Estimating Volume

Estimating Volume of Tree Slice

FLMath 4 - MW Geometry Group

	First, we traced the slice of the tree trunk to find its perimeter. This let us find the area of the base of the slice using big graph paper.
	Then we found the height (thickness) of the tree slice using 1 inch cubes. The slice is 5 inches thick or has a height of 5 inches.
	We made rectangles inside the perimeter of the tree slice to find the area in square inches. Then we added all the extra bits together. We found the slice had an area of 606 square inches.
	Last, we found the volume of the slice by multiplying the area of 606 square inches by height of 5 inches and got a volume of 3030 cubic inches!

MissionX

Grade 4 Science & Physical Education

Sci4 has been participating in MissionX: Train Like an Astronaut program. This is a physical fitness and health curriculum developed by NASA. We are doing different physical exercises in phys ed classes that are similar to those the astronauts do. We have also been looking at how our bodies are affected by exercise and how our bodies use nutrients in science class. 

As part of this study, we had a Google Hangout with NASA Flight Surgeon Dr. Josef Schmid and NASA Nutrition Scientist Sara Zwart, PhD. We asked them all kinds of questions about their work and how our bodies work in Earth gravity and microgravity.

Sara Zwart

Josef Schmid

How many astronauts have you been Flight Surgeon for? Who?

Josef has been a flight surgeon for seven different astronauts. Most recently for Tracy Caldwell Dyson when she was on the International Space Station for Expedition 23-24.

Did any astronauts not listen to you as a Flight Surgeon? What did they do? Why did they not follow your directions?

Sometimes they don’t listen to food recommendations.

What happens if someone breaks a bone in space?

Bones lose calcium in space. To help reduce bone loss, the astronauts exercise and eat less sodium and iron.

How do you, or can you, monitor the exercise equipment in space? How you know how the astronauts are doing in their training?

The exercise equipment sends messages by satellites back to Earth. That way they know how the exercises are going. The astronauts record their exercise and diet and report back to Earth.

How do you do a medical examination while your patient is in space?

The astronauts do the exam themselves but while they’re on the telephone with Joe.

Are there special medical tools that you use in space?

There is a special bag to collect urine samples that are used to test nutrition intake. There is also a special blood tube to keep specimens from mixing in microG after they’ve been centrifuged to separate the plasma and red blood cells.

What’s it like to be a space doctor?

“It is the best job on Earth!” He really likes it because there are always new things to study and he gets to work with really healthy people that are trying to stay healthy. Sara likes to see how the body reacts to microG. It’s a way of learning faster how our bodies work because the changes happen faster in space.

How does being in space affect your heart rate?

The heart rate isn’t really affected by microG. At first it might be sped up because the astronauts are a little queasy and excited with all the newness. After they get used to being in space, they go back to their normal heart rates.

What would you do if your patient gets sick in space?

It doesn’t happen a lot because they make sure the astronauts are really healthy before they go up. They have medicine on the space station just in case and talk to their doctor. If it were a very bad illness, they might come back to Earth.

Do you tell astronauts in space to go on diets?

We don’t really give them diets because it’s hard to tell them what to eat. Eating the same thing all the time gets boring. Enjoying food is really important to keeping the astronauts moods up. The nutritionists and doctors do make recommendations and hope the astronauts follow them.

Have any of the astronauts you’ve worked with had injuries in space? What kind? How did you treat?

Only minor things. The astronauts get sore fingers a lot of times after space walks. Sadly, Joe lost one of his patients when the space shuttle Columbia was lost in re-entry.

What are the most common illnesses in space?

Common colds are the most common thing.

Is it hard to treat patients in space?

It’s hard because you can’t see them or touch them directly. You have to rely on the patient making the observations and giving them to you.

How is working with astronauts in space different than working with patients on Earth?

You can see your patient on Earth. In space, you can only hear from them how they are doing.

How do you do surgery in space if you need to?

They’ve never had to do it. There are only tools for minor things on the Space Station. But for deep space, longer missions, they think they will need a medical doctor as part of the crew. They might also use telerobotic surgery that Joe is experimenting with.

What is the difference in medical school to be a space doctor?

Sometimes there are different classes that focus on how the body works in microG.

What kinds of things change about your body in space?

Your vision can be impaired. This is something they are trying to figure out why it happens and how to prevent it from happening. Your balance is affected, but the body adapts pretty quickly to it. Bone and muscle loss are the most common. Diet and exercise are used to prevent this. Your spine stretches out in space 3-6 cm. It goes back to your normal length when you come back to Earth.

How does being in space affect how you go to the bathroom? Does it affect the size of your bladder?

At first your body is trying to get rid of fluid it doesn’t need so your kidneys and bladder are working more. That slows down after a few days and goes back to normal. Your intestines take time to get used to microG and you sometimes become constipated. Going to the bathroom is hard because you have to go into a tube, kind of like a vacuum cleaner hose.

Mars On Earth

by MA, Science 5HSquires

The 5th grade did a rover simulation. The purpose of the simulation was to compare to the real Mars rovers. Another purpose of the rover simulation is to find out the different temperatures in the room. We were trying to figure out why some temperatures were different in the same room. We experienced both driving rovers and moving as rovers.

The simulation worked by dividing everyone in groups of four. There would be two drivers and two rovers. The drivers would send one-step commands and the rovers would follow the command. The rovers would not bump into an object and destroy itself. It would go around the object and continue. There would be a two minute delay when drivers were sending the commands. If the rovers could follow the command successfully, they would send back complete. If the rovers could not follow the command, they would send back fail.

The simulation was different than I thought it would be, because the delay feels longer than it really is. It is really exciting when you plan a path for the rover. It is frustrating when there is a fail. It can also be frustrating when the plan is long and slow. The simulation helped me understand how mars rovers communicate with the drivers.

We had a conversation with the real rover driver Scott Maxwell. He told us about failures, rovers, procedures, and commands. He also told us about when Spirit fell into a sand trap. The procedure for getting Spirit to still work was to have it take sample info and send it back. He told us about microorganisms that probably lived on Mars. He told us it usually takes a few hours to make a program.

In conclusion, the experience is great because you know what is like to be the rover and the driver. The delay is less than it really is in space, but it sets a good example for timing. With Scott Maxwell, we learned about many interesting things. I had a great time doing this, and I hope to do something like this again!

Germination Experiments

Investigations in Germination

by Sci 4 Oppy & Spirit

We have been studying germination. Germination is the stage when the seed sprouts - the seed coat splits and the radicle comes out. We were trying to find out what would work best for alfalfa seeds to germinate.

We had these hypotheses, seeds need:

• need water to germinate (wwc)
• need light to germinate (ds)
• need soil to germinate (es)
• need carbon dioxide to germinate (al)
• need nitrogen to germinate (al)
• need potassium to germinate (ar)
• need phosphorous to germinate (jrs)
• need oxygen to germinate (lt)
• needs proper temperature (ar)
• needs bacteria to germinate (es)
• needs proper pH (es)

*“proper” amount may vary by species of plants

To test our hypotheses we glued 5 seeds to a piece of circular filter paper and put that in a petri dish. The petri dishes went into a container with water about 1 cm deep.

In our first trial, we put seeds in water and under constant light. We also put seeds under the light without water. The seeds that were dry did not germinate. The seeds that were wet germinated in two days. From this we concluded that seeds need water to trigger germination.

In our second trial, we asked, do they need light. We put the seeds in a dark cupboard to test this. The seeds germinated without light, but the cotyledons didn’t turn green, they were a pale yellow instead. The hypocotyls were white and very long. This tells us that seeds don’t need light to trigger germination. We think the hypocotyls were so long because they were trying to reach light.

In the third trial, we tested how temperature would affect germination. We put one set of seeds in an incubator at 35°C and another set in the refrigerator at 18°C. The seeds in the incubator germinated faster than at room temperature. Most of the seeds in the refrigerator did not germinate at all. The ones that did, grew v-e-r-y s-l-o-w-l-y. So, seeds like warmer temperatures to germinate. We wondered if the embryos in the cold seeds were still alive. We moved them to the room temperature and they germinated. The embryos were still alive.

Our fourth trial tested if the seeds could germinate in salt water. We made salt water solutions of 10 g/L, 5 g/L, 2 ½ g/L and 1 ¼ g/L. Only 7 of 40 seeds germinated at 5 or 10 g/L after 5 days. We moved these seeds to freshwater to see if the embryos were still alive. After 2 days, 6 more seeds germinated when moved to the fresh water for a total of 13 of 40 seeds. In 2 ½ and 1 ¼ g/L, most of the seeds germinated after two days. So that means the embryos can tolerate salt water at a low level. Less than 2 ½ g/L.

Our fifth experiment was to see if seeds needed air to germinate. We put seeds in a test tube completely filled with water and no air bubbles and put a rubber stopper to seal the test tube. After 5 days, the seeds had swelled up and the seed coats had lost color, but no germination. We put these seeds in petri dishes to see if the embryos had drowned or suffocated. We found that some of them were still able to germinate.

Doing these experiments, we learned that seeds need certain things to trigger germination. We also learned that science takes time. You can’t rush an experiment or you will mess things up. Sometimes you have to wait a few days to get your data. Experiments have to be carefully planned out. You can’t just say, “Let’s go!” and jump into action. You have to plan before you can do science. We also learned that the most important part of an experiment is the control. We have to have a control to see if there is any difference in the experiments. Our control was seeds germinated in “regular” conditions: room temperature, water and constant light.

Make Way for the Wintermaker - Sky & Telescope

Make Way for the Wintermaker - Sky & Telescope

Maths Likes

Math5 asked mathematicians on Twitter, "What do you like about math(s)?" We got some great responses. You can see the responses by clicking this link: https://storify.com/mwilkinson3/maths-likes?utm_content=storify-pingback&utm_medium=sfy.co-twitter&utm_campaign=&utm_source=t.co&awesm=sfy.co_bzd6

Soil Nutrient Lab

Soil Nutrient Lab

Our work in Michael’s 4th Grade Science class this year started with looking at the needs of living things. We came up with all kinds of things we thought we needed, but narrowed down to the basic needs of living things: food, water, air, habitat. We’ve been told that the plants bring the nutrients into the ecosystem by absorbing them from the soil. We wanted to see if we could find those nutrients ourselves. We learned that there are three main nutrients for life: nitrogen, potassium, and phosphorous. So we decided to test for these in the garden. Shouldn’t there be plenty of nutrients there since we were growing things to eat?

Collecting Soil Samples

We collected soil samples from the garden beds, the pond, the area outside the garden beds under the woodchips, and in the runoff from the playground by the bridge. We tested each of these soils for the three nutrients and found that while there was sufficient phosphorous and potassium in the soil, there was very little nitrogen. When we went back to the garden, we could see the effect on the squash plants. Their leaves were yellow-green with yellow and brown spots and the edges of the leaves were dry brown. These were signs of not enough nitrogen.

These leaves don't look healthy.

How can we grow healthy plants to eat in a garden without enough nitrogen? We wanted to find a way to improve the soil, so we brainstormed some solutions. We thought adding compost or fertilizer might help. We also remembered that there are some plants that help put nitrogen into the soil. We remembered from our “Three-Sisters” study last year (corn-beans-squash) that one of the things the beans did was help with nitrogen, we thought planting beans might help. We also wanted to try alfalfa. So we took some small pots and prepared the soil five different ways: control soil with no change, soil mixed with osmocote pellets, soil mixed with compost, soil planted with beans, soil planted with alfalfa. We put these under constant light and water and will test the soil nitrogen levels in a few weeks.

In the meantime, we learned that bacteria helped convert nitrogen from the air into nitrogen that plant roots could absorb. Maybe there wasn’t enough bacteria in the soil from the garden. Upperschool Science Teacher (and class parent) Howie Waldman came to class to help us grow some bacteria from the soil and compost. It only took a day for there to be a lot of growth. Howie is going to help us to try to make microscope slides of the bacteria next, so we can see individual cells.

We also noticed a lot of living things in the compost - macroinvertibrate decomposers. We found nematodes, earthworms, pseudoscorpions, weevils, isopods, and others we haven’t yet identified.

We’re learning a lot about soil, how it works and how it helps us to be healthy. Like the song says, dirt really did make our lunch. We can’t live without healthy soil.

DATA UPDATE 10/21/14

After one month, we tested our soil treatments for nitrogen levels with Rapitest kits:

Soil Treatment	Nitrogen Level after 1 month
Control	Depleted (N0)
Osmocote	Surplus (N4+)
Compost	Surplus (N4+)
Beans	Deficient (N1)
Alfalfa	Deficient (N1)

Conclusions

We can improve the nitrogen in the soil using compost and Osmocote. It only takes a little of these to raise the nitrogen in the soil. Planting beans and alfalfa changed the nitrogen a little bit, we need a lot more bean and alfalfa or more time to bring the nitrogen up enough. So, if we want healthy garden soil, we need to add a little compost to the soil.