The word "science" has been originated from a Latin word "Scientia" which means "to know". Therefore, science is to know about everything in nature. Science is the study of physical nature and its aspects. It contains imagination, experimentation, and deduction. Humans have gained knowledge about Science through experiments, observations, and trials conducted on the surrounding matters. The organized knowledge collected through several sources has formed a huge pool, which is so vast today that it has been divided into many branches. Two main branches are: Physical Sciences and Biological Sciences. The study of life is referred to as the biological sciences. It includes branches like Botany, Zoology, Genetics, Medicine, etc. The science about the study of non-living objects is referred to as the physical sciences. It majorly includes the branches like Physics, Chemistry, Geology, Geography, etc. In this book, we will see the impact that physics will have on our life and career.
Physics plays a vital role in all parts of our lives. Physics discusses everything in our surrounding: from atom (which is small enough that can't be seen even with an electron microscope) to galaxies. Everything either natural (such as, the sky, stars, planets, moons, seas, and birds etc.) or artificial (such as, submarines, heavy ships, vehicles, satellites, laptops, and cellular phones etc.), all involve the laws of physics.
For example, a cell phone, which has become the most common component of our life in today's technological world, can be used to facilitate us in many ways. It helps us to locate the position of any person, the car that we have booked, or to follow the map by using GPS satellite. Aeroplanes and ships also use signals from GPS to follow their path towards the right destination and stay connected with the control office.
An aeroplane runs on the runway to create a pressure difference above and below its wings before it takes off. Similarly, birds use the difference in air pressures above and below their wings to keep themselves high up. Feathers of birds give good thermal insulation especially when fluffed up during winter. The sky seems blue when sunlight strikes and scatters off by the gas molecules in our atmosphere. The presence of large water reservoirs such as lakes and seas keeps the climates of nearby land moderate due to the large heat capacity of water. Vehicles use the principles of mechanics and thermodynamics to transfer stored chemical energy in fuel to kinetic energy in rotating wheels. Submarines and heavy ships work on the principle of floatation. Cellular phones use electronic components and the principles of electromagnetic waves to transfer energy and information from one cellular phone to another. These are just a few examples that involve physics.
Physics is the branch of science that describes the matter, energy, space, time, and their mutual connections and interactions throughout the universe.
The objective of physics is to offer an understanding of the physical world by developing theories based on observations and experiments. A scientist who specializes in the field of physics is termed as 'physicist'. Physicists engage in theoretical and experimental research to explore and explain the fundamental laws of nature. Physicists express everyday happenings in mathematical formulas. These mathematical formulas are then used by all physicists and engineers to guess the results of their experiments. For example, Isaac Newton (1642-1727) found the laws behind the motion of bodies, which we now use to design rockets that travel in outer space (to the moon and other planets). Physicists also improve the laws of physics from time to time according to experimental results. For example, Isaac Newton established the laws of motion working at normal speeds, but these laws fail for objects moving with high speed that approaches the speed of light. Albert Einstein (1879-1955) solved this issue by giving the theory of relativity. The theory of relativity gives the same result as Newton's laws of motion at slow speeds, but is more accurate as speeds approach the speed of light. Hence, science is a collaborative field that requires interdisciplinary researchers working together to share knowledge and critique ideas.