Introduction

• Everyday applications of quantum jumps, states, and energy levels
• How quantum physics lights our streets and brewpubs
• Atomic clocks and global positioning
• Semiconductors and superconductivity

Quantum physics has not only improved our fundamental understanding of nature. It has also spawned a new breed of technology, thanks in part to the ingenious experiments that validated many aspects of quantum theory over the past century.

We will begin our survey of today’s quantum technologies, carefully relating each to the principles we developed throughout this book. We will describe how quantum jumps help light your homes. We’ll see how quantum states can print your boarding passes and scan them in, too. We’ll even explain how energy levels can help you to avoid traffic jams.

Finally, we will introduce you to the quantum theory of solids, and see how armies of atoms resemble, and differ from, atoms in isolation. Then we’ll see how these unique features power the internet and provide hope for a secure energy future.