Latest published articles

Physical quantity

A physical quantity is defined as a physical property of a body or entity with which it is possible to describe phenomena that can be measured (quantified by measurement). A physical quantity can be expressed as the combination of a magnitude expressed by a number – usually a real number – and a unit of measurement. They


Vaporization. Evaporation. Water vapor. Saturated vapor. Wet saturated vapor. Dry saturated vapor. Superheated vapor.


Ferrofluids (sometimes referred as magnetic liquids) are colloidal suspensions of magnetic nanoparticles, represent a special class of magnetic fluids and are manufactured fluids consisting of dispersions of magnetized nanoparticles in a variety of non-magnetic liquid carriers. They were originally invented independently around the same time in the early 1960s at NASA Lewis Laboratories, and aslo by

Astronomical coordinate systems

Astronomical coordinate systems (also called celestial coordinates) are organized arrangements for specifying positions of satellites, planets, stars, galaxies, and other celestial objects relative to physical reference points available to a situated observer (e.g. the true horizon and north cardinal direction to an observer situated on the Earth’s surface). Astronomers use astronomical coordinates on the sky


Astrometry is a branch of Astronomy that studies stellar motions (i.e., studies the geometric relationships between celestial objects, their motion, and their position). Astrometry is now one of many fields of research within astronomy. Historically, astrometry was all that astronomy was about until about the 19th century. Toward the end of the 19th century not


Friction can be defined as the force between surfaces in contact that resists their relative tangential motion (slipping). Friction is a passive resistance that tends to hinder the relative motion of two bodies in contact. Passive resistance, which produces the loss of dynamic work in contact between bodies in relative motion, can be distinguished in various

Gravitational field

A gravitational field is a model used to explain the influence that a massive body extends into the space around itself, producing a force on another massive body.


Gravity, or gravitation, is a natural phenomenon that manifests itself with a force by which all things with mass or energy—including planets, stars, galaxies, and even light—are brought toward (or gravitate toward) one another. Gravity is the first force to be postulated as an action-at-a-distance force, that is, objects exert a gravitational force on one another without physical contact


Humidity is the amount of water vapor in the air, measured as mass of water per unit volume or mass of air, or as a percentage of the maximum amount the air would support without condensation, or indirectly via the dew point. Saturation of the air occurs when the water vapor pressure reaches the vapor pressure

Gravitational energy

Gravitational energy is the potential energy a body with mass has in relation to another massive object due to gravity. It is the potential energy associated with the gravitational field. Gravitational energy is dependent on the masses of two bodies, their distance apart, and the gravitational constant G. The general expression for gravitational potential energy arises from the law of


The force may be thought of as an influence which tends to change the motion of an object. Forces are inherently vector quantities, requiring vector addition to combine them. The SI unit for force is the newton [N], which is defined by Newton = kg·m/s2 as may be seen from Newton’s second law. In mechanics, forces are seen as the causes of


Temperature is a physical property of a material that gives a measure of the average kinetic energy of the molecular movement in an object or a system. Temperature can be defined as a condition of a body by virtue of which heat is transferred from one system to another. It is pertinent to mention here


Biophysics is an interdisciplinary science that applies approaches and methods traditionally used in physics to study biological phenomena and processes.


A scientist who works in the field of acoustics is an acoustician. The application of acoustics in technology is called acoustical engineering. There is often much overlap and interaction between the interests of acousticians and acoustical engineers. There are many different kinds of acousticians. Here are some examples: An acoustical engineer can design transducers such as microphones, earphones, and loudspeakers.


Psychoacoustics, the study of the physical effects of sound on biological systems, has been of interest since Pythagoras first heard the sounds of vibrating strings and of hammers hitting anvils in the 6th century BC, but the application of modern ultrasonic technology has only recently provided some of the most exciting developments in medicine.

Demagnetization [degaussing]

The demagnetization is the process by which the magnetic charge is eliminated from an object, both of a ferrous metal nature and of another nature. Degaussing is the process of decreasing or eliminating a remnant magnetic field. It is named after the gauss, a unit of magnetism, which in turn was named after Carl Friedrich Gauss. Due to magnetic hysteresis, it


Magnetization (symbol M, or Hi) is a process by which magnetic properties are conferred on a body. It is obtained by orienting the magnetic dipoles of the atomic structure thanks to an external magnetic field; its quantification is established by the intensity of magnetization, a vector quantity that represents the magnetic moment of the volume