"Big data" is a field that treats ways to analyze, systematically extract information from, or otherwise deal with data sets that are too large or complex to be dealt with by traditional data-processing application software. Data with many cases offer greater statistical power, while data with higher complexity may lead to a higher false discovery rate. Big data challenges include capturing data, data storage, data analysis, sharing, visualization, updating, information privacy and data source. Big data was associated with three key concepts: volume and velocity. Other concepts attributed with big data are veracity and value. Current usage of the term big data tends to refer to the use of predictive analytics, user behavior analytics, or certain other advanced data analytics methods that extract value from data, to a particular size of data set. "There is little doubt that the quantities of data now available are indeed large, but that's not the most relevant characteristic of this new data ecosystem."
Analysis of data sets can find new correlations to "spot business trends, prevent diseases, combat crime and so on." Scientists, business executives, practitioners of medicine and governments alike meet difficulties with large data-sets in areas including Internet search, urban informatics, business informatics. Scientists encounter limitations in e-Science work, including meteorology, connectomics, complex physics simulations and environmental research. Data sets grow rapidly- in part because they are gathered by cheap and numerous information- sensing Internet of things devices such as mobile devices, software logs, microphones, radio-frequency identification readers and wireless sensor networks; the world's technological per-capita capacity to store information has doubled every 40 months since the 1980s. Based on an IDC report prediction, the global data volume will grow exponentially from 4.4 zettabytes to 44 zettabytes between 2013 and 2020. By 2025, IDC predicts. One question for large enterprises is determining who should own big-data initiatives that affect the entire organization.
Relational database management systems, desktop statistics and software packages used to visualize data have difficulty handling big data. The work may require "massively parallel software running on tens, hundreds, or thousands of servers". What qualifies as being "big data" varies depending on the capabilities of the users and their tools, expanding capabilities make big data a moving target. "For some organizations, facing hundreds of gigabytes of data for the first time may trigger a need to reconsider data management options. For others, it may take tens or hundreds of terabytes before data size becomes a significant consideration." The term has been in use since the 1990s, with some giving credit to John Mashey for popularizing the term. Big data includes data sets with sizes beyond the ability of used software tools to capture, curate and process data within a tolerable elapsed time. Big data philosophy encompasses unstructured, semi-structured and structured data, however the main focus is on unstructured data.
Big data "size" is a moving target, as of 2012 ranging from a few dozen terabytes to many exabytes of data. Big data requires a set of techniques and technologies with new forms of integration to reveal insights from datasets that are diverse, of a massive scale. A 2016 definition states that "Big data represents the information assets characterized by such a high volume and variety to require specific technology and analytical methods for its transformation into value". Kaplan and Haenlein define big data as "data sets characterized by huge amounts of updated data in various formats, such as numeric, textual, or images/videos." Additionally, a new V, veracity, is added by some organizations to describe it, revisionism challenged by some industry authorities. The three Vs have been further expanded to other complementary characteristics of big data: Machine learning: big data doesn't ask why and detects patterns Digital footprint: big data is a cost-free byproduct of digital interactionA 2018 definition states "Big data is where parallel computing tools are needed to handle data", notes, "This represents a distinct and defined change in the computer science used, via parallel programming theories, losses of some of the guarantees and capabilities made by Codd's relational model."
The growing maturity of the concept more starkly delineates the difference between "big data" and "Business Intelligence": Business Intelligence uses descriptive statistics with data with high information density to measure things, detect trends, etc. Big data uses inductive statistics and concepts from nonlinear system identification to infer laws from large sets of data with low information density to reveal relationships and dependencies, or to perform predictions of outcomes and behaviors. Big data can be described by the following characteristics: Volume The quantity of generated and stored data; the size of the data determines the value and potential insight, whether it can be considered big data or not. Variety The type and nature of the data; this helps people who analyze it to use the resulting insight. Big data draws from text, audio, video.
University of Helsinki
The University of Helsinki is a university located in Helsinki, Finland since 1829, but was founded in the city of Turku in 1640 as the Royal Academy of Åbo, at that time part of the Swedish Empire. It is the largest university in Finland with the widest range of disciplines available. Around 36,500 students are enrolled in the degree programs of the university spread across 11 faculties and 11 research institutes; as of 1 August 2005, the university complies with the harmonized structure of the Europe-wide Bologna Process and offers Bachelor, Master and Doctoral degrees. Admission to degree programmes is determined by entrance examinations, in the case of bachelor's degrees, by prior degree results, in the case of master and postgraduate degrees. Entrance is selective, it has been ranked a top 100 university in the world according to the 2016 ARWU, QS and THE rankings. The university is bilingual, with teaching by law provided both in Swedish. Since Swedish, albeit an official language of Finland, is a minority language, Finnish is by far the dominating language at the university.
Teaching in English is extensive throughout the university at Master and Doctoral levels, making it a de facto third language of instruction. Remaining true to its traditionally strong Humboldtian ethos, the University of Helsinki places heavy emphasis on high-quality teaching and research of a top international standard, it is a member of various prominent international university networks, such as Europaeum, UNICA, the Utrecht Network, is a founding member of the League of European Research Universities. The first predecessor of the university, The Cathedral School of Åbo, was founded in 1276 for education of boys to become servants of the Church; as the university was founded in 1640 by Queen Christina of Sweden in Turku, as the Åbo Kungliga Akademi, the senior part of the school formed the core of the new university, while the junior year courses formed a grammar school. It was the third university founded in the Swedish Empire, following Uppsala University and the Academia Gustaviana in Dorpat.
The second period of the university's history covers the period when Finland was a Grand Duchy of the Russian Empire, from 1809 to 1917. As Finland became part of the Russian Empire in 1809, Emperor Alexander I expanded the university and allocated substantial funds to it. Following the Great Fire of Turku in 1827, higher education within the country was moved to Helsinki, the new administrative heart of the Grand Duchy, in 1828, renamed the Imperial Alexander University in Finland in honour of the late benefactor of the university. In the capital the primary task of the university was to educate the Grand Duchy’s civil servants; the university became a community subscribing to the new Humboldtian ideals of science and culture, studying humanity and its living environment by means of scientific methods. The new statutes of the university enacted in 1828 defined the task of the university as promoting the development of “the Sciences and Humanities within Finland and, educating the youth for the service of the Emperor and the Fatherland”.
The Alexander University was a centre of national life that promoted the birth of an independent Finnish State and the development of Finnish identity. The great men of 19th century Finland, Johan Vilhelm Snellman, Johan Ludvig Runeberg, Elias Lönnrot and Zachris Topelius, were all involved in the activities of the university; the university became a major center of Finnish cultural and legal life in 19th century Finland, became a remarkable primum mobile of the nationalist and liberal cultural movements, political parties, student organisations. In the 19th century university research changed from being collection-centred to being experimental and analytical; the more scientific approach of the university created new disciplines. As the scientific disciplines developed, Finland received more scholarly knowledge and educated people, some of whom entered evolving industry or the government; the third period of the university's history began with the creation of the independent Republic of Finland in 1917, with the renaming of the university as the University of Helsinki.
Once Finland gained her independence in 1917 the university was given a crucial role in building the nation state and, after World War II, the welfare state. Members of the academic community promoted the international relations of the new state and the development of its economic life. Furthermore, they were involved in national politics and the struggle for equality. In the interwar period the university was the scene of a conflict between those who wanted to advance the usage of Finnish language in the university, to the detriment of Swedish and those who opposed such move. Geographer Väinö Tanner was one of the most vocal defenders of Swedish language usage. Swedish People's Party of Finland initiated a campaign collecting 153 914 signatures in defense of the Swedish language that were handed to the parliament and government in October 1934. On an international front academics from Denmark, Sweden and Iceland sent letters to the diplomatic representations of Finland in their respective countries warning about a weakening of the Nordic unity that would result from diminishing the role of Swedish in the University of Helsinki.
In the 20th century, scholarly research at the University of Helsinki reached the level of the
Finland the Republic of Finland, is a country in Northern Europe bordering the Baltic Sea, Gulf of Bothnia, Gulf of Finland, between Norway to the north, Sweden to the northwest, Russia to the east. Finland is situated in the geographical region of Fennoscandia; the capital and largest city is Helsinki. Other major cities are Espoo, Tampere and Turku. Finland's population is 5.52 million, the majority of the population is concentrated in the southern region. 88.7% of the population is Finnish and speaks Finnish, a Uralic language unrelated to the Scandinavian languages. Finland is the eighth-largest country in Europe and the most sparsely populated country in the European Union; the sovereign state is a parliamentary republic with a central government based in the capital city of Helsinki, local governments in 311 municipalities, one autonomous region, the Åland Islands. Over 1.4 million people live in the Greater Helsinki metropolitan area, which produces one third of the country's GDP. Finland was inhabited when the last ice age ended 9000 BCE.
The first settlers left behind artefacts that present characteristics shared with those found in Estonia and Norway. The earliest people were hunter-gatherers; the first pottery appeared in 5200 BCE. The arrival of the Corded Ware culture in southern coastal Finland between 3000 and 2500 BCE may have coincided with the start of agriculture; the Bronze Age and Iron Age were characterised by extensive contacts with other cultures in the Fennoscandian and Baltic regions and the sedentary farming inhabitation increased towards the end of Iron Age. At the time Finland had three main cultural areas – Southwest Finland and Karelia – as reflected in contemporary jewellery. From the late 13th century, Finland became an integral part of Sweden through the Northern Crusades and the Swedish part-colonisation of coastal Finland, a legacy reflected in the prevalence of the Swedish language and its official status. In 1809, Finland was incorporated into the Russian Empire as the autonomous Grand Duchy of Finland.
In 1906, Finland became the first European state to grant all adult citizens the right to vote, the first in the world to give all adult citizens the right to run for public office. Following the 1917 Russian Revolution, Finland declared itself independent. In 1918, the fledgling state was divided by civil war, with the Bolshevik-leaning Red Guard supported by the new Soviet Russia, fighting the White Guard, supported by the German Empire. After a brief attempt to establish a kingdom, the country became a republic. During World War II, the Soviet Union sought to occupy Finland, with Finland losing parts of Karelia, Kuusamo and some islands, but retaining their independence. Finland established an official policy of neutrality; the Finno-Soviet Treaty of 1948 gave the Soviet Union some leverage in Finnish domestic politics during the Cold War era. Finland joined the OECD in 1969, the NATO Partnership for Peace in 1994, the European Union in 1995, the Euro-Atlantic Partnership Council in 1997, the Eurozone at its inception, in 1999.
Finland was a relative latecomer to industrialisation, remaining a agrarian country until the 1950s. After World War II, the Soviet Union demanded war reparations from Finland not only in money but in material, such as ships and machinery; this forced Finland to industrialise. It developed an advanced economy while building an extensive welfare state based on the Nordic model, resulting in widespread prosperity and one of the highest per capita incomes in the world. Finland is a top performer in numerous metrics of national performance, including education, economic competitiveness, civil liberties, quality of life, human development. In 2015, Finland was ranked first in the World Human Capital and the Press Freedom Index and as the most stable country in the world during 2011–2016 in the Fragile States Index, second in the Global Gender Gap Report, it ranked first on the World Happiness Report report for 2018 and 2019. A large majority of Finns are members of the Evangelical Lutheran Church, freedom of religion is guaranteed under the Finnish Constitution.
The earliest written appearance of the name Finland is thought to be on three runestones. Two have the inscription finlonti; the third was found in Gotland. It dates back to the 13th century; the name can be assumed to be related to the tribe name Finns, mentioned at first known time AD 98. The name Suomi has uncertain origins, but a candidate for a source is the Proto-Baltic word *źemē, meaning "land". In addition to the close relatives of Finnish, this name is used in the Baltic languages Latvian and Lithuanian. Alternatively, the Indo-European word * gʰm-on "man" has been suggested; the word referred only to the province of Finland Proper, to the northern coast of Gulf of Finland, with northern regions such as Ostrobothnia still sometimes being excluded until later. Earlier theories suggested derivation from suomaa or suoniemi, but these are now considered outdated; some have suggested common etymology with saame and Häme, but that theory is uncertain
Facility for Antiproton and Ion Research
The Facility for Antiproton and Ion Research is an international accelerator facility under construction which will use antiprotons and ions to perform research in the fields of: nuclear and particle physics and anti-matter physics, high density plasma physics, applications in condensed matter physics and the bio-medical sciences. It is situated in Darmstadt in Germany. FAIR will be based upon an expansion of the GSI Helmholtz Centre for Heavy Ion Research, the details of which have been laid out in the FAIR Baseline Technical Report 2006. On October 4, 2010 the Facility for Antiproton and Ion Research in Europe limited liability company, abbreviated as FAIR GmbH, was founded which coordinates the construction of the new accelerators and experiments; the construction begun at summer of 2017. Commissioning is planned for 2025; the budget is estimated at 1262 million euro. The four scientific pillars of FAIR are: Atomic, Plasma Physics and Applications - APPA, Compressed Baryonic Matter - CBM, Nuclear Structure and Reactions - NUSTAR, antiProton ANnihilation at DArmstadt - PANDA.
Those are described on the web pages of FAIR. Beams of protons will be prepared in the proton linear accelerator, p-LINAC, while heavy ions will be prepared in the UNILAC. Both of them will be fed into the SIS18. From there they will be directed into SIS100. Protons will be used either to produce antiproton beams by directing them on a dedicated production target or directly used for experiments within APPA; these antiprotons will be captured and cooled in the Collector Ring, CR before being injected into HESR, where they will be utilised within the PANDA experiment. High energetic heavy ions will either be used directly for studies with the CBM or APPA experiments or to produce unstable ion beams; the latter will be produced in the Rare Isotope Production Target and filtered the Super-FRS, where the NUSTAR experiments will take place. 3,000 scientists from more than 50 countries are working on the planning of the experiment and accelerator facilities. This project is realised by partners from Finland, Germany, Poland, Russia and Sweden that have signed an international treaty, the FAIR Convention, which formally entered into force in March 2014.
The UK has joined as first associate member. Further countries, like Italy, are in negotiations. GSI Helmholtz Centre for Heavy Ion Research PANDA experiment Facility for Antiproton and Ion Research in Europe GmbH: FAIR Home Public information Planned experiments at FAIR
Compact Muon Solenoid
The Compact Muon Solenoid experiment is one of two large general-purpose particle physics detectors built on the Large Hadron Collider at CERN in Switzerland and France. The goal of CMS experiment is to investigate a wide range of physics, including the search for the Higgs boson, extra dimensions, particles that could make up dark matter. CMS is 21.6 metres long, 15 m in diameter, weighs about 14,000 tonnes. 3,800 people, representing 199 scientific institutes and 43 countries, form the CMS collaboration who built and now operate the detector. It is located in an underground cavern at Cessy in France, just across the border from Geneva. In July 2012, along with ATLAS, CMS tentatively discovered the Higgs boson.. By March 2013 its existence was confirmed. Recent collider experiments such as the now-dismantled Large Electron-Positron Collider and the newly renovated Large Hadron Collider at CERN, as well as the closed Tevatron at Fermilab have provided remarkable insights into, precision tests of, the Standard Model of Particle Physics.
A principle achievement of these experiments is the discovery of a particle consistent with the Standard Model Higgs boson, the particle resulting from the Higgs mechanism, which provides an explanation for the masses of elementary particles. However, there are still many questions; these include uncertainties in the mathematical behaviour of the Standard Model at high energies, tests of proposed theories of dark matter, the reasons for the imbalance of matter and antimatter observed in the Universe. The main goals of the experiment are: to explore physics at the TeV scale to further study the properties of the Higgs boson discovered by CMS and ATLAS to look for evidence of physics beyond the standard model, such as supersymmetry, or extra dimensions to study aspects of heavy ion collisions; the ATLAS experiment, at the other side of the LHC ring is designed with similar goals in mind, the two experiments are designed to complement each other both to extend reach and to provide corroboration of findings.
CMS and ATLAS uses different technical solutions and design of its detector magnet system to achieve the goals. CMS is designed as a general-purpose detector, capable of studying many aspects of proton collisions at 0.9-13 TeV, the center-of-mass energy of the LHC particle accelerator. The CMS detector is built around a huge solenoid magnet; this takes the form of a cylindrical coil of superconducting cable that generates a magnetic field of 4 teslas, about 100 000 times that of the Earth. The magnetic field is confined by a steel'yoke' that forms the bulk of the detector's weight of 12 500 tonnes. An unusual feature of the CMS detector is that instead of being built in-situ underground, like the other giant detectors of the LHC experiments, it was constructed on the surface, before being lowered underground in 15 sections and reassembled, it contains subsystems which are designed to measure the energy and momentum of photons, electrons and other products of the collisions. The innermost layer is a silicon-based tracker.
Surrounding it is a scintillating crystal electromagnetic calorimeter, itself surrounded with a sampling calorimeter for hadrons. The tracker and the calorimetry are compact enough to fit inside the CMS Solenoid which generates a powerful magnetic field of 3.8 T. Outside the magnet are the large muon detectors, which are inside the return yoke of the magnet. For full technical details about the CMS detector, please see the Technical Design Report; this is the point in the centre of the detector at which proton-proton collisions occur between the two counter-rotating beams of the LHC. At each end of the detector magnets focus the beams into the interaction point. At collision each beam has a radius of 17 μm and the crossing angle between the beams is 285 μrad. At full design luminosity each of the two LHC beams will contain 2,808 bunches of 1.15×1011 protons. The interval between crossings is 25 ns, although the number of collisions per second is only 31.6 million due to gaps in the beam as injector magnets are activated and deactivated.
At full luminosity each collision will produce an average of 20 proton-proton interactions. The collisions occur at a centre of mass energy of 8 TeV. But, it is worth noting that for studies of physics at the electroweak scale, the scattering events are initiated by a single quark or gluon from each proton, so the actual energy involved in each collision will be lower as the total centre of mass energy is shared by these quarks and gluons; the first test which ran in September 2008 was expected to operate at a lower collision energy of 10 TeV but this was prevented by the 19 September 2008 shutdown. When at this target level, the LHC will have a reduced luminosity, due to both fewer proton bunches in each beam and fewer protons per bunch; the reduced bunch frequency does allow the crossing angle to be reduced to zero however, as bunches are far enough spaced to prevent secondary collisions in the experimental beampipe. Momentum of particles is crucial in helping us to build up a picture of events at the heart of the collision.
One method to calculate the momentum of a particle is to track its path through a magnetic field. The CMS tracker records the paths taken by charged particles by finding their positions at a number of key points; the tracker can reconstruct the paths of high-energy muons and hadrons as well as see tracks coming from the decay of short-lived particles such as beauty or “b quarks” that will be used to
Aalto University is a university located in Greater Helsinki, Finland. It was established in 2010 as a merger of three major Finnish universities: the Helsinki University of Technology, the Helsinki School of Economics, the University of Art and Design Helsinki; the close collaboration between the scientific and arts communities is intended to foster multi-disciplinary education and research. The Finnish government, in 2010, set out to create a university that fosters innovation, merging the three institutions into one; the university is composed of six schools with close to 17,500 students and 4,000 staff members, making it Finland's second largest university. The main campus of Aalto University is located in Otaniemi, where the engineering schools as well as the bachelor programs of the School of Business operate. Other functions of the School of Business are located in Töölö; the School of Arts and Architecture is located in Arabianranta. All of the university's activities will be located in the Otaniemi campus by 2020.
In addition to the Greater Helsinki area, the university operates in Mikkeli and Pori. Aalto University's operations showcase Finland’s experiment in higher education; the Aalto Design Factory, Aalto Ventures Program and Aalto Entrepreneurship Society, among others, drive the university's mission for a radical shift towards multidisciplinary learning and have contributed to the emergence of Helsinki as a hotbed for startups. Aaltoes is Europe’s largest and most active student run entrepreneurship community that has founded major concepts such as the Startup Sauna accelerator program and the Slush startup event; the university is named in honour of Alvar Aalto, a prominent Finnish architect and alumnus of the former Helsinki University of Technology, instrumental in designing a large part of the university's main campus in Otaniemi. In 2004, a workgroup led by Anne Brunila of the Finnish Ministry of Finance concluded that Finland had too many universities and other institutes of tertiary education which should be consolidated.
Following this, Yrjö Sotamaa, president of the University of Art and Design Helsinki at the time, proposed the merger of Aalto University's founding schools in his president's opening speech in 2005. Sotamaa's line of reasoning was that this move would create a unique interdisciplinary university, needed to create new innovative thought; the idea received attention within the Finnish Ministry of Education, which appointed Raimo Sailas, a leading official at the Ministry of Finance, to investigate the possibility of a merger. After Sailas' group reported that it considered the merger to be beneficial to the Finnish academic world and economy, the Finnish government decided to go on with the project on November 11, 2007. On May 29, 2008, the government announced that the new university would be named after the Finnish architect Alvar Aalto in honor of his achievements in technology and art; the Finnish Minister of Education at the time, Ms. Sari Sarkomaa, together with representatives of Finnish industries and professional organisations, signed the Aalto University charter on June 25, 2008 in Helsinki.
On December 19, 2008, Prof. Tuula Teeri was selected by the Board to be the first President of Aalto University. Aalto University started operating on January 1, 2010. In the process of creating the university the university law of Finland was rewritten for the university to be allowed to collect endowment; the university managed to reach its goal of collecting 200 million euros in private donations. The sum was augmented by 2.5 times by the Finnish state. As the Aalto University was founded the four schools of science and engineering were formed out of the departments of the Helsinki University of Technology, founded in 1849 by Grand Duke Nicholas I, it received university status in 1908. In 1966, the University of Technology moved from Hietalahti in downtown Helsinki to its current Otaniemi campus, designed by Alvar Aalto. At the time of creation of Aalto University, TKK had about 250 professors and 15,000 students; this means the largest part of the Aalto University is formed from the former Helsinki University of Technology.
In 2011, the former University of Technology was split up into four schools, corresponding to the former TKK faculties: School of Chemical Technology, School of Electrical Engineering, School of Engineering, School of Science. The Helsinki School of Economics was established in Helsinki in 1904 by the business community and was given the status of a university in 1911, it operated as a private university until 1974, when the state of Finland was given the financial responsibility of the university. Following the merger, the university was renamed Aalto University School of Economics, is known as Aalto University School of Business; the University of Art and Design Helsinki has been the largest art university in the Nordic countries. It was founded in 1871. Media Centre Lume - the National Research and Development Center of audiovisual media - is located in the university; the university awarded the following academic degrees: Bachelor of Arts, Master of Arts, Doctor of Arts. The university has been active in establishing research projects and industrial collaborations via the private sector.
During the rectorship of Yrjö Sotamaa the university was active in integrating design into Finnish innovation networks. Following the merger, the university was renamed Aalto University School of Art and Design. In 2012, the Department of Archit
ALICE is one of seven detector experiments at the Large Hadron Collider at CERN. The other six are: ATLAS, CMS, TOTEM, LHCb, LHCf and MoEDAL. ALICE is optimized to study heavy-ion collisions at a centre of mass energy of 2.76 TeV per nucleon pair. The resulting temperature and energy density are expected to be high enough to produce quark–gluon plasma, a state of matter wherein quarks and gluons are freed. Similar conditions are believed to have existed a fraction of the second after the Big Bang before quarks and gluons bound together to form hadrons and heavier particles. ALICE is focusing on the physics of interacting matter at extreme energy densities; the existence of the quark–gluon plasma and its properties are key issues in quantum chromodynamics for understanding color confinement and chiral symmetry restoration. Recreating this primordial form of matter and understanding how it evolves is expected to shed light on questions about how matter is organized, the mechanism that confines quarks and gluons and the nature of strong interactions and how they result in generating the bulk of the mass of ordinary matter.
Quantum chromodynamics predicts that at sufficiently high energy densities there will be a phase transition from conventional hadronic matter, where quarks are locked inside nuclear particles, to a plasma of deconfined quarks and gluons. The reverse of this transition is believed to have taken place when the universe was just 10−6 s old, may still play a role today in the hearts of collapsing neutron stars or other astrophysical objects; the idea of building a dedicated heavy-ion detector for the LHC was first aired at the historic Evian meeting "Towards the LHC experimental Programme" in March 1992. From the ideas presented there, the ALICE collaboration was formed and in 1993, a LoI was submitted. ALICE was first proposed as a central detector in 1993 and complemented by an additional forward muon spectrometer designed in 1995. In 1997, ALICE received the green light from the LHC Committee to proceed towards final design and construction; the first ten years were spent on an extensive R&D effort.
Like for all other LHC experiments, it became clear from the outset that the challenges of heavy ion physics at LHC could not be met with existing technology. Significant advances, in some cases a technological break-through, would be required to build on the ground what physicists had dreamed up on paper for their experiments; the very broad and more focused, well organised and well supported R&D effort, sustained over most of the 1990s, has led to many evolutionary and some revolutionary advances in detectors and computing. Designing a dedicated heavy-ion experiment in the early'90s for use at the LHC some 15 years posed some daunting challenges; the detector had to be general purpose - able to measure most signals of potential interest if their relevance may only become apparent - and flexible, allowing additions and modifications along the way as new avenues of investigation would open up. In both respects ALICE did quite well, as it included a number of observables in its initial menu whose importance only became clear later.
Various major detection system were added, from the muon spectrometer in 1995, the transition radiation detectors in 1999 to a large jet calorimeter added in 2007. ALICE recorded data from the first lead-lead collisions at the LHC in 2010. Data sets taken during heavy-ion periods in 2010 and 2011 as well as proton-lead data from 2013 have provided an excellent basis for an in-depth look at the physics of quark–gluon plasma; as of 2014 After more than three years of successful operation, the ALICE detector is about to undergo a major programme of consolidation and upgrade during the long shutdown of CERN's accelerator complex. A new subdetector called the dijet calorimeter will be installed, all 18 of the existing ALICE subdetectors will be upgraded. There will be major renovation work on the ALICE infrastructure, including the electrical and cooling systems; the wealth of published scientific results and the intense upgrade programme of ALICE have attracted numerous institutes and scientists from all over the world.
Today the ALICE Collaboration has more than 1800 members coming from 176 institutes in 41 countries Searches for Quark Gluon plasma and a deeper understanding of the QCD started at CERN and Brookhaven with lighter ions in the 1980s. Today's programme at these laboratories has moved on to ultrarelativistic collisions of heavy ions, is just reaching the energy threshold at which the phase transition is expected to occur; the LHC, with a centre-of-mass energy around 5.5 TeV/nucleon, will push the energy reach further. During head-on collisions of lead ions at the LHC, hundreds of protons and neutrons smash into one another at energies of upwards of a few TeVs. Lead ions are accelerated to more than 99.9999% of the speed of light and collisions at the LHC are 100 times more energetic than those of protons - heating up matter in the interaction point to a temperature 100,000 times higher than the temperature in the core of the sun. When the two lead nuclei slam into each other, matter undergoes a transition to form for a brief instant a droplet of primordial matter, the so-called quark–gluon plasma, believed to have filled the universe a few microseconds after the Big Bang.
The quark–gluon plasma is formed as protons and neutrons "melt" into their elementary constituents and gluons become asymptotically free. The droplet of QGP cools, the individual quarks and gluons recombine into a blizzard of ordinary matter that speeds away in all directions; the debris contains particles