## Gravitational Force

### Description

Isaac Newton explained the workings of the universe through mathematics. He formulated laws of motion and gravitation. These laws are math formulas that explain how objects move when a force acts on them. Isaac published his most famous book, Principia, in 1687 while he was a mathematics professor at Trinity College, Cambridge. In the Principia, Isaac explained three ..

## Bimetallic Strip

### Description

A bimetallic strip is used to convert a temperature change into mechanical displacement. The strip consists of two strips of different metals which expand at different rates as they are heated, usually steel and copper, or in some cases steel and brass. The strips are joined together throughout their length by riveting, brazing or welding. The different expansions for..

## Pendulum Clock

### Description

A pendulum clock is a clock that uses a pendulum, a swinging weight, as its timekeeping element. The advantage of a pendulum for timekeeping is that it is a harmonic oscillator; it swings back and forth in a precise time interval dependent on its length, and resists swinging at other rates. From its invention in 1656 by Christiaan Huygens until the 1930s, the pendulum..

## Magic Lantern

### Description

The magic lantern or Laterna Magica is an early type of image projector employing pictures on sheets of glass. It was developed in the 17th century and commonly used for educational and entertainment purposes.There has been some debate about who the original inventor of the magic lantern is, but the most widely accepted theory is that Christiaan Huygens developed the ..

## Pitot Tube

### Description

A pitot tube is a pressure measurement instrument used to measure fluid flow velocity. The pitot tube was invented by the French engineer Henri Pitot in the early 18th century and was modified to its modern form in the mid-19th century by French scientist Henry Darcy.It is widely used to determine the airspeed of an aircraft, water speed of a boat, and to measure liqu..

## Mercury Thermometer

### Description

The mercury-in-glass or mercury thermometer was invented by physicist Daniel Gabriel Fahrenheit in Amsterdam (1714). It consists of a bulb containing mercury attached to a glass tube of narrow diameter; the volume of mercury in the tube is much less than the volume in the bulb. The volume of mercury changes slightly with temperature; the small change in volume drives ..

## Ball Bearing

### Description

A ball bearing is a type of rolling-element bearing that uses balls to maintain the separation between the bearing races.The purpose of a ball bearing is to reduce rotational friction and support radial and axial loads. It achieves this by using at least two races to contain the balls and transmit the loads through the balls. In most applications, one race is stationa..

## Lever

### Description

The lever was first described in 260 B.C.E. by Archimedes(c.287-212 B.C.E.),but probably came in to play in prehistoric times.A lever can be used to raise a weight or overcome resistance.it consists of a bar,pivoted bat a fixed point known as the fulcrum.Extra power can be gained for the same effort if the position of the fulcrum is changed.Levers may be divided in to..

## Color photography

### Description

Color photography is photography that uses media capable of reproducing colors. By contrast, black-and-white (monochrome) photography records only a single channel of luminance (brightness) and uses media capable only of showing shades of gray.In color photography, electronic sensors or light-sensitive chemicals record color information at the time of exposure. This i..

## Cathode ray tube

### Description

The mid- to late- 1800s was a period of scientific revolution with phtsical processes such as electricity beginnning to reveal their secrets.Early investigations in to electricity led to the development of the cathode ray tube,which would eventually lead to the discovery of the electron,as well as to the invention of television.Michael Faraday(1791-1867) noticed that ..

## Fresnel lens

### Description

A Fresnel lens is a type of compact lens originally developed by French physicist Augustin-Jean Fresnel for lighthouses.The design allows the construction of lenses of large aperture and short focal length without the mass and volume of material that would be required by a lens of conventional design. A Fresnel lens can be made much thinner than a comparable conventio..

## Photography

### Description

The history of photography has roots in remote antiquity with the discovery of the principle of the camera obscura and the observation that some substances are visibly altered by exposure to light. As far as is known, nobody thought of bringing these two phenomena together to capture camera images in permanent form until around 1800, when Thomas Wedgwood made the firs..

## Aneroid Barometer

### Description

An aneroid barometer is an instrument for measuring pressure as a method that does not involve liquid. Invented in 1844 by French scientist Lucien Vidi,the aneroid barometer uses a small, flexible metal box called an aneroid cell (capsule), which is made from an alloy of beryllium and copper. The evacuated capsule (or usually more capsules) is prevented from collapsin..

## Cloud Chamber

### Description

The cloud chamber, also known as the Wilson chamber, is a particle detector used for detecting ionizing radiation.Charles Thomson Rees Wilson (1869–1959), a Scottish physicist, is credited with inventing the cloud chamber. Inspired by sightings of the Brocken spectre while working on the summit of Ben Nevis in 1894, he began to develop expansion chambers for studyin..

## Stellarator

### Description

A stellarator is a device used to confine a hot plasma with magnetic fields in order to sustain a controlled nuclear fusion reaction. It is one of the earliest controlled fusion devices, first invented by Lyman Spitzer in 1950 and built the next year at what later became the Princeton Plasma Physics Laboratory. The name refers to the possibility of harnessing the powe..

## Orbitrap Mass Spectrometer

### Description

An orbitrap is an ion trap mass analyzer consisting of an outer barrel-like electrode and a coaxial inner spindle-like electrode that traps ions in an orbital motion around the spindle.The image current from the trapped ions is detected and converted to a mass spectrum using the Fourier transform of the frequency signal.Alexander Alexeyevich Makarov is a Russian physi..

## Reflectron

### Description

A reflectron (mass reflectron) is a type of time-of-flight mass spectrometer (TOF MS) that comprises a pulsed ion source, field-free region, ion mirror, and ion detector and uses a static or time dependent electric field in the ion mirror to reverse the direction of travel of the ions entering it. Using the reflectron, one can substantially diminish a spread of flight..

## Graphene

### Description

Graphene is an allotrope of carbon in the form of a two-dimensional, atomic-scale, hexagonal lattice in which one atom forms each vertex. It is the basic structural element of other allotropes, including graphite, charcoal, carbon nanotubes and fullerenes. It can also be considered as an indefinitely large aromatic molecule, the limiting case of the family of flat pol..

## Jolly balance

### Description

Jolly balance is an instrument for determining specific gravities. Invented by the German physicist Philipp von Jolly in 1864.PrincipleJolly balance for determining the specific gravity (relative density) of solids and liquids.It consists in its usual form of a long, delicate, helical spring suspended by one end in front of a graduated scale. To the lower end of the s..

## Cyclotron

### Description

A cyclotron is a type of particle accelerator invented by Ernest O. Lawrence in 1932 in which charged particles accelerate outwards from the center along a spiral path.The particles are held to a spiral trajectory by a static magnetic field and accelerated by a rapidly varying (radio frequency) electric field.In 1929, Dr. Ernest Lawrence came across a German scientifi..

## Analytical ultracentrifuge

### Description

The ultracentrifuge is a centrifuge optimized for spinning a rotor at very high speeds, capable of generating acceleration as high as 2?000?000 g (approx. 19?600 km/s²).There are two kinds of ultracentrifuges, the preparative and the analytical ultracentrifuge. Both classes of instruments find important uses in molecular biology, biochemistry, and polymer science.Dev..

## Traveling-wave tube

### Description

The traveling wave tube is a form of thermionic valve or tube that is still used for high power microwave amplifier designs. The travelling wave tube can be used for wideband RF amplifier designs where even now it performs well against devices using newer technologies. TWTs are used in applications including broadcasting, radar and in satellite transponders. The TWT i..

## Optical tweezers

### Description

Optical tweezers were invented by Ashkin in 1970. If a laser beam is focussed by a high numerical aperture objective, small objects with an index of refraction higher that the immersion medium are attracted to the focal spot [2,3]. Typically, plastic beads in water will be trapped to the focal spot. This allows one to move them about and thus to manipulate micron-size..

## Richter magnitude scale

### Description

The Richter magnitude scale assigns a magnitude number to quantify the energy released by an earthquake. The Richter scale is a base-10 logarithmic scale, which defines magnitude as the logarithm of the ratio of the amplitude of the seismic waves to an arbitrary, minor amplitude.DevelopmentIn 1935, the seismologists Charles Francis Richter and Beno Gutenberg, of the C..

## Kaleidoscope

### Description

The kaleidoscope was invented in 1816 by Scottish scientist, Sir David Brewster (1781-1868), a mathematician and physicist noted for his various contributions to the field of optics. He patented it in 1817 (GB 4136), but thousands of unauthorized copycats were constructed and sold, resulting in Brewster receiving little financial benefits from his most famous inventio..

## Magnetic Atom Trap

### Description

A magnetic trap is an apparatus which uses a magnetic field gradient to trap neutral particles with magnetic moments. Although such traps have been employed for many purposes in physics research, they are best known as the last stage in cooling atoms to achieve Bose–Einstein condensation. The magnetic trap (as a way of trapping very cold atoms) was first proposed by..

## Foucault pendulum

### Description

In 1851, Leon Foucault, A French physicist, demonstrated the rotation of the Earth on its axis by his new invented Foucault pendulum, or Foucault's pendulum, named after him, by suspending a 67-metre wire from the dome of the Panthéon in Paris.The Foucault pendulum is a tall pendulum free to oscillate in any vertical plane and capable of running for many hours. I..

## Quantum Well Laser

### Description

A quantum well laser is a laser diode in which the active region of the device is so narrow that quantum confinement occurs. Laser diodes are formed in compound semiconductor materials that (quite unlike silicon) are able to emit light efficiently. The wavelength of the light emitted by a quantum well laser is determined by the width of the active region rather than j..

## Golgi's method

### Description

Golgi's method is a silver staining technique discovered by Italian physician and scientist Camillo Golgi (1843–1926) in 1873 that is used to visualize nervous tissue under light microscopy. It was initially named the black reaction (la reazione nera) by Golgi, but it became better known as the Golgi stain or later, Golgi method.In contrast, the Golgi method, fo..

## Dye-sensitized solar cell

### Description

Dye Sensitized solar cells (DSSC), also sometimes referred to as dye sensitised cells (DSC), are a third generation photovoltaic (solar) cell that converts any visible light into electrical energy.This new class of advanced solar cell can be likened to artificial photosynthesis due to the way in which it mimics nature’s absorption of light energy.Dye Sensitized sola..

## Fabry–Perot interferometer

### Description

In optics, a Fabry–Perot interferometer or etalon is typically made of a transparent plate with two reflecting surfaces, or two parallel highly reflecting mirrors. (Technically the former is an etalon and the latter is an interferometer, but the terminology is often used inconsistently.) Its transmission spectrum as a function of wavelength exhibits peaks of large t..

## Total internal reflection fluorescence m..

### Description

Total internal reflection fluorescence microscopy (TIRFM) is an elegant optical technique utilized to observe single molecule fluorescence at surfaces and interfaces. The technique is commonly employed to investigate the interaction of molecules with surfaces, an area which is of fundamental importance to a wide spectrum of disciplines in cell and molecular biology.Hi..

## Competitive exclusion principle

### Description

In ecology, the competitive exclusion principle,sometimes referred to as Gause's law of competitive exclusion or just Gause's law, is a proposition that states that two species competing for the same resource cannot coexist at constant population values, if other ecological factors remain constant. When one species has even the slightest advantage or edge over..

## Coanda effect

### Description

The Coanda effect is the tendency of a fluid jet to be attracted to a nearby surface.The principle was named after Romanian aerodynamics pioneer Henri Coanda, who was the first to recognize the practical application of the phenomenon in aircraft development.An early description of this phenomenon was provided by Thomas Young in a lecture given to The Royal Society in ..

## Theory of sonics

### Description

The theory of sonics is a branch of continuum mechanics which describes the transmission of mechanical energy through vibrations. The birth of the theory of sonics can be considered the publication of the book A treatise on transmission of power by vibrations in 1918 by the Romanian scientist Gogu Constantinescu.History of Sonic DrillingThe roots of sonic drilling tec..