Students follow the steps of the engineering design process as they design and construct balloons for aerial surveillance. After their first attempts to create balloons, they are given the associated Estimating Buoyancy lesson to learn about volume, buoyancy and density to help them iterate more successful balloon designs.Applying their newfound knowledge, the young engineers build and test balloons that fly carrying small flip cameras that capture aerial images of their school. Students use the aerial footage to draw maps and estimate areas.

Students hypothesize whether vinegar and ammonia-based glass cleaner are acids or bases. They create designs on index cards using these substances as invisible inks. After the index cards have dried, they apply red cabbage juice as an indicator to reveal the designs.

Momentum is not only a physical principle; it is a psychological phenomenon. Students learn how the "Big Mo" of the bandwagon effect contributes to the development of fads and manias, and how modern technology and mass media accelerate and intensify the effect. Students develop media literacy and critical thinking skills to analyze trends and determine the extent to which their decisions may be influenced by those who manipulate a few opinion leaders. Note: The literacy activities for the Mechanics unit are based on physical themes that have broad application to our experience in the world concepts of rhythm, balance, spin, gravity, levity, inertia, momentum, friction, stress and tension.

Students learn about biomimicry and how engineers often imitate nature in the design of innovative new products. They demonstrate their knowledge of biomimicry by practicing brainstorming and designing a new product based on what they know about animals and nature.

Students are introduced to the concepts of biomimicry and sustainable design. Countless examples illustrate the wisdom of nature in how organisms are adapted for survival, such as in body style, physiological processes, water conservation, thermal radiation and mutualistic relationships, to assure species perpetuation. Students learn from articles and videos, building a framework of evidence substantiating the indisputable fact that organisms operate "smarter" and thus provide humans with inspiration in how to improve products, systems and cities. As students focus on applying the ecological principles of the previous lessons to the future design of our human-centered world, they also learn that often our practices are incapable of replicating the precision in which nature completes certain functions, as evidenced by our dependence on bees as pollinators of the human food supply. The message of biomimicry is one of respect: study to improve human practices and ultimately protect natural systems. This heightened appreciation helps students to grasp the value of industry and urban mimetic designs to assure protection of global resources, minimize human impact and conserve nonrenewable resources. All of these issues aid students in creating a viable guest resort in the Sonoran Desert.

Students study how heart valves work and investigate how valves that become faulty over time can be replaced with advancements in engineering and technology. Learning about the flow of blood through the heart, students are able to fully understand how and why the heart is such a powerful organ in our bodies.

Students are introduced to the circulatory system, the heart, and blood flow in the human body. Through guided pre-reading, during-reading and post-reading activities, students learn about the circulatory system's parts, functions and disorders, as well as engineering medical solutions. By cultivating literacy practices as presented in this lesson, students can improve their scientific and technological literacy.

Students are introduced to the challenge question, which revolves around proving that a cabinet x-ray system can produce bone mineral density images. Students work independently to generate ideas from the questions provided, then share with partners and then with the class as part of the Multiple Perspectives phase of this unit. Then, as part of the associated activity, students explore multiple websites to gather information about bone mineral density and answer worksheet questions, followed by a quiz on the material covered in the articles.

In their reading from activity 1 of this unit, students should have discovered the term "logarithm." It is at this point that they begin their study of logarithms. Specifically, students examine the definition, history and relationship to exponents; they rewrite exponents as logarithms and vice versa, evaluating expressions, solving for a missing piece. Students then study the properties of logarithms (multiplication/addition, division/subtraction, exponents). They complete a set of practice problems to apply the skills they have learned (rewriting logarithms and exponents, evaluating expressions, solving/examining equations for a missing variable.) Then they complete a short quiz covering what they have studied thus far concerning logarithms (problems similar to the practice problems). They consider how what they have learned moves them closer to answering the unit's challenge question.

Students revisit the mathematics required to find bone mineral density, to which they were introduced in lesson 2 of this unit. They learn the equation to find intensity, Beer's law, and how to use it. Then they complete a sheet of practice problems that use the equation.

Students examine an image produced by a cabinet x-ray system to determine if it is a quality bone mineral density image. They write in their journals about what they need to know to be able to make this judgment. Students learn about what bone mineral density is, how a BMD image can be obtained, and how it is related to the x-ray field. Students examine the process used to obtain a BMD image and how this process is related to mathematics, primarily through logarithmic functions. They study the relationship between logarithms and exponents, the properties of logarithms, common and natural logarithms, solving exponential equations and Beer's law.

Students find the volume and surface area of a rectangular box (e.g., a cereal box), and then figure out how to convert that box into a new, cubical box having the same volume as the original. As they construct the new, cube-shaped box from the original box material, students discover that the cubical box has less surface area than the original, and thus, a cube is a more efficient way to package things. Students then consider why consumer goods generally aren't packaged in cube-shaped boxes, even though they would require less material to produce and ultimately, less waste to discard. To display their findings, each student designs and constructs a mobile that contains a duplicate of his or her original box, the new cube-shaped box of the same volume, the scraps that are left over from the original box, and pertinent calculations of the volumes and surface areas involved. The activities involved provide valuable experience in problem solving with spatial-visual relationships.

Students are presented with a brief history of bridges as they learn about the three main bridge types: beam, arch and suspension. They are introduced to two natural forces tension and compression common to all bridges and structures. Throughout history, and today, bridges are important for connecting people to resources, places and other people. Students become more aware of the variety and value of bridges around us in our everyday lives.

Students learn a simple technique for quantifying the amount of photosynthesis that occurs in a given period of time, using a common water plant (Elodea). They can use this technique to compare the amounts of photosynthesis that occur under conditions of low and high light levels. Before they begin the experiment, however, students must come up with a well-worded hypothesis to be tested. After running the experiment, students pool their data to get a large sample size, determine the measures of central tendency of the class data, and then graph and interpret the results.

In this lesson, students learn that navigational techniques change when people travel to different places land, sea, air and in space. For example, an explorer traveling by land uses different methods of navigation than a sailor or an astronaut.

This lesson introduces students to the concept of air pressure. Students will explore how air pressure creates force on an object. They will study the relationship between air pressure and the velocity of moving air.

Few people are aware of how crucial the sense of smell is to identifying foods, or the adaptive value of being able to identify a food as being familiar and therefore safe to eat. In this lesson and activity, students conduct an experiment to determine whether or not the sense of smell is important to being able to recognize foods by taste. The teacher leads a discussion that allows students to explore why it might be adaptive for humans and other animals to be able to identify nutritious versus noxious foods. This is followed by a demonstration in which a volunteer tastes and identifies a familiar food, and then attempts to taste and identify a different familiar food while holding his or her nose and closing his or her eyes. Then, the class develops a hypothesis and a means to obtain quantitative results for an experiment to determine whether students can identify foods when the sense of smell has been eliminated.

In this lesson, the students look at the components of cells and their functions. The lesson focuses on the difference between prokaryotic and eukaryotic cells. Each part of the cell performs a specific function that is vital for the cell's survival. Bacteria are single-celled organisms that are very important to engineers. Engineers can use bacteria to break down toxic materials in a process called bioremediation, and they can also kill or disable harmful bacteria through disinfection.

In this lesson, students learn about the basics of cellular respiration. They also learn about the application of cellular respiration to engineering and bioremediation. And, students are introduced to the process of bioremediation and several examples of how bioremediation is used during the cleanup of environmental contaminants.

Two lessons and their associated activities explore cellular respiration and population growth in yeasts. Yeast cells are readily obtained and behave predictably, so they are very appropriate to use in middle school classrooms. In the first lesson, students are introduced to yeast respiration through its role in the production of bread and alcoholic beverages. A discussion of the effects of alcohol on the human body is used both as an attention-getting device, and as a means to convey important information at an impressionable age. In the associated activity, students set up a simple way to indirectly observe and quantify the amount of respiration occurring in yeast-molasses cultures. Based on questions that arise from this activity, in the second lesson students work in small groups as they design and execute their own experiments to determine how environmental factors affect yeast population growth.