In physics, electromagnetic radiation (EMR) consists of waves of the electromagnetic (EM) field, which propagate through space and carry momentum and electromagnetic radiant energy. It includes radio waves, microwaves, infrared, (visible) light, ultraviolet, X-rays, and gamma rays. All of these waves form part of the electromagnetic spectrum.Classically, electromagnetic radiation consists of electromagnetic waves, which are synchronized oscillations of electric and magnetic fields. Depending on the frequency of oscillation, different wavelengths of electromagnetic spectrum are produced. In a vacuum, electromagnetic waves travel at the speed of light, commonly denoted c. In homogeneous, isotropic media, the oscillations of the two fields are perpendicular to each other and perpendicular to the direction of energy and wave propagation, forming a transverse wave. The position of an electromagnetic wave within the electromagnetic spectrum can be characterized by either its frequency of oscillation or its wavelength. Electromagnetic waves of different frequency are called by different names since they have different sources...

In physics, electromagnetic radiation (EMR) consists of waves of the electromagnetic (EM) field, which propagate through space and carry momentum and electromagnetic radiant energy. It includes radio waves, microwaves, infrared, (visible) light, ultraviolet, X-rays, and gamma rays. All of these waves form part of the electromagnetic spectrum.Classically, electromagnetic radiation consists of electromagnetic waves, which are synchronized oscillations of electric and magnetic fields. Depending on the frequency of oscillation, different wavelengths of electromagnetic spectrum are produced. In a vacuum, electromagnetic waves travel at the speed of light, commonly denoted c. In homogeneous, isotropic media, the oscillations of the two fields are perpendicular to each other and perpendicular to the direction of energy and wave propagation, forming a transverse wave. The position of an electromagnetic wave within the electromagnetic spectrum can be characterized by either its frequency of oscillation or its wavelength. Electromagnetic waves of different frequency are called by different names since they have different sources...

In physics, electromagnetic radiation (EMR) consists of waves of the electromagnetic (EM) field, which propagate through space and carry momentum and electromagnetic radiant energy. It includes radio waves, microwaves, infrared, (visible) light, ultraviolet, X-rays, and gamma rays. All of these waves form part of the electromagnetic spectrum.Classically, electromagnetic radiation consists of electromagnetic waves, which are synchronized oscillations of electric and magnetic fields. Depending on the frequency of oscillation, different wavelengths of electromagnetic spectrum are produced. In a vacuum, electromagnetic waves travel at the speed of light, commonly denoted c. In homogeneous, isotropic media, the oscillations of the two fields are perpendicular to each other and perpendicular to the direction of energy and wave propagation, forming a transverse wave. The position of an electromagnetic wave within the electromagnetic spectrum can be characterized by either its frequency of oscillation or its wavelength. Electromagnetic waves of different frequency are called by different names since they have different sources...

Rosetta is a dynamic binary translator developed by Apple Inc. for macOS, an application compatibility layer between different instruction set architectures. It enables a transition to newer hardware, by automatically translating software. The name is a reference to the Rosetta Stone, the artifact which enabled translation of Egyptian hieroglyphs.The first version of Rosetta, introduced in 2006 in Mac OS X Tiger, was part of the Mac transition from PowerPC processors to Intel processors, allowing PowerPC applications to run on Intel-based Macs. The second version, introduced in 2020 as a component of macOS Big Sur, is part of the Mac transition from Intel processors to Apple silicon, allowing Intel applications to run on Apple silicon Macs. Background Macintosh has used CPUs with several different instruction set architectures: the Motorola 68000 series, PowerPC, Intel x86, and ARM64 in Apple silicon. Each instruction set architecture is incompatible with its predecessor, necessitating a transition plan based on a software layer to emulate the previous instruction set on the succeeding one...

Music is generally defined as the art of arranging sound to create some combination of form, harmony, melody, rhythm or otherwise expressive content. Exact definitions of music vary considerably around the world, though it is an aspect of all human societies, a cultural universal. While scholars agree that music is defined by a few specific elements, there is no consensus on their precise definitions. The creation of music is commonly divided into musical composition, musical improvisation, and musical performance, though the topic itself extends into academic disciplines, criticism, philosophy, and psychology. Music may be performed or improvised using a vast range of instruments, including the human voice. In some musical contexts, a performance or composition may be to some extent improvised. For instance, in Hindustani classical music, the performer plays spontaneously while following a partially defined structure and using characteristic motifs. In modal jazz the performers may take turns leading and responding, while sharing a changing set of notes. In a free jazz context, there may be no structure...

The Boston Celtics ( SEL-tiks) are an American professional basketball team based in Boston. The Celtics compete in the National Basketball Association (NBA) as a member of the league's Eastern Conference Atlantic Division. Founded in 1946 as one of the league's original eight teams, the Celtics play their home games at TD Garden, which is also the home of the National Hockey League's Boston Bruins. The Celtics are one of the most successful basketball teams in NBA history. The franchise is one of two teams with 17 NBA Championships, the other franchise being the Los Angeles Lakers. The Celtics currently hold the record for the most recorded wins of any NBA team.The Celtics have a notable rivalry with the Los Angeles Lakers, which was heavily highlighted throughout the 1960s and 1980s. During the two teams' many match-ups in the 1980s, the Celtics' star, Larry Bird, and the Lakers' star, Magic Johnson, had an ongoing feud. The franchise has played the Lakers a record 12 times in the NBA Finals (including recent appearances in 2008 and 2010), of which the Celtics have...

The Boston Celtics ( SEL-tiks) are an American professional basketball team based in Boston. The Celtics compete in the National Basketball Association (NBA) as a member of the league's Eastern Conference Atlantic Division. Founded in 1946 as one of the league's original eight teams, the Celtics play their home games at TD Garden, which is also the home of the National Hockey League's Boston Bruins. The Celtics are one of the most successful basketball teams in NBA history. The franchise is one of two teams with 17 NBA Championships, the other franchise being the Los Angeles Lakers. The Celtics currently hold the record for the most recorded wins of any NBA team.The Celtics have a notable rivalry with the Los Angeles Lakers, which was heavily highlighted throughout the 1960s and 1980s. During the two teams' many match-ups in the 1980s, the Celtics' star, Larry Bird, and the Lakers' star, Magic Johnson, had an ongoing feud. The franchise has played the Lakers a record 12 times in the NBA Finals (including recent appearances in 2008 and 2010), of which the Celtics have...

Ormolu (; from French or moulu, "ground/pounded gold") is the gilding technique of applying finely ground, high-carat gold–mercury amalgam to an object of bronze, and for objects finished in this way. The mercury is driven off in a kiln leaving behind a gold coating. The French refer to this technique as "bronze doré"; in English, it is known as "gilt bronze". Around 1830, legislation in France had outlawed the use of mercury for health reasons, though use continued to the 1900s. Craftsmen principally used ormolu for the decorative mountings of furniture, clocks, lighting devices, and porcelain. Process The manufacture of true ormolu employs a process known as mercury-gilding or fire-gilding, in which a solution of mercuric nitrate is applied to a piece of copper, brass, or bronze; followed by the application of an amalgam of gold and mercury. The item is then exposed to extreme heat until the mercury vaporizes and the gold remains, adhering to the metal object. This process has generally been supplanted by the electroplating of gold over a nickel substrate, which is more economical...

The coulomb (symbol: C) is the unit of electric charge in the International System of Units (SI). In the present version of the SI it is equal to the electric charge delivered by a 1 ampere constant current in 1 second and to 5×1027/801088317 elementary charges, e, (about 6.241509×1018 e). Name and history The coulomb is named after Charles-Augustin de Coulomb. As with every SI unit named for a person, its symbol starts with an upper case letter (C), but when written in full it follows the rules for capitalisation of a common noun; i.e., "coulomb" becomes capitalised at the beginning of a sentence and in titles, but is otherwise in lower case.By 1878, the...

The Villanovan culture (c. 900–700 BC), regarded as the earliest phase of the Etruscan civilization, was the earliest Iron Age culture of Italy. It directly followed the Bronze Age Proto-Villanovan culture which branched off from the Urnfield culture of Central Europe. The name derives from the locality of Villanova, a fraction of the municipality of Castenaso in the Metropolitan City of Bologna where, between 1853 and 1855, Giovanni Gozzadini found the remains of a necropolis, bringing to light 193 tombs, of which there were 179 cremations and 14 inhumations.The Villanovans introduced iron-working to the Italian Peninsula. They practiced cremation and buried the ashes of their dead in pottery urns of distinctive double-cone shape. History The name Villanovan of the early phases of the Etruscan civilization comes from the site of the first archaeological finds relating to this advanced culture, which were remnants of a cemetery found near Villanova (Castenaso, 12 kilometres south-east of Bologna) in northern Italy. The excavation...