vania-janet/multiturn-rag-retrieval-data huggingface dataset:
2004 Indian Ocean earthquake and tsunami
3.4 m ( 11.2 ft ) at Kerala , inundation distance of 0.5 -- 1.5 km ( 0.31 -- 0.62 miles ) with 250 km ( 155.3 miles ) of coastline affected . 4.5 m ( 14.8 ft ) at southern coastline of Tamil Nadu , inundation distance of 0.2 -- 2.0 km ( 0.12 -- 1.24 miles ) with 100 km ( 62.1 miles ) of coast affected . 5 m ( 16.4 ft ) at eastern coastline of Tamil Nadu facing tsunami source , inundation distance of 0.4 -- 1.5 km ( 0.25 -- 0.93 miles ) with 800 km ( 497 miles ) of coastline affected . 4 m ( 13.1 ft ) at Pondicherry , inundation distance of 0.2 -- 2.0 km ( 0.12 -- 1.24 miles ) with 25 km ( 15.5 miles ) of coast affected . 2.2 m ( 7.22 ft ) at Andhra Pradesh , inundation distance of 0.2 -- 1.0 km ( 0.12 -- 0.62 miles ) with 985 km ( 612 miles ) of coast .
Metrication in the United States
That said , U.S. track - and - field competitions are commonly run in increments of 400 meters , which roughly correspond to traditional mile - based lengths . In the Olympics , athletes run 1500 meters , not 1600 meters .
International Date Line
In journeying eastward he ( Fogg ) had gone towards the sun , and the days therefore diminished for him as many times four minutes as he crossed degrees in this direction . There are three hundred and sixty degrees on the circumference of the earth ; and these three hundred and sixty degrees , multiplied by four minutes , gives precisely twenty - four hours -- that is , the day unconsciously gained . In other words , while Phileas Fogg , going eastward , saw the sun pass the meridian eighty times , his friends in London only saw it pass the meridian seventy - nine times .
Speed of light
In the second half of the 20th century much progress was made in increasing the accuracy of measurements of the speed of light , first by cavity resonance techniques and later by laser interferometer techniques . These were aided by new , more precise , definitions of the metre and second . In 1950 , Louis Essen determined the speed as 7008299792500000000 ♠ 299 792. 5 ± 1 km / s , using cavity resonance . This value was adopted by the 12th General Assembly of the Radio - Scientific Union in 1957 . In 1960 , the metre was redefined in terms of the wavelength of a particular spectral line of krypton - 86 , and , in 1967 , the second was redefined in terms of the hyperfine transition frequency of the ground state of caesium - 133 .
Binary star
Since about 1995 measurement of extragalactic eclipsing binaries ' fundamental parameters has become possible with 8 meter class telescopes . This makes it feasible to use them to directly measure the distances to external galaxies , a process that is more accurate than using standard candles . By 2006 they had been used to give direct distance estimates to the LMC , SMC , Andromeda Galaxy and Triangulum Galaxy . Eclipsing binaries offer a direct method to gauge the distance to galaxies to a new improved 5 % level of accuracy . Non-eclipsing
International System of Units
The reliability of the SI depends not only on the precise measurement of standards for the base units in terms of various physical constants of nature , but also on precise definition of those constants . The set of underlying constants is modified as more stable constants are found , or may be more precisely measured . For example , in 1983 the metre was redefined as the distance that light propagates in vacuum in a given fraction of a second , thus making the value of the speed of light in terms of the defined units exact .
Time
the fraction 1 / 31,556,925.9747 of the tropical year for 1900 January 0 at 12 hours ephemeris time .
Mount Everest
Debilitating effects of the death zone are so great that it takes most climbers up to 12 hours to walk the distance of 1.72 kilometres ( 1.07 mi ) from South Col to the summit . Achieving even this level of performance requires prolonged altitude acclimatisation , which takes 40 -- 60 days for a typical expedition . A sea - level dweller exposed to the atmospheric conditions at the altitude above 8,500 m ( 27,900 ft ) without acclimatisation would likely lose consciousness within 2 to 3 minutes .
Kuiper belt
N ∝ D 1 − q + a constant . ( \ displaystyle N \ propto D ^ ( 1 - q ) + ( \ text ( a constant ) ) . )
Kuiper belt
d N d D ∝ D − q ( \ displaystyle ( \ frac ( dN ) ( dD ) ) \ propto D ^ ( - q ) ) where the current measures give q = 4 ± 0.5 .
Global Positioning System
Δ t ( Δ r ( Δ s ( φ 1 , 1 , 1 ) ) ) ( \ displaystyle \ \ Delta ^ ( t ) ( \ Delta ^ ( r ) ( \ Delta ^ ( s ) ( \ phi _ ( 1 , 1 , 1 ) ) ) ) )
Speed of light
In 1972 , using the laser interferometer method and the new definitions , a group at the US National Bureau of Standards in Boulder , Colorado determined the speed of light in vacuum to be c = 7008299792456200000 ♠ 299 792 456. 2 ± 1.1 m / s . This was 100 times less uncertain than the previously accepted value . The remaining uncertainty was mainly related to the definition of the metre . As similar experiments found comparable results for c , the 15th General Conference on Weights and Measures in 1975 recommended using the value 7008299792458000000 ♠ 299 792 458 m / s for the speed of light .
Base pair
bp = base pair ( s ) -- one bp corresponds to approximately 3.4 Å ( 340 pm ) of length along the strand , and to roughly 618 or 643 daltons for DNA and RNA respectively . kb ( = kbp ) = kilo base pairs = 1,000 bp Mb ( = Mbp ) = mega base pairs = 1,000,000 bp Gb = giga base pairs = 1,000,000,000 bp .
Area of a circle
u 2 n = U 2 n u n ( \ displaystyle u_ ( 2n ) = ( \ sqrt ( U_ ( 2n ) u_ ( n ) ) ) ) ( geometric mean ) , and
Time dilation
Consider then , a simple clock consisting of two mirrors A and B , between which a light pulse is bouncing . The separation of the mirrors is L and the clock ticks once each time the light pulse hits either of the mirrors .
International System of Units
In March 1791 , the Assembly adopted the committee 's proposed principles for the new decimal system of measure including the metre defined to be 1 / 10,000,000 th of the length of the quadrant of earth 's meridian passing through Paris , and authorised a survey to precisely establish the length of the meridian . In July 1792 , the committee proposed the names metre , are , litre and grave for the units of length , area , capacity , and mass , respectively . The committee also proposed that multiples and submultiples of these units were to be denoted by decimal - based prefixes such as centi for a hundredth and kilo for a thousand . Thomson
Geologic time scale
Hadean Eon -- 4600 -- 4031 MYA Chaotian Era -- 4600 -- 4404 MYA -- the name alluding both to the mythological Chaos and the chaotic phase of planet formation Jack Hillsian or Zirconian Era -- 4404 -- 4031 MYA -- both names allude to the Jack Hills Greenstone Belt which provided the oldest mineral grains on Earth , zircons Archean Eon -- 4031 -- 2420 MYA Paleoarchean Era -- 4031 -- 3490 MYA Acastan Period -- 4031 -- 3810 MYA -- named after the Acasta Gneiss Isuan Period -- 3810 -- 3490 MYA -- named after the Isua Greenstone Belt Mesoarchean Era -- 3490 -- 2780 MYA Vaalbaran Period -- 3490 -- 3020 MYA -- a portmanteau based on the names of the Kapvaal ( Southern Africa ) and Pilbara ( Western Australia ) cratons Pongolan Period -- 3020 -- 2780 MYA -- named after the Pongola Supergroup Neoarchean Era -- 2780 -- 2420 MYA Methanian Period -- 2780 -- 2630 MYA --
Precambrian
Accretion and differentiation : a period of planetary formation until giant Moon - forming impact event . Hadean : dominated by heavy bombardment from about 4.51 Ga ( possibly including a Cool Early Earth period ) to the end of the Late Heavy Bombardment period . Archean : a period defined by the first crustal formations ( the Isua greenstone belt ) until the deposition of banded iron formations due to increasing atmospheric oxygen content . Transition : a period of continued iron banded formation until the first continental red beds . Proterozoic : a period of modern plate tectonics until the first animals .
Exoplanet
Planets form within a few tens of millions of years of their star forming . The planets of the Solar System can only be observed in their current state , but observations of different planetary systems of varying ages allows us to observe planets at different stages of evolution . Available observations range from young proto - planetary disks where planets are still forming to planetary systems of over 10 Gyr old . When terrestrial planets form in a gaseous protoplanetary disk , they have hydrogen envelopes that cool and contract over time and , depending on the mass of the planet , some or all of the hydrogen is eventually lost to space . This means that even terrestrial planets may start off with large radii if they form early enough . An example is Kepler - 51b which has only about twice the mass of Earth but is almost the size of Saturn which is a hundred times the mass of Earth . Kepler - 51b is quite young at a few hundred million years old .
Precambrian
A terminology has evolved covering the early years of the Earth 's existence , as radiometric dating has allowed real dates to be assigned to specific formations and features . The Precambrian Supereon is divided into three eons : the Hadean ( 4600 -- 4000 Ma ) , Archean ( 4000 - 2500 Ma ) and Proterozoic ( 2500 - 541 Ma ) . See Timetable of the Precambrian .
Main sequence
τ M S ≈ 10 10 years ⋅ ( M M ⨀ ) ⋅ ( L ⨀ L ) = 10 10 years ⋅ ( M M ⨀ ) − 2.5 ( \ displaystyle ( \ begin ( smallmatrix ) \ tau _ ( \ rm ( MS ) ) \ \ approx \ 10 ^ ( 10 ) ( \ text ( years ) ) \ cdot \ left ( ( \ frac ( M ) ( M_ ( \ bigodot ) ) ) \ right ) \ cdot \ left ( ( \ frac ( L_ ( \ bigodot ) ) ( L ) ) \ right ) \ =\ 10 ^ ( 10 ) ( \ text ( years ) ) \ cdot \ left ( ( \ frac ( M ) ( M_ ( \ bigodot ) ) ) \ right ) ^ ( - 2.5 ) \ end ( smallmatrix ) ) )
Precambrian
Precambrian Eon 4600 -- 541 million years ago The geological eons and eras view discuss edit - 4500 -- -- - 4000 -- -- - 3500 -- -- - 3000 -- -- - 2500 -- -- - 2000 -- -- - 1500 -- -- - 1000 -- -- - 500 -- -- 0 -- Hadean Archean Protero - zoic Phanero - zoic Eo Paleo Meso Neo Paleo Meso Neo Paleo Meso Ceno Scale : millions of years
Evidence of common descent
For many years , geologists could only roughly estimate the ages of various strata and the fossils found . They did so , for instance , by estimating the time for the formation of sedimentary rock layer by layer . Today , by measuring the proportions of radioactive and stable elements in a given rock , the ages of fossils can be more precisely dated by scientists . This technique is known as radiometric dating .
Grand Canyon
The Grand Canyon is part of the Colorado River basin which has developed over the past 70 million years , in part based on apatite ( U-Th ) / He thermochronometry showing that Grand Canyon reached a depth near to the modern depth by 20 Ma . A recent study examining caves near Grand Canyon places their origins beginning about 17 million years ago . Previous estimates had placed the age of the canyon at 5 -- 6 million years . The study , which was published in the journal Science in 2008 , used uranium - lead dating to analyze calcite deposits found on the walls of nine caves throughout the canyon . There is a substantial amount of controversy because this research suggests such a substantial departure from prior widely supported scientific consensus . In December 2012 , a study published in the journal Science claimed new tests had suggested the Grand Canyon could be as old as 70 million years . However , this study has been criticized by those who support the `` young canyon '' age of around six million years as `` ( an ) attempt to push the interpretation of their new data to their limits without consideration of the whole range of other geologic data sets . ''
Geologic time scale
The ICS 's Geologic Time Scale 2012 book which includes the new approved time scale also displays a proposal to substantially revise the Precambrian time scale to reflect important events such as the formation of the Earth or the Great Oxidation Event , among others , while at the same time maintaining most of the previous chronostratigraphic nomenclature for the pertinent time span . ( See also Period ( geology ) # Structure . )
Precambrian
Proterozoic : this eon refers to the time from the lower Cambrian boundary , 541 Ma , back through 2500 Ma . As originally used , it was a synonym for `` Precambrian '' and hence included everything prior to the Cambrian boundary . The Proterozoic eon is divided into three eras : the Neoproterozoic , Mesoproterozoic and Paleoproterozoic . Neoproterozoic : The youngest geologic era of the Proterozoic Eon , from the Cambrian Period lower boundary ( 541 Ma ) back to 1000 Ma . The Neoproterozoic corresponds to Precambrian Z rocks of older North American geology . Ediacaran : The youngest geologic period within the Neoproterozoic Era . The `` 2012 Geologic Time Scale '' dates it from 541 to 635 Ma . In this period the Ediacaran fauna appeared . Cryogenian : The middle period in the Neoproterozoic Era : 635 - 720 Ma . Tonian : the earliest period of the Neoproterozoic Era : 720 - 1000 Ma . Mesoproterozoic : the middle era of the Proterozoic Eon , 1000 - 1600 Ma . Corresponds to `` Precambrian Y '' rocks of older North American geology . Paleoproterozoic : oldest era of the Proterozoic Eon , 1600 - 2500 Ma . Corresponds to `` Precambrian X '' rocks of older North American geology . Archean Eon : 2500 - 4000 Ma . Hadean Eon : 4000 -- 4600 Ma . This term was intended originally to cover the time before any preserved rocks were deposited , although some zircon crystals from about 4400 Ma demonstrate the existence of crust in the Hadean Eon . Other records from Hadean time come from the moon and meteorites .
86 (term)
This section needs additional citations for verification . Please help improve this article by adding citations to reliable sources . Unsourced material may be challenged and removed . ( March 2018 ) ( Learn how and when to remove this template message )
Geologic time scale
named for the inferred predominance of methanotrophic prokaryotes Siderian Period -- 2630 -- 2420 MYA -- named for the voluminous banded iron formations formed within its duration Proterozoic Eon -- 2420 -- 541 MYA Paleoproterozoic Era -- 2420 -- 1780 MYA Oxygenian Period -- 2420 -- 2250 MYA -- named for displaying the first evidence for a global oxidizing atmosphere Jatulian or Eukaryian Period -- 2250 -- 2060 MYA -- names are respectively for the Lomagundi -- Jatuli δ C isotopic excursion event spanning its duration , and for the ( proposed ) first fossil appearance of eukaryotes Columbian Period -- 2060 -- 1780 MYA -- named after the supercontinent Columbia Mesoproterozoic Era -- 1780 -- 850 MYA Rodinian Period -- 1780 -- 850 MYA -- named after the supercontinent Rodinia , stable environment Neoproterozoic Era -- 850 -- 541 MYA Cryogenian Period -- 850 -- 630 MYA -- named for the occurrence of several glaciations Ediacaran Period -- 630 -- 541 MYA
Radioactive decay
where : N N 0 = 4 / 14 ≈ 0.286 , ( \ displaystyle ( \ frac ( N ) ( N_ ( 0 ) ) ) = 4 / 14 \ approx 0.286 , )
Main sequence
where M and L are the mass and luminosity of the star , respectively , M ⨀ ( \ displaystyle ( \ begin ( smallmatrix ) M_ ( \ bigodot ) \ end ( smallmatrix ) ) ) is a solar mass , L ⨀ ( \ displaystyle ( \ begin ( smallmatrix ) L_ ( \ bigodot ) \ end ( smallmatrix ) ) ) is the solar luminosity and τ M S ( \ displaystyle \ tau _ ( \ rm ( MS ) ) ) is the star 's estimated main sequence lifetime .
Plate tectonics
Venus shows no evidence of active plate tectonics . There is debatable evidence of active tectonics in the planet 's distant past ; however , events taking place since then ( such as the plausible and generally accepted hypothesis that the Venusian lithosphere has thickened greatly over the course of several hundred million years ) has made constraining the course of its geologic record difficult . However , the numerous well - preserved impact craters have been utilized as a dating method to approximately date the Venusian surface ( since there are thus far no known samples of Venusian rock to be dated by more reliable methods ) . Dates derived are dominantly in the range 500 to 750 million years ago , although ages of up to 1,200 million years ago have been calculated . This research has led to the fairly well accepted hypothesis that Venus has undergone an essentially complete volcanic resurfacing at least once in its distant past , with the last event taking place approximately within the range of estimated surface ages . While the mechanism of such an impressive thermal event remains a debated issue in Venusian geosciences , some scientists are advocates of processes involving plate motion to some extent .
History of calendars
The Vague Year began with the month of Pop . The Maya 20 - day month always begins with the seating of the month , followed by days numbered 1 to 19 , then the seating of the following month , and so on . This ties in with the Maya notion that each month influences the next . The Maya new year would start with 1 Pop , followed by 2 Pop , all the way through to 19 Pop , followed by the seating of the month of Uo , written as 0 Uo , then 1 Uo , 2 Uo and so on . These two cycles coincided every 52 years . The 52 - year period of time was called a `` bundle '' and was similar to a modern - day century .
Earth
A crust formed when the molten outer layer of Earth cooled to form a solid . The two models that explain land mass propose either a steady growth to the present - day forms or , more likely , a rapid growth early in Earth history followed by a long - term steady continental area . Continents formed by plate tectonics , a process ultimately driven by the continuous loss of heat from Earth 's interior . Over the period of hundreds of millions of years , the supercontinents have assembled and broken apart . Roughly 7002750000000000000 ♠ 750 million years ago ( Mya ) , one of the earliest known supercontinents , Rodinia , began to break apart . The continents later recombined to form Pannotia 7002600000000000000 ♠ 600 -- 540 Mya , then finally Pangaea , which also broke apart 7002180000000000000 ♠ 180 Mya .
Atmosphere of Venus
The early Earth during the Hadean eon is believed by most scientists to have had a Venus - like atmosphere , with roughly 100 bar of CO and a surface temperature of 230 ° C , and possibly even sulfuric acid clouds , until about 4.0 billion years ago , by which time plate tectonics were in full force and together with the early water oceans , removed the CO and sulfur from the atmosphere . Early Venus would thus most likely have had water oceans like the Earth , but any plate tectonics would have ended when Venus lost its oceans . Its surface is estimated to be about 500 million years old , so it would not be expected to show evidence of plate tectonics .
Vredefort crater
The 40 km diameter center of the Vredefort crater consists of a granite dome ( where it is not covered by much younger rocks belonging to the Karoo Supergroup ) which is an exposed part of the Kaapvaal craton , one of the oldest microcontinents which formed on earth 3900 million years ago . This central peak uplift , or dome , is typical of a complex impact crater , where the liquefied rocks splashed up in the wake of the meteor as it penetrated the surface .
Julian calendar
31 , 29 / 30 , 31 , 30 , 31 , 30 , 31 , 30 , 31 , 30 , 31 , 30 .
Observable universe
Observable universe Visualization of the whole observable universe . The scale is such that the fine grains represent collections of large numbers of superclusters . The Virgo Supercluster -- home of Milky Way -- is marked at the center , but is too small to be seen . Diameter 7026880000000000000 ♠ 8.8 × 10 m ( 28.5 Gpc or 93 Gly ) Volume 7080400000000000000 ♠ 4 × 10 m Mass ( ordinary matter ) 10 kg Density 6973990000000000000 ♠ 9.9 × 10 g / cm ( equivalent to 6 protons per cubic meter of space ) Age 7010137990000000000 ♠ 13.799 ± 0.021 billion years Average temperature 2.72548 K Contents Ordinary ( baryonic ) matter ( 4.9 % ) Dark matter ( 26.8 % ) Dark energy ( 68.3 % )
Geologic time scale
Corresponding to eons , eras , periods , epochs and ages , the terms `` eonothem '' , `` erathem '' , `` system '' , `` series '' , `` stage '' are used to refer to the layers of rock that belong to these stretches of geologic time in Earth 's history .
Precambrian
The Precambrian ( colored green in the timeline figure ) is a supereon that is subdivided into three eons ( Hadean , Archean , Proterozoic ) of the geologic time scale . It spans from the formation of Earth about 4.6 billion years ago ( Ga ) to the beginning of the Cambrian Period , about 541 million years ago ( Ma ) , when hard - shelled creatures first appeared in abundance .
Maya calendar
Table of Long Count units Long Count unit Long Count period Days Approximate Solar Years 1 K'in 1 Winal 20 K'in 20 1 Tun 18 Winal 360 7000100000000000000 ♠ 1 1 K'atun 20 Tun 7,200 7001200000000000000 ♠ 20 1 B'ak'tun 20 K'atun 144,000 7002394000000000000 ♠ 394 1 Piktun 20 B'ak'tun 2,880,000 7003788500000000000 ♠ 7,885 1 Kalabtun 20 Piktun 57,600,000 7005157704000000000 ♠ 157,704 1 K'inchiltun 20 Kalabtun 1,152,000,000 7006315407100000000 ♠ 3,154,071 1 Alautun 20 K'inchiltun 23,040,000,000 7007630814290000000 ♠ 63,081,429
Precambrian
The term `` Precambrian '' is recognized by the International Commission on Stratigraphy as the only `` supereon '' in geologic time ; it is so called because it includes the Hadean ( ~ 4.6 - 4 billion ) , Archean ( 4 - 2.5 billion ) , and Proterozoic ( 2.5 billion - 541 million ) eons . ( There is only one other eon : the Phanerozoic , 541 million - present . ) `` Precambrian '' is still used by geologists and paleontologists for general discussions not requiring the more specific eon names .
Halley's Comet
Halley has probably been in its current orbit for 16,000 -- 200,000 years , although it is not possible to numerically integrate its orbit for more than a few tens of apparitions , and close approaches before 837 AD can only be verified from recorded observations . The non-gravitational effects can be crucial ; as Halley approaches the Sun , it expels jets of sublimating gas from its surface , which knock it very slightly off its orbital path . These orbital changes cause delays in its perihelion of four days , average .
Star formation
MWC 349 was first discovered in 1978 , and is estimated to be only 1,000 years old . VLA 1623 -- The first exemplar Class 0 protostar , a type of embedded protostar that has yet to accrete the majority of its mass . Found in 1993 , is possibly younger than 10,000 years . L1014 -- An extremely faint embedded object representative of a new class of sources that are only now being detected with the newest telescopes . Their status is still undetermined , they could be the youngest low - mass Class 0 protostars yet seen or even very low - mass evolved objects ( like a brown dwarf or even an interstellar planet ) . IRS 8 * -- The youngest known main sequence star in the Galactic Center region , discovered in August 2006 . It is estimated to be 3.5 million years old .
Maya civilization
Long Count periods Period Calculation Span Years ( approx . ) k'in 1 day 1 day winal 1 x 20 20 days tun 18 x 20 360 days 1 year k'atun 20 x 18 x 20 7,200 days 20 years bak'tun 20 x 18 x 20 x 20 144,000 days 394 years piktun 20 x 18 x 20 x 20 x 20 2,880,000 days 7,885 years kalabtun 20 x 18 x 20 x 20 x 20 x 20 57,600,000 days 157,700 years kinchiltun 20 x 18 x 20 x 20 x 20 x 20 x 20 1,152,000,000 days 3,154,004 years alawtun 20 x 18 x 20 x 20 x 20 x 20 x 20 x 20 23,040,000,000 days 63,080,082 years
History of calendars
The ancient Athenian calendar was a lunisolar calendar with 354 - day years , consisting of twelve months of alternating length of 29 or 30 days . To keep the calendar in line with the solar year of 365.242 days , an extra , intercalary month was added in every other year . The Athenian months were called Hekatombion , Metageitnion , Boedromion , Pyanepsion , Maimakterion , Poseidon , Gamelion , Anthesterion , Elaphebolion , Munychion , Thargelion , and Skirophorion . The intercalary month usually came after Poseidon , and was called second Poseidon .