Electron microscopeAn electron microscope is a microscope that uses a beam of electrons as a source of illumination. They use electron optics that are analogous to the glass lenses of an optical light microscope. As the wavelength of an electron can be up to 100,000 times shorter than that of visible light, electron microscopes have a higher resolution of about 0.1 nm, which compares to about 200 nm for light microscopes.
Quantum wellA quantum well is a potential well with only discrete energy values. The classic model used to demonstrate a quantum well is to confine particles, which were initially free to move in three dimensions, to two dimensions, by forcing them to occupy a planar region. The effects of quantum confinement take place when the quantum well thickness becomes comparable to the de Broglie wavelength of the carriers (generally electrons and holes), leading to energy levels called "energy subbands", i.e.
Mean free pathIn physics, mean free path is the average distance over which a moving particle (such as an atom, a molecule, or a photon) travels before substantially changing its direction or energy (or, in a specific context, other properties), typically as a result of one or more successive collisions with other particles. Imagine a beam of particles being shot through a target, and consider an infinitesimally thin slab of the target (see the figure). The atoms (or particles) that might stop a beam particle are shown in red.
Live electronic musicLive electronic music (also known as live electronics) is a form of music that can include traditional electronic sound-generating devices, modified electric musical instruments, hacked sound generating technologies, and computers. Initially the practice developed in reaction to sound-based composition for fixed media such as musique concrète, electronic music and early computer music. Musical improvisation often plays a large role in the performance of this music.
Electrical telegraphElectrical telegraphs were point-to-point text messaging systems, primarily used from the 1840s until the late 20th century. It was the first electrical telecommunications system and the most widely used of a number of early messaging systems called telegraphs, that were devised to communicate text messages quicker than physical transportation. Electrical telegraphy can be considered to be the first example of electrical engineering. Text telegraphy consisted of two or more geographically separated stations, called telegraph offices.
