Introduction

• Potential applications of superposition and entanglement
• How to build a quantum computer, and then keep it secure
• The facts behind quantum teleportation
• The future of quantum physics

We have learned throughout this book that discoveries in quantum physics have allowed us to better understand nature. Though it provides many answers, it also continues to open up even deeper puzzles. To address these, scientists keep expanding and improving their theories and experiments, and have occasionally stumbled upon major discoveries so unexpected that they didn’t quite know what to make of them at the time.

The concepts of quantum superposition and entanglement are examples of such phenomenon. These notions were not only startling upon discovery, they boggle the minds of quantum physicists (and nonphysicists) to this day.

We see how these concepts could one day underpin the next generation of computation. We’ll learn about the principles of quantum computers, and how one might go about building one. We’ll see how quantum physics weakens and strengthens internet security all at the same time. Finally, we’ll ponder how entangled states could one day enable the seemingly impossible.