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Talk:Relationship between latency and throughput

Opening comments
Some related concepts should be included in this same discussion, but I'm still not sure on how to write about them, or how to translate it in english. The first one is throughput, or the sustained speed of the communications channel; another one (still unnamed) is the ability to sustain a continuous stream of communications over a large period of time. An example will help to make my point clear.

A truck filled with magnetic tapes has a bigger throughput than a 2.4 Gbps optical link; it is able to transfer more information in some definite amount time. It does not make much sense to talk about bandwidth in this case, and throughtput seems to define better its transfer capacity. It also has a much bigger latency. However, if you have only one truck, you have both high latency, and low availabity; if have an entire fleet of trucks, you still have high latency, but the communications channel is available for a lot of time, which means that you will be able to achieve a much higher throughput than with one truck only.

That's what I mean to say that something is missing. I'll let it rest a little, think about it, and if I come up with a good writeup, I'll post it here.

CarlosRibeiro 12:22, 2 Aug 2004 (UTC)

Some people include packet-transmission time in the latency, while others do not. A few try to do it both ways: Sean Breheny: "for protocols which need to receive the whole packet before making any of it available to the destination (i.e., to check the FCS to see if it was received correctly) it [latency] includes the time it takes to transfer the data over the RF link."

I thought that packet protocols *always* receive the whole packet before treating any of it as valid. Does there really exist any kind of protocol that immediately uses some of the data in the packet (to reduce latency) before the packet finishes transmission? ( ZMODEM doesn't count -- the reciever still recieves a whole packet (some people call it a "sub-packet" or "block") before treating any of it as valid, right? ) -- DavidCary
 * I don't know of any protocol that allows a higher layer to use packet data before that data has been validated (via the checksum) - you may be thinking of packet ordering; as in not worrying if all packets are recieved. I think some applications using UDP ignore packet order, where it's more important to get some of the data it a timely fashion, than it is to get all of the data eventually (eg voice communication; Skype is an example) - but don't take my word for it, i'm not a protocol expert, I only have a limited knowledge of the intricacies of various protocols.

 * Besides, latency should include actual transmition time, because even if a system was able to use packet data before it had been validated (or the entire packet received), it still needs to be transmitted for the destination to be able to use it at all - Lee Carré 17:42, 3 October 2006 (UTC)

 * No protocol that I know of hands data off to a higher layer before it has received the entire packet. However, if you look at devices such as Ethernet switches they can start to forward a packet after they just receive the header.  So sometimes work is done with the packet before the entire thing is received. Danoelke (talk) 14:49, 27 February 2008 (UTC)

I propose that this article be moved to "relationship between latency and throughput" to better describe the content - because this article doesn't really compare the 2 factors - Lee Carré 17:42, 3 October 2006 (UTC)

 * I concur. I will reorganize this article with that in mind and see if consensus likes it before I make the move official. HatlessAtless (talk) 16:31, 29 April 2008 (UTC)

Maybe we should explain how you can measure each property: that latency is measured using *ping*, and throughput is basically what your download manager tells you that the speed of the connection is.

 * 'ping' does not measure latency. It measures round trip delay, which is a different thing altogether. Latency is altogether more difficult to measure as it generally requires well synchronised, accurate clocks in two places. Latency is one-way, round-trip delay is two-way, as measured by 'ping'. WLD 15:50, 25 October 2006 (UTC)

It would also be practical to explain that the ADSL protocol provides for two transmission modes. One uses interleaving to spread out packets; this protects them better against burst errors, because an error will hit many packets a little, and these small errors can be corrected by the error-correcting codes. The other mode is called fastpath; it simply does not interleave. When an error occurs, the damaged packets usually have to be resent. Because interleaving spreads the packet over a longer period of time, the packet takes longer to arrive completely: the latency is high. Fastpath has lower latency, but on a marginal connections where many errors occur, the resending of packets takes up a large share of the available bandwidth; this reduces throughput. Typical latencies would be 20ms for fastpath and 80 ms for interleaved connections.

I am not sure how to source this; googling for *adsl fastpath interleaving* gets some sources. (mendel)

Bandwidth-delay product
I added some info on the bandwidth-delay product. This entire article could possibly be merged into the bandwidth-delay product article, since there's really very little useful information here. Gigs 10:13, 6 July 2007 (UTC) Actually, lets merge with just "latency" Gigs

Complete article reconstruct, with additional citations.
I just rebuilt the article, and I believe that it should be moved to "Relationship between Latency and Throughput". See what you think. Since this rewrite was pretty much a brain dump, it will probably require cleanup. —Preceding unsigned comment added by HatlessAtlas (talk • contribs) 19:02, 29 April 2008 (UTC)

Limited bandwidth causing latency
In my work I've tried improving throughput of servers sending data to a tape drive. The drive will have a rated top speed of X MB/s but it needs a steady stream of data. (Drive-based data compression complicates this further so I will disregard it here) Oversimplifying a little, tape drives have two speeds - "fast" and "stop". If the data provided is not sufficient the drive will stop, wait for a buffer to fill, then resume. Each time this happens it imposes a time penalty. If the server and it's related communication elements (bus speed, network speed, source data rate, etc) are just fast enough to provide sufficient data for this tape drive, then upgrading the drive can slow down overall throughput because the new drive may have a higher minimum speed that exceeds the server's capability. It was difficult in our scenario to prove that the server (network card) was the bottleneck because the server/card does not use 100% of its capacity if the tape drive is taking time to stop and start so often.

A potential reference: http://storagemagazine.techtarget.com/ and search "How faster tape drives can slow down your backups"

I'd love to see an animation that might illustrate this or similar phenomena. Can someone think of other examples of this relationship between throughput and latency?

The idea could use some more work. Feel free to point me somewhere more appropriate if there is another label for this concept.

Walkingstick3 (talk) 02:09, 26 July 2008 (UTC)

Essay-like and hardly relevant article. Rename or delete?
What makes this article relevant to Wikipedia? Only one other wp article links to it. I believe it originally aimed at promoting two white papers by Stuart Cheshire: It's the Latency, Stupid and Latency and the Quest for Interactivity. There are a few other Wikipedia articles of the character |"relationship between a and b" or "a vs b", but those are typically well-known debates, and have numerous references. Part of this article, for example the article lead, suffer from essay-style rather than encyclopedic style.

Would it be possible to make the article more encyclopedic, if it was renamed e.g. perceived network speed (see related academic papers and books), or focused upon web response time (see "academic papers" and books). Would it help if it relied upon more academic papers related to latency and network throughput? Or is it better to simply delete it? Mange01 (talk) 22:06, 9 February 2009 (UTC)

Requested move

 * The following discussion is an archived discussion of a requested move. Please do not modify it. Subsequent comments should be made in a new section on the talk page. No further edits should be made to this section.

The result of the move request was merge to Network performance. This isn't conclusive, though, since merge discussions are traditionally carried out on the talk page of the target. I'll start the discussion at Talk:Network performance and add the merge tags to the articles, so knowledgeable authors there can perform the merge. Aervanath (talk) 07:19, 9 June 2009 (UTC)

Relationship between latency and throughput → perceived network speed — Maybe the above discussion has something to do with this? —harej (talk) 03:33, 30 May 2009 (UTC)

 * Comment I don't really understand the topic, but in terms of English Network speed perceptions is better than what's being proposed. YeshuaDavid (talk) 19:19, 30 May 2009 (UTC)
 * Really? The proposed title sounds all right to me. Dekimasu よ! 11:04, 31 May 2009 (UTC)
 * "Network speed perceptions" gives 0 hits in scholar.google.com and books.google.com. Perceived network speed gives a handful hits. "Web response time" gives a couple of hundreds of hits, but is only one aspect of the article topic. "Perceived speed"+network gives several hundreds of hits. Mange01 (talk) 20:27, 31 May 2009 (UTC)

 * Merge into Network performance which already discusses this in a concise, easy to understand way. Vegaswikian (talk) 19:37, 8 June 2009 (UTC)
 * Merge as per above. Dekimasu よ! 04:19, 9 June 2009 (UTC)
 * The above discussion is preserved as an archive of a requested move. Please do not modify it. Subsequent comments should be made in a new section on this talk page. No further edits should be made to this section.


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Nuri Bilge Ceylan

Nuri Bilge Ceylan (born 26 January 1959) is a Turkish director, screenwriter, photographer and actor. His film Winter Sleep (2014) won the Palme d'Or at the 67th Cannes Film Festival, while six of his films have been selected as Turkey's submission for the Academy Award for Best International Feature Film.

Early life and education
Ceylan was born in Bakırköy, Istanbul, Turkey on 26 January 1959, to Mehmet Emin Ceylan, an agricultural engineer, and Fatma Ceylan. Ceylan spent most of his childhood in his father's hometown of Yenice, Çanakkale. He completed his primary education in Yenice before finishing high school in Istanbul. In 1976, Ceylan started studying chemistry at Istanbul Technical University; in 1978, he transferred to Boğaziçi University in order to study electrical engineering.

During his time at Boğaziçi University, Ceylan began to receive recognition for his work as a photographer; in 1982, he was featured in an article in the arts and culture magazine Milliyet Sanat on young Turkish photographers. During the 1980s, photographs by Ceylan were featured in magazines including Gergedan; in 1989, he won a national competition to represent Turkey at an international event organised by Kodak, and took part in shoots in London and Kathmandu. After returning to Turkey, he completed military service in Mamak, Ankara. After completing his military service, Ceylan studied film at Mimar Sinan University.

1993–2006
In 1993, he acted in Mehmet Eryılmaz's short film Seviyorum Ergo Sum, where he also helped with the film's production. After the production of Seviyorum Ergo Sum, Ceylan bought the camera used to film it and subsequently used it in the production of his own short film, Koza (English: "cocoon"). The film, which Ceylan directed, wrote, and produced, became the first Turkish short film to be screened at the 48th Cannes Film Festival in 1995.

In 1997, Ceylan's first feature film Kasaba screened at various international film festivals including the Berlin International Film Festival. The film, which has been called the first in Ceylan's "provincial trilogy" (Turkish: "taşra üçlemesi") of films (alongside Mayıs Sıkıntısı and Uzak) has been considered a sequel to Koza, with Ceylan doing much of the production roles, including screenwriting and cinematography in addition to directing; it also features a cast consisting primarily of his family members.

Ceylan's next film Mayıs Sıkıntısı (1999) screened in competition at the Berlin International Film Festival, while Uzak (2003) competed for the Palme d'Or at the 56th Cannes Film Festival; it ultimately won the Grand Prix, while its stars Muzaffer Özdemir and Mehmet Emin Toprak (who died shortly after the film's production) were jointly awarded the Best Actor prize. Ceylan subsequently published a novelisation of Uzak in 2004.

Climates (2006) marked Ceylan's first film in which he did not act as cinematographer, with it instead being his first collaboration with Gökhan Tiryaki. Ceylan also did not act as producer, and the film was produced by Zeynep Özbatur Ataken. Ceylan appeared in the leading role in Climates alongside his wife, Ebru Ceylan. The film premiered in competition at the 59th Cannes Film Festival.

2008–present
Ceylan's 2008 film Three Monkeys marked his first time working with professional actors. He was awarded the Best Director prize at the 61st Cannes Film Festival, and the film was shortlisted for Best International Feature Film at the 81st Academy Awards, although was not ultimately nominated. Ceylan served as a member of the jury at the 62nd Cannes Film Festival in 2009. In 2011, his film Once Upon a Time in Anatolia won the Grand Prix at the 64th Cannes Film Festival, alongside The Kid with a Bike. Critic Roger Ebert praised the director writing, "The Turkish director doesn't slap us with big dramatic moments, but allows us to live along with his characters as things occur to them."

His next film, Winter Sleep (2014) premiered at the 67th Cannes Film Festival, where it won the Palme d'Or, becoming the first Turkish film to win the award since Yol in 1982. Peter Bradshaw of The Guardian described the film as "chilly but touching" adding, "[it's] a huge, sombre and compelling tragicomedy set in Turkey's vast Anatolian steppe". His film The Wild Pear Tree (2018) competed at the 71st Cannes Film Festival. The film is a character study involving a writer who returns to his hometown after graduating, where he seeks sponsors to publish his book while dealing with his father's deteriorating indulgence into gambling. Pat Brown of Slant Magazine praised it as a "rich, textured film, [which] is ostensibly about patrimony—namely, what sons inherit from and owe to their fathers. In many ways it’s a coming-of-age story, featuring a protagonist whose immature callousness gradually gives way to a more mature openness to his family."

Ceylan's film About Dry Grasses competed for the Palme d'Or at the 76th Cannes Film Festival. Merve Dizdar won the Best Actress award for her performance in the film. The film involves a young teacher hoping to be appointed to Istanbul after mandatory duty at a small village. Siddhant Adlakha of IndieWire wrote of the film, " Your mileage may vary, but “About Dry Grasses” is among the most brilliantly off-putting works to be featured at Cannes in recent years, with so rotten a core that every hint of virtue or even normalcy in the camera’s peripheral vision becomes a tragedy unto itself, simply by way of being ignored."

Styles and themes
Recurring themes in Ceylan's films include estrangement, existentialism, monotony, and the human experience. He often features static shots and long takes, usually in natural settings and without the use of staged sets. Ceylan's use of sound includes using silence to cause unease. He has been noted for filming his protagonists from behind, which he has stated is in order to leave the audience speculating on their motives and emotions. Ceylan's earlier films were made on low budgets with casts consisting primarily of amateur actors, often family members and neighbours of Ceylan himself.

Personal life
Ceylan is married to filmmaker, photographer and actress Ebru Ceylan, with whom he co-starred in Climates. Ceylan's cousin Mehmet Emin Toprak featured in three of his films, most notably Uzak; he died in 2002 following a car crash in Çan.

In Sight and Sound 's 2012 poll of the world's greatest films, Ceylan named his ten favourite films as being Andrei Rublev (1966), Au Hasard Balthazar (1966), L'Avventura (1960), L'Eclisse (1962), Late Spring (1949), A Man Escaped (1956), The Mirror (1975), Scenes from a Marriage (1973), Shame (1968), and Tokyo Story (1953).

Accolades

 * FIPRESCI Award (1997 – Kasaba ("Small Town" or "The Town"), 2000 – Clouds of May, 2006 – Iklimler ("Climates")), 2014 – Winter Sleep
 * Golden Orange Award for Best Director (1999 – Clouds of May, 2002 – Uzak (Distant), 2006 – Iklimler ("Climates"))
 * Golden Orange Award for Best Screenplay (2002 – Uzak ("Distant"))
 * Grand Jury Prize / Grand Prix at Cannes Film Festival (2002 – Uzak ("Distant"), 2011 – Once Upon a Time in Anatolia)
 * Cannes Film Festival Best Director Award (2008 - Three Monkeys)
 * Asia Pacific Screen Award for Best Director (2008 – Üç Maymun ("Three Monkeys"), 2011 – Once Upon a Time in Anatolia, 2014 – Winter Sleep
 * Palme d'Or (2014 - "Winter Sleep")

Ceylan has also received an honorary PhD from Boğaziçi University, his alma mater.

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/

title: Nuri Bilge Ceylan


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Death's-head hawkmoth

The name death's-head hawkmoth refers to any of three moth species of the genus Acherontia (Acherontia atropos, Acherontia styx and Acherontia lachesis). The former species is found throughout Africa and in Europe, the latter two are Asian; most uses of the common name refer to the African species. These moths are easily distinguishable by the vaguely human skull-shaped pattern of markings on the thorax. They are large nocturnal moths with brown and yellow or orange coloring, and all three species are fairly similar in size, coloration and life cycle.

Description
The African death's-head hawkmoth (Acherontia atropos) is the largest moth in the British Isles (though not in Africa), with a wingspan of 13 cm; it is a powerful flier, having sometimes been found on ships far from land. The forewings are a mottled dark brown and pale brown, and the hind wings are orangey-buff with two narrow dark bands parallel with the hind margin. The abdomen is a similar orangey-brown, with a broad, dark dorsal stripe. The most notable feature is a patch of short yellowish hairs on the thorax that gives the impression of depicting a human skull. It is a striking insect, but is seldom seen because it flies late in the night.

A 2020 study describes how, when viewed upside-down, Acherontia atropos creates an illusion of a head with eyes: the mark on its thorax likened to a human skull is the "nose", with the skull's eye-sockets resembling nostrils. Spots on its forewings can be seen as eyes, and various other markings and features can be interpreted as ears, muzzle and lips. This illusion is also present in Agrius convolvuli (convolvulus hawk-moth) and five other species, with the study author suggesting that the function of the illusion of an eyed head is "almost certainly to deter, distract or otherwise deceive predators".

The caterpillar of the African death's-head hawkmoth is also sturdy and somewhat variable in colour, being some shade of buff, green or brown, with seven diagonal blue lines. At the rear is a curved, thorn-like horn. It can attain a length of 5 to 6 in. The other two species of death's-head hawkmoth similarly have three larval color forms: typically, green, brown and yellow. The pupa is stout and reddish-brown, and is formed 8 to 10 in under the ground in a chamber the size of a large hen's egg.

Development
Eggs are laid singly under old leaves of a host plant and are green or greyish-blue. In the greater death's-head hawkmoth the host plant is usually the potato, but may also be tomato, woody nightshade, jasmine or common buckthorn. None of the three species is restricted to a single family of host plant, but hosts are typically in the families Solanaceae, Verbenaceae, Oleaceae, Bignoniaceae and others. The larvae are stout, reaching 120–130 mm, with a prominent tail horn. Larvae do not move much, and will click their mandibles or even bite if threatened. When mature, they burrow underground and excavate a chamber where they pupate.

Behaviour
These moths have several unusual features. All three species have the ability to emit a loud chirp if irritated. The sound is produced by inhaling and expelling air, which vibrates the epipharynx like an accordion, often accompanied by flashing of the brightly colored abdomen in a further attempt to deter predators. The chirp of the death's head hawkmoth takes approximately one-fifth of a second. A study by National Geographic found that the epipharynx was originally built to suck up honey, but later evolved to produce sound.

Adults of all three species are commonly observed raiding beehives of different species of honey bee; A. atropos only invades colonies of the well-known western honey bee, Apis mellifera, and feeds on both nectar and honey. They can move about in hives without being disturbed because they mimic the scent of the bees and are not recognised as intruders. If their disguise is discovered, the moth's thick waxy cuticle helps to protect it against stings.

Leaves of the potato plant contain calystegines, a group of polyhydroxy alkaloids, which are toxic. The larva of A. atropos feeding on potato foliage accumulates these alkaloids.

In popular culture
The species names atropos, lachesis and styx are all from Greek myth and related to death. The first refers to the member of the three Moirai who cuts the threads of life of all beings; the second to the Moira who allots the correct amount of life to a being; and the last refers to the river of the dead. In addition the genus name Acherontia is derived from Acheron, a river of Greek myth that was said to be a branch of the river Styx.

According to John Jarvis Bisset in his 1875 work Sport and War in South Africa, "The death's-head moth, as found in South Africa, is about the size and length of a man's finger, and it has a most perfect death's-head-and-marrowbones painted by Nature with all her beauty on its back. The legend both amongst the Dutch and the natives of the Cape of Good Hope, is, that this moth has a sting, and that a puncture from it causes instant death. This moth is generally found in beehives, particularly when they are in the ground or in decayed trees."

The skull-like pattern and its fanciful associations with the supernatural and evil have fostered superstitious fears of Acherontia species, particularly Acherontia atropos, perhaps because it is the most widely known. The moths' sharp, mouse-like squeaking intensify the effect. Nor is this a new attitude: during the mid-19th century, entomologist Edward Newman, having earlier mentioned the mark on the thorax wrote: "However, let the cause of the noise be what it may, the effect is to produce the most superstitious feelings among the uneducated, by whom it is always regarded with feelings of awe and terror."

According to legend, the species (atropos) was first seen in Britain at the time of the execution of King Charles I, but it is more likely to have simply become more common by that time, having arrived with the first transportation of potatoes some decades earlier. Though rarer, it is still occasionally sighted in the country.

Edgar Allan Poe's short story The Sphinx describes a close encounter with a death's-head sphinx moth, describing it as "the genus Sphinx, of the family Crepuscularia of the order Lepidoptera."

These moths have often been featured in art, such as by German artist Sulamith Wülfing and English artist William Holman Hunt in his 1851 painting The Hireling Shepherd.

Films such as Un Chien Andalou (1929, by Luis Buñuel and Salvador Dalí) and the 1991 film The Silence of the Lambs (and in Chapter 33 of the source novel, whereas in Chapter 14 a different moth species is used, the black witch moth ) feature the moth. The death's-head moth also featured in the 1968 horror film The Blood Beast Terror starring Peter Cushing. The species Acherontia atropos is mentioned, though the costume of the human-moth hybrid creature is not an accurate representation of the moth. The moth plays a central role in the 2015 Taiwanese horror film The Tag-Along.

In 2018 survival horror game, Remothered: Tormented Fathers by Italian artist Chris Darril, they represent both the transformation and the human psyche. They also work as a parasite which interfere with people's memories, old repressed events, and feelings of guilt.

title: Death's-head hawkmoth


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Januarius

Januarius (Ianuarius; Neapolitan and Gennaro), also known as Januarius I of Benevento, was Bishop of Benevento and is a martyr and saint of the Catholic Church and the Eastern Orthodox Church. While no contemporary sources on his life are preserved, later sources and legends claim that he died during the Great Persecution, which ended with Diocletian's retirement in 305.

Januarius is the patron saint of Naples, where the faithful gather three times a year in Naples Cathedral to witness the liquefaction of what is claimed to be a sample of his blood kept in a sealed glass ampoule.

Life
Little is known of the life of Januarius, and what follows is mostly derived from later Christian sources, such as the Acta Bononensia (BHL 4132, not earlier than 6th century) and the Acta Vaticana (BHL 4115, 9th century), and from later folk traditions.

Legend
According to various hagiographies, Januarius was born in Benevento to a rich patrician family that traced its descent to the Caudini tribe of the Samnites. At a young age of 15, he became local priest of his parish in Benevento, which at the time was relatively pagan. When Januarius was 20, he became Bishop of Naples and befriended Juliana of Nicomedia and Saint Sossius whom he met during his priestly studies. During the $1 1/2$-year-long persecution of Christians by Emperor Diocletian, he hid his fellow Christians and prevented them from being caught. Unfortunately, while visiting Sossius in jail, he too was arrested. He and his colleagues were condemned to be thrown to wild bears in the Flavian Amphitheater at Pozzuoli, but the sentence was changed due to fear of public disturbances, and they were instead beheaded at the Solfatara crater near Pozzuoli. Other legends state either that the wild beasts refused to eat them, or that he was thrown into a furnace but came out unscathed.

History
The earliest extant mention of him is contained in a 432 letter by Uranius, bishop of Nola, on the death of his mentor Saint Paulinus of Nola, where it is stated that the ghosts of Januarius and Saint Martin appeared to Paulinus three days before the latter's death in 431. About Januarius, the account says only that he was "bishop as well as martyr, an illustrious member of the Neapolitan church". The Acta Bononensia says that "At Pozzuoli in Campania [is honored the memory] of the holy martyrs Januarius, Bishop of Beneventum, Festus his deacon, and Desiderius lector, together with Sossius deacon of the church of Misenum, Proculus, deacon of Pozzuoli, Eutyches, and Acutius, who after chains and imprisonment were beheaded under the emperor Diocletian".

Celebrations
The Feast of San Gennaro is celebrated on 19 September in the General Roman Calendar of the Catholic Church. In the Eastern Church, it is celebrated on 21 April. The city of Naples has more than fifty official patron saints, although its principal patron is Saint Januarius.

In the United States, the Feast of San Gennaro is also a highlight of the year for New York's Little Italy, with the saint's polychrome statue carried through the middle of a street fair stretching for blocks.

Relics
According to an early hagiography, Januarius's relics were transferred by order of Saint Severus, Bishop of Naples, to the Neapolitan catacombs "outside the walls" (extra moenia). In the early ninth century the body was moved to Beneventum by Sico, prince of Benevento, with the head remaining in Naples. Subsequently, during the turmoil at the time of Frederick Barbarossa, his body was moved again, this time to the Territorial Abbey of Montevergine where it was rediscovered in 1480.

At the instigation of Cardinal Oliviero Carafa, his body was finally transferred in 1497 to Naples, where he is the city's patron saint. Carafa commissioned a richly decorated crypt, the Succorpo, beneath the cathedral to house the reunited body and head properly. The Succorpo was finished in 1506 and is considered one of the prominent monuments of the High Renaissance in the city.

Blood
Saint Januarius is famous for the annual liquefaction of his blood, which, according to legend, was saved by a woman called Eusebia just after the saint's death. A chronicle of Naples written in 1382 describes the cult of Saint Januarius in detail, but mentions neither the relic nor the miracle. The first certain date is 1389, when it was found to have melted. Then, over the following two and a half centuries official reports began to appear declaring that the blood spontaneously melted, at first once a year, then twice, and finally three times a year. While the report of the very first incidence of liquefaction did not make any explicit reference to the skull of the saint, soon afterwards assertions began to appear that this relic was activating the melting process, as if the blood, recognizing a part of the body to which it belonged, "were impatient while waiting for its resurrection". This explanation was definitively abandoned only in the eighteenth century.

Thousands of people assemble to witness this event in Naples Cathedral three times a year: on 19 September (Saint Januarius's Day, commemorating his martyrdom), on 16 December (celebrating his patronage of Naples and its archdiocese), and on the Saturday before the first Sunday of May (commemorating the reunification of his relics).

The blood is also said to spontaneously liquefy at certain other times, such as papal visits. It supposedly liquefied in the presence of Pope Pius IX in 1848, but not that of John Paul II in 1979 or Benedict XVI in 2007. On March 21, 2015, Pope Francis venerated the dried blood during a visit to Naples Cathedral, saying the Lord's Prayer over it and kissing it. Archbishop Sepe then declared that "The blood has half liquefied, which shows that Saint Januarius loves our pope and Naples."

Ritual liquefaction
The blood is stored in two hermetically sealed small ampoules, held since the 17th century in a silver reliquary between two round glass plates about 12 cm wide. The smaller, cylindrical ampoule contains only a few reddish spots on its walls, the bulk having allegedly been removed and taken to Spain by Charles III. The larger, almond-shaped ampoule, with a capacity of about 60 ml, is about 60% filled with a dark reddish substance. Separate reliquaries hold bone fragments believed to belong to Saint Januarius.

For most of the time, the ampoules are kept in a bank vault, whose keys are held by a commission of local notables, including the mayor of Naples; the bones are kept in a crypt under the main altar of Naples Cathedral. On feast days, all these relics are taken in procession from the cathedral to the Monastery of Santa Chiara, where the archbishop holds up the reliquary and tilts it to show that the contents are solid, then places it on the high altar next to the saint's other relics. After intense prayers by the faithful, including the so-called "relatives of Saint Januarius" (parenti di San Gennaro), the content of the larger vial typically appears to liquify. The archbishop then holds up the vial and tilts it again to demonstrate that liquefaction has taken place. The announcement of the liquifaction is greeted with at the 13th-century Castel Nuovo. The ampoules remain exposed on the altar for eight days, while the priests move or turn them periodically to show that the contents remain liquid. Sir Francis Ronalds gives a detailed description of the May 1819 ritual in his travel journal.

The liquifaction sometimes takes place almost immediately, but can take hours or even days. Records kept at the Duomo tell that on rare occasions the contents fail to liquify, are found already liquified when the ampoules are taken from the safe, or liquify outside the usual dates.

Scientific studies
While the Catholic Church has always supported the celebrations, it has never formulated an official statement on the phenomenon and maintains a neutral stance about scientific investigations. It does not permit the vials to be opened, for fear that doing so may cause irreparable damage. This makes close analysis impossible. Nevertheless, a spectroscopic analysis performed in 1902 by Gennaro Sperindeo claimed that the spectrum was consistent with hemoglobin. A later analysis, with similar conclusions, was carried out by a team in 1989. However, the reliability of these observations has been questioned. While clotted blood can be liquefied by mechanical stirring, the resulting suspension cannot solidify again.

Measurements made in 1900 and 1904 claimed that the ampoules' weight increased by up to 28 grams during liquefaction. However, later measurements with a precision balance, performed over five years, failed to detect any variation.

Various suggestions for the content's composition have been advanced, such as a material that is photosensitive, hygroscopic, or has a low melting point. However, these explanations run into technical difficulties, such as the variability of the phenomenon and its lack of correlation to ambient temperature.

A recent hypothesis by Garlaschelli & al. is that the vial contains a thixotropic gel, In such a substance viscosity increases if left unstirred and decreases if stirred or moved. Researchers have proposed specifically a suspension of hydrated iron oxide, FeO(OH), which reproduces the color and behavior of the 'blood' in the ampoule. The suspension can be prepared from simple chemicals that would have been easily available locally since antiquity.

In 2010, Giuseppe Geraci, a professor in the Department of Molecular Biology at Naples's Frederick II University, conducted an experiment on a vial containing old blood—a relic dating back to the 18th century from the Eremo di Camaldoli near Arezzo in Tuscany—having the same characteristics of the blood of St. Januarius. Prof. Geraci showed that the Camaldoli relic also contains blood that can change its solid-liquid phase by shaking. He further reproduced the phenomenon with his own blood stored in the same conditions as the Camaldoli relic. He stated that, "There is no univocal scientific fact that explains why these changes take place. It is not enough to attribute to the movement the ability to dissolve the blood, the liquid contained in the Treasure case changes state for reasons still to be identified." He ultimately argued that "there's blood, no miracle".

Similar rites
Although Naples became known as "City of Blood" (urbs sanguinum), legends of blood liquefaction are not a unique phenomenon. Other examples include vials of the blood of Saint Patricia and Saint John the Baptist in the monastery of San Gregorio Armeno, and of Saint Pantaleon in Ravello. In all, the church has recognized claims of miraculous liquefying blood for seven or about twenty saints from Campania and virtually nowhere else. The blood cults of the other saints have been discontinued since the 16th century, which noted skeptic James Randi takes as evidence that local artisans or alchemists had a secret recipe for manufacturing this type of relic. A team of three Italian chemists managed to create a liquid that reproduces all the characteristics and behavior of the liquid in the vial, using only local materials and techniques that were known to medieval workers. Jordan Lancaster leaves open the possibility that the practice was a Christian survival of a pagan ritual intended to protect the locals from unexpected eruptions from Mount Vesuvius.

Museum of the Treasure of St. Januarius
The Treasure of St Januarius is a collection of magnificent works and donations collected in seven centuries from popes, kings, emperors, famous and ordinary people. According to studies done by a pool of experts who have analyzed all the pieces in the collection, the Treasure of St Januarius is of higher value than the crown of Queen Elizabeth II of the United Kingdom and the Tsar of Russia. The Treasure is a unique collection of art masterpieces, kept untouched thanks to the Deputation of the Chapel of St Januarius, an ancient secular institution founded in 1527 by a vote of the city of Naples, still existing.

Today, the Treasure is exhibited in the Museum of the Treasure of St Januarius, whose entrance is located on the right side of the Dome of Naples, under the arcades. By visiting the museum, the Chapel of San Gennaro is accessible even when the cathedral is closed.

title: Januarius


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Graham Island

Graham Island is the largest island in the Haida Gwaii archipelago (previously known as the Queen Charlotte Islands), lying off the mainland coast of British Columbia, Canada. It is separated by the narrow Skidegate Channel from the other principal island of the group to the south, Moresby Island (T'aaxwii X̱aaydag̱a Gwaay.yaay linag̱waay in the language of the Haida people). It has a population of 3,858 (2016 census), an area of 6361 km2, and is the 101st largest island in the world and Canada's 22nd largest island.

Graham Island was named in 1853 by James Charles Prevost, commander of HMS Virago, for Sir James Graham, 2nd Baronet, who was First Lord of the Admiralty at the time.

Communities

 * Daajing Giids (formerly known as Queen Charlotte City)
 * Juskatla
 * Masset
 * Old Massett
 * Port Clements
 * Skidegate
 * Tlell

Attractions

 * Naikoon Provincial Park
 * North Beach
 * Kano Inlet

title: Graham Island


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Acherontia

Acherontia may refer to:
 * Acherontia (city), a city in ancient Apulia, Italy
 * Acherontia (moth), three species in the genus Acherontia
 * Acherontia atropos
 * Acherontia lachesis
 * Acherontia styx
 * Acherontia (film), a 1972 Mexican film

title: Acherontia


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Talk:High-voltage hazards

Administrative note: I deleted the original version of this page, which was just a redirect, and then renamed High-voltage differential to become this page. I doing so, I destroyed the history for this page. Just for the record, the lost history contained only two entries: the first was the creation of the article by Reddi, and the second was a minor edit by me. -- Heron 12:29, 2 Aug 2004 (UTC)

Arc welding
The article says that voltages below 500 volts can't produce an arc. However, electric arc welding sets typically have an open circuit voltage less than 50 volts, and anyone who's seen one in operation can testify to the very bright sparks produced. This needs a re-write, I think. --Wtshymanski 23:16, 6 May 2005 (UTC)

The key word is "produce." Take two wires from a 500V supply and move them together. No spark appears until they're a fraction of a millimeter apart. A 500V supply doesn't produce significant sparks. Now try a 20,000V supply and a spark appears even when the wires are separated by many millimeters. But if you separate the wires once a spark has appeared, all bets are off. In that case the spark length is more determined by wattage and by the metal of the wire tips rather than voltage. --Wjbeaty 09:56, May 7, 2005 (UTC)
 * It wasn't apparent to me that the article was talking about breakdown of air as opposed to all the other ways electrical sparks get initiated. I guess I know how to fix that...--Wtshymanski 15:58, 7 May 2005 (UTC)

Buried Cables
Several types of cable are approved for direct earth burial in the Canadian electrical code that are not armoured or metal-sheathed. Neither metal sheathing nor armour provides complete protection from electric shock hazards to unwary diggers - for that matter, even a concrete duct bank can be penetrated by a determined jackhammer operator. Yes, the excavator operator may survive the inital contact because he's usually sitting in a machine isolated by rubber tires from the ground; the previous language in the article was baffling to me and so I've revised it. --Wtshymanski 16:44, 11 July 2005 (UTC)

Spam
I removed the link to SafetySmart as it is not an informative site. It is a company selling HV saftey services.

Lightbulb
It is stated that 500J can power a 100W lightbulb for 2 months. That's way off: 500J can power a 100W lightbulb for 5 seconds... changing to 500MJ which is about right (it actually takes about 518MJ, but...)

Choice of standard voltages?
Why choose odd voltages like 11kV, 33kV and 66kV rather than round voltages like say 10kV, 20kV, 30kV, or 60kV?

Tabletop 02:17, 29 September 2006 (UTC)

GA
This is a very good article and I would like to thank all who have contributed. It is very very interseting to read.  Penubag  03:52, 1 May 2007 (UTC)

Definition
The definition here is confusing. There is a bit of waffle about how you define the definition but at the end of the day high voltage is 1000V (AC) as defined by the various standards agencies. I am not so sure about DC though and will investigate a bit further. The entire definition section should be only a couple of sentences. I would like to change this and ask for any comment first. Lumberjack Steve 12:33, 7 July 2007 (UTC)

Can anyone here provide even a single authoritative reference that describes normal household mains voltage (100–240 V AC) as "high voltage"? This currently claimed usage seems rather naive and unusual to me and I would have thought that even most lay people would associate with the term "high voltage" something that one would normally express in kilovolts. Markus Kuhn (talk) 18:51, 9 February 2008 (UTC)

title: Talk:High-voltage hazards


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Present

The present is the period of time that is occurring now. The present is contrasted with the past, the period of time that has already occurred, and the future, the period of time that has yet to occur.

It is sometimes represented as a hyperplane in space-time, typically called "now", although modern physics demonstrates that such a hyperplane cannot be defined uniquely for observers in relative motion. The present may also be viewed as a duration.

Historiography
Contemporary history describes the historical timeframe immediately relevant to the present time and is a certain perspective of modern history.

Philosophy of time
"The present" raises the question: "How is it that all sentient beings experience now at the same time?" There is no logical reason why this should be the case and no easy answer to the question.

In Buddhism
Buddhism and many of its associated paradigms emphasize the importance of living in the present moment—being fully aware of what is happening, and not dwelling on the past or worrying about the future. This does not mean that they encourage hedonism, but merely that constant focus on one's current position in space and time (rather than future considerations, or past reminiscence) will aid one in relieving suffering. They teach that those who live in the present moment are the happiest. A number of meditative techniques aim to help the practiser live in the present moment.

Christianity and eternity
Christianity views God as being outside of time and, from the divine perspective past, present and future are actualized in the now of eternity. This trans-temporal conception of God has been proposed as a solution to the problem of divine foreknowledge (i.e. how can God know what we will do in the future without us being determined to do it) since at least Boethius. Thomas Aquinas offers the metaphor of a watchman, representing God, standing on a height looking down on a valley to a road where past, present and future, represented by the individuals and their actions strung out along its length, are all visible simultaneously to God. Therefore, God's knowledge is not tied to any particular date.

Special relativity
The original intent of the diagram on the right was to portray a 3-dimensional object having access to the past, present, and future in the present moment (4th dimension). It follows from Albert Einstein's Special Theory of Relativity that there is no such thing as absolute simultaneity. When care is taken to operationalise "the present", it follows that the events that can be labeled as "simultaneous" with a given event, can not be in direct cause-effect relationship. Such collections of events are perceived differently by different observers. Instead, when focusing on "now" as the events perceived directly, not as a recollection or a speculation, for a given observer "now" takes the form of the observer's past light cone. The light cone of a given event is objectively defined as the collection of events in causal relationship to that event, but each event has a different associated light cone. One has to conclude that in relativistic models of physics there is no place for "the present" as an absolute element of reality, and only refers to things that are close to us. Einstein phrased this as: "People like us, who believe in physics, know that the distinction between past, present, and future is only a stubbornly persistent illusion".

Cosmology
In physical cosmology, the present time in the chronology of the universe is estimated at 13.8 billion years after the singularity determining the arrow of time. In terms of the cosmic expansion history, it is in the dark-energy-dominated era, after the universe's matter content has become diluted enough for dark energy to dominate the total energy density. It is also in the universe's Stelliferous Era, after enough time for superclusters to have formed (at about 5 billion years), but before the accelerating expansion of the universe has removed the local supercluster beyond the cosmological horizon (at about 150 billion years).

Archaeology, geology, etc.
In radiocarbon dating, the "present" is defined as AD 1950.

Grammar
In English grammar, actions are classified according to one of the following twelve verb tenses: past (past, past continuous, past perfect, or past perfect continuous), present (present, present continuous, present perfect, or present perfect continuous), or future (future, future continuous, future perfect, or future perfect continuous). The present tense refers to things that are currently happening or are always the case. For example, in the sentence, "she walks home everyday," the verb "walks" is in the present tense because it refers to an action that is regularly occurring in the present circumstances.

Verbs in the present continuous tense indicate actions that are currently happening and will continue for a period of time. In the sentence, "she is walking home," the verb phrase "is walking" is in the present continuous tense because it refers to a current action that will continue until a certain endpoint (when "she" reaches home). Verbs in the present perfect tense indicate actions that started in the past and is completed at the time of speaking. For example, in the sentence, "She has walked home," the verb phrase "has walked" is in the present perfect tense because it describes an action that began in the past and is finished as of the current reference to the action. Finally, verbs in the present perfect continuous tense refer to actions that have been continuing up until the current time, thus combining the characteristics of both the continuous and perfect tenses. An example of a present perfect continuous verb phrase can be found in the sentence, "she has been walking this route for a week now," where "has been walking" indicates an action that was happening continuously in the past and continues to happen continuously in the present.

title: Present


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Isla Grande de Tierra del Fuego

Isla Grande de Tierra del Fuego (English: Big Island of the Land of Fire) also formerly Isla de Xátiva is an island near the southern tip of South America from which it is separated by the Strait of Magellan. The western portion (61.4%) of the island (29,484.7 km2) is in Chile (Province of Tierra del Fuego and Antártica Chilena Province), while the eastern portion (38.6%, 18,507.3 km2) is in Argentina (Tierra del Fuego Province). It forms the major landmass in an extended group of islands or archipelago also known as Tierra del Fuego.

The island has an area of 47,992 km2, making it the largest island in South America and the 29th largest island in the world. Its two biggest towns are Ushuaia and Río Grande, both in Argentina. Other towns are Tolhuin, Porvenir, Camerón, and Cerro Sombrero. The Argentine side, Tierra del Fuego Province, has 127,205 inhabitants (2010), whereas the Chilean side has only 6,656 (2012), almost all located in the Tierra del Fuego Province.

Its highest point is unofficially named Monte Shipton (2,580 m), in Chile. Nearby Mount Darwin was previously thought to be the tallest mountain on the island, but is just less than a hundred metres shorter. The northern parts of the island have oil deposits; Cerro Sombrero in Chile is the main extraction centre in the island.

On 17 December 1949, an earthquake occurred in the Chilean portion, near the Argentine border. Recorded as 7.8 on the moment magnitude scale, it was the most powerful ever recorded in the south of Argentina.

Geography
Tierra del Fuego is bounded on the east by the South Atlantic, on the north by the Magellan Straits and on the south and west by a series of fjords and channels linked to the Pacific Ocean. One of the few prominent features of the northeast shore is San Sebastián Bay. To the south the island is bounded by the Beagle Channel, south of which lie a series of islands included in Chilean territory. To the west the island has two major inlets, Inútil Bay and Almirantazgo Fjord. The latter lies along the Magallanes–Fagnano Fault and is a continuation of the Cami Lake depression in southern Tierra del Fuego.

The southwest part of the island, between the Almirantazgo Fjord and the Beagle Channel and extending west to end at Brecknock Peninsula on the Pacific Ocean, is mountainous with a heavily indented coastline, dominated by the Cordillera Darwin. Most of this part of the island is included in the Alberto de Agostini National Park of Chile.

History
The earliest human settlement occurred more than 10,000 years ago, as people migrated from the mainland, perhaps under pressure from competitors. The Yaghan people were some of the earliest known humans settling in Tierra del Fuego. Certain archeological sites at locations such as Navarino Island, within the islands of Tierra del Fuego, have yielded artifacts and evidence of their culture from the Megalithic era.

The name Tierra del Fuego derives from Portuguese explorer Ferdinand Magellan, who was the first European to visit these lands in 1520, on his voyage to the Philippines from Spain. He believed he was seeing the many fires (fuego in Spanish) of the Amerindians, which were visible from the sea and that the "Indians" were waiting in the forests to ambush his armada. These were fires lit by the Yamana Indians who live in the northern part of the island, to ward off the low temperatures in the area. Originally called the "Land of Smoke", it was later changed to the more exciting "Land of Fire".

The British commander Robert Fitzroy, on his first voyage aboard HMS Beagle in 1830, captured four native Fuegians after they stole a boat from his ship. The men included Orundellico, later named Jemmy Button by his crew. Fitzroy taught them English and took them with him on his return to England, where he took them to Court to meet the King and Queen in London. They became early celebrities. The surviving three were returned to Tierra del Fuego on the second voyage of Beagle, which included the naturalist Charles Darwin, who made extensive notes about his visit to the islands.

In July 1881 the island was divided between Argentina and Chile, each of which had previously claimed it entirely during the East Patagonia, Tierra del Fuego and Strait of Magellan Dispute.

The 1949 Tierra del Fuego earthquake took place on 17 December 1949, at 06:53:30. It recorded magnitude 7.8 in the Richter scale. Its epicenter was located in the east of the Chilean Tierra del Fuego Province, close to the Argentine border, at a depth of 30 km (19 mi).

This was the most powerful earthquake ever recorded in the south of Argentina. It was felt with grade VIII in the Mercalli intensity scale, and affected the settlements and some others like Punta Arenas and Río Gallegos. Due to low population density, damage was limited.

Climate
The region has a subpolar oceanic climate and a mild tundra climate (Köppen climate classification Cfc and ET) with short, cool summers with a mean at around 10 C and long, cool and wet winters with a mean at around 0 C. The northeast is characterized by strong winds and little precipitation, while in the south and west it is very windy, foggy, and wet most of the year, with precipitation levels averaging 3,000 mm a year. The permanent snow line begins at 700 m. Places in the world with comparable climates are the Aleutian Islands, Iceland, Kuril Islands, Campbell Island, the Kerguelen Islands, the Scottish Highlands, and coastal areas of Norway.

In August 1995 the island was hit by an event of intense winds, cold and snowfall known as the White Earthquake. This caused the ferry service across Primera Angostura to be suspended, as well as the international road to Río Gallegos to be closed. In Timaukel alone the mayor reported that 150 thousand sheep and 6,500 heads of cattle were threatened by the event.

Flora
Only 30% of the islands have forests, which are classified as Magellanic subpolar; the northeast is made up by steppe and cool semidesert.

There are six species of tree found in Tierra del Fuego: Canelo or Winter's Bark (Drimys winteri), Maytenus magellanica, Pilgerodendron uviferum the southernmost conifer in the world, and three kinds of southern beech; Nothofagus antarctica, Nothofagus pumilio and the evergreen Nothofagus betuloides. Edible fruits grow in open spaces in these forests, such as beach strawberry (Fragaria chiloensis var. chiloensis forma chiloensis) and calafate (Berberis buxifolia), which have been collected by Indians and residents alike. These forests are unique in the world for having developed in a climate with such cold summers. Tree cover extends very close to the southernmost tip of South America. Winds are so strong that trees in wind-exposed areas grow twisted by the force of winds, and people call the trees "flag-trees" for the shape that they need to take in the fight with the wind. Tree vegetation extends as far south as the Isla de los Estados, Navarino Island and the north of Hoste Island. At altitudes above, dwarf Nothofagus communities are found. Going further south, Wollaston Islands and the south of Hoste Island are covered by subantarctic tundra.

The forests of Tierra del Fuego have been a source of trees that have been planted abroad in places with a similar climate but that were devoid of trees, such as the Faroe Islands and nearby archipelagos. Most species were gathered from the coldest places in Tierra del Fuego bordering the tundra. This resulted in positive changes, as the heavy winds and cool summers in the Faroe Islands had not formerly allowed the growth of trees from other regions in the world. In the Faroe Islands, the imported trees are used ornamentally, as curtains against wind, and for fighting erosion caused by storms and grazing.

Economy
The main industries are oil, natural gas, sheep farming and ecotourism. On the Argentine side several electronics companies have been established. Ushuaia is home to the small brewing company Cervecería Fueguina, which produces three beers under the Beagle brand name.

title: Isla Grande de Tierra del Fuego


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Dissolution of Czechoslovakia

The dissolution of Czechoslovakia (Rozdělení Československa, Rozdelenie Československa), which took effect on December 31, 1992, was the self-determined secession of the federal republic of Czechoslovakia into the independent countries of the Czech Republic and Slovakia. Both mirrored the Czech Socialist Republic and the Slovak Socialist Republic, which had been created in 1969 as the constituent states of the Czechoslovak Socialist Republic until the end of 1989.

It is sometimes known as the Velvet Divorce, a reference to the bloodless Velvet Revolution of 1989, which had led to the end of the rule of the Communist Party of Czechoslovakia.

Background
Czechoslovakia was created with the dissolution of Austria-Hungary at the end of World War I. In 1918, a meeting took place in the American city of Pittsburgh, at which the future Czechoslovak President Tomáš Garrigue Masaryk and other Czech and Slovak representatives signed the Pittsburgh Agreement, which promised a common state consisting of two equal nations: Slovaks and Czechs. However, the Czechoslovak Constitution of 1920 specified a single "Czechoslovak nation".

In subsequent years, there were political tensions in the new country between Czechoslovakists and those seeking greater autonomy for the Slovaks in particular. In March 1939, with pressure from Adolf Hitler, the First Slovak Republic was created as a satellite state of Germany with limited sovereignty. The alignment with the Soviet Union after World War II oversaw the reunification into the Third Czechoslovak Republic.

In 1968, the Constitutional Law of Federation reinstated an official federal structure of the 1917 type, but during the Normalization Period in the 1970s, Gustáv Husák, despite being a Slovak himself, returned most control to Prague. That approach encouraged a regrowth of Slovak separatism after the fall of communism.

Partition into two entities
By 1991, the Czech Republic's GDP per capita was some 20% higher than Slovakia's. Transfer payments from the Czech budget to Slovakia, which had been the rule in the past, were stopped in January 1991.

Many Czechs and Slovaks desired the continued existence of a federal Czechoslovakia. Some major Slovak parties, however, advocated a looser form of coexistence and the Slovak National Party sought complete independence and sovereignty. For a few years, political parties re-emerged, but Czech parties had little or no presence in Slovakia and vice versa. To have a functioning state, the government demanded continued control from Prague, but Slovaks continued to ask for decentralisation.

In 1992, the Czech Republic elected Václav Klaus and others, who demanded either an even tighter federation ("viable federation") or two independent states. Vladimír Mečiar and other leading Slovak politicians wanted a kind of confederation. Both sides opened frequent and intense negotiations in June. On July 17, the Slovak parliament adopted the declaration of independence of the Slovak nation. Six days later, Klaus and Mečiar agreed to secede Czechoslovakia into two separate states at a meeting in Bratislava. Czechoslovak President Václav Havel resigned, rather than oversee the secession, which he had opposed. In a September 1992 opinion poll, only 37% of Slovaks and 36% of Czechs favoured dissolution.

The goal of negotiations switched to achieving a peaceful division. Peaceful division was prioritized as the process ran in parallel with the violent breakup of Yugoslavia (another formerly socialist, Slavic federal state created after the dissolution of Austria-Hungary). On November 13, the Federal Assembly passed Constitution Act 541, which settled the division of property between the Czech lands and Slovakia. With Constitution Act 542, passed on November 25, they agreed to the secession of Czechoslovakia into two entities as of December 31, 1992.

The partition occurred without violence and so was thus said to be "velvet", much like the "Velvet Revolution", which had preceded it and had been accomplished by massive peaceful demonstrations and actions. In contrast, other post-communist breakups (such as the Soviet Union and Yugoslavia) involved violent conflict. Czechoslovakia is the only former Eastern Bloc state that had an entirely peaceful breakup. In the following years, as Slovakia's economy struggled, Slovaks began to describe the dissolution as a "sandpaper divorce".

Causes
A number of reasons have been given for the dissolution of Czechoslovakia, with the main debates focusing on whether dissolution was inevitable or whether dissolution occurred in conjunction with or even in contrast to the events that occurred between the Velvet Revolution of 1989 and the end of the joined state in 1992.

Those who argue from the inevitability stance tend to point to the differences between the two nations, which date back to the Austro-Hungarian Empire, and to other issues. There are differences between the Czechs and Slovaks, such as problems with the shared state during communism, the success of the state in the Czech lands, its failure in the Slovak lands that still resulted in the adoption of communism since the Czechs were more influential in the running of the state than Slovaks, and the 1968 constitution with its minority veto.

Those who argue that events between 1989 and 1992 led to the dissolution point to international factors such as the breakaway of the Soviet satellite nations, the lack of unified media between the Czech Republic and Slovakia, and most importantly the actions of the political leaders of both nations like the disagreements between Prime Ministers Klaus and Mečiar.

National symbols
Since the coat of arms of Czechoslovakia was a composition of those of the historic geographic areas forming the country, each republic simply kept its own symbol: the Czechs the lion and the Slovaks the double cross. The same principle was applied to the two-part bilingual Czechoslovak national anthem that comprised two separate pieces of music, the Czech stanza Kde domov můj and the Slovak stanza Nad Tatrou sa blýska. Disputes occurred only with respect to the Czechoslovak flag. During the 1992 negotiations on the details of dissolution of Czechoslovakia, as demanded by Vladimír Mečiar and Václav Klaus, a clause forbidding the use of the state symbols of Czechoslovakia by its successor states was inserted into the constitutional law on the dissolution of Czechoslovakia.

From 1990 to 1992, the red and white flag of Bohemia (differing only slightly from the Polish flag by proportion and tone) officially served as the flag of the Czech Republic. Eventually, after a search for new symbols, the Czech Republic unilaterally decided to ignore the aforementioned law and to keep the Czechoslovak flag, with an altered meaning. Slovakia, meanwhile, adopted its traditional flag; however, just before independence, on September 3, 1992, the coat of arms was added in order to prevent confusion with the similar flags of Russia and Slovenia.

Territory
The national territory was divided along the existing internal borders, but the border was not clearly defined at some points and, in some areas, the border cut across streets, access roads and communities that had coexisted for centuries. The most serious issues occurred around the following areas:

 * U Sabotů or Šance (cs:Šance (Vrbovce)) – historically part of Moravia, awarded to Slovakia in 1997
 * Sidonie or Sidónia (cs:Sidonie) – historically part of Hungary (which contained all present-day Slovak territory until 1918), awarded to the Czech Republic in 1997
 * Kasárna (cs:Kasárna (Makov)) recreational area – historically Moravian, disputed between Moravia and Hungary since the 16th century, formally part of Hungary since 1734; accessible by car only from the Czech side until early 2000s; remained in Slovakia despite heavy objections from the mostly-Czech property owners, whose real estate effectively fell into a foreign country.

The new countries were able to solve the difficulties via mutual negotiations, financial compensation and then an international treaty covering the border modifications.

People living or owning property in the border area, however, continued to experience practical problems until both new countries entered the Schengen Agreement Area in 2007, rendering the border less significant.

Division of national property
Most federal assets were divided in a ratio of two to one, the approximate ratio between the Czech and Slovak population in Czechoslovakia, including army equipment, rail and airliner infrastructure. Some minor disputes, such as gold reserves stored in Prague and federal know-how valuation, lasted for a few years after the dissolution.

Currency division

Initially, the old Czechoslovak currency, the Czechoslovak koruna, remained in use by both countries. Czech fears of an economic loss caused the adoption of two national currencies as early as February 8, 1993. On February 2, 1993 Act No. 60/1993 Coll. came in effect in the Czech Republic to create a separate currency that was already envisaged in the Czech Constitution and in Act No. 6/1993 Coll. that created the Czech National Bank by stamping Czechoslovak banknotes. The stamps had already been prepared in secret in 1992 after the decision about the dissolution of Czechoslovakia. In December 1992 some of the reserve banknotes started to be stamped in the selected banks in secret. From 8 February to 12 February old banknotes of 100, 500 and 1,000 Kčs (Czechoslovak crowns) were exchanged for the stamped ones in the Czech Republic and a new 200 Kč banknote was introduced. Each person over 15 could exchange banknotes up to 4,000 crowns, and minors below 15 years of age up to 1,000 crowns. Banknotes of lower denominations and coins remained until new ones were printed and minted. Banks in the Czech Republic converted all money on 8 February 1993 from Kčs to Kč. In Slovakia stamps were also applied on banknotes, and a new 10 SK coin was introduced. At the beginning, the currencies could be exchanged at par, but later the value of the Slovak koruna was usually lower than that of the Czech koruna (in 2004, around 25–27% lower). On August 2, 1993, both currencies were distinguished by different stamps that were first affixed to and then printed on old Czechoslovak koruna banknotes. New Czech and Slovak coins replaced old ones during 1993.

On January 1, 2009, Slovakia adopted the euro as its currency, with a conversion rate of 30.126 SK/€, and the €2 commemorative coin for 2009, Slovakia's first, featured the 20th anniversary of the Velvet Revolution in remembrance of the common struggle of the Czechoslovaks for democracy. By a quirk of fate, the welcoming speech on the behalf of the European Union on the occasion of Slovakia's entry to the eurozone was delivered by Mirek Topolánek, the prime minister of the presiding country, the Czech Republic, naturally in his native language, but the other guest speakers used English. The Czech Republic continues to use the Czech koruna, or crown.

International law
Neither the Czech Republic nor Slovakia sought recognition as the sole successor state to Czechoslovakia. This can be contrasted to the dissolution of the Soviet Union, when the Russian Federation was recognized as successor state not only to the Russian SFSR but also to the Soviet Union itself, and also contrasts with the dissolution of Yugoslavia, where the rump Federal Republic of Yugoslavia, dominated by Serbia and encompassing only it and Montenegro, unsuccessfully demanded recognition as the sole successor to the Socialist Federative Republic of Yugoslavia, even though the four remaining ex-Yugoslav states, now independent, collectively encompassed around three-fifths of former Yugoslavia, both in population and in territory. Therefore, Czechoslovakia's membership in the United Nations ceased upon the dissolution of the country, but on January 19, 1993, the Czech Republic and Slovakia were admitted as new, separate states.

With respect to other international treaties, the Czechs and the Slovaks agreed to honour the treaty obligations of Czechoslovakia. The Slovaks transmitted a letter to the Secretary General of the United Nations on May 19, 1993, to express their intent to remain a party to all treaties signed and ratified by Czechoslovakia and to ratify treaties signed but not ratified before dissolution of Czechoslovakia. The letter acknowledged that under international law, all treaties signed and ratified by Czechoslovakia would remain in force. For example, both countries are recognized as signatories of the Antarctic Treaty from the date that Czechoslovakia had signed the agreement in 1962.

Both countries have ratified the Vienna Convention on Succession of States in respect of Treaties, but it was not a factor in the dissolution of Czechoslovakia since it did not come into force until 1996.

Economy
The dissolution had some negative impact on the two economies, especially in 1993, as traditional links were severed to accommodate the bureaucracy of international trade, but the impact was considerably less than expected by many people.

A customs union between the Czech Republic and Slovakia remained in place from the dissolution until May 1, 2004, when both countries entered the European Union (EU).

Many Czechs hoped that dissolution would quickly start an era of high economic growth in the Czech Republic, which no longer had to sponsor the "less-developed Slovakia". Similarly, others looked forward to an independent unexploited Slovakia that might become a new "economic tiger".

According to The Prague Post, "Slovak GDP reached 95 percent of the Czech GDP, and it is likely to draw level with it. The Slovak gross national product (GNP), which includes citizens' incomes abroad and deducts the money multinational companies move out of the country, is higher than the Czech one. Old-age pensions are more or less at the same level in both countries, and the consumption per capita is slightly higher in Slovakia. However, salaries are 10 percent lower on average in Slovakia than in the Czech Republic".

However, Martin Filko, the head of the Institute of Financial Policy of the Slovak Finance Ministry, pointed out that Slovakia is among the EU countries whose salaries form the lowest portion of their GDP. In other words, some of people's incomes come from sources other than their main employment, which reduces the real difference between the Czech and the Slovak salaries.

Slovaks have become a more integral part of the EU because of their adoption of the euro and are more resolved to take part in the banking and fiscal unions. In the Czech Republic, the right wing opened the economy, and the left wing privatised banks and attracted foreign investors.

Until 2005, the GDP of the two countries was growing at a similar rate. However, from 2005 to 2008, the Slovak economy grew faster than the Czech economy. Economists agree that this growth was caused by the right-wing reforms of the Mikuláš Dzurinda government and the promise to adopt the euro, which attracted investors.

When the left-wing populist Robert Fico replaced Dzurinda as Slovak prime minister after eight years in 2006, he reduced the right-wing reforms only moderately, but he did not abolish them, unlike the Czech Social Democrats (ČSSD).

Meanwhile, the Czechs had three ČSSD prime ministers in four years (2002–06), followed by a centre-right cabinet, which cut and simplified taxes but failed to push through other reforms and did not want to adopt the euro because of the financial crisis and the Civic Democrats' ideological stance.

Citizenship
Since federalisation in 1968, Czechoslovakia had divided citizenship, either of the Czech Socialist Republic or of the Slovak Socialist Republic, the word Socialist being dropped from both names shortly after the Velvet Revolution. That distinction, however, had little effect on citizens' life. On January 1, 1993, all Czechoslovak citizens automatically became citizens either of the Czech Republic or the Slovak Republic, based on their previous citizenship, permanent residence address, birthplace, family ties, job and other criteria. Additionally, people had one year's time to claim the other citizenship under certain conditions.

Slovak legislation allowed dual citizenship until 2010, when it was abolished under the Citizenship Act. Only a handful of people have exercised that right, but its significance is lessened by both nations' membership in the EU as the freedom of movement for workers, a policy that guarantees EU citizens the right to work and to live anywhere in the Union. In the case of movement between the Czech Republic and Slovakia, the policy took effect from 2004.

By contrast, the Czech Republic has prohibited dual citizenship for naturalized citizens and requires them to give up existing citizenship(s) prior to receiving citizenship of the Czech Republic. That requirement can be waived only if giving up an existing citizenship might put the applicant or their relatives in danger of persecution in their homeland, which was not the case of applicants from Slovakia. That situation changed with the new Citizenship Act of 2013 (186/2013 Sb.), in force since January 1, 2014. However, most Slovak citizens are still unable to become dual citizens of both the Czech Republic and Slovakia since they automatically lose Slovak citizenship upon voluntarily acquiring another one (see previous paragraph). Exempt from that law are only Slovak citizens who obtain a foreign citizenship by virtue of marriage with a foreign national. Some Slovak politicians have speculated in the media about softening the Citizenship Act, but no change has yet materialised as of January 2015.

Citizens of both countries were allowed to cross the border using an ID card instead of a passport and were allowed to work anywhere without the need to obtain an official permit. Border checks were completely removed on December 21, 2007, when both countries joined the Schengen Agreement.

Under the current European regulations, citizens of either country are entitled to the diplomatic protection of any other EU country and so both have been considering merging their embassies, together with nations of the Visegrád Group, to reduce costs.

Roma people
One of the problems not solved during dissolution was the question of a large number of Romani living in the Czech Republic born and officially registered in today's Slovakia. Most of them did not re-register their official place of stay during the months before dissolution and so the question of their citizenship was left open. The 1992 Czech Nationality Act allowed a grant of automatic citizenship only to those who were born on Czech territory. For others, the right to citizenship required proof of a five-year period of residence, an "unobjectionable" criminal record, significant fees and a complicated bureaucratic process, which reportedly excluded a rather large percentage of Roma.

The Slovak government did not want to grant citizenship to nonresidents. Significant numbers of Roma living in Czech orphanages did not have their legal status clarified and were released from care as adult noncitizens without any right to work or live in the Czech Republic. Under pressure from the European Union, the Czech government made amendments to its nationality law in 1999 and 2003, which effectively solved the problem, but compensation has not been provided to those rendered stateless in 1992.

Language contacts
In the former Czechoslovakia, the first television channel was a federal one, and the Czech and Slovak languages were used in equal ratios in the television news there, but foreign films and television series were almost exclusively dubbed into Czech, for example. That and the great similarity of the two languages made almost all people of both nations passively bilingual: they could understand but not necessarily speak the other language. After the dissolution in 1990s, the new television channels in the Czech Republic practically stopped using Slovak, and young Czech people now have a much lower understanding of Slovak. Also, the number of Slovak-language books and newspapers sold in the Czech Republic dropped drastically. The Czech television news, however, started to reintroduce Slovak-language coverage from Slovakia and Slovak television (STV2) rebroadcasts the Czech television newscast Události ČT daily, ten minutes after midnight.

On the public Radio and Television of Slovakia, it is common to have at least one daily newscast from the Czech Republic during prime time news. Furthermore, many programmes on Slovak television channels are still dubbed into Czech, some films in cinemas are subtitled in Czech and there are far more Czech-language books and periodicals on the market than there were before the dissolution. The major boost for the language interchange has come from private television channel providers like CS Link (Czech Republic) and Sky Link (Slovakia) that offer Slovak channels in the Czech Republic and vice versa. Additionally, several channels, regardless of their national origin, offer programs both in Czech and Slovak (CSFilm, TV Barrandov) or even mix like TV Nova's Nova Sport coverage of the English Premier League. New impulses to mutual contacts coming via television are also common shows like the Intelligence Test of Nations, Czechoslovakia's Got Talent, and Masked Singer broadcast by PRIMA and TV JOJ, and Czecho-Slovak SuperStar, the latter being the first international edition of the Pop Idol song contest broadcast by TV Nova and Markíza (both owned by CME), which also organized joint versions of MasterChef and The Voice in 2012. Also, the New Year's Eve Program for 2009 was prepared and broadcast jointly by ČT and STV and for 2010 by the Czech TV PRIMA and the Slovak TV JOJ, this time even including the singing of the Czechoslovak national anthem.

Young Slovak people still have the same knowledge of Czech as their predecessors, if not better. In Slovakia, Czech may still be used automatically in all judicial proceedings, and all documents written in Czech are acknowledged by Slovak authorities and vice versa. Further, the Slovak Official Language Act, passed in 2009, reconfirmed the right of Czechs to use their language in all official communication when dealing with Slovak authorities although it explicitly limited the use of Czech in Slovakia to persons with Czech as their mother tongue. The same is true about using Slovak in the Czech Republic under the Administration Procedure Act of 2004. Gustáv Slamečka, a Slovak citizen who was the Czech transport minister (2009–2010), used only Slovak exclusively during his official communication.

See also differences between Slovak and Czech languages.

Sport
The official breakup occurred right in the middle of the 1993 World Junior Ice Hockey Championships, which took place in Sweden. The team representing Czechoslovakia was renamed "Czech–Slovak" on January 1. In international ice hockey tournaments, the Czech Republic took over Czechoslovakia's place in the A-groups, and Slovakia had to start in the lower divisions.

During the FIS Nordic World Ski Championships 1993 in Falun, Sweden, the ski jumping team competed as a combined Czech–Slovakia team in the team large hill event and won silver. The team had been selected before the dissolution. Jaroslav Sakala won two medals in the individual hill events for the Czech Republic at those games along with his silver in the team event.

In their qualifying section for the 1994 FIFA World Cup, the Czechoslovakia national football team competed under the name RCS, which stood for "Representation of Czechs and Slovaks". In their last game as "Representation of Czechs and Slovaks", the team failed to qualify after it got only a draw in its final match against Belgium, a match that it must win to qualify. It was afterward that it was officially split up into Czech and Slovak national teams, with both being declared successors to Czechoslovakia.

The mutual encounters between the national teams of both countries in many sports are followed by most of the populations, and the number of players and coaches active in the other republic is significant. Martin Lipták, a Slovak handball coach, successfully led the Czech national team to the EHF 2010 Handball European Championship in Austria. A Slovak team under his coaching, Tatran Prešov, won the Czech national league in 2008 and 2009. Czech ice hockey coach Vladimír Vůjtek led the Slovak national team to the silver medal at the 2012 IIHF World Championship, having beaten the Czech team in the semifinals.

Several sports have featured a common league, and discussions about having a common football or ice hockey league continue.

The road cyclist Ján Svorada earned Slovak citizenship in 1993. In 1994, he became the first Slovak rider ever to win a Tour de France stage. Two years later, he earned Czech citizenship, and he became the first Czech rider ever to win another Tour de France stage in 1998.

Telecommunications
The two successor states continued to use the country code +42 until February 1997, when it was replaced by two separate codes: +420 for the Czech Republic and +421 for Slovakia. Since then, telephone calls between both countries have required international dialing.

Referendum controversy
Soon after the dissolution, public contentment was at relatively low levels with high shares of the population on both sides of the border protesting the fact that the dissolution of the common state was not put towards a vote, as described by politologist Lubomír Kopeček of Masaryk University. A March 1993 study conducted by Martin Bútora and his wife Zora indicated that in case of a referendum about 50% of the population would've voted against the dissolution of the state with only about 30% in favour of the dissolution.

Former Slovak Minister of Culture Marek Maďarič, pointed out, in January 2023, that the dissolution without a referendum reflected the historic practice and a tradition of constitutional stately affairs decided without a referendum in Czechoslovak history. Namely, both the formation of the First Czechoslovak Republic from the rubbles of Austria-Hungary in 1918 as well as the reunion of the Protectorate and Slovak State to form a Third Republic in 1945 after the conclusion of the World War II were achieved without a referendum, solely through the pursuit of political representatives of the era.

Public polling
Public perception of the dissolution has not changed much, with a December 2017 poll showing that just 42% of Czechs and 40% of Slovaks agree with what happened (compared to 36% and 37% in 1992, respectively). Surveys from 2010 showed that the majority of the population of Prague (Czechs) still considers the division of the country a mistake; similarly, the general representative survey in Slovakia (from 2008) showed that society is still divided in opinion on the dissolution, with 47% favouring the dissolution and 44% considering it a mistake.

Reactionary movements
In 2015, a Slovak movement called "Czechoslovakia 2018" was established to try to get a referendum by 2018. Its leader, Ladislav Zelinka, said that he had received thousands of emails and calls from supporters, but it was unable to reach the necessary 350,000 petition signatures. The younger generations of both countries are largely indifferent to the issue since they never experienced the previous period themselves, and older generations are more focused on present issues such as immigration and favour their own separate nationalism.

Governmental cooperation
Political influences between the countries are minimal, but social democrats tend to cooperate very closely on regional and European topics in recent years. Furthermore, it has become customary that the elected presidents pay their first and last official foreign visits during their term to the other republic of the former Czechoslovakia. Appointed foreign ministers tend to follow that unwritten rule. On October 29, 2012, to commemorate Czechoslovakia's declaration of independence, which occurred on October 28, 1918, the Czech and the Slovak governments held, for the first time, a joint cabinet meeting in the communities of Trenčín and Uherské Hradiště, near the common border.

Military cooperation
Peacekeeping troops stationed in the former Yugoslavia were put under joint command on several occasions. For example, from 2002 to July 2005, the Czech Armed Forces joined with the Armed Forces of the Slovak Republic to form a joint Czech–Slovak KFOR battalion in Kosovo, which contributed to the Multinational Brigade CENTRE.

Trade and tourism
Trade relations were re-established and stabilised, and the Czech Republic continues to be Slovakia's most important business partner. After a short interruption, Slovakia's resorts in the Carpathian mountains, especially High Tatras and Low Tatras are again the destination of a growing number of Czech tourists.

Commemorations
Following the death of the last Czechoslovak (and the first Czech) president, Václav Havel, on December 18, 2011, both the Czech Republic and Slovakia observed a day of national mourning. During the funeral mass in Prague's St. Vitus Cathedral, prayers were recited in an equal ratio in Czech and Slovak.

title: Dissolution of Czechoslovakia