|Welcome to the Laboratory|
|Home||The Bulletin||Nature Walks||The Time Machine||Experiments and Lesson Plans||Useful Links|
|What is the basis of all science?    Experimentation    |
Science grows because curious people ask questions, propose hypothetical answers then test them. Coincidentally that is also one way a child learns about his world. Experimenting seems to be an intimate part of what makes us human. Throughout history people have done simple experiments, like trial and error, but the organized body of experimental knowledge that science has become is relatively recent. One can find glimmers of the idea of an experiment-based approach to nature in Aristotle and some of the other philosophers of his time. Their ability to make accurate observations and to reason from them was as highly developed as ours, but their insistence on the ultimate power of the human mind rather than the experimental test often led to erroneous conclusions such as the belief that the sun revolved around the earth.
Euclid's wonderful geometrical propositions and proofs are a sort of experimental science, depending as they frequently do on the drawing and construction of appropriate figures for demonstrating the truth or falseness of an hypothesis. If this idea could only have been extended to the world of matter and energy instead of only numbers, science and its mechanical brother, technology, might have been advanced by as much as a millennium. Of course, the imagination falters at the thought of Medieval society equipped with electric motors or even steam power. Perhaps the slow pace of technology is just as well. We have at least a chance to attain wisdom before we overpopulate the planet and destroy ourselves through a combination of the ancient elements of pestilence, famine and war.
|Introduction to the Experimental Basis of Science|
When and where did the concept of experimentalism arise and how has it progressed since then? Herbalists and medicine men have always been experimenters, but of a very practical sort. The development of a coherent theory to explain why certain drugs did certain things would not have occurred to them. They knew, for example, that administering an extract of wormwood would expel intestinal parasites or that digitalis would strengthen the heart, but they did not look for the reasons behind these actions. It was usually all they could do just to keep the patient alive. Spinning theories was the job of philosophers--but philosophers did not perform experiments.
The early practitioners of medicine were very keen observers and their reasoning powers were as acute as ours, but the framework upon which they placed the results of their 'experiments' was not a scientific theory but the prevaling common wisdom of their time. The conclusions were wrong because the premises were wrong, and it would take many centuries before the basics of anatomy, physiology and drug action would be known.
Other areas of science such as biology hardly existed as independent disciplines as they do today. One studied and classified plants to use them as food, medicines, dyestuffs, or in some other practical way. Likewise animals were domesticated and raised for meat, fur and hides, or as transportation and a source of power. Whatever experimentation that was done with plants and animals must have been of a very practical type and not simply for the sake of understanding as we perform basic research today. A considerable amount of this type of experimentation must have been carried on over the years, but unfortunately, there are very few records of it because those who did this sort of work depended primarily on oral transmission of the results or kept the formulas secret to prevent copying by their competitors in the trade.
The alchemists were an unusual group of natural philosophers who actually did combine the reasoning and theorizing ability of a scientist with the apparatus and chemicals of the laboratory. The old woodcuts and engravings show them with their assistants in dark rooms with fires burning under huge glass retorts and a large book of formulas open in front of them. Though they worked under primitive and hazardous conditions by the standards of today, their experiments were carried out in a more or less organized way. They gathered the natural materials around them and tested them singly and in combinations using the primary agents of fire and water. What they observed in their experiments may have been valid but their reasoning was frequently flawed because of the commonly accepted theories of the day, such as the doctrine of signatures, which were held to be true without adequate proof.
Technological advances in the smelting of metals, the compounding of medicines, the grinding of lenses, engineering, military armaments, architecture, road building, and so on, all came about through testing of new methods and materials, but there was no organized, written body of theoretical knowledge such as provides the scientific basis for the technological creations of our own time. Occasionally we find in the writing of one person such as the thirteenth century scholar, Roger Bacon, a clear statement of the importance of setting up hypotheses and testing them, but this is the exception until we reach the sixteenth century and that other Bacon, Sir Francis (not related to Roger as far as we know). From his time on, persons of intellect and curiosity have grasped the idea that workable knowledge of a subject can only come from the controlled, logical application of observation, experiment and thought, followed by publication of the results for scrutiny by other scientists. As the community of scientists grew and blossomed into scientific societies and departments in the universities, the sharing of knowledge through teaching and reporting of experimental results vastly stimulated the rapid growth of technolgical advance in the 18th, 19th and 20th centuries.
|Resources for Teaching|
|Carolina Biological Supply Company
Carolina Biological Supply Co. was founded in 1927 in Burlington NC as a supplier of biological specimens for teachers. This is where the frogs, earthworms, crayfish and grasshoppers that we dissected in high school biology came from. The company is still the premier supplier of biological specimens in America, but they have expanded to provide many more resources for science teachers. Today, the 'Carolina Curriculum' has become the source for a full spectrum of biology and math lessons for K-12 classes including kits for classroom projects and demonstrations.
In collaboration with the Smithsonian Institution's National Science Resource Center, Carolina now provides the STC Program for science teaching in grades K-8. This is a complete curriculum with lesson plans, science kits, testing materials and teacher's guides. The programs have been extensively tested in many schools and really work.
|Experiments and Lesson Plans |
In what follows, I will give an outline of the areas of science covered and list the types of experiments described. My goal in designing these pages in twofold. First, I want to provide middle school and high school teachers with a large group of tested experiments to use in their science classes and second, I want to inspire students to see that science is a way of asking questions and getting reliable answers and not just looking at pondwater under a microscope. With that idea firmly in mind I looked for experiments that do not have obvious outcomes and are challenging because they require a cerain amount of student input in the selection of a question to be asked. These experiments are designed to provide students with a strong grasp of the biology involved and the role that experimentation plays in the discovery of new knowledge. Teachers need to emphasize to the class that these exercises are designed with two purposes in mind: to illustrate principles of biology and, more importantly, to show them how to construct a hypothesis, test it and interpret the results. I have tried to set up the experiments so that inexpensive, readily available materials and apparatus can be used. It is assumed that the lab has basic glassware and reagents, scales, thermometers, microscopes, dissecting tools, and computers. For teachers with some mechanical skill and time I will include plans for do-it-yourself construction of lab equipment such as digital photomicrography setups, electrophoresis chambers, computer-assisted data acquisition networks, etc.
Emphasis is placed upon preparing the students thoroughly for the experiments so that they understand the questions asked, what importance attaches to the results and how the methods are designed to answer the questions accurately and completely. I have tried to design experiments that arouse curiosity and do not have obvious answers. Examples from the scientific literature are presented to point out how previous workers have struggled with the same sorts of questions and even how they have failed when experiments were designed poorly. In this way, students should see that science is a work of people--not just a catalog of facts and theories in a textbook. The importance of making accurate observations, of working carefully, and of recording all results--even ones that seem irrelevant--is continuously stressed.
It is hoped that teachers will also consult the other pages on this site, particularly the science history and nature walks sections. I don't like to teach history as 'History' because I believe it tends to generate a preconceived attitude that what follows is just a boring bunch of dates and dead people. There is an art to bringing the past to life and it is something that I feel very strongly about. Why are we here if all that happens gets shoved into a dusty archive to be dredged up only in scholarly discussions? How can we make students see that Galileo was a real person with loves and pains and frustration and moments of wonderful insight? I can't tell you how to do that but I can try to provide some unusual material and engaging details that you can use perhaps to create the imagery of a past time. Once students realize the connectedness between all scientists and the passage of knowledge and truth from one to the next, then I believe they have grasped the essence of science.
Finally, as teachers I believe it is our responsibility to listen carefully to what our students are saying and to ask them to participate in their own education. We have come a long way since the time when a student was thought of simply as a passive vessel waiting to be filled with the vast knowledge and experience of our superior minds. Flexibility and diversity must be built into the process so that teachers feel free to experiment with novel methods of education in order to capture that willful spark of attention without which true learning is impossible.
|Featured Experiments and Methods for the Classroom|
Computer Simulations of Global Climate Change
Climate change researchers use highly complex computer simulations to model what happens when certain changes, like temperature or CO2 increase, are introduced into the earth's ecosystem. They use software that has to run on multiple supercomputers, so that makes such experiments beyond our reach as classroom teachers, right? Not so! NASA has produced a scaled-down but still valid simulation program called EdGCM, for Educational Global Climate Model, that you can download here free with registration.
Students can quickly learn to use EdGCM and then design research projects to test the effects of changing a variety of global climate parameters. Running the simulation gives them a graphic demonstration of the effects of even small changes in human activities on sea levels, plant growth and other measures. Great for classroom demonstrations or independent projects, try out the EdGCM and let me know how it works for you.
National Science Project to Study Effects of Climate Change on Animal Migration
Want to participate in a great scientific adventure where you learn by becoming a partner in a project rather than just reading a textbook? Then join the Journey North!
Journey North is a nationwide science network sponsored by the Annenberg Foundation through its Annenberg Media division. Their goal is to utilize the best combination of online graphic, text, video and interactive methods to improve K-12 education in science and math. The website, tells you how to join as a teacher or a student, and the registration is free. I think this is one of the greatest amateur science projects in our country.
This year over 17,000 classrooms in all 50 states and 7 Canadian provinces are participating in the Journey North. The plan of the project is for students to watch for the signs of seasonal change in their area's first appearance of flowers and leaves on sentinel plants, sightings of migrating birds, weather changes, and the like, and to record them and publish their data online for other students to see. In this way, everyone can track the progress of the seasons and see if there are any significant changes to the normal pattern, for example an earlier appearance of flowering because of global warming.
Classes can choose to concentrate on one species like the monarch butterfly, ruby-throated hummingbird or, here in Florida, the manatee. The students are hooked up with scientists across the country who volunteer their help by providing tracking data, scientific advice and mentoring. Spring migration monitoring lasts from February to June, but there's also a fall watch for signs of the southward migration. The animal sightings, plant information, weather data and other observations are gathered together by the dedicated Journey North staff and published on the website for all to study. The information from so many observers can provide surprisingly useful scientific data, especially now when climate change is such an important topic for environmental planners.
The Journey North has been a model for excellence in science education since its establishment in 1991. Involving students in real-life observation, careful data recording and processing and online publication gives them an exceptional experience of the way real scientists work. They can be proud of their part on the team, and what they learn on the job is going to stick with them. And for some, this experience may be the stimulus to a great career as a scientist.
|Areas of Biology Included in Experiments|
Basic techniques and culture conditions
Classes of molecules
Properties of water
Solutions, buffers and pH
DNA and RNA
|USEFUL SITES |
The descriptions and opinions appended to each link are my own and do not necessarily reflect an accurate or complete picture of the site. The order of the entries does not imply anything about relative rank or importance. I have no interest in promoting one site over another. The sites included here are simply ones that I find useful in teaching, following the news in science, setting up lab experiments and gathering information.
|Science News||Ref Desk||Organizations||Teaching &
|Science Books &
|Chemistry & |
|Cell Biol. &
|Physiology & |