The classic Stern-Gerlach Experiment shows that atoms have a property called spin. Spin is a kind of intrinsic angular momentum, which has no classical counterpart. When the z-component of the spin is measured, one always gets one of two values: spin up or spin down.

Students work through an online tutorial on MIT's App Inventor to learn how to create Android applications. Using those skills, they create their own applications and use them to collect data from an Android device accelerometer and store that data to databases. NOTE: Teachers and students must have a working knowledge of basic programming and App Inventor to complete this lesson. This lesson is not an introduction to MIT's App Inventor and is not recommended for use without prior knowledge of App Inventor to produce an end product. This lesson is an application for App Inventor that allows for the storage of persistent data (data that remains in memory even if an app is closed). This required prior knowledge can come from other experiences with the App Inventor. Also, many additional resources are available, such as tutorials from MIT. This lesson could also be used as an enrichment project for students who are self-motivated to learn the App Inventor software.

Students learn about civil engineers and work through each step of the engineering design process in two mini-activities that prepare them for a culminating challenge to design and build the tallest straw tower possible, given limited time and resources. First they examine the profiles of the tallest 20 towers in the world. Then in the first mini-activity (one-straw tall tower), student pairs each design a way to keep one straw upright with the least amount of tape and fewest additional straws. In the second mini-activity (no "fishing pole"), the pairs determine the most number of straws possible to construct a vertical straw tower before it bends at 45 degrees—resembling a fishing pole shape. Students learn that the taller a structure, the more tendency it has to topple over. In the culminating challenge (tallest straw tower), student pairs apply what they have learned and follow the steps of the engineering design process to create the tallest possible model tower within time, material and building constraints, mirroring the real-world engineering experience of designing solutions within constraints. Three worksheets are provided, for each of two levels, grades K-2 and grades 3-5. The activity scales up to school-wide, district or regional competition scale.

Street lights of the same type will look brighter when they are close to you, and less bright when they are farther away. The same applies to astronomical objects: a given star will look brighter to a nearby observer than to an observer far away. In both cases, the difference in brightness can be used to deduce the relative distances of suitable objects. Standard candles, objects of constant intrinsic brightness or whose intrinsic brightness can be determined by careful measurements, are a key tool for astronomical distance determination. In this exploration, you will explore standard candles (and also effects that complicate distance measurements) in a simple everyday setting, namely that of street lights, using a digital camera and freely available software.

Students are introduced to the concepts of stress and strain with examples that illustrate the characteristics and importance of these forces in our everyday lives. They explore the factors that affect stress, why engineers need to know about it, and the ways engineers describe the strength of materials. In an associated literacy activity, while learning about the stages of group formation, group dynamics and team member roles, students discover how collective action can alleviate personal feelings of stress and tension.

Explore stretching just a single strand of DNA using optical tweezers or fluid flow. Experiment with the forces involved and measure the relationship between the stretched DNA length and the force required to keep it stretched. Is DNA more like a rope or like a spring?

This module is about a particular effect of the frequency, which is the stroboscopic effect. The lesson discusses and demonstrates low frequency phenomena - less than 16 Hz - that can usually be observed clearly by the human eye, as well as high frequency phenomena - more than 25 Hz - that are difficult for the human eye to catch. This video also explores and demonstrates how high frequency phenomena can be observed by freezing the fast moving phenomena using a device called a stroboscope. The only prerequisite for this video is that students understand the definition of the frequency of a periodic phenomenon.

To introduce the two types of stress that materials undergo compression and tension students examine compressive and tensile forces and learn about bridges and skyscrapers. They construct their own building structure using marshmallows and spaghetti to see which structure can hold the most weight. In an associated literacy activity, students explore the psychological concepts of stress and stress management, and complete a writing activity.

In this lesson the students will learn how the heart functions. Students will be introduced to the concept of action potential generation. The lesson will explain how action potential generation causes the electrical current that causes muscle contraction in the heart. Students will be introduced to the basic electrical signal generated by the heart; P, QRS, and T waves. The lesson will approach the heart from an engineering standpoint and encourage students to design ways to improve heart function. Students will also learn the basic steps of the engineering design process.

Through two lessons and their associated activities, students do the work of scientists by designing their own experiments to answer questions they generate. Through a simple activity involving surface tension, students learn what a hypothesis is—and isn't—and why generating a hypothesis is an important aspect of the scientific method. In the second activity, with bubble gum to capture their interest, students learn to design and conduct controlled experiments to answer their own questions about the amounts of sugar (or artificial sweetener) in bubble or chewing gum.

Students observe natural selection in action and investigate the underlying mechanism, including random mutation and differential fitness based on environmental characteristics. They do this through use of the free AVIDA-ED digital evolution software application.

What happens when sugar and salt are added to water? Pour in sugar, shake in salt, and evaporate water to see the effects on concentration and conductivity. Zoom in to see how different sugar and salt compounds dissolve. Zoom in again to explore the role of water.

Students are introduced to static equilibrium by learning how forces and torques are balanced in a well-designed engineering structure. A tower crane is presented as a simplified two-dimensional case. Using Popsicle sticks and hot glue, student teams design, build and test a simple tower crane model according to these principles, ending with a team competition.

Watch shadows during the course of the day to explore the influence of the Sun’s position in the sky on them, as well as how they change over the seasons. During the next season, repeat the experiment and note the changes from the previous season. Repeat over a period of one year for each season.

Use this hands-on activity to demonstrate rotational inertia, rotational speed, angular momentum, and velocity. Students build at least two simple spinners to conduct experiments with different mass distributions and shapes, as they strive to design and build the spinner that spins the longest.

Students are introduced to superhydrophobic surfaces and the "lotus effect." Water spilled on a superhydrophobic surface does not wet the surface, but simply rolls off. Additionally, as water moves across the superhydrophobic surface, it picks up and carries away any foreign material, such as dust or dirt. Students learn how plants create and use superhydrophobic surfaces in nature and how engineers have created human-made products that mimic the properties of these natural surfaces. They also learn about the tendency of all superhydrophobic surfaces to develop water droplets that do not roll off the surface but become "pinned" under certain conditions, such as water droplets formed from condensation. They see how the introduction of mechanical energy can "unpin" these water droplets and restore the desirable properties of the superhydrophobic surface.

Surface tension accounts for many of the interesting properties we associate with water. By learning about surface tension and adhesive forces, students learn why liquid jets of water break into droplets rather than staying in a continuous stream. Through hands-on activities, students learn how the combination of adhesive forces and cohesive forces cause capillary motion. They study different effects of capillary motion and use capillary motion to measure surface tension. Students explore the phenomena of wetting and hydrophobic and hydrophilic surfaces and see how water's behavior changes when a surface is treated with different coatings. A lotus leaf is a natural example of a superhydrophobic surface, with its water-repellent, self-cleaning characteristics. Students examine the lotus effect on natural leaves and human-made superhydrophobic surfaces, and explore how the lotus leaf repels dewy water through vibration. See the Unit Overview section for details on each lesson in this unit.

Students are presented with the question: "Why does a liquid jet break up into droplets?" and introduced to its importance in inkjet printers. A discussion of cohesive forces and surface tension is included, as well as surface acting agents (surfactants) and their ability to weaken the surface tension of water. Students observe the effects of surface tension using common household materials. Finally, students return to the original question through a homework assignment that helps them relate surface tension and surface area to the creation of water droplets from a liquid jet.

Students extend their understanding of surface tension by exploring the real-world engineering problem of deciding what makes a "good" soap bubble. Student teams first measure this property, and then use this measurement to determine the best soap solution for making bubbles. They experiment with additives to their best soap and water "recipes" to increase the strength or longevity of the bubbles. In a math homework, students perform calculations that explain why soap bubbles form spheres.

In an activity that integrates science and art, students see, experience and harness the phenomenon of surface tension as they create beautiful works of art. Students conduct two experiments related to surface tension floating objects on the surface of water and creating original artwork using floating inks. They also learn historical and cultural information through an introduction to the ancient Japanese art form of suminagashi. They take the topic a step further by discussing how an understanding of surface tension can be applied to solve real-world engineering problems and create useful inventions.