12 Safety and security

Humans are resilient but vulnerable beings, requiring devices to help keep them safe and well. From bicycle helmets to automobile crash protection systems, physical technologies safe lives. Safety monitoring and hazard response technologies are key for homes and workplaces. Other technologies are used when humans go into more extreme environments and subject themselves to natural hazards like avalanches or floods. When problems occur, first responders need tools for their own protection and for finding, rescuing, reviving, and caring for victims.Meanwhile, a recent spate of television dramas about crime scene investigation showed that tremendous popular interest could focus on the applications of science to processing forensic evidence and providing facts needed to bring justice for people who fall victim to crime. Crime prevention, of course, depends on a wide range of technologies deployed as security systems: motion detectors, intrusion sensors (including invisible light beams), surveillance imaging and sound-monitoring, etc. Biometric devices such as fingerprint scanners, retina scanners, and identification card scanners rely on physical technology to determine who has authorized access. Once bad events happen, either due to criminal or to natural events, public safety officers use various technologies to locate, apprehend and subdue suspects. Another realm of investigation and prevention lies with the analysis of accidents, including major transportation accidents and structural failures, to determine causes and guide improvements in engineering of vehicles, buildings, bridges, etc. Modeling of natural phenomena like storms and even extreme events like asteroid collisions can help us prepare for these huge disruptions. Finally, in their current state, human societies must devote a large amount of resources – including highly sophisticated physics-based technologies – to military defense.