What is Physics?
Physics is often considered the basis for all sciences. It studies and describes the motion, energy, momentum, and forces on matter throughout the entire universe. Many scientists believe that in order to truly understand the other sciences (biology, chemistry, geology, astronomy, etc.) one must first have an understanding of physics. For example, in biology, the movement of blood is related to motion, gravity, and fluid dynamics – all rely on the Law of Universal Gravitation. Physics has a place in all the sciences, which explains why physics is often regarded as the fundamental science.
Physics is an organized way of conversing with nature. Physicists ask questions; nature responds. For many questions, the answers are almost predictable, but when the question is a particularly good one, the answer can be unexpected and gives us new knowledge of the way the world works. These are the moments physicists live for. The fundamental ideas of physics underlie all basic science–astronomy, biology, chemistry, and geology. Physics also is essential to the applied science and engineering that has taken our world from the horse and the buggy to the supersonic jet, from the candle to the laser, from the pony express to the fax, from the beads of an abacus to the chips of a computer. Today physics is as exciting as ever. The animated conversation between physicists and nature goes on and it shows no sign of stopping.
Physics is all around us. It is in the electric light you turn on in the morning; the car you drive to work; your wristwatch, cell phone, CD player, radio, and that big plasma TV set you got for Christmas. It makes the stars shine every night and the sun shine every day, and it makes a baseball soar into the stands for a home run. Physics is the science of matter, energy, space, and time. It explains ordinary matter as combinations of a dozen fundamental particles (quarks and leptons), interacting through four fundamental forces. It describes the many forms of energy—such as kinetic energy, electrical energy, and mass—and the way energy can change from one form to another. It describes a malleable space-time and the way objects move through space and time. There are many fields of physics, for example: mechanics, electricity, heat, sound, light, condensed matter, atomic physics, nuclear physics, and elementary particle physics. Physics is the foundation of all the physical sciences—suc
SI units & Physics constants The main task of Physics is to investigate general properties and motion of matter. The term “motion of matter” means any change in position or internal state of matter. In physics, the matter is everything that can be measured with instruments. Matter is subdivided into two categories, substance and field. Substance is everything that has rest mass being fixed. So substance is the substantial characteristic of matter Field is matter with zero rest mass, which exists only in motion. Any interaction inside the substance is produced by means of field. So field is the power characteristic of matter. The substance is made up of over one hundred known elements, called atoms, combined into the periodic table of chemical elements, from Hydrogen, , to Meitnerium . Atom is the smallest piece of substance that retains its chemical properties. The atoms consist of elementary particles, such as protons, neutrons, electrons, photons, mesons, muons, neutrino, and etc. Th
