we've been learning about germs, we've often found ourselves joking around with analogies as we compare bacteria or viruses with things familiar to our lives. We imagined comicsthat joke about the comparisons and give the reader a hilarious look into to world of microbes.

As we started to make the comics, it was very difficult to make them as well as we had imagined. (Have you ever tried to make a comic? I gave it a try and it is HARD!!! Much harder than I thought it would be.) Many of our funny conversations never even turned into comics. I am OK with that. I've decided that the power was in the comparison. The laughing and joking where one person builds off another person until we've created a very detailed scene is the place the real magic exists. If the comic never gets drawn by hand it is OK because it has already been drawn in the mind, the important work has already been done. The magic is in the conversation itself.

Here are some of the scenarios the children have imagined. I'm sure you can conjure up some funny mental images to accompany the humor.

Fact: The body has defense mechanisms to help keep germs out (wet eyes wash germs out, eye lashes catch germs, throat and mouth are wet to make germs slip down to the stomach, stomach acid kills germs, skin prevents germs from entering the body etc.)

Comic Scenario:
"It is kind of like the body has booby traps for germs!"
"I imagine it like Home Alone for germs! They try to get in the eyes and 'wahoooo' they are washed out with a giant title wave."
"Then they try to go in the mouth and they slide down the throat to a pool of acid."
"And they come out all beat up like 'yikes'... but then they decide to try to go in another way."
"The skin is like running into a brick wall and they smash all flat!"
"And then finally the germs get in the body and they are like, "Finally I made it!" Just in time for the white blood cell to come 'You are under arrest, sir!"



Fact: Bacteria help to break down dead plants and animals in nature.

Comic Scenario:
"It is a good things that they explained what they meant by 'break it down' because we might have thought it was 'break it down' like [begins to dance wildly]."
"Ha! That would be a funny comic."
"All these germs are at work having a dance party. 'Break it down.' But then the boss comes in an is like, 'What are you doing!?!?' "
"The bacteria are like, "Uh oh! We are so fired!!' "
"The caption at the bottom could say, 'Bacteria who misunderstood their purpose in life.' "




Fact: Bacteria use enzymes to further break things down into simpler liquids they can absorb for food.

Comic Scenario:
"It is kind of like making a smoothie."
"Yeah. Like an enzyme smoothie."
"No, it would be more like a rotten log smoothie."
"The enzyme is like the blender."
[In a commercial announcer voice] "Come try our new amazing enzyme blender! It turns anything into liquid... PERMINANTLY!"
"You see some bacteria sitting on a fence and they see a deer walk past and in their minds they see a nice tall deer smoothie made with their enzyme blender."



Fact: Germs spread and travel the world. They change as they go and by the time they get back to us, our bodies no longer recognize them.

Comic Scenario:
"There is this little germ with a suitcase and a passport!"
"He travels to Hawaii and gets a flower necklace. Then on to Japan and gets a sun umbrella."
"Then Russia for a fur hat!"
"Then he goes to Hollywood and gets a camera and sunglasses."
"He comes back with a French accent. 'Oui, Oui!' "
"By the time he gets back the cells in your body don't recognize him AT ALL, so he sneaks past the white blood cells."

Thinking about Time in the Forest

We go to the forest every week. It is so nice to have the time set aside to be in nature and take in the beauty each week. It feels slow and purposeful. Last year we did science work in the forest. This year I wanted to try to do more writing in the forest and decided I also liked having the dedicated time to think about our school wide umbrella topic of TIME.

 

I sent the children on a photo scavenger hunt. "Take pictures of things you feel are evidence of time passing in the forest."

 

Trees falling. Logs crumbling.

Water falling. New water coming.

Water splashing. Water flowing and smoothing the rocks. Leaves on the ground.

Small cave formed. Rocks broke.

Leaves change colors. 

We sat down at the beginning of our trip today to observe. "What is different today than it was last week? How do you know time has passed since last time we were here?"

"I hear fewer birds chirping."
"More bare branches."
"Way more leaves on the ground. They make lots of noise when we walk."
"Leaves are covering the creek. You can't even see the creek! Sometimes it is even making a dam."
"It is colder. We are dressed differently."
"The weeds are dying and turning brown."
"New water is falling down the waterfall."
"I'm sitting in a different place saying different things."

We think about our observations.
What changes in an instant? A minute? An hour? A day? A month? A year? What could our forest have been like back in dinosaur times?

"I think there would have been fewer rocks that were bigger. Over time I think they broke into pieces making more smaller rocks.
"I think there would have been a creek. The dinosaurs drank water and some lived in the water."
"I think there was a creek, just not THAT exact same creek."
"I think the grass was greener?"
"Say more about that."
"Well I think there was less pollution. There were no people to pollute, so everything was more colorful and healthy."
"I think things were more colorful back then because things fade over time. That was like the beginning of time, so it was pretty bright and colorful. Over time things have gotten old and faded."
"I think there were newer trees... actually I wonder if there were trees or if the trees were the same kind."
"I bet there was more undergrowth because there were less people to trample it. We weren't around to build houses and roads."
"The hiking path wouldn't exist."