Peer-to-peer computing or networking is a distributed application architecture that partitions tasks or workloads between peers. Peers are privileged, equipotent participants in the application, they are said to form a peer-to-peer network of nodes. Peers make a portion of their resources, such as processing power, disk storage or network bandwidth, directly available to other network participants, without the need for central coordination by servers or stable hosts. Peers are both suppliers and consumers of resources, in contrast to the traditional client-server model in which the consumption and supply of resources is divided. Emerging collaborative P2P systems are going beyond the era of peers doing similar things while sharing resources, are looking for diverse peers that can bring in unique resources and capabilities to a virtual community thereby empowering it to engage in greater tasks beyond those that can be accomplished by individual peers, yet that are beneficial to all the peers.

While P2P systems had been used in many application domains, the architecture was popularized by the file sharing system Napster released in 1999. The concept has inspired new philosophies in many areas of human interaction. In such social contexts, peer-to-peer as a meme refers to the egalitarian social networking that has emerged throughout society, enabled by Internet technologies in general. While P2P systems had been used in many application domains, the concept was popularized by file sharing systems such as the music-sharing application Napster; the peer-to-peer movement allowed millions of Internet users to connect "directly, forming groups and collaborating to become user-created search engines, virtual supercomputers, filesystems." The basic concept of peer-to-peer computing was envisioned in earlier software systems and networking discussions, reaching back to principles stated in the first Request for Comments, RFC 1. Tim Berners-Lee's vision for the World Wide Web was close to a P2P network in that it assumed each user of the web would be an active editor and contributor and linking content to form an interlinked "web" of links.

The early Internet was more open than present day, where two machines connected to the Internet could send packets to each other without firewalls and other security measures. This contrasts to the broadcasting-like structure of the web; as a precursor to the Internet, ARPANET was a successful client-server network where "every participating node could request and serve content." However, ARPANET was not self-organized, it lacked the ability to "provide any means for context or content-based routing beyond'simple' address-based routing."Therefore, USENET, a distributed messaging system, described as an early peer-to-peer architecture, was established. It was developed in 1979 as a system; the basic model is a client-server model from the user or client perspective that offers a self-organizing approach to newsgroup servers. However, news servers communicate with one another as peers to propagate Usenet news articles over the entire group of network servers; the same consideration applies to SMTP email in the sense that the core email-relaying network of mail transfer agents has a peer-to-peer character, while the periphery of e-mail clients and their direct connections is a client-server relationship.

In May 1999, with millions more people on the Internet, Shawn Fanning introduced the music and file-sharing application called Napster. Napster was the beginning of peer-to-peer networks, as we know them today, where "participating users establish a virtual network independent from the physical network, without having to obey any administrative authorities or restrictions." A peer-to-peer network is designed around the notion of equal peer nodes functioning as both "clients" and "servers" to the other nodes on the network. This model of network arrangement differs from the client–server model where communication is to and from a central server. A typical example of a file transfer that uses the client-server model is the File Transfer Protocol service in which the client and server programs are distinct: the clients initiate the transfer, the servers satisfy these requests. Peer-to-peer networks implement some form of virtual overlay network on top of the physical network topology, where the nodes in the overlay form a subset of the nodes in the physical network.

Data is still exchanged directly over the underlying TCP/IP network, but at the application layer peers are able to communicate with each other directly, via the logical overlay links. Overlays are used for indexing and peer discovery, make the P2P system independent from the physical network topology. Based on how the nodes are linked to each other within the overlay network, how resources are indexed and located, we can classify networks as unstructured or structured. Unstructured peer-to-peer networks do not impose a particular structure on the overlay network by design, but rather are formed by nodes that randomly form connections to each other.. Because there is no structure globally imposed upon them, unstructured networks are easy to build and allow for localized optimizations to different regions of the overlay; because the role of all peers in the network is the same, unstructured networks are robust in the face of high rates of "churn"—that is, when large numbers of peers are joining and leaving the network.

However, the

Death from the Skies!: These Are The Ways The World Will End is a book by the American astronomer Phil Plait known as "the Bad Astronomer". The book was published in 2008 and explores the various ways in which the human race could be rendered extinct by astronomical phenomena; the author stated during an interview that one of the reasons for writing the book was that "the Universe is inhospitable, yet we have this planet that’s doing OK by us. Another is that the Universe is cool and interesting. Black holes are fun to think about. Most of this is mind-stretching and fun. What happens to the Sun after 100 quadrillion years? One hundred octillion? A googol?" He said that the reason for using doomsday scenarios was to take a scientific viewpoint, make it like a roller coaster or horror movie to make it fun and exciting. The stories make it cool to read about it; the book has had positive reviews from Todd Dailey of Wired Magazine, Nancy Atkinson of Universe Today, Rebecca Watson from Skepchick. It was reviewed for Smithsonian magazine by Sarah Zielinski.

In 2010 the Discovery Channel had a documentary called Phil Plait’s Bad Universe. This show was based on a few chapters of the book. George Hrab and Phil Plait recorded a song called "Death from the Skies" whose lyrics is based on some of the events covered in the book. Astronomy Cast Podcast Interview Paul Harris Radio Interview TalkingHeadTV interview Bad Astronomy, Plait's blog as of February 2017 Bad Astronomy, Plait's personal blog archive

In Guards We Trust is the debut album by American rock band Guards, released in 2013. The band released their first full-length album “In Guards We Trust" in 2013; the Wall Street Journal touted the record as “one of the years best albums.”, Pitchfork proclaimed “...slack verses with palm-muted guitars give way to a monster chorus delivered with the confidence that tells you Guards know they have a hit on their hands.”. The NME would refer to the band as “Cali reverb scuzz kings”. NPR stated, “At a time in music when pop, rock and hip-hop acts all strain to create anthems that will inspire sing- along devotion in large-size audiences, Guards — a band that's only been around for a few years and has released comparatively little music — is well on its way to giving the anthem form more interest and gravitas than musicians with far more experience.”. Stereogum added in their review of the album, “...widescreen indie-pop garnished with epic hooks and hum-along melodies... takes a simple new-wave riff and builds layers upon it, reaching soaring, cinematic climaxes on the chorus, showcasing singer Richie Follin’s yearning vocal, always in service of the song's central and indelible hook.”

The Los Angeles Times proclaimed, “Guards toy with loud-soft dynamics, touch on pastel harmonies and thick ‘60s garage rock riffs, but it’s the back and forth between keyboardist Kaylie Church and Richie Follin that sets the group apart.”. IFC premiered the band's video for "Silver lining" and stated, “It’s a boisterous and driving track that shows Guards doing what it does best: Making raucous rock with a retro edge and undeniable appeal.”Guards toured worldwide the entire year in support of their debut album opening for such acts as Queens of the Stone Age, MGMT, Two Door Cinema Club, Palma Violets, playing such festivals as Coachella and Primavera Sound. The song "I know it's you" off the album was featured in the film Endless Love; the song "Silver lining" is featured in the BIG 10 "Maps" television commercial. Nightmare – 3:54 Giving Out – 3:22 Ready to Go – 3:39 Silver Lining – 2:58 Heard the News – 4:29 Not Supposed to – 3:34 I Know It's You – 5:01 Coming True – 3:45 Your Man – 3:10 Can't Repair – 3:57 Home Free – 3:31 1 & 1 – 5:20

Nointel - Mours is a railway station located in Nointel, France. It is on the Épinay-Villetaneuse–Le Tréport-Mers railway, between Épinay-Villetaneuse and Persan-Beaumont; the station is used by Transilien line H trains from Paris to Persan-Beaumont. The daily number of passengers was between 500 and 2,500 in 2002; the station was opened in 1877, along with the Épinay-Villetaneuse - Montsoult-Maffliers - Persan-Beaumont section of the Épinay-Le Tréport Line. It was first exploited by the Compagnie des chemins de fer du Nord. Haut Val d'Oise: 63 and 64 Gare de Nointel - Mours at Transilien, the official website of SNCF

Henry Keep was an American currency speculator, stock speculator, railroad financier who invested in the Chicago and North Western Railway and Toledo Railroad, Michigan Southern and Northern Indiana Railroad, New York Central Railroad. He was treasurer of the Michigan Southern and Northern Indiana Railroad from 1861 to 1863, president of the New York Central Railroad in 1866. Henry Keep was born on June 22, 1818, in Adams, New York, to Herman Chandler Keep and his wife, Dorothy, he had two sisters and Martha. He was a descendant of John Keep, emigrant from the Kingdom of England who arrived in the Massachusetts Bay Colony in 1660 and was killed in 1676 during King Philip's War, he was related to William Ezra Keep, a successful builder in Hartford, Connecticut. Keep had no schooling as a child, his father died in 1835 when Keep was just 17. His family was left impoverished and lost their home, so his mother turned herself and her children over to the county poorhouse; the county loaned children out as workers to local businessmen and farmers, if the employer provided a wage or some other means of improvement to the child.

Keep was sent to work for Joseph Grammon, a local farmer who promised to send the boy to public school. Grammon failed to keep his word, beat the Henry mercilessly, fed him. With $1.50 and a coat given to him by a friend, Keep ran away. Grammon offered a reward of two cents for his return. Keep settled in Honeoye Falls, New York, where he got a job as a teamster on the Erie Canal, found a position as a hack driver in nearby Rochester, New York. During the Panic of 1837, Keep would buy purchased depreciated Watertown banknotes in Rochester travel to Watertown and cash them for a profit, he quadrupled his net worth. He invested in notes issued by the state, which were trading at a discount due to the economic recession, he began traveling around upstate New York, where he would approach people carrying Canadian banknotes. These were worthless in the United States, so Keep would exchange his state notes for the Canadian banknotes; when he had enough Canadian banknotes in hand, Keep would travel to Canada and cash the banknotes at par.

He made $500 to $1,000 a week a week in these exchanges. On September 28, 1847, Keep established Henry Keep's Bank in New York; some time in 1850, Keep opened the Frontier Bank in Watertown. On August 1, 1850, Keep opened the Citizens' Bank in Watertown, in 1852 opened a branch of this bank in Fulton, New York. On September 17, 1851, he opened the Mechanic's Bank in Watertown, invested in the Union Bank of Watertown. Keep proved so successful at banking that he moved to New York City in 1850, began investment banking operations on Wall Street. Just prior to the American Civil War, railroad stocks were worth about a nickel each. Keep invested in railroad stocks on the eve of the war saw his stocks soar in value as railroads became essential to the war effort, he made bold trades in undervalued railroads, earning hundreds of thousands of dollars. Along with Jacob Barker, Daniel Drew, James Fisk, Jay Gould, Jacob Little, Cornelius Vanderbilt, Keep was one of the greatest speculators on the stock market in his day.

He became one of the ablest stock pool managers in the history of the New York Stock Exchange. He was so successful at stock pools that he became one of the first managers of a "blind pool", where not the contributors to the pool knew which stocks were being bought or sold, when, or at what price, his refusal to talk about his trading schemes earned him the nickname "Henry the Silent". Keep formed a partnership with co-founder of Lockwood & Company; the firm was one of Wall Street's leading brokerage houses, Lockwood was a longtime ally of Cornelius Vanderbilt. Together, the two men manipulated the stock of the Michigan Southern and Northern Indiana Railroad in the 1850s, buying large quantities whenever they forced the price down, they won control of the company in 1859. On April 25, 1860, Keep was elected to its board of directors, he served as its treasurer from 1861 to 1863. Keep solidified his hold on the company in 1863 by breaking Addison G. Jerome, who controlled a majority of the company's stock.

Keep noticed. Keep called a secret meeting of the board, which excluded Jerome, the board authorized the issue. Keep began selling small numbers of these shares, Jerome began buying them up in an attempt to force Keep off the board of directors. To finance his purchases, Jerome engaged in short sales of stock. Keep dumped the majority of the 14,000 shares on the market, causing the price to drop significantly. Jerome lost $3 million covering his short sales, was financially broken. Keep invested in the New York Central Railroad. Beginning in 1865, Cornelius Vanderbilt began to wage a long and bitter war for control of the Central; the Central was governed by a clique of men known as the "Albany Regency", controlled most of the rail traffic outside of New York City. But Vanderbilt's Hudson River Railroad not only had the only direct link between Albany, New York, New York City but had the only rail line into lower Manhattan. Vanderbilt won an agreement with the Central to transfer freight to his line.

The contract required the Central to pay the Hudson River Railroad $100,000 a year for keeping extra rolling stock on hand in the summer to handle the increased traffic moving north. Keep, LeGrand Lockwo

The Lod Mosaic is a mosaic floor dated to ca. 300 CE discovered in 1996 in the Israeli town of Lod. Believed to have been created for a private villa, it is one of the largest and best-preserved mosaic floors uncovered in the country, it depicts land animals and two Roman ships. It was restored in the labs of the Israel Antiquities Authority. After an overseas tour of several years it will be displayed in the purpose-built Shelby White and Leon Levy Lod Mosaic Archaeological Center; the mosaic was discovered in 1996 by construction workers widening HeHalutz Street. Archaeologist Miriam Avissar of the Israel Antiquities Authority was called to the site; the mosaic was put on 30,000 people traveled to Lod to see it. It was reburied while funding was sought for its conservation; the Leon Levy Foundation and Shelby White, wife of Leon Levy and Chairman of the Friends of the Israel Antiquities Authority, funded the conservation of the mosaic and the establishment of the Shelby White and Leon Levy Lod Mosaic Center.

The mosaic has been on an exhibition tour to eleven museums around the world since 2010. While it is expected to return to Lod for public display, the date has been postponed, first from 2012/13 to 2014; the last exhibition outside Israel was scheduled to close in May 2016. There are hopes; the mosaic covers an area of 180 m2 and dates to the third century CE, or to somewhere around the year 300, given that debris covering the mosaic contained datable remains from both the third and fourth centuries. The patterns depict birds, fish and plants, in addition to providing detailed images of Roman-era ships. However, the mosaic prominently feature rhinoceroses and giraffes, which were not common in ancient art. Mythical beings are portrayed. Nothing is written on the mosaic. Unusually for a mosaic floor of this age, the mosaic is in near-perfect condition; the exception is damage to one of the two ships depicted, done when an Ottoman-era cesspit was dug into the mosaic. Despite the damage, students of maritime history have been able to glean a great deal of information from the images.

The ships are of the navis oneraria type, Roman merchant ships displacing 80-150 tons, used to carry such commodities as garum and grain from Egypt to Rome. Archaeologists Elie Haddad and Miriam Avissar suggest that the absence of human figures, rare in Roman-era mosaics, may indicate that the mosaic was commissioned by a Jew who observed the Biblical prohibition of graven images, they further suggest that it may have been commissioned as a kind of ex-voto, a thank offering in fulfillment of a vow made upon being delivered from grave danger, in this case, shipwreck. Other maritime historians demur, but Haddad and Avissar point to what appear to be torn ropes, a broken mast and damaged steering oars, together with the central placement of the damaged ship in the mosaic and the fact that it is about to be swallowed by a giant fish as an artists representation of disaster at sea. Archaeology of Israel The official website of the Lod Mosaic exhibition tour 2010-2016 Article about the Lod Mosaic by Metropolitan Museum of Art Curator, Christopher S. Lightfoot Artist & Scholar Lillian Sizemore discusses the Lod Mosaic and how ancient Greeks and Romans used the geometric shapes they saw in nature as a foundation for learning by Kathryn Kukula Video clip The Lod Mosaic: From Excavation to Exhibition on The Metropolitan Museum of Art YouTube channel Video clip The Lod Mosaic Floor and Its Menagerie: Roman Influence on Local Mosaic Art on The Metropolitan Museum of Art YouTube channel