One of the major themes that runs through many facets of science is the notion of surface area to volume ratio. I remember being a Peace Corps Volunteer in Kenya and using an experimental, guided-inquiry curriculum, inspired by the British Nuffield science program. Students made plasticine cubes of various sizes. I’m not sure why British people have an aversion to clay, but plasticine seems to be their school sculpting material. Then students measured the surface area of the cubes and calculated the volume. Then they calculated the surface area to volume ratio and discover that the larger the object, the smaller the surface area to volume ratio.
Which helps to explain many types of adaptations in biology and why individual cells can’t be the size of houses; they would simply not have enough surface area to absorb the materials they need, like oxygen, or to expel waste. From villi in the intestines to convolutions in the brain, our bodies have many adaptations to increase surface area.
Adaptive Curriculum has a guided inquiry Activity Object called “Surface Area to Volume Ratio in Organisms.” A clever engagement draws the students into the interactive experience. You have a plate of cheese with different size cubes that you are going to put into the microwave. But first, learners predict whether the large cubes or the small cubes will melt first.
Obviously, the small cheese cubes will melt before the larger ones. If you thought this, you have experienced a discrepant event. In actuality, the large cubes melt first. Since the microwave heats from the inside, the smaller cubes lose their heat faster than the large ones. The larger cubes, thus retain more heat and melt faster. Discrepant events are powerful, because learners want to know why they were wrong.
From this, learners virtually change the size of cubes and see the changes in surface area, volume, and surface area to volume ratio. Then body sizes and shapes of animals are explored, as students learn about the implications of size and shape for heat loss.
My Peace Corps teaching and Adaptive Curriculum are different modes of guided inquiry and discovery learning, but both can help produce deep and life long learning.
Back in 1985 I was fortunate enough to visit George Awad’s New York studio where he was using his architectural skills and space interests to construct a scale model of the universe. Awad used one million of his own dollars to make this and it was very impressive and enlightening.
This is how Carl Sagan (1997) described it in his book THE DEMON-HAUNTED WORLD: Science as a Candle in the Dark:
Perhaps the grandest museum exhibit can’t be seen. It has no home: George Awad is one of the leading architectural model makers in America, specializing in skyscrapers. He is also a dedicated student of astronomy who has made a spectacular model of the Universe. Starting with a prosaic scene on Earth, and following a scheme proposed by the designers Charles and Ray Eames, he goes progressively by factors of ten to show us the whole Earth, the Solar System, the Milky Way and the Universe. Every astronomical body is meticulously detailed. You can lose yourself in them. It’s one of the best tools I know of to explain the scale and nature of the Universe to children. Isaac Asimov described it as ‘the most imaginative representation of the universe that I have ever seen, or could have conceived of. I could have wandered through it for hours, seeing something new at every turn that I hadn’t observed before.’ Versions of it ought to be available throughout the country – for stirring the imagination, for inspiration and for teaching. But instead, Mr Awad cannot give this exhibit to any major science museum in the country. No one is willing to devote to it the floor space needed. As I write, it still sits forlornly, crated in storage.
In my office, I have the model of the Big Dipper that George Awad gave me during that 1985 visit. After seeing so many 2-dimensional drawings of the big dipper, the model is a 3-dimensional view that shows how relative size and distance influence what we see in the night sky.
Then there was the famous Powers of Ten Video (or applet) that gave us the broad view of the universe and kept on magnifying by ten, until we arrived in Florida, and then descended into a plant.
Now the folks at Primax Studio have done their own Scale of the Universe with drawn images, instead of partially using photographs, but the music and the interactive aspects make it delightful to explore.
The scale of the universe is difficult to fully appreciate but we are getting closer due to multimedia tools. A 3-d Imax movie will soon be in theaters.
The videos on television show some of the massive destruction and the human toll of the recent earthquake in Haiti. It is difficult to imagine the suffering of the Haitian people. It is an unfortunate example of the devastation of a magnitude 7 earthquake.
It is natural to wonder why or how. When students are ready, teachers may want to discuss earthquakes and their causes.
The folks at IRIS have a website with a PowerPoint presentation and Quicktime movie that explain a lot of details associated with this particular earthquake and earthquakes in general. The PowerPoint has excellent pictures of the destruction to buildings, without presenting images of human suffering that would be difficult for some students. The image to the right is taken from the PowerPoint.
IRIS (AKA the Incorporated Research Institutes for Seismology) has lots of resources for learning about earthquakes including SeisMac 2.0 which allows Macintosh computers to become seismographs.
In the quest for Science Literacy, we strive to give students an understanding of natural events before they happen. Adaptive Curriculum has two strong Activity Objects, one is on determining the magnitude of an earthquake and the other is determining the location of the earthquake. The image below is from “Earthquakes: Measuring Magnitude.“
We all want to avoid having children get hurt doing school science. We also don’t want teachers to avoid doing hands-on science because of fears related to safety issues in the science classroom. For the elementary school classroom there are a couple of valuable resources that can help teachers and administrators develop safer practices for science instruction.
Many of these practices have been written with common sense in mind. And if you are safety minded, you are on the lookout for all the potential things that can go wrong and ways to prevent these accidents. Unfortunately, K-5 classrooms would not have some of this safety equipment, such as eyewash fountains, fume hoods, and safety showers, and probably most middle school science classrooms would come up short in these areas.
While going all virtual to avoid safety problems may be tempting, a more pragmatic solution is to avoid dangerous hands-on materials and be very careful to try science activities before hand, and monitor student behavior.
Technology For K-6 Science Safety
While technology is often thought of as electronic stuff, a better and wider view is that it is any human made products that make our lives better or safer. With this in mind, I present my top ten safety technologies.
1. Teacher Developed Safety Rules Contract: A teacher and students who are safety minded is probably the best defense against accidents. There should be no toleration of inappropriate behavior when doing hands-on science.
2. Goggles: Chemical splash safety goggles should be worn whenever what you are working with has the potential to hurt or damage eyes. Please don’t adopt the view, such as, “I use ammonia at home without goggles, so it is okay to use it in school without goggles.” An adult can decide not to use goggles at home and it is at their peril. If a teacher decides not to have students wear goggles with materials that could harm eyes, and eyes are damaged, the teacher will probably be held culpable, as will the administrators, the school, and the district.
3. Disposable Nitrile Gloves: From dissections to handling chemicals, these can prevent problems. And if a student is bleeding for any reason, an adult should put on gloves to help with the situation.
4. Locked Chemical Cabinet
5. Fire blanket and extinguisher
6. First aid kit
7. Proper waste containers
8. Rubber covered muslin aprons
9. Safety posters and signs
10. Non-mercury thermometers
Teachers should be urged to provide hands-on experiences for their students. But teachers are also responsible for the safety of their students.
I am at the NYSCATE Metro Conference, in Rye, NY. I grew up about 45 minutes from here but I forgot that it is still cold in mid-May. But of course, everything is relative, and relative to Arizona almost everywhere else is cooler.
This activity series on weather is presented by PBS, and it has a great feature–you can add the activities directly to your school web site. I present the activities and what this would look like on your website below.
Resources:
Adaptive Curriculum’s “Hurricane Formation” (which allows students to learn that humidity, water temperature, and wind speed are important factors in hurricane development).
I have the good fortune to be in beautiful Austin, Texas today for the Texas Computer Education Association’s (TCEA) annual convention. Austin is a delightful city, and this conference is huge. In a couple of hours I am going to be doing my presentation “Critical Thinking and TEKS Science Content Via Online Activities.”
I am placing the PowerPoint file here for participants and anyone else interested in this topic. Below are some titles and resources from the presentation.
demonstrate basic relationships between force and motion using simple machines including pulleys and levers (TEKS: 7.6)
http://2dboy.com/games.php
Creature Creator
prelude to Spore
Free trial edition
How can students making creatures
Develop science content?
Develop critical thinking?
Or both?
Adaptive Curriculum Activity Objects
Dancing with the Bees
TEKS 6.12: responses to external stimuli
Determining Planet Layers from Seismic Waves
TEKS 6.6 identify forces that shape features of the Earth; 7.2: organize, analyze, make inferences, and predict trends from direct and indirect evidence
Groundwater
TEKS 6.1: make wise choices in the use and conservation of resources; 6.14 groundwater
From this, learners virtually change the size of cubes and see the changes in surface area, volume, and surface area to volume ratio. Then body sizes and shapes of animals are explored, as students learn about the implications of size and shape for heat loss.
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