In "Silent Spring" by Rachel Carson, the experience of the people changes over time as a result of the negative effects of pesticides and other chemicals on the environment. At the beginning of the book, people are largely unaware of the dangers posed by these chemicals and are using them indiscriminately. As the book progresses, however, people begin to experience the harmful effects of these chemicals firsthand, including the loss of wildlife, the contamination of water and soil, and the development of health problems. This leads to a growing awareness of the need to protect the environment and to use chemicals more responsibly. By the end of the book, there is a sense of urgency and a call to action to address the environmental problems caused by human activities.