Henry Carter Hull

Visit the beach with a geologist's eyes and see how the interaction of waves, ocean currents, and winds lead to the ebb and flow of sediments and blending of landforms. Consider the four types of waves and what they reveal about the ocean floor just offshore. Also, zero in on individual grains of sand, identifying their minerals and tracing their origin. Reflect on why beaches are sandy at all.

With the advent of logic gates that could be assembled to perform mathematical or logical calculations, engineers could build up from very simple transistors and diodes to a powerful graphic calculator or complex system of facial recognition. Learn about why the numerical basis for logic gates is binary, and how they can be combined to form logic gate circuits.

Discover the four revolutions in electrical engineering that have brought major opportunities and benefits to masses of people in just the past 150 years. Learn, specifically, what each of the four periods brought and the basic properties of the electron and electric circuits on which our entire electrified world is based.

Investigate glaciers, which now cover about 10% of Earth's land area; 25,000 years ago, they covered 30%. Learn how to spot evidence of past glaciation—from sculpted valleys in Yosemite National Park, to the cliffs at Vicksburg, Mississippi (which formed far from glaciers), to Minnesota's 10,000 lakes. Dig into the physics of glaciers: how they develop and the forces they exert.

Go outside and find an outcrop—a roadcut, cliff face, or other site where rocks are exposed. These are ideal places for practicing field geology. Professor Cotter gives tips on safety, maps, tools, and techniques. A notebook and careful record-keeping are essential. Amateur geologists can make important discoveries, so field geology is your chance to advance knowledge while enjoying the outdoors.

Since 2006, the number of landlines has decreased, while the quantity of mobile phones and other communication devices now outnumber the entire human population. Explore how engineers have created the cellular systems required to manage large numbers of calls at once, even as the user moves from place to place.

In the old-style analog telephone system, voltage increased and decreased across the wires, corresponding to the human voice signal. But in a digital system, that all changes. Learn how the human voice is changed into binary values, sent over the system, and then converted back into volts with the voltage applied to the speaker in the phone handset. The human ear takes it from there.

Reduce costly leaks and breakdowns and increase the value of your RV with some simple maintenance. In this class, you'll learn how to inspect and refresh the sealants on the roof and sidewall. You'll also learn how to address faded fiberglass, damaged awnings, cracked decals and black streaks that can drop your RV's value. Finally, you'll see how to maintain the tires and deal with other common motorhome issues.

While sound is not part of the electromagnetic spectrum, it can be manipulated, generated, and shaped by electric circuits. Explore what the signalscope output can tell you about the makeup of various sounds, from a single tone to the human voice to piano chords, and how these can be manipulated by circuits to synthesize entirely new sounds.

Consider how to put your knowledge of geology to use. Issues faced by your community may benefit from geologic insights about groundwater, watersheds, roadways, pollution, and historic questions such as abandoned mines and quarries. Practical geology will only grow in importance as the world deals with climate change, resource shortages, and the pressing need to live in harmony with the planet.