Project Director: Paul Horwitz
Project Staff: Stephen Bannasch, Scott Cytacki, Ed Hazzard, Carolyn Staudt
Our work this year consists of a combination of after-school and in-class activities involving fundamental concepts of heat flow and temperature. (We piloted some of these activities in sixth grade classes at the Fowler School, last year.) We will use advanced data collection and simulation technology to help your children link their mental models of heat and temperature to data that they will collect themselves on handheld and desktop computers. As they work their way up from simple objects, which can be characterized by a single temperature, to larger systems with more complex behaviors, we will link their investigations to topics on the forefront of science, such as weather forecasting and global climate change. An important aspect of the project is the creation of technology that will enable young children to collect and analyze data from multiple temperature probes and to run simulations of their experiments, based on simple models of heat flow that they can inspect and modify. Naturally, their models will not always agree with their observations. By comparing the results of simulations to the experimental data they collect, students will come to appreciate a most important aspect of science: that neither theories nor experiments alone embody ultimate truth, that either may be revised to account for anomalies, and that the creation of scientific knowledge is ultimately driven by a complex and delicate interplay between models and data.
Here are the details of the what we will be doing. We plan to form a "Hot and Cold Club" for interested sixth-graders. Membership in this club will be limited to fifteen students, to be selected on a "first-come-first-served" basis. The club will meet after school on Thursday afternoons, approximately every two weeks, starting on December 7th. Attendance will of course be voluntary, though we expect that the activities will be intriguing enough that drop outs will not be a problem. Each session of the club will last about two hours, and may end with suggestions for activities to be worked on at home during the period between sessions. To the extent that these activities involve handheld computers, we will provide these to students; activities involving desktops with access to the internet can be done using home computers, if possible, or by arrangement with the Maynard schools where necessary.
Here is a tentative list of topics that we plan to cover. (The early topics are definite, the later ones may be altered somewhat, based on our experience.):
Temperature changes and heat flow. What happens when an object has more than one temperature (for instance, it may be hot on one side and cold on the other)? Kids will use instrumented blocks of various materials connected to handheld computers that automatically graph the temperatures at various points on each block. A simple computer program will model what happens when the blocks are placed in contact with one another, representing the outcome by a display similar to that produced by the data itself. We also hope to produce a computer-generated animated representation of the heat flow that results when two blocks of idffering temperatures touch one another.
The human body is both a heat source and a "thermometer." This can lead to a good deal of confusion. For example, if you touch a metal lamppost and a tree (in winter) the lamppost will feel much colder than the tree, even though they are both at the same temperature. Why? The answer is intimately connected to the fact that we are warm-blooded mammals. Students will use small, lightweight probes to measure the temperature of their fingertips when they touch various objects. They will model this situation on the computer to see why the lamppost and the tree feel so different.
Convection. Solid objects conduct heat -- fluids can move heat around by simply moving themselves. With immersible temperature probes in a water-filled tank, students will be able to visualize this process. Modeling it involves notions of density and buoyancy. The applications to abrupt weather changes -- especially in New England! -- can connect a table-top experiment to its real-world implications.
Radiation. It is colder in winter than it is in summer, even though the Earth is actually closer to the Sun in January than it is in July. Why? Heat can flow through a vacuum, but the amount of heating depends on distances and angles in a very surprising way. Students will past temperature probes to various spots on a globe, and use a heat lamp represent the sun. In this way, they will measure temperature differences at different latitudes on the Earth and form models of how those differences will vary as the Earth goes around the Sun.
Weather, climate, and global change -- all this emphasis on heat and temperature relates to some very important questions! How does the weather bureau predict what the temperature will be tomorrow? Why can't they predict the weather more than a few days in advance? Why is it cold at the North and South Poles and hot at the equator? Is the whole Earth warming up? How would we know if it were? If it is, what does that mean, and what can we do about it? These topics and more will be discussed in the later sessions of the "Hot and Cold Club."
Paul Horwitz - December 12, 2000