where was the hope diamond found and where is it now

The jewel is believed to have originated in India, where the original (larger) stone was purchased in 1666 by French gem merchant Jean-Baptiste Tavernier as the Tavernier Blue.[1] The Tavernier Blue was cut and yielded the French Blue (Le bleu de France), which Tavernier sold to King Louis XIV in 1668. Stolen in 1791, it was recut, with the largest section acquiring its "Hope" name when it appeared in the catalogue of a gem collection owned by a London banking family called Hope in 1839. After going through numerous owners, it was sold to Washington socialite Evalyn Walsh McLean who was often seen wearing it. It was purchased in 1949 by New York gem merchant Harry Winston, who toured it for a number of years before giving it to Washington’s National Museum of Natural History in 1958, where it has since remained on permanent exhibition.

Hope Diamond

The Hope Diamond is one of the most famous jewels in the world, with ownership records dating back almost four centuries. Its much-admired rare blue color is due to trace amounts of boron atoms. Weighing 45.52 carats, its exceptional size has revealed new findings about the formation of gemstones.

The Hope Diamond has long been rumored to carry a curse, possibly due to agents trying to arouse interest in the stone. It was last reported to be insured for $250 million.

The Hope Diamond, also known as Le Bijou du Roi ("the King's Jewel"),[2] Le bleu de France ("France's Blue"), and the Tavernier Blue, is a large, 45.52-carat (9.104Â g),[w][3][4][5] deep-blue diamond, and now housed in the National Gem and Mineral collection at the National Museum of Natural History in Washington, D.C. It is blue to the naked eye because of trace amounts of boron within its crystal structure, and exhibits a red phosphorescence under exposure to ultraviolet light.[6][7]

It is classified as a Type IIb diamond, and has changed hands numerous times on its way from India to France to Britain and eventually to the United States, where it has been regularly on public display since. It has been described as the "most famous diamond in the world".[8]

People typically think of the Hope Diamond as a historic gem, but this study underscores its importance as a rare scientific specimen that can provide vital insights into our knowledge of diamonds and how they are formed in the earth.

You cradle the 45.5-carat stone—about the size of a walnut and heavier than its translucence makes it appear—turning it from side to side as the light flashes from its facets, knowing it's the hardest natural material yet fearful of dropping it.

The Hope Diamond was formed deep within the Earth approximately 1.1 billion years ago.[23] Like all diamonds, it is formed when carbon atoms form strong bonds.[23] The Hope Diamond was originally embedded in kimberlite, and was later extracted and refined to form the gem it is today. The Hope Diamond contains trace amounts of boron atoms intermixed with the carbon structure, which results in the rare blue color of the diamond.[23]

Several accounts, based on remarks written by French gem merchant Jean-Baptiste Tavernier, who obtained the gem in India in 1666, suggest that the gemstone originated in India, in the Kollur mine in the Guntur district of Andhra Pradesh (which at the time was part of the Golconda kingdom), in the seventeenth century.[24][25][26] It is unclear who had initially owned the gemstone, where it had been found, by whom, and in what condition. But the first historical records suggest that Tavernier obtained the stone in 1666, possibly by purchase[13][1] or by theft.[18] Tavernier brought to Paris a large uncut stone which was the first known precursor to the Hope Diamond. This large stone became known as the Tavernier Blue diamond. It was a crudely cut triangular shaped stone of 115 carats (23.0 g).[12] Another estimate is that it weighed 112.23 carats (22.446 g) before it was cut.[18] Tavernier's book, the Six Voyages (French: Les Six Voyages de J. B. Tavernier), contains sketches of several large diamonds that he sold to Louis XIV in possibly 1668[10] or 1669; while the blue diamond is shown among these, Tavernier mentions the mines at "Gani" Kollur as a source of colored diamonds, but made no direct mention of the stone. Historian Richard Kurin builds a highly speculative case for 1653 as the year of acquisition,[27] but the most that can be said with certainty is that Tavernier obtained the blue diamond during one of his five voyages to India between the years 1640 and 1667. One report suggests he took 25 diamonds to Paris, including the large rock which became the Hope, and sold all of them to King Louis XIV.[28] Another report suggested that in 1669, Tavernier sold this large blue diamond along with approximately one thousand other diamonds to King Louis XIV of France for 220,000 livres, the equivalent of 147 kilograms of pure gold.[12][29] In a newly published historical novel, The French Blue, gemologist and historian Richard W. Wise proposed that the patent of nobility granted Tavernier by Louis XIV was a part of the payment for the Tavernier Blue. According to the theory, during that period Colbert, the King's Finance Minister, regularly sold offices and noble titles for cash, and an outright patent of nobility, according to Wise, was worth approximately 500,000 livres making a total of 720,000 livres, a price about half Tavernier's estimate of the gem's true value.[30] There has been some controversy regarding the actual weight of the stone; Morel believed that the 112 3⁄16 carats[18] stated in Tavernier's invoice would be in old French carats, thus 115.28 metric carats.

In 1678, Louis XIV commissioned the court jeweller, Sieur Pitau, to recut the Tavernier Blue, resulting in a 67.125-carat (13.4250Â g) stone[9] which royal inventories thereafter listed as the Blue Diamond of the Crown of France (French: diamant bleu de la Couronne de France[31]). Later English-speaking historians have simply called it the French Blue. The king had the stone set on a cravat-pin.[32] According to one report, Louis ordered Pitau[33] to "make him a piece to remember", and Pitau took two years on the piece, resulting in a "triangular-shaped 69-carat gem the size of a pigeon's egg that took the breath away as it snared the light, reflecting it back in bluish-grey rays."[13] It was set in gold and was supported by a ribbon for the neck which was worn by the king during ceremonies.[9]

At the diamond's dazzling heart was a sun with seven facets – the sun being Louis' emblem, and seven being a number rich in meaning in biblical cosmology, indicating divinity and spirituality.

In 1749, Louis XIV's great-grandson, Louis XV, had the French Blue set into a more elaborate jewelled pendant for the Order of the Golden Fleece by court jeweler AndrÃ© Jacquemin.[9] The assembled piece included a red spinel of 107 carats shaped as a dragon breathing "covetous flames", as well as 83 red-painted diamonds and 112 yellow-painted diamonds to suggest a fleece shape.[13] The piece fell into disuse after the death of Louis XV. The diamond became the property of his grandson Louis XVI.[12] whose wife, queen Marie Antoinette, used many of the French Crown Jewels for personal adornment by having the individual gems placed in new settings and combinations, but the French Blue remained in this pendant except for a brief time in 1787, when the stone was removed for scientific study by Mathurin Jacques Brisson, and returned to its setting soon thereafter.

On September 11, 1792, while Louis XVI and his family were imprisoned in the Temple in the early stages of the Reign of Terror during the French Revolution, a group of thieves broke into the Royal Storehouse, the Hôtel du Garde-Meuble de la Couronne (now Hôtel de la Marine), and stole most of the Crown Jewels during a five-day looting spree.[13] While many jewels were later recovered, including other pieces of the Order of the Golden Fleece, the French Blue was not among them and it disappeared from history.[10] On 21 January 1793, Louis XVI was guillotined and Marie Antoinette was guillotined on 16 October of the same year: these beheadings are commonly cited as a result of the diamond's "curse", but the historical record suggests that Marie Antoinette had never worn the Golden Fleece pendant because it had been reserved for the exclusive use of the king.[citation needed]

A likely scenario is that the French Blue, sometimes also known as the Blue Diamond,[13] was "swiftly smuggled to London" after being seized in 1792 in Paris.[13] But the exact rock known as the French Blue was never seen again, since it almost certainly was recut during this decades-long period of anonymity,[13] probably into two pieces, and the larger one became the Hope Diamond. One report suggested that the cut was a "butchered job" because it sheared off 23.5 carats from the larger rock as well as hurting its "extraordinary lustre."[13] It had long been believed that the Hope Diamond had been cut from the French Blue[34] until confirmation finally happened when a three-dimensional leaden model of the latter was rediscovered in the archives of the National Museum of Natural History in Paris in 2005. Previously, the dimensions of the French Blue had been known only from two drawings made in 1749 and 1789; although the model slightly differs from the drawings in some details, these details are identical to features of the Hope Diamond, allowing CAD technology to digitally reconstruct the French Blue around the recut stone.[35][36] Historians suggested that one robber, Cadet Guillot, took several jewels, including the French Blue and the Côte-de-Bretagne spinel, to Le Havre and then to London, where the French Blue was cut in two pieces. Morel adds that in 1796, Guillot attempted to resell the Côte-de-Bretagne in France but was forced to relinquish it to fellow thief Lancry de la Loyelle, who put Guillot into debtors' prison.

In a contrasting report, historian Richard Kurin speculated that the "theft" of the French Crown Jewels was in fact engineered by the revolutionary leader Georges Danton as part of a plan to bribe an opposing military commander, Duke Karl Wilhelm of Brunswick.[13] When under attack by Napoleon in 1805, Karl Wilhelm may have had the French Blue recut to disguise its identity; in this form, the stone could have come to Britain in 1806, when his family fled there to join his daughter Caroline of Brunswick. Although Caroline was the wife of the Prince Regent George (later George IV of the United Kingdom), she lived apart from her husband, and financial straits sometimes forced her to quietly sell her own jewels to support her household. Caroline's nephew, Duke Karl Friedrich, was later known to possess a 13.75-carat (2.750Â g) blue diamond which was widely thought to be another piece of the French Blue. This smaller diamond's present whereabouts are unknown, and the recent CAD reconstruction of the French Blue fits too tightly around the Hope Diamond to allow for the existence of a sister stone of that size.

A blue diamond with the same shape, size, and color as the Hope Diamond was recorded by John Francillon in the possession of the London diamond merchant Daniel Eliason in September 1812, the earliest point when the history of the Hope Diamond can be definitively fixed,[9][13] although a second less definitive report claims that the Hope Diamond's "authentic history" can only be traced back to 1830.[34] The jewel was a "massive blue stone of 45.54 carats"[13] and weighed 177 grains (4 grains = 1 carat).[9] It is often pointed out that the 1812 date was almost exactly twenty years after the theft of the French Blue, just as the statute of limitations for the crime had taken effect.[13] While the diamond had disappeared for two decades, there were questions whether this diamond now in Great Britain was exactly the same one as had belonged to the French kings, but scientific investigation in 2008 confirmed "beyond reasonable doubt" that the Hope Diamond and that owned by the kings of France were, indeed, the same gemstone, in the sense that the Hope Diamond had been cut from the French Blue.[9][13]

There are conflicting reports about what happened to the diamond during these years. Eliason's diamond may have been acquired by George IV of the United Kingdom,[10] possibly through Caroline of Brunswick;[13] however, there is no record of the ownership in the Royal Archives at Windsor, although some secondary evidence exists in the form of contemporary writings and artwork, and George IV tended to mix up the Crown property of the Crown Jewels with family heirlooms and his own personal property. A source at the Smithsonian suggested there were "several references" suggesting that George had, indeed, owned the diamond.[9] After his death in 1830, it has been alleged that some of this mixed collection was stolen by George's last mistress, Elizabeth Conyngham, and some of his personal effects were discreetly liquidated to cover the many debts he had left behind him. Another report states that the king's debts were "so enormous" that the diamond was probably sold through "private channels".[9] In either case, the blue diamond was not retained by the British royal family.

The stone was later reported to have been acquired by a rich London banker named Thomas Hope, for either $65,000[12] or $90,000.[18] It has been suggested that Eliason may have been a "front" for Hope,[13] acting not as a diamond merchant venturing money on his own account, but rather as an agent to acquire the diamond for the banker. In 1839, the Hope Diamond appeared in a published catalog of the gem collection of Henry Philip Hope, who was a member of the same Anglo-Dutch banking family.[9] The stone was set in a fairly simple medallion surrounded by many smaller white diamonds, which he sometimes lent to Louisa de la Poer Beresford, the widow of his brother, Thomas Hope, for society balls. After falling into the ownership of the Hope family, the stone came to be known as the "Hope Diamond".[12]

Henry Philip Hope died in 1839, the same year as the publication of his collection catalog. His three nephews, the sons of Thomas and Louisa, fought in court for ten years over his inheritance, and ultimately the collection was split up. The oldest nephew, Henry Thomas Hope, received eight of the most valuable gems, including the Hope Diamond. It was displayed in the Great Exhibition of London in 1851 and at the 1855 Exposition Universelle in Paris, but was usually kept in a bank vault. In 1861, Henry Thomas Hope's only child, Henrietta, married Henry Pelham-Clinton (and later Duke of Newcastle). When Hope died on December 4, 1862, his wife Anne Adele inherited the gem, but she feared that the profligate lifestyle of her son-in-law might cause him to sell the Hope properties. Upon Adele's death in 1884, the entire Hope estate, including the Hope Diamond, was entrusted to Henrietta's younger son, Henry Francis Pelham-Clinton, on the condition that he add the name of "Hope" to his own surnames when he reached the age of legal majority. As Lord Francis Hope, this grandson received his legacy in 1887. However, he had only a life interest in his inheritance, meaning that he could not sell any part of it without court permission.

In 1894, Lord Francis Hope met the American concert hall singer May Yohé, who has been described as "the sensation of two continents",[12] and they were married the same year; one account suggests that Yohé wore the Hope Diamond on at least one occasion.[12] She later claimed that she had worn it at social gatherings and had an exact replica made for her performances, but her husband claimed otherwise. Lord Francis lived beyond his means, and this eventually caught up with him, leading to marriage troubles and financial reverses, and he found that he had to sell the diamond.[12] In 1896, his bankruptcy was discharged, but, as he could not sell the Hope Diamond without the court's permission, he was supported financially by his wife during these intervening years. In 1901, the financial situation had changed, and after a "long legal fight,"[28] he was given permission to sell the Hope Diamond by an order of the Master in Chancery[28] to "pay off debts".[13] But May Yohé ran off with a gentleman friend named Putnam Strong, who was a son of the former New York City mayor William L. Strong. Francis Hope and May Yohé were divorced in 1902.[12]

Francis sold the diamond for £29,000 (£2.89 million today), to Adolph Weil, a London jewel merchant. Weil later sold the stone to the diamond dealer Simon Frankel, based in New York and/or London[12] who took it to New York. One report stated that he had paid $250,000 ($7.2 million today).[28] However, in New York it was evaluated to be worth $141,032 ($4.06 million today).

Accounts vary about what happened to the diamond during the years 1902â€“1907; one account suggested that it lay in the William & Theodore safe during these years while the jewelers took it out periodically to show it to wealthy Americans; a rival account, probably invented to help add "mystery" to the Hope Diamond story, suggested that some persons had bought it but apparently sold it back to Frankel.[12] There were reports in one story in The New York Times of several owners of the gem, perhaps who had bought it from Frankel and owned it temporarily who met with ill-fortune,[citation needed] but this report conflicts with the more likely possibility that the gem remained in the hands of the Frankel jewelry firm during these years. Like many jewelry firms, the Frankel business ran into financial difficulties during the depression of 1907 and referred to the gem as the "hoodoo diamond."[12]

In 1908, Frankel sold the diamond for $400,000 ($10.66 million today)[37] to a Salomon or Selim Habib, a wealthy Turkish diamond collector,[38] reportedly on behalf of Sultan Abdulhamid of Ottoman Empire; however, on June 24, 1909, the stone was included in an auction of Habib's assets to settle his own debts,[9] and the auction catalog explicitly stated that the Hope Diamond was one of only two gems in the collection which had never been owned by the Sultan. A contrary report, however, suggested that Sultan Abdul Hamid did own the gem but ordered Habib to sell it when his throne "began to totter."[12] Habib reportedly sold the stone in Paris in 1909 for $80,000 ($2.13 million today).[12] The Parisian jewel merchant Simon Rosenau bought the Hope Diamond for 400,000 francs and resold it in 1910 to Pierre Cartier for 550,000 francs. In 1910, it was offered for $150,000 ($3.86 million today), according to one report.[11]

Pierre Cartier tried to sell the Hope Diamond to Washington D.C. socialite Evalyn Walsh McLean and her husband in 1910.[10] Cartier was a consummate salesman who used an understated presentation to entice Mrs. McLean.[39] He described the gem's illustrious history to her while keeping it concealed underneath special wrapping paper.[39] The suspense worked: McLean became impatient to the point where she suddenly requested to see the stone. She recalled later that Cartier "held before our eyes the Hope Diamond."[39] Nevertheless, she initially rejected the offer. Cartier had it reset. She found the stone much more appealing in this new modern style. There were conflicting reports about the sale in the New York Times; one account suggested that the young McLean couple had agreed to purchase the diamond, but after having learned about its unfortunate supposed history, the couple had wanted to back out of the deal[40] since they knew nothing of the "history of misfortunes that have beset its various owners."[40]

Both Ned McLean and his pretty wife are quite young, and in a way unsophisticated, although they were born and reared in an atmosphere of wealth and luxury. All their lives they have known more of jewelry, finery, banquets, automobiles, horses, and other articles of pleasure than they have of books, with their wealth of knowledge.

The brouhaha over the diamond's supposed "ill luck" prompted a worried editor of The Jewelers' Circular-Weekly to write:

No mention of any ill luck having befallen Eliason, Hope, or any of their descendants was ever made. The Frankels surely were very prosperous while the stone was in their possession, as were the dealers who held it in Europe. Habib's misfortune referred to in the newspaper accounts occurred long after he had sold the stone... As Francis Hope never had the stone and May Yohe probably never saw it... the newspaper accounts at the time mentioned were laughed at, but since then it has been the custom not only to revive these stories every time mention of the stone appears in the public press, but to add to them fictitious incidents of misfortune as to alleged possessors of the stone at various times.

The tenuous deal involved wrangling among attorneys for both Cartier and the McLeans, but finally, in 1911, the couple bought the gem for over $300,000 (over $7.7 million today),[12] although there are differing estimates of the sales price at $150,000 and $180,000. An alternative scenario is that the McLeans may have fabricated concern about the supposed "curse" to generate publicity to increase the value of their investment.

A description was that the gemstone "lay on a bed of white silk and surrounded by many small white diamonds cut pear shaped".[12] The new setting was the current platinum framework surrounded by a row of sixteen diamonds which alternated between Old Mine Cut and pear-shaped variants. Mrs. McLean wore it to a "brilliant reception" in February 1912 when it was reported that it was the first time it had been worn in public since it had "changed owners."[41] She would "sport the diamond at social events"[10] and wore it numerous social occasions that she had organized.

The Hope Diamond in its original pendant must have looked fantastic at parties circa the 1920s, when it hung around the neck of owner Evalyn Walsh McLean's Great Dane, Mike.

There were reports that she misplaced it at parties,[43] deliberately and frequently, and then make a children's game out of "finding the Hope", and times when she hid the diamond somewhere on her estate during the "lavish parties she threw and invite guests to find it."[10] The stone prompted elaborate security precautions:

William Schindele, a former Secret Service man, has been engaged to guard the stone. He in turn will be guarded by Leo Costello and Simeon Blake, private detectives. The stone will be kept at the McLean mansion during the day and each night will be deposited in a safe deposit vault. When Mrs. McLean wears the gem at balls and receptions arrangements have been made to keep the safe deposit building open until after the function that the stone may be safely stored away. A special automobile has been purchased to convey the guards to and from the house to the trust company's building.

But the stone was not stolen during their ownership. When Mrs. McLean died in 1947, she bequeathed the diamond to her grandchildren through a will which insisted that her former property would remain in the custody of trustees until the eldest child had reached 25 years of age. This requirement would have prevented any sale for the next two decades. However, the trustees gained permission to sell her jewels to settle her debts, and in 1949 sold them to New York diamond merchant Harry Winston. He purchased McLean's "entire jewelry collection".[10] Over the next decade, Winston exhibited McLean's necklace in his "Court of Jewels," a tour of jewels around the United States,[10] as well as various promotional events and charity balls. The diamond appeared on the television quiz show The Name's the Same, in an episode which first aired on August 16, 1955,[44] when a teenaged contestant with the actual name Hope Diamond was one of the mystery guests, as well as at the August 1958 Canadian National Exhibition.[8] At some point, Winston also had the Hope Diamond's bottom facet slightly recut to increase its brilliance.

Smithsonian mineralogist George Switzer is credited with persuading jeweler Harry Winston to donate the Hope Diamond for a proposed national gem collection to be housed at the National Museum of Natural History.[45] On November 10, 1958,[13] Winston acquiesced, sending it through U.S. Mail in a box wrapped in brown paper as simple registered mail[10] insured for $1 million at a cost of $145.29, of which $2.44 was for postage and the balance insurance.[10][46] Upon its arrival it became Specimen #217868.[47]

Winston had never believed in any of the tales about the curse; he donated the diamond with the hope that it would help the United States "establish a gem collection."[8] Winston died many years later, in 1978, of a heart attack. Winston's gift, according to Smithsonian curator Dr. Jeffrey Post, indeed helped spur additional gifts to the museum.[21]

For its first four decades in the National Museum of Natural History, the Hope Diamond lay in its necklace inside a glass-fronted safe as part of the gems and jewelry gallery, except for a few brief excursions: a 1962 exhibition to the Louvre;[9] the 1965 Rand Easter Show in Johannesburg, South Africa;[9] and two visits back to Harry Winston's premises in New York City, once in 1984,[9] and once for a 50th anniversary celebration in 1996.[9] To guard against theft during the diamond's trip to the 1962 Louvre exhibition, Switzer traveled to Paris with the Hope Diamond tucked inside a velvet pouch sewn by his wife.[48] The Hope Diamond was placed into the pouch, which was pinned inside Switzer's pants pocket for the flight.[48]

When the Smithsonian's gallery was renovated in 1997, the necklace was moved onto a rotating pedestal inside a cylinder made of 3-inch (76Â mm) thick bulletproof glass in its own display room, adjacent to the main exhibit of the National Gem Collection, in the Janet Annenberg Hooker Hall of Geology, Gems, and Minerals. The Hope Diamond is the most popular jewel on display and the collection's centerpiece.[49] In 1988, specialists with the Gemological Institute of America graded it and noticed "evidence of wear" and its "remarkably strong phosphorescence" with its clarity "slightly affected by a whitish graining which is common to blue diamonds."[9] A highly sensitive colorimeter found tiny traces of a "very slight violet component" which is imperceptible to normal vision.[9]

In 2005, the Smithsonian published a year-long computer-aided geometry research which officially acknowledged that the Hope Diamond is, in fact, part of the stolen French Blue crown jewel.[50]

In 2009, the Smithsonian announced a temporary new setting for the jewel to celebrate a half-century at the National Museum of Natural History. Starting in September 2009, the 45.52-carat (9.104Â g) diamond[4] was exhibited as a stand-alone gem with no setting. It had been removed from its setting for cleaning from time to time, but this was the first time it would be on public display by itself. Previously it had been shown in a platinum setting, surrounded by 16 white pear-shaped and cushion-cut diamonds, suspended from a chain containing forty-five diamonds.

The Hope returned to its traditional setting in late 2010.[51]

On November 18, 2010, the Hope Diamond was unveiled and displayed at the Smithsonian in a temporary newly designed necklace called "Embracing Hope", created by the Harry Winston firm.[10] Three designs for the new setting, all white diamonds and white metal, were created and the public voted on the final version. The Hope Diamond also is resting on a new dark blue neck form, which the Harry Winston firm commissioned from display organization, Pac Team Group. Previously, the Hope Diamond had been displayed as a loose gem since late summer of 2009 when it was removed from its former Cartier-designed setting. A Smithsonian curator described it as "priceless" because it was "irreplaceable", although it was reported to be insured for $250 million.[10] On January 13, 2012 the diamond was returned to its historic setting, and the current necklace was implanted with another diamond worth "at least a million dollars". The necklace with the new diamond will be sold to benefit the Smithsonian.[10]

The diamond has been surrounded by a mythology of a reputed curse to the effect that it brings misfortune and tragedy to persons who own it or wear it, but there are strong indications that such stories were fabricated to enhance the stone's mystery and appeal, since increased publicity usually raised the gem's value and newsworthiness.[53][54][55]

According to specious accounts in the late nineteenth and early twentieth century, the original form of the Hope Diamond was stolen from an eye of a sculpted statue of the goddess Sita, the wife of Rama, the seventh Avatar of Vishnu. However, much like the "curse of Tutankhamun", this general type of "legend" was most likely the invention of Western authors during the Victorian era,[56] and the specific legends about the Hope Diamond's "cursed origin" were invented in the early 20th century to add mystique to the stone and increase its sales appeal as well as increase newspaper sales. It fueled speculation that humans possessing the gemstone were fated to have bad luck with varying reports of undetermined veracity. A report in 2006 in The New York Times, however, suggested that "any hard evidence linking it to tragedy has yet to be officially proven."[57]

There is evidence of several newspaper accounts which helped spread the curse story.[55] A New Zealand newspaper article in 1888 described the supposedly lurid history of the Hope Diamond, including a claim that it was "said once to have formed the single eye of a great idol", as part of a confused description that also claimed that its namesake owner had personally "brought it from India", and that the diamond's true color was "white, [although] when held to the light, it emits the most superb and dazzling blue rays."[58] An article entitled "Hope Diamond Has Brought Trouble To All Who Have Owned It" appeared in the Washington Post in 1908.[59] An additional account of the Hope Diamond's "cursed origins" was a fanciful and anonymously written newspaper article in 1909. It was followed by another New York Times article in 1911[12] which gave a list of supposed cases of ill-fortune, but with few confirmations from other sources:

The mainstream view is that these accounts are specious and speculative since there are few, if any, independent confirmations to back them up.[55] A few months later, perhaps compounded by inaccurate reports in The New York Times on November 17, 1909, it was incorrectly reported that the diamond's former owner, Selim Habib, had drowned in a shipwreck of the steamer Seyne near Singapore;[38] in fact, it was a different person with the same name, not the owner of the diamond.[60] There was speculation that jeweler Pierre Cartier further embroidered the lurid tales to intrigue Evalyn Walsh McLean into buying the Hope Diamond in 1911.[53]

The theme of greedy robbers stealing a valuable metal from the tomb or shrine of an ancient god or ruler, and then being punished by it, is one which repeats in many different forms of literature. A likely source of inspiration for the fabrications was the Wilkie Collins' 1868 novel The Moonstone, which created a coherent narrative from vague and largely disregarded legends which had been attached to other diamonds such as the Koh-i-Noor and the Orloff diamond. The theme can be seen in films such as The Mummy as well as stories about the curse of Egyptian king Tutankhamun and in more recent films such as the Indiana Jones films. In keeping with these scripts, according to the legend, Tavernier did not buy the Hope diamond but stole it from a Hindu temple where it had been set as one of two matching eyes of an idol, and the temple priests then laid a curse on whoever might possess the missing stone. Largely because the other blue diamond "eye" never surfaced, historians dismissed the fantastical story.[55] The stories generally do not bear up to more pointed examination; for example, the legend that Tavernier's body was "torn apart by wolves"[12] is inconsistent with historical evidence which shows that he lived to 84 and died of natural causes.

It is possible that the overblown story of the curse, possibly fueled by Cartier and others, may have caused some hesitation on the part of the prospective buyers, the McLeans, around 1911. When a lawsuit between buyer and seller erupted about the terms of the deal, newspapers kept alive reports of the diamond's "malevolent influence" with reports like this one, which blamed the stone's "curse" on having caused, of all things, the lawsuit itself:

The malevolent influence that has for centuries dogged with discord and disaster the owners of the famous Hope diamond has started again and without waste of time, despite special precautions against ill-luck taken at the time of its last sale, according to John S. Wise, Jr., of 20 Broad Street, attorney for Cartiers, the Fifth Avenue jewelers, who are suing Mr. and Mrs. Edward B. McLean for $180,000, its alleged purchase price.

The Hope Diamond was also blamed for the unhappy fates of other historical figures vaguely linked to its ownership, such as the falls of Madame Athenais de Montespan and French finance minister Nicolas Fouquet during the reign of Louis XIV of France; the beheadings of Louis XVI and Marie Antoinette and the rape and mutilation of the Princesse de Lamballe during the French Revolution; and the forced abdication of Turkish Sultan Abdul Hamid who had supposedly killed various members of his court for the stone (despite the annotation in Habib's auction catalog).[12] Even jewelers who may have handled the Hope Diamond were not spared from its reputed malice: the insanity and suicide of Jacques Colot, who supposedly bought it from Eliason, and the financial ruin of the jeweler Simon Frankel, who bought it from the Hope family, were linked to the stone.[12] But although he is documented as a French diamond dealer of the correct era, Colot has no recorded connection with the stone, and Frankel's misfortunes were in the midst of economic straits that also ruined many of his peers. The legend includes deaths of numerous other characters who had been previously unknown: Diamond cutter Wilhelm Fals, killed by his son Hendrik, who stole it and later committed suicide; Francois Beaulieu, who received the stone from Hendrik but starved to death after selling it to Eliason; a Russian prince named Kanitowski, who lent it to French actress Lorens Ladue and promptly shot her dead on the stage, and was himself stabbed to death by revolutionaries; Simon Montharides, hurled over a precipice with his family.[12] However, the existence of only a few of these characters has been verified historically, leading researchers to conclude that most of these persons are fictitious.[citation needed]

The actress May Yohe made repeated attempts to capitalize on her identity as the former wife of the last Hope to own the diamond, and sometimes blamed the gemstone for her misfortunes. In July 1902, months after Lord Francis divorced her, she told police in Australia that her lover, Putnam Strong, had abandoned her and taken her jewels. In fact, the couple reconciled, married later that year, but divorced in 1910. On her third marriage in 1920, she persuaded film producer George Kleine to back a 15-episode serial The Hope Diamond Mystery, which added fictitious characters to the tale, but the project was not successful. In 1921, she hired Henry Leyford Gates to help her write The Mystery of the Hope Diamond, in which she starred as Lady Francis Hope. The film added more characters, including a fictionalized Tavernier, and added Marat among the diamond's "victims". She also wore her copy of the Hope, trying to generate more publicity to further her career.

Evalyn Walsh McLean added her own narrative to the story behind the blue jewel, including that one of the owners had been Catherine the Great, although there are no confirmations that the Russian ruler ever owned the diamond. McLean would bring the Diamond out for friends to try on, including Warren G. Harding and Florence Harding.

Since the Smithsonian acquired the gemstone, the "curse appears to have gone dormant."[10] Owning the diamond has brought "nothing but good luck" for the nonprofit national museum, according to a Smithsonian curator, and has helped it build a "world-class gem collection" with rising attendance levels.[21]

In 2007,[62] an important discovery was made which enabled a slew of activity to help scientists, historians and gemologists further explore the history of the Hope Diamond, as well as create replicas of the larger pieces, from which it had been cut, believed to have been owned by eighteenth-century French monarchs. A lead cast of the French Blue diamond was discovered in the gemmological collections of the National Museum of Natural History in Paris, reported in a bilingual French–English press release,[63] and the unique finding triggered an investigation by an international team of researchers into the stone's history. It was an important event since previously investigators had to rely on two-dimensional sketches of the diamond, but now they had a three-dimensional structure with which to apply techniques such as computer-aided drawing analysis. It allowed creation of the first numeric reconstruction of the French Blue including a virtual snapshot video. Even the emblem of the Golden Fleece of Louis XV was numerically reconstructed around the French Blue, including the "Côte de Bretagne" spinel of 107 carats (21.4 g), the "Bazu" diamond of 32.62 carats (6.524 g), 3 oriental topazes (yellow sapphires), five brillants of up to 5 carats (1,000 mg) brillants and nearly 300 smaller diamonds. Special care was taken to reconstruct the major gemstones precisely by using CAD analysis as well as knowledge of historical gemsetting techniques. As part of the investigation, the "Tavernier Blue" diamond was also reconstructed from the original French edition of Tavernier's Voyages (rather than the later London edition that somewhat distorted and modified Tavernier's original figures), and the Smithsonian Institution provided ray-tracing and optical spectroscopic data about the Hope diamond. These events culminated in an event and a documentary to celebrate the making of these replicas, with celebrations by the French museum including H. Horovitz, Martin du Daffoy who was the historian and jeweller from the Place Vendôme in Paris, as well as directors and leaders from the museum. The event was filmed by Gédéon programmes for a documentary on the French Blue diamond, to be presented by 2011 worldwide.

The lead cast of the French Blue, itself, has a history. It had been catalogued at the French museum in 1850 and was provided by a prominent Parisian jeweler named Charles Archard who lived during the same generation as René Just Haüy, who died in 1822. Most likely, the lead cast was made near 1815, since that was the year that similar entries from the 1850 catalogue had been made. The model was accompanied by a label stating that the French Blue was in the possession of a person known as "Mr. Hope of London". Other archives at the Muséum suggests that Achard had Mr. Hope as a good customer for many long years, particularly for blue gems.[64]

These findings have helped investigators piece together what may have happened during the rock's anonymous years during the several decades following 1792. According to one line of reasoning, the first "Hope" to have the "Hope Diamond"—Henry Phillip Hope—might have possessed the French Blue that he had acquired some time after the 1792 robbery in Paris, perhaps around 1794-1795, when the Hopes were believed to have left Holland for London to escape Napoleon's armies.[65] At about the same time, Cadet Guillot, who may have been one of the thieves to have stolen the Golden Fleece, arrived in London.[66] This places Mr. Hope and Mr. Guillot in London at the same time. According to a late nineteenth century historian named Bapts, a contract was made between Cadet Guillot and a French aristocrat named Lancry de la Loyelle, in 1796, to sell the 107-carat (21.4 g) spinel-dragon of the Golden Fleece. According to this line of reasoning, in 1802 Hope sold his assets, and the continental blockade by Napoleon led the Hope's bank into a serious financial crisis by 1808, and the crisis peaked during the winter of 1811–1812[67] This put Mr. Hope in a financial bind. There is a possibility that, given his financial predicament, Hope pawned the French Blue to jewel merchant Eliason to get much-needed cash when the British currency, sterling, was highly depreciated.[68] This is consistent with the entry in Eliason's records about having the stone in 1812. However, the diamond's owners may have felt pressure to recut the stone quickly to disguise its identity, since if the French government had learned of its existence, it may have sued the owners for repossession.[64] Regardless of whether Mr. Hope had lost possession or kept it during these years, by 1824 it was again in his possession. It was around this time that Eliason died; Hope's financial situation has been restored thanks to efforts by the Barings, who saved the Hope bank in the difficult financial years of 1812-1820.[68] Accordingly, if this is correct, then the lead cast of the French Blue and the "Hope" diamond are likely to have been created in the same workshop, possibly in London, and probably a little before 1812.

The lead cast had important ramifications since it gave enough information to curators at the French museum to commission the first exact replicas of both the Tavernier and French Blue diamonds using a material which simulates diamonds called cubic zirconia, with the help of artisans who work with gems known as lapidaries, led by Scott Sucher. These replicas have been completed and displayed with the French Crown Jewels and the Great Sapphire of Louis XIV, a Moghul-cut sapphire of 135.7 carats (27.14 g). Artisans recreated the elaborate parure of different-colored gems known as the Golden Fleece of King Louis XV of France, which is arguably the most fabulous work in the history of French jewelry; this happened from 2007–2010. The original parure, created in 1749 by royal jeweler Pierre-André Jacqumin, was stolen and broken in 1792. The reassembled jewel contained the French Blue and the Bazu diamonds, as well as the Côte de Bretagne spinel and hundreds of smaller diamonds. Three years of work were needed to recreate this jewel, and it required exacting and precise skill which revealed not only the skill of today's lapidaries, but the skill of its original eighteenth-century designers. The reconstructed jewel was presented by Herbert Horovitz, with François Farges (fr) of the French museum in attendance, at the former Royal Storehouse in Paris on June 30, 2010, which was the same site where the original had been stolen 218 years before.

Additional recreations were made possible by new discoveries. A previously unknown drawing of the Golden Fleece was rediscovered in Switzerland in the 1980s, and two blue diamonds that had ornamented the jewel were found as well, and these recent findings enabled artisans to recreate a copy of the emblem.[69] It led to the construction, using cubic zirconia, of a piece that almost exactly resembles[70] the mythic French Blue 69 carats (13.8Â g) masterpiece.

The emblem has another great blue diamond, which was later named "the Bazu" in reference to a dealer who reportedly had sold it to Louis XIV in 1669.[71] This Bazu diamond was recut in 1749 as a baroque cushion weighing 32.62 carats (6.524 g). The 1791 inventory mentioned that the Bazu was "light sky blue",[72] which is consistent with the fact that the Golden Fleece of the Color Adornment was made of a variety of great colored gems. Based on documents kept in a private collection,[73] it could be shown that this particular diamond was not hexagonal-shaped, as some historians had previously thought,[74] but was in a shape best described as "rounded squared",[75] similar to the so-called Régent diamond.[70] There is a report that a curator from the French museum will assert that the hexagonal cut from the Bazu is inconsistent historically and gemologically.[citation needed] The Bazu stone referred to another version of Louis XV’s great Golden Fleece, made out of blue sapphires instead of blue diamonds.[73] According to one view, this version appears to have never been manufactured but only suggested to the king as an alternative to the effective final version, bearing two blue diamonds. Nevertheless, replicas of both blue diamonds were cut by Scott Sucher using cubic zirconia, one being colored deep blue and the other light blue.

The emblem had a third great gem known as The Côte de Bretagne dragon. Its replica was based on a wax likeness sculpted by Pascal Monney, who had based his recreation from three-dimensional scaled pictures of the original object which had been made by French artist François Farges; Farges, in turn, had seen the original objects displayed at the Louvre's Galerie d’Apollon. In addition, artist Etienne Leperlier cast a "crystal" lead glass duplicate of the wax replica of the carved Côte de Bretagne. Its pigmentation is made out of gold and manganese pigments to simulate as close as possible the original color of the spinel.

The 500-plus remaining replicas of diamonds were cut from cubic zirconia using a baroque cushion cut. Colors were used to recall the original artwork: red for the flames, and yellow for the fleece, and in keeping with the original work, the materials used were initially colorless but were painted in the same fashion used by the artist Jacqumin when the original Golden Fleece was completed in 1749. Since the original was most likely made out of gold plated with silver, a choice was made to use a matrix mostly made out of 925-grade silver to keep costs under control without compromising quality. A number of different artists helped with this project:

All stones were set according to 18th century techniques. Finally, a luxury box containing the Golden Fleece was recreated by Frédéric Viollet using crimson-colored Moroccan leather.[76] The box was gilded by Didier Montecot to the arms of Louis XV, using the king’s original iron stamp made by the Simier house.[77] A dark red cramoisi ribbon, made of crimson satin moire, holds the jewel inside the box.

Lead cast of the "French Blue" diamond, discovered in 2007 at the National Museum of Natural History (France) by Farges (ca. 31 × 26 mm)

Computer reconstruction of the "French Blue" diamond, as cut by Pitan for King Louis XIV of France in 1673 (ca. 31 × 25 mm)

The recreated great Golden Fleece of King Louis XV of France, presented by H. Horovitz (left) and François Farges (fr) (right) at the Hôtel de la Marine, formerly the royal Storehouse in Paris on June 30, 2010

Detailed view of the recreated great Golden Fleece of king Louis XV of France. Below the 107 carats (21.4 g) spinel Côte de Bretagne hangs the French Blue diamond and the fleece itself, set with hundreds of yellow diamond replicas


what is the electric charge on a proton

A proton is a subatomic particle, symbol p or p+, with a positive electric charge of +1e elementary charge and mass slightly less than that of a neutron. Protons and neutrons, each with masses of approximately one atomic mass unit, are collectively referred to as "nucleons".

Proton

6973167262189800000♠1.672621898(21)×10−27 kg[1]
7002938272081300000♠938.2720813(58) MeV/c2[2]

6974141060678730000♠1.4106067873(97)×10−26 J⋅T−1[2]
6997152103220530000♠1.5210322053(46)×10−3 μB[2]

One or more protons are present in the nucleus of every atom; they are a necessary part of the nucleus. The number of protons in the nucleus is the defining property of an element, and is referred to as the atomic number (represented by the symbol Z). Since each element has a unique number of protons, each element has its own unique atomic number.

The word proton is Greek for "first", and this name was given to the hydrogen nucleus by Ernest Rutherford in 1920. In previous years, Rutherford had discovered that the hydrogen nucleus (known to be the lightest nucleus) could be extracted from the nuclei of nitrogen by atomic collisions. Protons were therefore a candidate to be a fundamental particle, and hence a building block of nitrogen and all other heavier atomic nuclei.

In the modern Standard Model of particle physics, protons are hadrons, and like neutrons, the other nucleon (particles present in atomic nuclei), are composed of three quarks. Although protons were originally considered fundamental or elementary particles, they are now known to be composed of three valence quarks: two up quarks of charge +2/3 e and one down quark of charge –1/3 e. The rest masses of quarks contribute only about 1% of a proton's mass, however.[3] The remainder of a proton's mass is due to quantum chromodynamics binding energy, which includes the kinetic energy of the quarks and the energy of the gluon fields that bind the quarks together. Because protons are not fundamental particles, they possess a physical size, though not a definite one; the root mean square charge radius of a proton is about 0.84–0.87 fm or 6984840000000000000♠0.84×10−15 to 6984870000000000000♠0.87×10−15 m.[4][5]

At sufficiently low temperatures, free protons will bind to electrons. However, the character of such bound protons does not change, and they remain protons. A fast proton moving through matter will slow by interactions with electrons and nuclei, until it is captured by the electron cloud of an atom. The result is a protonated atom, which is a chemical compound of hydrogen. In vacuum, when free electrons are present, a sufficiently slow proton may pick up a single free electron, becoming a neutral hydrogen atom, which is chemically a free radical. Such "free hydrogen atoms" tend to react chemically with many other types of atoms at sufficiently low energies. When free hydrogen atoms react with each other, they form neutral hydrogen molecules (H2), which are the most common molecular component of molecular clouds in interstellar space.

Protons are spin-½ fermions and are composed of three valence quarks,[6] making them baryons (a sub-type of hadrons). The two up quarks and one down quark of a proton are held together by the strong force, mediated by gluons.[7]:21–22A modern perspective has a proton composed of the valence quarks (up, up, down), the gluons, and transitory pairs of sea quarks. Protons have a positive charge distribution which decays approximately exponentially, with a mean square radius of about 0.8 fm.[8]

Protons and neutrons are both nucleons, which may be bound together by the nuclear force to form atomic nuclei. The nucleus of the most common isotope of the hydrogen atom (with the chemical symbol "H") is a lone proton. The nuclei of the heavy hydrogen isotopes deuterium and tritium contain one proton bound to one and two neutrons, respectively. All other types of atomic nuclei are composed of two or more protons and various numbers of neutrons.

The concept of a hydrogen-like particle as a constituent of other atoms was developed over a long period. As early as 1815, William Prout proposed that all atoms are composed of hydrogen atoms (which he called "protyles"), based on a simplistic interpretation of early values of atomic weights (see Prout's hypothesis), which was disproved when more accurate values were measured.[9]:39â€“42

In 1886, Eugen Goldstein discovered canal rays (also known as anode rays) and showed that they were positively charged particles (ions) produced from gases. However, since particles from different gases had different values of charge-to-mass ratio (e/m), they could not be identified with a single particle, unlike the negative electrons discovered by J. J. Thomson. Wilhelm Wien in 1898 identified the hydrogen ion as particle with highest charge-to-mass ratio in ionized gases.[10]

Following the discovery of the atomic nucleus by Ernest Rutherford in 1911, Antonius van den Broek proposed that the place of each element in the periodic table (its atomic number) is equal to its nuclear charge. This was confirmed experimentally by Henry Moseley in 1913 using X-ray spectra.

In 1917 (in experiments reported in 1919), Rutherford proved that the hydrogen nucleus is present in other nuclei, a result usually described as the discovery of protons.[11] Rutherford had earlier learned to produce hydrogen nuclei as a type of radiation produced as a product of the impact of alpha particles on nitrogen gas, and recognize them by their unique penetration signature in air and their appearance in scintillation detectors. These experiments were begun when Rutherford had noticed that, when alpha particles were shot into air (mostly nitrogen), his scintillation detectors showed the signatures of typical hydrogen nuclei as a product. After experimentation Rutherford traced the reaction to the nitrogen in air, and found that when alphas were produced into pure nitrogen gas, the effect was larger. Rutherford determined that this hydrogen could have come only from the nitrogen, and therefore nitrogen must contain hydrogen nuclei. One hydrogen nucleus was being knocked off by the impact of the alpha particle, producing oxygen-17 in the process. This was the first reported nuclear reaction, 14N + α → 17O + p. (This reaction would later be observed happening directly in a cloud chamber in 1925).

Rutherford knew hydrogen to be the simplest and lightest element and was influenced by Prout's hypothesis that hydrogen was the building block of all elements. Discovery that the hydrogen nucleus is present in all other nuclei as an elementary particle, led Rutherford to give the hydrogen nucleus a special name as a particle, since he suspected that hydrogen, the lightest element, contained only one of these particles. He named this new fundamental building block of the nucleus the proton, after the neuter singular of the Greek word for "first", πρῶτον. However, Rutherford also had in mind the word protyle as used by Prout. Rutherford spoke at the British Association for the Advancement of Science at its Cardiff meeting beginning 24 August 1920.[12] Rutherford was asked by Oliver Lodge for a new name for the positive hydrogen nucleus to avoid confusion with the neutral hydrogen atom. He initially suggested both proton and prouton (after Prout).[13] Rutherford later reported that the meeting had accepted his suggestion that the hydrogen nucleus be named the "proton", following Prout's word "protyle".[14] The first use of the word "proton" in the scientific literature appeared in 1920.[15]

Recent research has shown that thunderstorms can produce protons with energies of up to several tens of MeV.[16][17]

Protons are routinely used for accelerators for proton therapy or various particle physics experiments, with the most powerful example being the Large Hadron Collider.

In a July 2017 paper, researchers measured the mass of a proton to be 7000100727646658300♠1.007276466583+15
−29 atomic mass units (the values in parentheses being the statistical and systematic uncertainties, respectively), which is lower than measurements from the CODATA 2014 value by three standard deviations.[18][19]

The free proton (a proton not bound to nucleons or electrons) is a stable particle that has not been observed to break down spontaneously to other particles. Free protons are found naturally in a number of situations in which energies or temperatures are high enough to separate them from electrons, for which they have some affinity. Free protons exist in plasmas in which temperatures are too high to allow them to combine with electrons. Free protons of high energy and velocity make up 90% of cosmic rays, which propagate in vacuum for interstellar distances. Free protons are emitted directly from atomic nuclei in some rare types of radioactive decay. Protons also result (along with electrons and antineutrinos) from the radioactive decay of free neutrons, which are unstable.

The spontaneous decay of free protons has never been observed, and protons are therefore considered stable particles according to the Standard Model. However, some grand unified theories (GUTs) of particle physics predict that proton decay should take place with lifetimes between 1031 to 1036 years and experimental searches have established lower bounds on the mean lifetime of a proton for various assumed decay products.[20][21][22]

Experiments at the Super-Kamiokande detector in Japan gave lower limits for proton mean lifetime of 7041208280159999999♠6.6×1033 years for decay to an antimuon and a neutral pion, and 7041258772319999999♠8.2×1033 years for decay to a positron and a neutral pion.[23] Another experiment at the Sudbury Neutrino Observatory in Canada searched for gamma rays resulting from residual nuclei resulting from the decay of a proton from oxygen-16. This experiment was designed to detect decay to any product, and established a lower limit to a proton lifetime of 7036662709600000000♠2.1×1029 years.[24]

However, protons are known to transform into neutrons through the process of electron capture (also called inverse beta decay). For free protons, this process does not occur spontaneously but only when energy is supplied. The equation is:

The process is reversible; neutrons can convert back to protons through beta decay, a common form of radioactive decay. In fact, a free neutron decays this way, with a mean lifetime of about 15 minutes.

In quantum chromodynamics, the modern theory of the nuclear force, most of the mass of protons and neutrons is explained by special relativity. The mass of a proton is about 80â€“100 times greater than the sum of the rest masses of the quarks that make it up, while the gluons have zero rest mass. The extra energy of the quarks and gluons in a region within a proton, as compared to the rest energy of the quarks alone in the QCD vacuum, accounts for almost 99% of the mass. The rest mass of a proton is, thus, the invariant mass of the system of moving quarks and gluons that make up the particle, and, in such systems, even the energy of massless particles is still measured as part of the rest mass of the system.

Two terms are used in referring to the mass of the quarks that make up protons: current quark mass refers to the mass of a quark by itself, while constituent quark mass refers to the current quark mass plus the mass of the gluon particle field surrounding the quark.[25]:285–286 [26]:150–151 These masses typically have very different values. As noted, most of a proton's mass comes from the gluons that bind the current quarks together, rather than from the quarks themselves. While gluons are inherently massless, they possess energy—to be more specific, quantum chromodynamics binding energy (QCBE)—and it is this that contributes so greatly to the overall mass of protons (see mass in special relativity). A proton has a mass of approximately 938 MeV/c2, of which the rest mass of its three valence quarks contributes only about 9.4 MeV/c2; much of the remainder can be attributed to the gluons' QCBE.[27][28][29]

The internal dynamics of protons are complicated, because they are determined by the quarks' exchanging gluons, and interacting with various vacuum condensates. Lattice QCD provides a way of calculating the mass of a proton directly from the theory to any accuracy, in principle. The most recent calculations[30][31] claim that the mass is determined to better than 4% accuracy, even to 1% accuracy (see Figure S5 in DÃ¼rr et al.[31]). These claims are still controversial, because the calculations cannot yet be done with quarks as light as they are in the real world. This means that the predictions are found by a process of extrapolation, which can introduce systematic errors.[32] It is hard to tell whether these errors are controlled properly, because the quantities that are compared to experiment are the masses of the hadrons, which are known in advance.

These recent calculations are performed by massive supercomputers, and, as noted by Boffi and Pasquini: "a detailed description of the nucleon structure is still missing because... long-distance behavior requires a nonperturbative and/or numerical treatment..."[33] More conceptual approaches to the structure of protons are: the topological soliton approach originally due to Tony Skyrme and the more accurate AdS/QCD approach that extends it to include a string theory of gluons,[34] various QCD-inspired models like the bag model and the constituent quark model, which were popular in the 1980s, and the SVZ sum rules, which allow for rough approximate mass calculations.[35] These methods do not have the same accuracy as the more brute-force lattice QCD methods, at least not yet.

The problem of defining a radius for an atomic nucleus (proton) is similar to the problem of atomic radius, in that neither atoms nor their nuclei have definite boundaries. However, the nucleus can be modeled as a sphere of positive charge for the interpretation of electron scattering experiments: because there is no definite boundary to the nucleus, the electrons "see" a range of cross-sections, for which a mean can be taken. The qualification of "rms" (for "root mean square") arises because it is the nuclear cross-section, proportional to the square of the radius, which is determining for electron scattering.

The internationally accepted value of a proton's charge radius is 6984876800000000000♠0.8768 fm (see orders of magnitude for comparison to other sizes). This value is based on measurements involving a proton and an electron (namely, electron scattering measurements and complex calculation involving scattering cross section based on Rosenbluth equation for momentum-transfer cross section), and studies of the atomic energy levels of hydrogen and deuterium.

However, in 2010 an international research team published a proton charge radius measurement via the Lamb shift in muonic hydrogen (an exotic atom made of a proton and a negatively charged muon). As a muon is 200 times heaver than an electron, its de Broglie wavelength is correspondingly shorter. This smaller atomic orbital is much more sensitive to the proton's charge radius, so allows more precise measurement. Their measurement of the root-mean-square charge radius of a proton is "6984841840000000000♠0.84184(67) fm, which differs by 5.0 standard deviations from the CODATA value of 6984876800000000000♠0.8768(69) fm".[36] In January 2013, an updated value for the charge radius of a proton—6984840870000000000♠0.84087(39) fm—was published. The precision was improved by 1.7 times, increasing the significance of the discrepancy to 7σ.[37] The 2014 CODATA adjustment slightly reduced the recommended value for the proton radius (computed using electron measurements only) to 6984875100000000000♠0.8751(61) fm, but this leaves the discrepancy at 5.6σ.

The international research team that obtained this result at the Paul Scherrer Institut in Villigen includes scientists from the Max Planck Institute of Quantum Optics, Ludwig-Maximilians-Universität, the Institut für Strahlwerkzeuge of Universität Stuttgart, and the University of Coimbra, Portugal.[38][39] The team is now attempting to explain the discrepancy, and re-examining the results of both previous high-precision measurements and complex calculations involving scattering cross section. If no errors are found in the measurements or calculations, it could be necessary to re-examine the world's most precise and best-tested fundamental theory: quantum electrodynamics.[38] The proton radius remains a puzzle as of 2017.[40] Perhaps the discrepancy is due to new physics, or the explanation may be an ordinary physics effect that has been missed.[41]

The radius is linked to the form factor and momentum transfer cross section. The atomic form factor G modifies the cross section corresponding to point-like proton.

The atomic form factor is related to the wave function density of the target:

The form factor can be split in electric and magnetic form factors. These can be further written as linear combinations of Dirac and Pauli form factors.[41]

Although protons have affinity for oppositely charged electrons, this is a relatively low-energy interaction and so free protons must lose sufficient velocity (and kinetic energy) in order to become closely associated and bound to electrons. High energy protons, in traversing ordinary matter, lose energy by collisions with atomic nuclei, and by ionization of atoms (removing electrons) until they are slowed sufficiently to be captured by the electron cloud in a normal atom.

However, in such an association with an electron, the character of the bound proton is not changed, and it remains a proton. The attraction of low-energy free protons to any electrons present in normal matter (such as the electrons in normal atoms) causes free protons to stop and to form a new chemical bond with an atom. Such a bond happens at any sufficiently "cold" temperature (i.e., comparable to temperatures at the surface of the Sun) and with any type of atom. Thus, in interaction with any type of normal (non-plasma) matter, low-velocity free protons are attracted to electrons in any atom or molecule with which they come in contact, causing the proton and molecule to combine. Such molecules are then said to be "protonated", and chemically they often, as a result, become so-called Bronsted acids.

In chemistry, the number of protons in the nucleus of an atom is known as the atomic number, which determines the chemical element to which the atom belongs. For example, the atomic number of chlorine is 17; this means that each chlorine atom has 17 protons and that all atoms with 17 protons are chlorine atoms. The chemical properties of each atom are determined by the number of (negatively charged) electrons, which for neutral atoms is equal to the number of (positive) protons so that the total charge is zero. For example, a neutral chlorine atom has 17 protons and 17 electrons, whereas a Cl− anion has 17 protons and 18 electrons for a total charge of −1.

All atoms of a given element are not necessarily identical, however, as the number of neutrons may vary to form different isotopes, and energy levels may differ forming different nuclear isomers. For example, there are two stable isotopes of chlorine: 35
17Cl with 35 − 17 = 18 neutrons and 37
17Cl with 37 − 17 = 20 neutrons.

Ross Stewart, The Proton: Application to Organic Chemistry (1985, p. 1)

In chemistry, the term proton refers to the hydrogen ion, H+. Since the atomic number of hydrogen is 1, a hydrogen ion has no electrons and corresponds to a bare nucleus, consisting of a proton (and 0 neutrons for the most abundant isotope protium 1
1H). The proton is a "bare charge" with only about 1/64,000 of the radius of a hydrogen atom, and so is extremely reactive chemically. The free proton, thus, has an extremely short lifetime in chemical systems such as liquids and it reacts immediately with the electron cloud of any available molecule. In aqueous solution, it forms the hydronium ion, H3O+, which in turn is further solvated by water molecules in clusters such as [H5O2]+ and [H9O4]+.[42]

The transfer of H+ in an acid–base reaction is usually referred to as "proton transfer". The acid is referred to as a proton donor and the base as a proton acceptor. Likewise, biochemical terms such as proton pump and proton channel refer to the movement of hydrated H+ ions.

The ion produced by removing the electron from a deuterium atom is known as a deuteron, not a proton. Likewise, removing an electron from a tritium atom produces a triton.

Also in chemistry, the term "proton NMR" refers to the observation of hydrogen-1 nuclei in (mostly organic) molecules by nuclear magnetic resonance. This method uses the spin of the proton, which has the value one-half. The name refers to examination of protons as they occur in protium (hydrogen-1 atoms) in compounds, and does not imply that free protons exist in the compound being studied.

The Apollo Lunar Surface Experiments Packages (ALSEP) determined that more than 95% of the particles in the solar wind are electrons and protons, in approximately equal numbers.[43][44]

Because the Solar Wind Spectrometer made continuous measurements, it was possible to measure how the Earth's magnetic field affects arriving solar wind particles. For about two-thirds of each orbit, the Moon is outside of the Earth's magnetic field. At these times, a typical proton density was 10 to 20 per cubic centimeter, with most protons having velocities between 400 and 650 kilometers per second. For about five days of each month, the Moon is inside the Earth's geomagnetic tail, and typically no solar wind particles were detectable. For the remainder of each lunar orbit, the Moon is in a transitional region known as the magnetosheath, where the Earth's magnetic field affects the solar wind but does not completely exclude it. In this region, the particle flux is reduced, with typical proton velocities of 250 to 450 kilometers per second. During the lunar night, the spectrometer was shielded from the solar wind by the Moon and no solar wind particles were measured.[43]

Protons also have extrasolar origin from galactic cosmic rays, where they make up about 90% of the total particle flux. These protons often have higher energy than solar wind protons, and their intensity is far more uniform and less variable than protons coming from the Sun, the production of which is heavily affected by solar proton events such as coronal mass ejections.

Research has been performed on the dose-rate effects of protons, as typically found in space travel, on human health.[44][45] To be more specific, there are hopes to identify what specific chromosomes are damaged, and to define the damage, during cancer development from proton exposure.[44] Another study looks into determining "the effects of exposure to proton irradiation on neurochemical and behavioral endpoints, including dopaminergic functioning, amphetamine-induced conditioned taste aversion learning, and spatial learning and memory as measured by the Morris water maze.[45] Electrical charging of a spacecraft due to interplanetary proton bombardment has also been proposed for study.[46] There are many more studies that pertain to space travel, including galactic cosmic rays and their possible health effects, and solar proton event exposure.

The American Biostack and Soviet Biorack space travel experiments have demonstrated the severity of molecular damage induced by heavy ions on micro organisms including Artemia cysts.[47]

CPT-symmetry puts strong constraints on the relative properties of particles and antiparticles and, therefore, is open to stringent tests. For example, the charges of a proton and antiproton must sum to exactly zero. This equality has been tested to one part in 7008100000000000000♠108. The equality of their masses has also been tested to better than one part in 7008100000000000000♠108. By holding antiprotons in a Penning trap, the equality of the charge-to-mass ratio of protons and antiprotons has been tested to one part in 7009600000000000000♠6×109.[48] The magnetic moment of antiprotons has been measured with error of 6997800000000000000♠8×10−3 nuclear Bohr magnetons, and is found to be equal and opposite to that of a proton.


who owns the gold spike in las vegas

Gold Spike (formerly Gold Spike Hotel & Casino) is a bar, lounge, residential building, and former boutique 112-room,[1] seven floor hotel. It is connected with the Oasis at the Gold Spike, a 50-room three floor hotel located in downtown Las Vegas. It was owned by entrepreneur Tony Hsieh and his Downtown Project, having bought it from The Siegel Group; and the casino was operated by Golden Gaming.

Gold Spike (property)

Hsieh closed the casino on April 14, 2013.[2] After a three-week remodel, Gold Spike re-opened the casino as a restaurant and bar on May 6, 2013. The hotel portion of the building was recently converted into permanent and temporary workforce housing for Downtown Project, entrepreneurs, and Zappos; Oasis hotel is a separate building on the same property.[3][4]

It originally opened in 1976 as the 112-room Rendezvous. In 1983 Jackie Gaughan purchased the property after it had been closed for several months.

The Gold Spike for years has been known as an inexpensive hotel with few amenities.[5]

On December 6, 2002, Gaughan agreed to sell the Gold Spike and three other casinos to Barrick Gaming.[6] This sale, along with several other downtown Las Vegas hotel/casinos, was completed in 2004, for a combined total of about $82 million.[7] Barrick Gaming Corp was in partnership with Tamares Group. After the purchase, management discontinued the table games and only offered slot machines. In a few years the property was offered for sale.[8]

On July 23, 2007, Greg Covin bought the property for $15.6 million with the intention of turning it into a boutique hotel.[9]

He sold it on February 4, 2008 for $21 million to The Siegel Group.[10]

The Siegel Group set out to completely renovate the property[11] and combine it with an old and forgotten 52-room motel located next to the property. As one author wrote, the Gold Spike now has "Quartz walls, tile floors, wood accents, and new everything", making it "a very modern boutique hotel in the heart of downtown".[12] The first floor, containing the gaming floor, the bar, and the restaurant, was completely renovated by February 2009.[1]

By April 2010, all guest floors and the exterior of the hotel has been completely remodeled and renovated. In May 2010, the Oasis Pool opened, giving Gold Spike a swimming pool.

In April 2013, it was reported that the property's debt had been acquired by Tony Hsieh's Downtown Project, a campaign to revitalize downtown Las Vegas.[13]

Siegel then announced that it had sold the Gold Spike to the Downtown Project, and that the casino would close on April 14.[2] Siegel retained rights to the Gold Spike name,[14] and said that the company needed to dispose of smaller properties on its way to owning larger casinos on the Strip.[2] Hsieh was reported to be considering several ideas for the property, including a boutique hotel, specialty retail space, or a club, but ruled out a casino, saying that he was "trying to help build a community".[14] In 2014, Gold Spike reopened the former casino area as a bar and lounge with social games. Gold Spike renovated its top floor into a penthouse suite for the thirty-first season of the MTV television series Real World, Real World: Go Big or Go Home. This suite can now be rented by the public and it is in the Gold Spike property and not The Oasis.[15]

The adjacent 3-story motel was originally built in 1962 as a 57-room Travel Inn Motel.[16] The property was abandoned, becoming a blight between the Fremont Street Experience and Las Vegas City Hall. The Siegel Group purchased this property in August 2007 for $5 million[11] and started making plans to renovate it and reopen the property. Plans were put on hold when they purchased the neighboring Gold Spike. Finally, by April 2010, the rooms had been completely renovated[17] and renamed "The Oasis at The Gold Spike"[18] and connected to the Gold Spike via an outdoor lounge and walkway.[19] After a reconfiguration of the property, it was left with 50-rooms, which have been modernized and turned into bungalow suites.[20]

The Oasis at the Gold Spike had the distinction of being the only downtown hotel with a Las Vegas Blvd. address.[21] In May 2010, the City of Las Vegas changed the entire Gold Spike property to this address.


where does the conductor sit on a train

Since nearly the beginning of railroading in North America, the conductor on freight trains rode aboard a caboose, along with the rear flagman and the rear brakeman, and performed duties from there. Advances in technology and pressure to reduce operating costs made cabooses redundant, and in most cases they have been eliminated. This relocated the conductor from the rear of the train to the locomotive (or locomotives) at the head of the train. In most cases, these same conditions gradually eliminated members of the train crew under the conductorâ€”head and rear brakemen, flagmen, and others.

Conductor (rail)

A conductor (American and Canadian English) or guard (Commonwealth English) is a train crew member responsible for operational and safety duties that do not involve actual operation of the train. The conductor title is most common in North American railway operations, but the role is common worldwide under various job titles.[citation needed] In Commonwealth English, a conductor is also known as guard or train manager.[1]

The responsibilities of a conductor in North America and of a guard in Commonwealth English typically include the following:

Some rapid transit systems employ conductors to make announcements and open and close doorsâ€”as opposed to a train operator performing those duties. The conductor often stays in the center of the train where they can best view the platform. While advances in automation allow most transit systems to use one person train operation (OPTO), a few, such as the New York City Subway, Toronto Transit Commission and Sydney Trains continue to employ conductors.

Conductor is also a crew member in some bus, trolleybus or tram operations.

In North America, the conductor manages a freight, passenger, or other types of train, and directly supervises the train crew, which can include a brakeman, flagman, ticket collector, assistant conductor, and on board service personnel. All crew members work under the conductor. The conductor, engineer, and additional engine crew members (fireman, pilot engineer) share responsibility for safe and efficient train operation and adherence to railway rules and procedures. On some railroads, union contracts specify that conductors must progress to engineer.

Other conductors duties include:

Passenger trains may employ one or more assistant conductors who assist the conductor and engineer in the safe and prompt movement of the train, to share the workload, and accept delegated responsibility. If a train crew's route, or tour of duty, exceeds a single shift, or conflicts with a legal or contractual limit on the number of work hours, more than one crew may be assigned, each with its own conductor. Onboard service crew members on passenger trains normally remain on duty for the entire run, including assigned meal and sleep breaks.

Most freight trains on most railroads today have a crew of two: one conductor and one engineer. Railroad companies continue to press for reduced operating and labor costs and this threatens to eliminate conductors. Railroads rationalize that since the engineer is already qualified as a conductor, he can easily assume the duties of a conductor. In fact, on most railroads, engineers begin as brakemen/assistant conductors, then become conductors, and finally engineers. Some railroads already implement such a strategy, notably the Montana Rail Link, and operate with an engineer, and an assistant engineer. However, most railroads are contractually obligated to employ at least one conductor in addition to the engineer, via crew consist agreements negotiated with the major rail unions, primarily the United Transportation Union (UTU). Therefore, eliminating the conductor position would require that the railroads and unions negotiate a new agreement. If the railroads were successful, conductors already trained and certified as engineers would theoretically be able to work as engineers. Those that have not yet progressed to engineer would have to be trained as engineers as positions became available. Others would have to accept other positions or possibly lose their jobs. The primary union for engineers, the Brotherhood of Locomotive Engineers does not support this movement, claiming that requiring its members to operate trains alone would be unsafe. The conductors' union, the United Transportation Union, also opposes this initiative, despite historical differences with the engineers' union.

By the late 1990s, remote control locomotives were increasingly popular on North American railroads for switching duties in rail yards. This system allows the conductor to directly control the locomotive(s) via a wireless remote unit, as opposed to radioing commands to an engineer in the cab. Some Class I Rail Yards utilize RCO packs for their conductors, while others do not, depending on the size and type of Yard. Class I Railroads train conductors on the use of RCO packs with classroom and hands-on instruction, culminating with on-the-job training and certification as a RCO operator. Currently, Class I railroads such as Norfolk Southern require RCO qualified conductors to work from job boards that perform RCO operations exclusively (when in a yard that utilizes RCO switching). This ensures the extra training and pay these conductors receive will provide the company with maximum value for the investment.

As there is no explicit Federal requirement for a two-person train crew in the United States, the Utah Transit Authority originally planned their FrontRunner service to be operated by an operator only, with revenue collected by a proof-of-payment system. Before operation began, the FRA required FrontRunner to employ a second crewmember on each train to assist with emergency evacuation, disabled access, and other safety-sensitive situations. FrontRunner classified this job as a train host, with a focus on customer service rather than railroad operations. Some other services, such as Amtrak's Downeaster, also use train hosts (paid or volunteer) to assist the conductor with non-revenue-related customer service duties.

In the UK, Australia and New Zealand, the person with ultimate responsibility for operation of a train is usually called the guard, a term that derives from stagecoach days.

Until the latter part of the 20th century, guards on passenger trains in these countries did not have routine responsibilities for ticket inspection or sale. Their jobs focused more on safe operation of their trains, timekeeping, handling parcels, and other consignments. A dedicated 'travelling ticket inspector' handled fare duties. In recent years, passenger train guards have been assigned more responsibility for on-train revenue collection and ticket inspection.

As well as ticketing and customer care, guards must be trained in "emergency protection" duties, should an emergency arise, along with other operational roles. This involves using emergency kit such as detonators, track circuit clips and flags to prevent other trains colliding with, for example a derailed train. If in a crash the driver became incapacitated, the guard is the only person left who can protect the train. Other day-to-day duties include operating the public address system and train doors.

Under British Railways, there were several grades of guard, depending on whether the guard worked on freight or passenger trainsâ€”and a purely operational guard grade worked freight and passenger trains without customer contact. When the guard has significant customer contact, the position is usually classified as conductor-guard or conductor. Since British Rail, there have been a number of titles for a guard's grade but, with a few exceptions, all now perform some sort of customer-facing role.

On long-distance expresses, the conductor's title is sometimes enhanced to senior conductor, in line with the implied prestige of operating these trains. Historically, under British Rail, long distance intercity trains were normally worked by the most senior guards at the depot, hence the name senior conductor. Several more recent private UK passenger train operators have further renamed the senior conductor's passenger facing title to "train manager".

In the UK, technological improvements and economic pressure have made some trains lose their guards and become driver-only operated (DOO). British Rail first brought this in on some commuter services in London and Glasgow, as well as on almost all non-passenger trains. In 2003, a controversial amendment to the UK operational rule book moved part of the guard's safety and operational role to the driver. With rail service privatisation, train operating companies (TOC) attempted to bring in DOO to other network areasâ€”c2c operating from London Fenchurch Street is an example of this. Pressure after several fatal train crashes[citation needed] reversed this trend to the point that some TOCs have restored guards to services previously stripped of them, First Great Western did this to certain services it acquired when it took over operation of Thames Trains.[citation needed] Currently, several titles describe a guard: train manager, train host, conductor, and South West Trains and Merseyrail still use the term guard. The role of the guard is set out by a mixture of the Railway Rule Book and train operating companies.

In Australia, there is today a mixture of driver-only operated trains and trains with a guard depending largely on state-based railway legislation.

All passenger trains in New South Wales operate with a driver and guard. Guards were removed from freight trains in the 1980s, but these still operate with a two-man locomotive crew.

Sydney Trains—which operates all metropolitan trains—and NSW TrainLink intercity trains have a train guard. The guard is ultimately responsible for the safety of all passengers on the train. They control the operation of doors and Public Address, perform platform duties, provide basic customer service, operate the train to timetable and accept and deliver internal mail. On Sydney Trains, the guard is normally located in the middle of the train, but on the newer Waratah trains, and on NSW TrainLink intercity services they normally work from the rear. The guard is not responsible for inspecting tickets - this role is performed by Transport Officers and NSW Police.

On NSW TrainLink regional Xplorer and XPT services the train guard is known as a Passenger Service Supervisor (PSS). While still responsible for the safety of passengers, the PSS is also in charge of delivering customer service and a number of value-add functions on the train including ticket inspections and manning the cafe alongside Passenger Attendants. On Xplorer trains, the driver operates the doors when the PSS gives clearance to depart. On XPT trains, the PSS performs the platform duties of a guard in conjunction with the driver.

Passenger trains are operated by Queensland Rail, and all operate with both driver and guard for suburban passenger services, or Passenger Services Supervisor for long distance passenger services.

Trains in metropolitan Melbourne have been driver-only since the early 1990s. When the city's rail franchise was offered to the current operator, Metro Trains Melbourne, a proposal existed to reinstate guards on some peak train services, however this option was spurned in favour of hiring additional platform staff.

Regional trains operated by V/Line are operated by a driver and conductor. The conductor performs platform duties and—on locomotive-hauled trains—operates the train doors. They are responsible for passenger safety and also perform ticket inspection duties.

Adelaide Metro's metropolitan rail network is configured for driver-only operation, but also operate with Passenger Service Assistants (PSA). This is safety role, but with a focus on customer service and revenue protection. Normally, the train driver operates the doors, but PSAs are also able to.

TransPerth trains are all driver-only operated.

In New Zealand, inner-city commuter rail networks are staffed by a driver and a train manager (guard) as a minimum.

In Wellington, where ticketing is still paper-based, each train has between one and three passenger operators (ticket collectors). The exact number of passenger operators depends on how many multiple units or carriages make up the train. In Auckland, off-board ticketing and smartcard systems have reduced the staff level to driver and train manager only. Auckland train managers are now not responsible for revenue on trains, as Revenue Protection officers carry out these roles.

In general, conductors in Switzerland collect or punch tickets, fine people the first charge of 100 CHF for not having a valid fare, and make announcements on the public address system. They also may fine passengers if they take a longer trip than normal. For example, if one takes a train to Bern via Biel, having departed from Geneva, which is a longer trip than taking the InterCity via Lausanne, the conductor can fine the passenger a supplementary fare. They sound a warning when the train's doors are going to close. Many conductors, especially those on night shift and on isolated regional lines, are being trained in self-defence against would-be assailants.

In Belgium and The Netherlands, train conductors have multiple tasks involving train safety and customer services. Belgian/Dutch train conductors are responsible for the departure of the train. In each station they give the permission to move on by giving a ready signal to the train driver. Therefore, train conductors in Belgium and The Netherlands always close (and in some scenarios also open) the doors. They are also responsible for performing safety tasks in case of an emergency or accident, such as fire, evacuation, etc. Because of these tasks, there has to be at least one conductor on each passenger train; a train without a conductor is uncommon, but still appears on some regional Dutch trains. The departure trains always have one conductor who is conductor-in-chief. He is responsible for the entire train, the on-board crew and the passengers. Some longer trains may have additional conductors who are under command of the conductor-in-chief. Besides the safety tasks, conductors also collect and punch tickets, fine people for not having a valid fare and make announcements to the passengers.

In Hungary a conductor may assist the train driver in testing the train's air brakes, and sometimes they have to lead the shunting, mostly when the trains are switching lines. Hungarian train conductors are responsible for the departure of the trains. In each station they give the permission to move on by giving a ready signal to the train driver. During the day they use a disc (which is white and has a green border) to give the ready signal to the train driver.

After sunset they give signals with flashlights. Train drivers are not allowed to move the train without the conductor in chief giving them the ready signal. Conductors, along with train drivers, are responsible for keeping the trains on schedule. There is always at least one conductor in chief on passenger trains in Hungary. No passenger trains may depart without one, as only they have the right to give the departure signal.

Some longer trains may have additional conductors who are under the command of the conductor in chief. If there is more than one conductor on a train, then the signal procedure is as follows:

After all passengers have left or entered the train and the departure time has arrived, the conductor in chief asks the other conductor for his ready signal. If it is safe to depart he gives a ready signal to the conductor in chief who then gives the same signal to the train driver.

As in Belgium and in the Netherlands conductors also collect and punch tickets, fine people for not having a valid fare and make announcements to the passengers. They also sell tickets on the trains; if the passengers have entered the train at a station where a ticket office is operating they can buy a ticket only with payment of a fine. However, if the passengers got on at a station or stop where they didn't have an option to buy a ticket, they can buy from the conductor without having to pay a fine.

In India guards are posted on all passenger trains and goods trains and no passenger-carrying train is allowed to move without a guard. The passenger train guard, generally called a mail guard, is completely responsible for the train, its schedule, and safety of passengers and the locomotive pilot. These guards wear a specific uniform (generally white).

During the day, the guard uses the traditional green flag to signal the pilot to depart, and the red flag to stop, assisted by two-way radios. After sunset, the guard uses lamp signals in place of the flags. A couple of minutes before signalling departure to the pilot, the guard blows a whistle to warn passengers to board the train. After ensuring all passengers are safe to travel, the guard signals the green flag by waving it from the brake van. In an emergency, the guard uses the red flag to indicate a stop, and may directly apply brakes to stop the train. The pilot is not allowed to move the train without a signal from the guard, as the guard is in charge of the train.

Passenger guards also accept heavy parcels and luggage boxes that passengers cannot carry in coaches. Some perishable goods like vegetables and milk are also transported under the guard's supervision, and he is responsible for their proper loading and unloading.

Keeping the passenger train on schedule is an important guard function. Guards carry a first aid box with their belongings, along with other important items, all in a medium-sized duty box (generally painted red). The name, designation and base location of the Guard are printed in white on the box. A designated passenger train, halting at all stations, carries a large heavy cast iron cash safe in the guard's brake van, where cash receipts from ticket sales is deposited in a leather pouch by the station manager (earlier called the station master). Since the late 1990s, all guards are provided with two-way radios so that they can communicate with the locomotive pilot, and other trains if required. The radio has not yet replaced the traditional red and green flags.

Many antique or heritage trams (streetcars), which operated through the earlier part of the 20th century, were designed for operation by a crew of two or more. The conductor primarily collected fares and signaled the driver when safe to depart from stopping places. The conductor also assisted with shunting when necessary, changing the trolley pole and attended to passengers' needs.

Modern vehicle design and ticketing arrangements have largely eliminated the need for conductors on street railways and Light Rail systems. In recent years a number of modern tram or Light Rail systems have introduced (or re-introduced) conductors to minimise fare evasion and to provide customer care, supervision and security functions, even in situations where a second crew member is not strictly needed.

In Britain, The Midland Metro and Sheffield Supertram modern Light Rail systems have both started using conductors due to problems with ticket machine reliability. Nottingham Express Transit started with conductors. Manchester Metrolink and Croydon Tramlink both rely on ticket machines at stops.

Systems of ticket checking and selling by a conductor:

Modern mass transit systems which operate with conductors on trams include:-


who sang don't rain on my parade first

"Don't Rain on My Parade" is a popular song from the 1964 musical Funny Girl. It was also featured in the 1968 movie version of the musical. The song was written by Bob Merrill and Jule Styne. Both the movie and stage versions feature Barbra Streisand performing the song. In 2004 it finished No. 46 in AFI's 100 Years...100 Songs survey of top tunes in American cinema.

Don't Rain on My Parade

Streisand has sung the song live on many occasions, including during her comeback tour Barbra Streisand: The Concert Tour (1993–1994), Timeless Live In Concert Tour (1999–2000), Streisand: The Tour (2006–2007) and the Barbra: The Music, The Mem'ries, The Magic (2016). The instrumental of this song can be heard during the Overture of the stage show, the film and on Streisand's 2006–2007 Tour.

There is a reprise version of this song with alternate lyrics which served as the finale for the stage show. This number was cut from the film. Streisand sang this version live for the first time since her run in the original Broadway production as an encore during her 2006â€“07 Tour.

American singer Bobby Darin[1][better source needed] performed a version of "Don't Rain on My Parade" on the 1965 album In a Broadway Bag[2][better source needed].

The song was covered by many artists, among the notable ones are Nancy Wilson in 1964, Bobby Darin in 1966, Shirley Bassey in 1965 and by Only Men Aloud! in 2008. The Bobby Darin version was used in the film American Beauty and the trailer for Catch Me If You Can.

The song was covered by Diana Ross and The Supremes on their 1968 album "Sing and Perform Funny Girl".

Robin Williams also sang this song while dressed as Streisand during a scene from Mrs. Doubtfire.

LaToya London sang the song on the third season of American Idol. Judy Garland, Liza Minnelli, Diana Ross and Donna Summer also sang this song live.

Lois Griffin sang parts of this song in Family Guy episode "Mind Over Murder".

The song was performed by Connie and Carla (Toni Collette and Nia Vardalos) in the movie Connie and Carla.

Tony Award Winner Idina Menzel also sings this song in the Kennedy Honors concert dedicated for original singer Barbra Streisand.

In the TV series Glee, Rachel Berry (played by actress Lea Michele) covered the song on the season one episode entitled Sectionals, and Santana Lopez (played by actress Naya Rivera) covered the song on the season five episode entitled Frenemies. The song was also released on the albums Glee: The Music, Volume 2, Glee: The Music, The Complete Season One, and Glee: The 3D Concert Movie Motion Picture Soundtrack

Lea Michele performed the song at the 2010 Tony Awards.

The Dorothys on Over the Rainbow, the TV show in which Andrew Lloyd Webber chooses a Dorothy for the west end production, also sing this song as a group number.

Mireille Mathieu sang this song on her 2006 Films and Shows album. It was also featured in the TV show God, the Devil and Bob.

British art rock Japan covered the song on their 1978 debut album Adolescent Sex, and released it as their debut single the same year.

It was also used in the BBC sitcom Beautiful People.

International champion barbershop quartet Max Q covered it on their 2009 album, Journey.

It was covered by WÃ© McDonald in the season finale of the Voice season 11.

January 13, 2017, the American Pops Orchestra presents “Don’t Rain on My Parade: 75 Years of Streisand”celebrating her 75th birthday. Hosted by Fran Drescher, featuring a parade of special Broadway guests, including Amber Iman, Lindsay Mendez, Will & Anthony Nunziata, Laura Osnes.