KNOWING THE UNKNOWN - III Challenges of Technology Past, Present, and Future In this third book in the series on Knowing the Unknown, we address the question, 'What am I doing?' The book provides a unique perspective on the origin of technology, its development, frontiers, and its future. The reader embarks on an exciting journey, which unfolds the mysteries of technology in simple terms, as we visit: * Origin and evolution of technology & machines * Communication, computers, & control Tech * Health related and genetic-based technology * Modern Tech: Intelligent computers, robots * Frontiers & future of technology * Top ten challenges This book is meant for any reader interested in technology. This is not just another book on technology. It integrates various technological developments derived from different scientific concepts. It explains various technologies in simple terms. It also takes an objective look at how technology has changed our lives. This book will heighten readers' interest in technology. It will also motivate and encourage young scientists and engineers to seek new technology. Finally, it can serve as a textbook for students of the history of technology. We take the reader on an exciting journey that unfolds the mysteries of technology. During this journey, we visit and cross various milestones in the history of technology that have changed our lives forever. We start with the development of machines from the laws of mechanics discovered by Newton, heat engines from the laws of thermodynamics, and wireless communications from the laws governing electro-magnetic phenomena unified by Maxwell. This takes us to the discussion of modern communication systems, internet, and GPS and mobile phones, etc. Next, We visit with energy conversion technology, and discuss various resources available for energy conversion. These sources include chemical, thermal, hydro, nuclear, solar, hydrogen fuel cell, wind, tidal, geothermal, and biomass. Then, we visit other areas of technology, lasers, integrated circuit chips, superconductors, and nanotechnology, etc., which are based on modern physics. As we move on, we visit control technology. The development of this technology was essential to control our environment, control the energy sources, control industrial plants, develop new materials, increase productivity, navigate, and send satellites into space. Next, we visit computer technology, based on computer science and solid-state physics, which has ushered in a revolution in technology and brought us at the threshold of amplifying our intellectual capabilities. We also visit health care technology, developed to help us live healthier and longer lives. We then discuss new challenges for technology, and list the top ten challenges. We conclude our journey by discussing the frontiers and the future of technology.