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82-576: The Arctic World Archive ( AWA ) is a facility for data preservation , located in the Svalbard archipelago on the island of Spitsbergen , Norway, not far from the Svalbard Global Seed Vault . It contains data of historical and cultural interest from several countries, as well as all of American multinational company GitHub 's open source code, in a deeply buried steel vault, with the data storage medium expected to last for 500 to 1,000 years. It

164-414: A core surrounded by a cladding layer, both of which are made of dielectric materials. To confine the optical signal in the core, the refractive index of the core must be greater than that of the cladding. The boundary between the core and cladding may either be abrupt, in step-index fiber , or gradual, in graded-index fiber . Light can be fed into optical fibers using lasers or LEDs . Fiber

246-411: A wavelength shifter collect scintillation light in physics experiments . Fiber-optic sights for handguns, rifles, and shotguns use pieces of optical fiber to improve the visibility of markings on the sight. An optical fiber is a cylindrical dielectric waveguide ( nonconducting waveguide) that transmits light along its axis through the process of total internal reflection. The fiber consists of

328-426: A 16,000-kilometer distance, means that there is a minimum delay of 80 milliseconds (about 1 12 {\displaystyle {\tfrac {1}{12}}} of a second) between when one caller speaks and the other hears. When light traveling in an optically dense medium hits a boundary at a steep angle of incidence (larger than the critical angle for the boundary), the light is completely reflected. This

410-423: A cladding made of pure silica, with an index of 1.444 at 1500 nm, and a core of doped silica with an index around 1.4475. The larger the index of refraction, the slower light travels in that medium. From this information, a simple rule of thumb is that a signal using optical fiber for communication will travel at around 200,000 kilometers per second. Thus a phone call carried by fiber between Sydney and New York,

492-659: A collection or back-up of personal files. Data holdings are generally the storage methods used in the past when data has been lost due to environmental and other historical disasters. Furthermore, data retention differs from data preservation in the sense that by definition, to retain an object (data) is to hold or keep possession or use of the object. To preserve an object is to protect, maintain and keep up for future use. Retention policies often circle around when data should be deleted on purpose as well, and held from public access, while preservation prioritizes permanence and more widely-shared access. Thus, data preservation exceeds

574-447: A digital audio optical connection. This allows the streaming of audio over light, using the S/PDIF protocol over an optical TOSLINK connection. Fibers have many uses in remote sensing . In some applications, the fiber itself is the sensor (the fibers channel optical light to a processing device that analyzes changes in the light's characteristics). In other cases, fiber is used to connect

656-522: A lasting impact on structures . It is based on the principle of measuring analog attenuation. In spectroscopy , optical fiber bundles transmit light from a spectrometer to a substance that cannot be placed inside the spectrometer itself, in order to analyze its composition. A spectrometer analyzes substances by bouncing light off and through them. By using fibers, a spectrometer can be used to study objects remotely. An optical fiber doped with certain rare-earth elements such as erbium can be used as

738-423: A network in an office building (see fiber to the office ), fiber-optic cabling can save space in cable ducts. This is because a single fiber can carry much more data than electrical cables such as standard category 5 cable , which typically runs at 100 Mbit/s or 1 Gbit/s speeds. Fibers are often also used for short-distance connections between devices. For example, most high-definition televisions offer

820-474: A sensor to a measurement system. Optical fibers can be used as sensors to measure strain , temperature , pressure , and other quantities by modifying a fiber so that the property being measured modulates the intensity , phase , polarization , wavelength , or transit time of light in the fiber. Sensors that vary the intensity of light are the simplest since only a simple source and detector are required. A particularly useful feature of such fiber optic sensors

902-463: A set of rules or attributes that contribute to its trust such as having persistent financial responsibility, organizational buoyancy, administrative responsibility security and safety. An example of a trusted digital repository is The Digital Repository of Ireland (DRI) which is a multi-site repository that hosts Ireland's humanity and social science data sets. Cyber infrastructures which consists of archive collections which are made available through

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984-567: A single site. An example of a major single-site repository the Data Archiving and Networking Services which is a repository which provides ongoing access to digital research resources for the Netherlands. Multi-Site Repositories A repository that hosts data set on multiple institutional sites. An example of a well known multi-site repository is OpenAIRE which is a repository that hosts research data and publications collaborating all of

1066-649: A target without a clear line-of-sight path. Many microscopes use fiber-optic light sources to provide intense illumination of samples being studied. Optical fiber is also used in imaging optics. A coherent bundle of fibers is used, sometimes along with lenses, for a long, thin imaging device called an endoscope , which is used to view objects through a small hole. Medical endoscopes are used for minimally invasive exploratory or surgical procedures. Industrial endoscopes (see fiberscope or borescope ) are used for inspecting anything hard to reach, such as jet engine interiors. In some buildings, optical fibers route sunlight from

1148-520: A transparent cladding. Later that same year, Harold Hopkins and Narinder Singh Kapany at Imperial College in London succeeded in making image-transmitting bundles with over 10,000 fibers, and subsequently achieved image transmission through a 75 cm long bundle which combined several thousand fibers. The first practical fiber optic semi-flexible gastroscope was patented by Basil Hirschowitz , C. Wilbur Peters, and Lawrence E. Curtiss, researchers at

1230-419: A wide range of historical and cultural data. Governments, researchers, religious institutions , media companies and others store some of their most significant records in the vault; Brazil and Norway have archived their constitutions and other important historical papers. The archive includes information about the biodiversity of Australia, and examples of culturally significant Australian works. It includes

1312-468: Is a mechanical splice , where the ends of the fibers are held in contact by mechanical force. Temporary or semi-permanent connections are made by means of specialized optical fiber connectors . The field of applied science and engineering concerned with the design and application of optical fibers is known as fiber optics . The term was coined by Indian-American physicist Narinder Singh Kapany . Daniel Colladon and Jacques Babinet first demonstrated

1394-591: Is a flexible glass or plastic fiber that can transmit light from one end to the other. Such fibers find wide usage in fiber-optic communications , where they permit transmission over longer distances and at higher bandwidths (data transfer rates) than electrical cables. Fibers are used instead of metal wires because signals travel along them with less loss and are immune to electromagnetic interference . Fibers are also used for illumination and imaging, and are often wrapped in bundles so they may be used to carry light into, or images out of confined spaces, as in

1476-453: Is a way of measuring the speed of light in a material. Light travels fastest in a vacuum , such as in outer space. The speed of light in vacuum is about 300,000 kilometers (186,000 miles) per second. The refractive index of a medium is calculated by dividing the speed of light in vacuum by the speed of light in that medium. The refractive index of vacuum is therefore 1, by definition. A typical single-mode fiber used for telecommunications has

1558-411: Is bent towards the perpendicular ... When the ray passes from water to air it is bent from the perpendicular... If the angle which the ray in water encloses with the perpendicular to the surface be greater than 48 degrees, the ray will not quit the water at all: it will be totally reflected at the surface... The angle which marks the limit where total reflection begins is called the limiting angle of

1640-412: Is called multi-mode fiber , from the electromagnetic analysis (see below). In a step-index multi-mode fiber, rays of light are guided along the fiber core by total internal reflection. Rays that meet the core-cladding boundary at an angle (measured relative to a line normal to the boundary) greater than the critical angle for this boundary, are completely reflected. The critical angle is determined by

1722-418: Is called total internal reflection . This effect is used in optical fibers to confine light in the core. Most modern optical fiber is weakly guiding , meaning that the difference in refractive index between the core and the cladding is very small (typically less than 1%). Light travels through the fiber core, bouncing back and forth off the boundary between the core and cladding. Because the light must strike

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1804-507: Is designed for use in the near infrared . Multi-mode fiber, by comparison, is manufactured with core diameters as small as 50 micrometers and as large as hundreds of micrometers. Some special-purpose optical fiber is constructed with a non-cylindrical core or cladding layer, usually with an elliptical or rectangular cross-section. These include polarization-maintaining fiber used in fiber optic sensors and fiber designed to suppress whispering gallery mode propagation. Photonic-crystal fiber

1886-559: Is far less than in electrical copper cables, leading to long-haul fiber connections with repeater distances of 70–150 kilometers (43–93 mi). Two teams, led by David N. Payne of the University of Southampton and Emmanuel Desurvire at Bell Labs , developed the erbium-doped fiber amplifier , which reduced the cost of long-distance fiber systems by reducing or eliminating optical-electrical-optical repeaters, in 1986 and 1987 respectively. The emerging field of photonic crystals led to

1968-564: Is immune to electrical interference as there is no cross-talk between signals in different cables and no pickup of environmental noise. Information traveling inside the optical fiber is even immune to electromagnetic pulses generated by nuclear devices. Fiber cables do not conduct electricity, which makes fiber useful for protecting communications equipment in high voltage environments such as power generation facilities or applications prone to lightning strikes. The electrical isolation also prevents problems with ground loops . Because there

2050-418: Is important in fiber optic communication. This is more complex than joining electrical wire or cable and involves careful cleaving of the fibers, precise alignment of the fiber cores, and the coupling of these aligned cores. For applications that demand a permanent connection a fusion splice is common. In this technique, an electric arc is used to melt the ends of the fibers together. Another common technique

2132-611: Is kept in the core by the phenomenon of total internal reflection which causes the fiber to act as a waveguide . Fibers that support many propagation paths or transverse modes are called multi-mode fibers , while those that support a single mode are called single-mode fibers (SMF). Multi-mode fibers generally have a wider core diameter and are used for short-distance communication links and for applications where high power must be transmitted. Single-mode fibers are used for most communication links longer than 1,050 meters (3,440 ft). Being able to join optical fibers with low loss

2214-405: Is made with a regular pattern of index variation (often in the form of cylindrical holes that run along the length of the fiber). Such fiber uses diffraction effects instead of or in addition to total internal reflection, to confine light to the fiber's core. The properties of the fiber can be tailored to a wide variety of applications. Attenuation in fiber optics, also known as transmission loss,

2296-412: Is monitored and analyzed for disturbances. This return signal is digitally processed to detect disturbances and trip an alarm if an intrusion has occurred. Optical fibers are widely used as components of optical chemical sensors and optical biosensors . Optical fiber can be used to transmit power using a photovoltaic cell to convert the light into electricity. While this method of power transmission

2378-439: Is no electricity in optical cables that could potentially generate sparks, they can be used in environments where explosive fumes are present. Wiretapping (in this case, fiber tapping ) is more difficult compared to electrical connections. Fiber cables are not targeted for metal theft . In contrast, copper cable systems use large amounts of copper and have been targeted since the 2000s commodities boom . The refractive index

2460-478: Is not as efficient as conventional ones, it is especially useful in situations where it is desirable not to have a metallic conductor as in the case of use near MRI machines, which produce strong magnetic fields. Other examples are for powering electronics in high-powered antenna elements and measurement devices used in high-voltage transmission equipment. Optical fibers are used as light guides in medical and other applications where bright light needs to be shone on

2542-487: Is run as a profit-making business by private company Piql and the state-owned coal-mining company Store Norske Spitsbergen Kulkompani (SNSK). Piql is a Norwegian data-storage company that specialises in long-term storage of digital media . Piql and SNSK created the deeply buried steel vault out of a mineshaft of an abandoned coal mine . At the time of its opening as the Arctic World Archive on 27 March 2017,

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2624-418: Is that they can, if required, provide distributed sensing over distances of up to one meter. Distributed acoustic sensing is one example of this. In contrast, highly localized measurements can be provided by integrating miniaturized sensing elements with the tip of the fiber. These can be implemented by various micro- and nanofabrication technologies, such that they do not exceed the microscopic boundary of

2706-422: Is the numerical aperture (NA) of the fiber. Fiber with a larger NA requires less precision to splice and work with than fiber with a smaller NA. The size of this acceptance cone is a function of the refractive index difference between the fiber's core and cladding. Single-mode fiber has a small NA. Fiber with large core diameter (greater than 10 micrometers) may be analyzed by geometrical optics . Such fiber

2788-474: Is the measurement of temperature inside jet engines by using a fiber to transmit radiation into a pyrometer outside the engine. Extrinsic sensors can be used in the same way to measure the internal temperature of electrical transformers , where the extreme electromagnetic fields present make other measurement techniques impossible. Extrinsic sensors measure vibration, rotation, displacement, velocity, acceleration, torque, and torsion. A solid-state version of

2870-428: Is the reduction in the intensity of the light signal as it travels through the transmission medium. Attenuation coefficients in fiber optics are usually expressed in units of dB/km. The medium is usually a fiber of silica glass that confines the incident light beam within. Attenuation is an important factor limiting the transmission of a digital signal across large distances. Thus, much research has gone into both limiting

2952-484: Is typical in deployed systems. Through the use of wavelength-division multiplexing (WDM), each fiber can carry many independent channels, each using a different wavelength of light. The net data rate (data rate without overhead bytes) per fiber is the per-channel data rate reduced by the forward error correction (FEC) overhead, multiplied by the number of channels (usually up to 80 in commercial dense WDM systems as of 2008 ). For short-distance applications, such as

3034-402: Is used as a medium for telecommunication and computer networking because it is flexible and can be bundled as cables. It is especially advantageous for long-distance communications, because infrared light propagates through the fiber with much lower attenuation compared to electricity in electrical cables. This allows long distances to be spanned with few repeaters . 10 or 40 Gbit/s

3116-696: Is vast. Everything from governmental to business records to art essentially can be represented as data, and is amenable to be lost. This then leads to loss of human history, for perpetuity. Data can be lost on a small or independent scale whether it's personal data loss, or data loss within businesses and organizations, as well as on a larger or national or global scale which can negatively and potentially permanently affect things such as environmental protection, medical research, homeland security, public health and safety, economic development and culture. The mechanisms of data loss are also as many as they are varied, spanning from disaster, wars, data breaches, negligence, all

3198-507: The Atlas of Living Australia , and machine learning models created by Geoscience Australia , which assist in understanding topics such as bushfires and climate change . The archive includes a digitised version of the painting The Scream by Edvard Munch for the National Museum of Norway , and a digitised version of Dante 's master-work of Italian literature, The Divine Comedy for

3280-462: The University of Michigan , in 1956. In the process of developing the gastroscope, Curtiss produced the first glass-clad fibers; previous optical fibers had relied on air or impractical oils and waxes as the low-index cladding material. Kapany coined the term fiber optics after writing a 1960 article in Scientific American that introduced the topic to a wide audience. He subsequently wrote

3362-673: The Vatican Library . In March 2018, German science TV show Galileo deposited their first show, and made a documentary about it for ProSieben . In October 2020, the first deposit from a Nobel Prize laureate went to the Archive: 14 books of the 2018 Nobel Prize in Literature winner, Olga Tokarczuk , were placed on PiqlFilm , undertaken by the Piql Polska and funded by publisher Wydawnictwo Literackie . In November 2019, GitHub (which

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3444-405: The gain medium of a fiber laser or optical amplifier . Rare-earth-doped optical fibers can be used to provide signal amplification by splicing a short section of doped fiber into a regular (undoped) optical fiber line. The doped fiber is optically pumped with a second laser wavelength that is coupled into the line in addition to the signal wave. Both wavelengths of light are transmitted through

3526-515: The "Tech Tree" details software development , programming languages and other information about computer programming . The Guide and the Tech Tree are written in a collaborative process as a public Git repository. Data preservation Most historical data collected over time has been lost or destroyed. War and natural disasters combined with the lack of materials and necessary practices to preserve and protect data has caused this. Usually, only

3608-762: The 1950s, which were usually flat or hierarchically structured. While there were still issues with these solutions, it made storing data much cheaper, and more easily accessible. In the 1970s relational databases as well as spreadsheets appeared. Relational data bases structure data into tables using structured query languages which made them more efficient than the preceding storage solutions, and spreadsheets hold high volumes of numeric data which can be applied to these relational databases to produce derivative data. More recently, non-relational ( non-structured query language ) databases have appeared as complements to relational databases which hold high volumes of unstructured or semi-structured data . The scope of data preservation

3690-456: The 200 platters of data carry 120 gigabytes ). The amount of code stored has been described thus: "If someone who types at about 60 words a minute sat down and tried to fill up all that space, it would take 111,300 years". The first reel holds the code of both the Linux and Android operating systems , plus that of 6,000 other major open source applications. Further to the general guide to the vault,

3772-578: The Brazilian, Mexican and Norwegian governments deposited copies of various historical documents in the vault. The Svalbard archipelago , situated north of mainland Norway , about 970 kilometres (600 mi) from the North Pole , is declared demilitarised by 42 nations, as established in the Svalbard Treaty signed after World War I . This means that the territory cannot be used for military purposes, and

3854-503: The EU countries and more. OpenAIRE promotes open scholarship and seeks to improves discover-ability and re-usability of data. Trusted Digital Repository A repository that seeks to provide reliable, trusted access over a long period of time. The repository can be single or multi-sited but must cooperate with the Reference Model for an Open Archival Information System, as well as adhere to

3936-553: The attenuation in fibers available at the time was caused by impurities that could be removed, rather than by fundamental physical effects such as scattering. They correctly and systematically theorized the light-loss properties for optical fiber and pointed out the right material to use for such fibers— silica glass with high purity. This discovery earned Kao the Nobel Prize in Physics in 2009. The crucial attenuation limit of 20 dB/km

4018-416: The boundary with an angle greater than the critical angle, only light that enters the fiber within a certain range of angles can travel down the fiber without leaking out. This range of angles is called the acceptance cone of the fiber. There is a maximum angle from the fiber axis at which light may enter the fiber so that it will propagate, or travel, in the core of the fiber. The sine of this maximum angle

4100-452: The cameras had to be supervised by someone with an appropriate security clearance. Charles K. Kao and George A. Hockham of the British company Standard Telephones and Cables (STC) were the first to promote the idea that the attenuation in optical fibers could be reduced below 20 decibels per kilometer (dB/km), making fibers a practical communication medium, in 1965. They proposed that

4182-416: The case of a fiberscope . Specially designed fibers are also used for a variety of other applications, such as fiber optic sensors and fiber lasers . Glass optical fibers are typically made by drawing , while plastic fibers can be made either by drawing or by extrusion . Optical fibers typically include a core surrounded by a transparent cladding material with a lower index of refraction . Light

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4264-473: The company describes the location as "one of the most geopolitically secure places in the world". The archive facility is on Spitsbergen, the biggest island in Svalbard. The facility is a large steel vault located somewhere between 150 metres (490 ft) and 300 metres (980 ft) below the ground or permafrost inside an abandoned coal mine (Store Norske Gruve 3) that reaches over 300 metres (980 ft) into

4346-489: The concept of having or possessing data or back up copies of data. Data preservation ensures reliable access to data by including back-up and recovery mechanisms that precede the event of a disaster or technological change. Digital preservation , is similar to data preservation, but is mainly concerned with technological threats, and solely digital data. Essentially digital data is a set of formal activities to enable ongoing or persistent use and access of digital data exceeding

4428-407: The core-cladding boundary. The resulting curved paths reduce multi-path dispersion because high-angle rays pass more through the lower-index periphery of the core, rather than the high-index center. The index profile is chosen to minimize the difference in axial propagation speeds of the various rays in the fiber. This ideal index profile is very close to a parabolic relationship between the index and

4510-479: The data is not presented on the site, but instead might act as metadata and aggregators, and may administer thorough inventories. Repositories are places where data archives and holdings can be accessed and stored. The goal of repositories is to make sure that all requirements and protocols of archives and holdings are being met, and data is being certified to ensure data integrity and user trust. Single-site Repositories A repository that holds all data sets on

4592-445: The data represents the "cold layer" of archiving. The "hot" (accessible online repositories ) and "warm" (e.g. Internet Archive ) layers both have the weakness of being founded upon electronics  – both would be wiped out in a repeat of the 19th-century geomagnetic storm known as the " Carrington Event ". It is an incomplete but more secure snapshot of data, with archiving intended at five-year intervals. Realising that people in

4674-442: The development in 1991 of photonic-crystal fiber , which guides light by diffraction from a periodic structure, rather than by total internal reflection. The first photonic crystal fibers became commercially available in 2000. Photonic crystal fibers can carry higher power than conventional fibers and their wavelength-dependent properties can be manipulated to improve performance. These fibers can have hollow cores. Optical fiber

4756-467: The difference in the index of refraction between the core and cladding materials. Rays that meet the boundary at a low angle are refracted from the core into the cladding where they terminate. The critical angle determines the acceptance angle of the fiber, often reported as a numerical aperture . A high numerical aperture allows light to propagate down the fiber in rays both close to the axis and at various angles, allowing efficient coupling of light into

4838-445: The distance from the axis. Fiber with a core diameter less than about ten times the wavelength of the propagating light cannot be modeled using geometric optics. Instead, it must be analyzed as an electromagnetic waveguide structure, according to Maxwell's equations as reduced to the electromagnetic wave equation . As an optical waveguide, the fiber supports one or more confined transverse modes by which light can propagate along

4920-621: The doped fiber, which transfers energy from the second pump wavelength to the signal wave. The process that causes the amplification is stimulated emission . Optical fiber is also widely exploited as a nonlinear medium. The glass medium supports a host of nonlinear optical interactions, and the long interaction lengths possible in fiber facilitate a variety of phenomena, which are harnessed for applications and fundamental investigation. Conversely, fiber nonlinearity can have deleterious effects on optical signals, and measures are often required to minimize such unwanted effects. Optical fibers doped with

5002-424: The fiber tip, allowing for such applications as insertion into blood vessels via hypodermic needle. Extrinsic fiber optic sensors use an optical fiber cable , normally a multi-mode one, to transmit modulated light from either a non-fiber optical sensor—or an electronic sensor connected to an optical transmitter. A major benefit of extrinsic sensors is their ability to reach otherwise inaccessible places. An example

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5084-404: The fiber. Fiber supporting only one mode is called single-mode . The waveguide analysis shows that the light energy in the fiber is not completely confined in the core. Instead, especially in single-mode fibers, a significant fraction of the energy in the bound mode travels in the cladding as an evanescent wave . The most common type of single-mode fiber has a core diameter of 8–10 micrometers and

5166-438: The fiber. However, this high numerical aperture increases the amount of dispersion as rays at different angles have different path lengths and therefore take different amounts of time to traverse the fiber. In graded-index fiber, the index of refraction in the core decreases continuously between the axis and the cladding. This causes light rays to bend smoothly as they approach the cladding, rather than reflecting abruptly from

5248-490: The first book about the new field. The first working fiber-optic data transmission system was demonstrated by German physicist Manfred Börner at Telefunken Research Labs in Ulm in 1965, followed by the first patent application for this technology in 1966. In 1968, NASA used fiber optics in the television cameras that were sent to the moon. At the time, the use in the cameras was classified confidential , and employees handling

5330-502: The guiding of light by refraction, the principle that makes fiber optics possible, in Paris in the early 1840s. John Tyndall included a demonstration of it in his public lectures in London , 12 years later. Tyndall also wrote about the property of total internal reflection in an introductory book about the nature of light in 1870: When the light passes from air into water, the refracted ray

5412-465: The gyroscope, using the interference of light, has been developed. The fiber optic gyroscope (FOG) has no moving parts and exploits the Sagnac effect to detect mechanical rotation. Common uses for fiber optic sensors include advanced intrusion detection security systems . The light is transmitted along a fiber optic sensor cable placed on a fence, pipeline, or communication cabling, and the returned signal

5494-413: The medium. For water this angle is 48°27′, for flint glass it is 38°41′, while for a diamond it is 23°42′. In the late 19th century, a team of Viennese doctors guided light through bent glass rods to illuminate body cavities. Practical applications such as close internal illumination during dentistry followed, early in the twentieth century. Image transmission through tubes was demonstrated independently by

5576-543: The most important data sets were saved, such as government records and statistics, legal contracts and economic transactions. Scientific research and doctoral theses data have mostly been destroyed from improper storage and lack of data preservation awareness and execution. Over time, data preservation has evolved and has generated importance and awareness. We now have many different ways to preserve data and many different important organizations involved in doing so. The first digital data preservation storage solutions appeared in

5658-405: The occurrence of technological malfunction or change. Digital preservation is aware of the inevitable change in technology and protocols, and prepares for data that will need to be accessible across new types of technologies and platforms while the integrity of the data and metadata are being conserved. Technology, while providing great process in conserving data that may not have been possible in

5740-479: The past, is also changing at such a quick rate that digital data may not be accessible anymore due to the format being incompatible with new software. Without the use of data preservation much of our existing digital data is at risk. The majority of methods used towards data preservation today are digital methods, which are so far the most effective methods that exist. Archives are a collection of historical documents and records. Archives contribute and work towards

5822-474: The preservation of data by collecting data that is well organized, while providing the appropriate metadata to confirm it. An example of an important data archive is The LONI Image Data Archive, which is an archive that collects data regarding clinical trials and clinical research studies. Catalogues, directories and portals are consolidated resources which are kept by individual institutions, and are associated with data archives and holdings. In other words,

5904-416: The radio experimenter Clarence Hansell and the television pioneer John Logie Baird in the 1920s. In the 1930s, Heinrich Lamm showed that one could transmit images through a bundle of unclad optical fibers and used it for internal medical examinations, but his work was largely forgotten. In 1953, Dutch scientist Bram van Heel first demonstrated image transmission through bundles of optical fibers with

5986-431: The roof to other parts of the building (see nonimaging optics ). Optical-fiber lamps are used for illumination in decorative applications, including signs , art , toys and artificial Christmas trees . Optical fiber is an intrinsic part of the light-transmitting concrete building product LiTraCon . Optical fiber can also be used in structural health monitoring . This type of sensor can detect stresses that may have

6068-431: The side of a mountain. The facility is secured with a concrete wall and a steel gate. The deposits themselves are stored in secure shipping containers behind the gate. Because of the island's Arctic climate and resulting permafrost, even if the power to the facility failed, the temperature inside the vault would remain below freezing point , which is cold enough to preserve the vault's contents for decades or more, with

6150-564: The speed of manufacture to over 50 meters per second, making optical fiber cables cheaper than traditional copper ones. These innovations ushered in the era of optical fiber telecommunication. The Italian research center CSELT worked with Corning to develop practical optical fiber cables, resulting in the first metropolitan fiber optic cable being deployed in Turin in 1977. CSELT also developed an early technique for splicing optical fibers, called Springroove. Attenuation in modern optical cables

6232-462: The system of hardware, technologies, software, policies, services and tools. Cyber infrastructures are geared towards the sharing of data supporting peer-to-peer collaborations and a cultural community. An example of a major cyber-infrastructure is The Canadian Geo-spatial Data Infrastructure which provides access to spatial data in Canada. Fibre optic An optical fiber , or optical fibre ,

6314-496: The vault 250 metres (820 ft) below the permafrost. The vault is situated deeply enough to avoid damage even from nuclear and EMP weapons . Data is stored offline on film reels made using a refined version of ordinary darkroom photography technology. The film is made of polyester coated in silver halide crystals and powder-coated with iron oxide , and has a life span of at least 500 and possibly up to 2,000 years, if stored in optimum conditions. The level of security of

6396-503: The vault, but it is not a quick process, because the data is not connected to the internet. If data is requested, the relevant reel of film has to be manually retrieved, then uploaded via a fibre optic connection to the mainland, to Piql's headquarters in Drammen ; the fastest possible retrieval time is 20–30 minutes, but it can take up to 24 hours with an active subscription and up to 72 hours without an active subscription. The archive stores

6478-501: The very far future may not understand what they see in the vault, a kind of " Rosetta Stone " has been devised to help decode the data, in the form of a guide to interpreting the archive. The guides are all readable by eye , after magnification , and written in English , Arabic , Spanish , Chinese , and Hindi . Clients who pay for the storage of data can send their data digitally or physically. The data can be retrieved at any time from

6560-662: The way through simple forgetting to natural decay. Ways in which data collections can be used when preserved and stored properly can be seen through the U.S. Geological Survey , which stores data collections on natural hazards, natural resources, and landscapes. The data collected by the Survey is used by federal and state land management agencies towards land use planning and management, and continually needs access to historical reference data. In contrast, data holdings are collections of gathered data that are informally kept, and not necessarily prepared for long-term preservation. For example,

6642-495: Was acquired by Microsoft in 2018) announced that all of its public open source code would be archived in a code vault at the Arctic World Archive, as part of its GitHub Archive Program. In July 2020, the 21 TB February site archive was stored at the AWA. The data is stored on 186 film reels measuring 1 kilometre (0.62 mi) long, covered in code stored as matrix (2D) barcode ( Boxing barcode ), which store data very densely (each of

6724-675: Was first achieved in 1970 by researchers Robert D. Maurer , Donald Keck , Peter C. Schultz , and Frank Zimar working for American glass maker Corning Glass Works . They demonstrated a fiber with 17 dB/km attenuation by doping silica glass with titanium . A few years later they produced a fiber with only 4 dB/km attenuation using germanium dioxide as the core dopant. In 1981, General Electric produced fused quartz ingots that could be drawn into strands 25 miles (40 km) long. Initially, high-quality optical fibers could only be manufactured at 2 meters per second. Chemical engineer Thomas Mensah joined Corning in 1983 and increased

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