Book excerpt: In every age, science and technology have advanced human civilization. From architecture to engineering, medicine to transportation, humans have invented extraordinary wonders. Over the centuries, new medicines and medical tools have cured and wiped out diseases. Medical technology has saved lives and has improved health for millions of people, increasing life expectancy for Americans from 49 years in 1900 to 77 years in 2000. In the twenty-first century, scientists continue developing new medical tools and techniques to treat cancer and other deadly diseases. In this book, we’ll explore seven wonders of medicine. These wonders include microscopes, which let doctors see the germs that cause disease. Other wonders are antibiotics, lifesaving drugs made from mold. We’ll learn how doctors are able to take a still-beating heart from one person and place it into another. And we’ll find out about nanomedicine, including tiny “robot doctors” that might one day travel inside the body. From the basic to the cutting edge, we’ll learn where medicine has been and where it’s headed.