The document discusses the impact of 19th and 21st century technologies on daily life and communication. Key developments in the 19th century included the widespread adoption of electric lights in homes and businesses, advances in transportation like railroads that linked the east and west coasts, and new forms of energy like oil. In the 21st century, daily life revolves around 24/7 connectivity through mobile devices, social media allows for constant sharing of ideas, and communication technologies have created an interconnected world where information spreads instantly.