In physics, mass–energy equivalence is the relationship between mass and energy in a system's rest frame, where the two quantities differ only by a multiplicative constant and the units of measurement. The principle is described by the physicist Albert Einstein's famous formula:  E = m c 2 {\displaystyle E=mc^{2}} . In a reference frame where the system is moving, its relativistic energy and relativistic mass (instead of rest mass) obey the same formula. The formula defines the energy E of a particle in its rest frame as the product of mass (m) with the speed of light squared (c2). Because...

In physics, mass–energy equivalence is the relationship between mass and energy in a system's rest frame, where the two quantities differ only by a multiplicative constant and the units of measurement. The principle is described by the physicist Albert Einstein's famous formula:  E = m c 2 {\displaystyle E=mc^{2}} . In a reference frame where the system is moving, its relativistic energy and relativistic mass (instead of rest mass) obey the same formula. The formula defines the energy E of a particle in its rest frame as the product of mass (m) with the speed of light squared (c2). Because...

The Rolling Stone Album Guide, previously known as The Rolling Stone Record Guide, is a book that contains professional music reviews written and edited by staff members from Rolling Stone magazine. Its first edition was published in 1979 and its last in 2004. The guide can be seen at Rate Your Music, while a list of albums given a five star rating by the guide can be seen at Rocklist.net. First edition (1979) The Rolling Stone Record Guide was the first edition of what would later become The Rolling Stone Album Guide. It was edited by Dave Marsh (who wrote a large majority of the reviews) and John Swenson, and included contributions from 34 other music critics. It is divided into sections by musical genre and then lists artists alphabetically within their respective genres. Albums are also listed alphabetically by artist although some of the artists have their careers divided into chronological periods. Dave Marsh, in his Introduction, cites as precedents Leonard Maltin's book TV Movies and Robert Christgau's review column...

Holi ( ) also known as the Festival of Colours, Festival of Spring and Festival of Love, is one of the most popular and significant festivals in Hinduism. It celebrates the eternal and divine love of god Radha and Krishna. The day also signifies the triumph of good over evil, as it commemorates the victory of god Vishnu as Narasimha Narayana over Hiranyakashipu. It was originated and is predominantly celebrated in the Indian subcontinent but has also spread to other regions of Asia and parts of the Western world through the Indian diaspora.Holi celebrates the arrival of Spring (season) in India, the end of winter, the blossoming of love and for many, it is a festive day to meet others, play and laugh, forget and forgive, and repair broken relationships. The festival is also an invocation for a good spring harvest season. It lasts for a night...

Michael Sendivogius (; Polish: Michał Sędziwój; 2 February 1566 – 1636) was a Polish alchemist, philosopher, and medical doctor. A pioneer of chemistry, he developed ways of purification and creation of various acids, metals and other chemical compounds. He discovered that air is not a single substance and contains a life-giving substance—later called oxygen—170 years before Scheele's discovery of the element. He correctly identified this 'food of life' with the gas (also oxygen) given off by heating nitre (saltpetre). This substance, the 'central nitre', had a central position in Sendivogius' schema of the universe. Biography Little is known of his early life: he was born in a noble family that was part of the Clan of Ostoja. His father sent him to study in university of Kraków but Sendivogius visited also most of the European countries and universities; he studied at Vienna, Altdorf, Leipzig and Cambridge. His acquaintances included John Dee and Edward Kelley. It was thanks to him that King Stephen Báthory agreed to finance their experiments. In the 1590s he was active...

An ingot is a piece of relatively pure material, usually metal, that is cast into a shape suitable for further processing. In steelmaking, it is the first step among semi-finished casting products. Ingots usually require a second procedure of shaping, such as cold/hot working, cutting, or milling to produce a useful final product. Non-metallic and semiconductor materials prepared in bulk form may also be referred to as ingots, particularly when cast by mold based methods. Precious metal ingots can be used as currency (with or without being processed into other shapes), or as a currency reserve, as with gold bars. Types Ingots are generally made of metal, either pure or alloy, heated past its melting point and cast into a bar or block using a mold chill method. A special case are polycrystalline or single crystal ingots made by pulling from a molten melt. Single crystal Single crystal ingots (called boules) of materials are grown (crystal growth) using methods such as the Czochralski process or Bridgeman technique. The boules may be either semiconductor (e.g. electronic...

Grassroots fundraising is a common fundraising method used by political candidates which has grown in popularity with the emergence of the Internet. It has been utilized by US presidential candidates like Howard Dean, Barack Obama, Ron Paul, and most recently, Bernie Sanders. Grassroots fundraising is a method of financing the campaigns of candidates who don't have significant media exposure of front runner status, or who are perhaps in opposition to the powerful lobby groups which influence the political party nominating process. It often involves mobilizing local communities to support and meet a specific fundraising goal or to donate to the campaign on a specific day. Grassroots fundraising can also be a method for organizations to get as many people as possible to help accomplish their goals. This method encompasses the efforts to reach out to the community being served and gaining connections and resources for one's campaign. Strategies of Grassroots Fundraising There are several methods of undertaking grassroots fundraising, including: Reaching donors...

A server-side dynamic web page is a web page whose construction is controlled by an application server processing server-side scripts. In server-side scripting, parameters determine how the assembly of every new web page proceeds, and including the setting up of more client-side processing. A client-side dynamic web page processes the web page using JavaScript running in the browser as it loads. JavaScript can interact with the page via Document Object Model, or DOM, to query page state and modify it. Even though a web page can be dynamic on the client-side, it can still be hosted on a static hosting service such as GitHub Pages or Amazon S3 as long as there isn't any server-side code included. A dynamic web page is then reloaded by the user or by a computer program to change some variable content. The updating information could come from the server, or from changes made to that page's DOM. This may or may not truncate the browsing history or create a saved version to go back to, but a dynamic web page update using AJAX technologies will neither create a page to go back to, nor truncate the web browsing history forward of the displayed page. Using...

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Elephant cognition is animal cognition as present in elephants. Most contemporary ethologists view the elephant as one of the world's most intelligent animals. With a mass of just over 5 kg (11 lb), an elephant's brain has more mass than that of any other land animal, and although the largest whales have body masses twenty times those of a typical elephant, a whale's brain is barely twice the mass of an elephant's brain. In addition, elephants have around 257 billion neurons. Elephant brains are similar to humans' and many other mammals' in terms of general connectivity and functional areas, with several unique structural differences. Although initially estimated to have as many neurons as a human brain, the elephant's cortex has about one-third of the number of neurons as a human brain.Elephants manifest a wide variety of behaviors, including those associated with grief, learning, mimicry, play, altruism, use of tools, compassion, cooperation, self-awareness, memory, and communication. Further evidence suggests elephants may understand pointing: the ability to nonverbally communicate an object by extending a finger, or equivalent. It is thought they are equal with...