# Physics Textbook/Physics in a Personal and Social Context

Classical physics had for its scope the three dimensions of space: length, width, and depth. With Einstein's Theory of Relativity, a fourth dimension was added, time. Now with science affecting almost all facets of our lives, a fifth dimension has emerged, society. As members of society, we would like to learn how physics can be used for personal development. Science through technology influences and determines not only the way we live our lives but our very being as well. We may not be aware of it but science pervades our daily life.
Right in our very homes we apply the laws and principles of physics even in simple activities like cooking. We know that food cooks faster in covered pots or pans. Preparing food is made even faster and more convenient with the invention of gadgets like the microwave oven, pressure cooker, turbo broiler, and food processor, all of which applies to the principles of physics.

## Physics, Technology, and Society

Physics is different from technology. Technology yields inventions; physics provides explanations of the natural world. Technology is concerned with the practical applications of scientific laws and theories. The cell phone, electric motor, flat screen colored TV, DVD players, and computers are technological advances. These are results of the application of the laws of electromagnetism.
A further explanation of the distinction between physics and technology is that during Newton's time, only the theory of space travel had been developed and not its technology. Landing on the moon was then only a dream, more so with studying Jupiter or the Sun up close. However, developments in space travel technology have turned those dreams into realities.
Many of our modern technologies are physics-based. The products of these technologies are in the form of goods and services utilized by the people: medical techniques for diagnosis and therapy using ultrasound or ionizing radiation; advances in transportation and communication such as natural gas or hybrid vehicles, the rapid mass transit system, satellites, and wireless communication. While physics provides solutions to our questions about nature, technology provides solutions to our practical problems such as better food production, greater supply of fuel, and alternative sources of energy for power generation or the transport industry.
The demands for energy or technology-related solutions stimulate developments in science. For instance, dwindling fossil fuel resources encouraged scientists to look for new energy sources.
On the other hand, science stimulates technological growth. Discovery of new energy sources and their most efficient utilization served as basis for the development of large-scale technologies. The scientist's need for better and accurate tools and instruments for observation and experiments motivates technologists to develop sophisticated equipment such as those used in the medical field and telecommunications industry.
Modern technology demands large quantities of energy. It is estimated that residents of industrialized countries use between 150 and 350 gigajoules per person each year; mostly in the form of electricity. Figure 1.5 shows the world's energy consumption.
The history of technology is a story of the mechanization of labor by using large amounts of energy. It all began with the invention of the steam engine which ushered in the Industrial Revolution. The steam engine, along with significant developments such as the internal combustion engine and the large-scale generation of electricity, has supplied energy requirements for producing goods and the delivery of services to people.
Through the use of transistors and IC's, electrical devices have been transistorized, miniaturized, and automated. Computers and robots are used not only in industry but in homes and business establishments as well. Their use has helped bring about greater productivity, although they have tended to displace people in the work force.
Computers and robots are considered technological advances which bring about increased efficiency. Fewer people can do more in less time because more extensive means are available to utilize nature more rapidly and completely.
Humankind's technological needs have been greatly met and many of our dreams like landing on the moon or living in space have been realized as a result of such high-energy consumption.
Science and technology have influenced to a great extent the quantity and the quality of the modern or technological man's life. A person's average life span has been increased by medical advances. We enjoy the conveniences that electrical appliances provide, like the light bulb and flatiron. Today's smart homes combine information and communication technology to make life easier and more efficient. At night, lights in a smart home automatically turn on or off depending on the presence of the people in the room. You don't need to open the refrigerator to get cold water. It can be dispensed right from the refrigerator door.
For increased mobility, there are cars, buses, bicycles, tricycles, trains, and airplanes. These fast and convenient means of transportation afford more time for other worthwhile activities.
Communication has also become fast and efficient with mobile phones and the services they offer. Gone are the days of the telegraph where the sender had to wait for at least three days before a message was received. Now, there is the fax, e-mail, and short messaging service (SMS) where information can be received in real time.
We must, however, remember that whatever the advancements made in science and technology are, these should benefit mankind. Their wise and proper utilization to ensure the greatest good for everyone lies in the hands of those who have studied and understood the pros and cons of every scientific endeavor.