This book aims to popularize physics by emphasizing conceptual ideas of physics and their interconnections, while avoiding mathematics entirely. The approach is to explore intriguing topics of daily relevance by asking and discussing questions: thereby the reader can participate in developing answers, which enables a deeper understanding than is achievable with memorization.The topic of this book — waves — is chosen because we experience waves in many forms every minute of our lives, from sound waves and light waves to quantum waves and brain waves.The target readership of this book is very broad: all those with a curious mind about nature and with a desire to understand how nature works, especially laymen, youngsters, secondary-school children and their teachers.