vania-janet/multiturn-rag-retrieval-data huggingface dataset:
Earth
The oldest material found in the Solar System is dated to 7000456720000000000 ♠ 4.5672 ± 0.0006 billion years ago ( Bya ) . By 7000454000000000000 ♠ 4.54 ± 0.04 Bya the primordial Earth had formed . The bodies in the Solar System formed and evolved with the Sun . In theory , a solar nebula partitions a volume out of a molecular cloud by gravitational collapse , which begins to spin and flatten into a circumstellar disk , and then the planets grow out of that disk with the Sun . A nebula contains gas , ice grains , and dust ( including primordial nuclides ) . According to nebular theory , planetesimals formed by accretion , with the primordial Earth taking 10 -- 7001200000000000000 ♠ 20 million years ( Mys ) to form .
Role of the United States in the Vietnam War
It is widely held that the average U.S. serviceman was nineteen years old , as evidenced by the casual reference in a pop song ( `` 19 '' by Paul Hardcastle ) ; the figure is cited by Lt. Col. Dave Grossman ret. of the Killology Research Group in his 1995 book On Killing : The Psychological Cost of Learning to Kill in War and Society ( p. 265 ) . However , it is disputed by the Vietnam Helicopter Flight Crew Network Website , which claims the average age of MOS 11B personnel was 22 . This compares with 26 years of age for those who participated in World War II . Soldiers served a one - year tour of duty . The average age of the U.S. military men who died in Vietnam was 22.8 years old .
Space Race
Unknown to the Americans , the Soviet Moon program was in deep trouble . After two successive launch failures of the N1 rocket in 1969 , Soviet plans for a piloted landing suffered delay . The launch pad explosion of the N - 1 on July 3 , 1969 , was a significant setback . The rocket hit the pad after an engine shutdown , destroying itself and the launch facility . Without the N - 1 rocket , the USSR could not send a large enough payload to the Moon to land a human and return him safely .
Geologic time scale
When William Smith and Sir Charles Lyell first recognized that rock strata represented successive time periods , time scales could be estimated only very imprecisely since estimates of rates of change were uncertain . While creationists had been proposing dates of around six or seven thousand years for the age of Earth based on the Bible , early geologists were suggesting millions of years for geologic periods , and some were even suggesting a virtually infinite age for Earth . Geologists and paleontologists constructed the geologic table based on the relative positions of different strata and fossils , and estimated the time scales based on studying rates of various kinds of weathering , erosion , sedimentation , and lithification . Until the discovery of radioactivity in 1896 and the development of its geological applications through radiometric dating during the first half of the 20th century , the ages of various rock strata and the age of Earth were the subject of considerable debate .
Bone age
Bone age is the degree of maturation of a child 's bones . As a person grows from fetal life through childhood , puberty , and finishes growth as a young adult , the bones of the skeleton change in size and shape . These changes can be seen by x-ray . The `` bone age '' of a child is the average age at which children reach this stage of bone maturation . A child 's current height and bone age can be used to predict adult height . For most people , their bone age is the same as their biological age but for some individuals , their bone age is a couple years older or younger . Those with advanced bone ages typically hit a growth spurt early on but stop growing early sooner while those with delayed bone ages hit their growth spurt later than normal . Kids who are below average height do not necessarily have a delayed bone age ; in fact their bone age could actually be advanced which if left untreated , will stunt their growth .
Space Race
The UN ultimately created a Treaty on Principles Governing the Activities of States in the Exploration and Use of Outer Space , including the Moon and Other Celestial Bodies , which was signed by the United States , USSR , and the United Kingdom on January 27 , 1967 , and went into force the following October 10 .
Atom
Most of the atoms that make up the Earth and its inhabitants were present in their current form in the nebula that collapsed out of a molecular cloud to form the Solar System . The rest are the result of radioactive decay , and their relative proportion can be used to determine the age of the Earth through radiometric dating . Most of the helium in the crust of the Earth ( about 99 % of the helium from gas wells , as shown by its lower abundance of helium - 3 ) is a product of alpha decay .
Space Race
During the summer of 1968 , the Apollo program hit another snag : the first pilot - rated Lunar Module ( LM ) was not ready for orbital tests in time for a December 1968 launch . NASA planners overcame this challenge by changing the mission flight order , delaying the first LM flight until March 1969 , and sending Apollo 8 into lunar orbit without the LM in December . This mission was in part motivated by intelligence rumors the Soviet Union might be ready for a piloted Zond flight during late 1968 . In September 1968 , Zond 5 made a circumlunar flight with tortoises on board and returned to Earth , accomplishing the first successful water landing of the Soviet space program in the Indian Ocean . It also scared NASA planners , as it took them several days to figure out that it was only an automated flight , not piloted , because voice recordings were transmitted from the craft en route to the Moon . On November 10 , 1968 , another automated test flight , Zond 6 was launched , but this time encountered difficulties in its Earth reentry , and depressurized and deployed its parachute too early , causing it to crash - land only 16 kilometers ( 9.9 mi ) from where it had been launched six days earlier . It turned out there was no chance of a piloted Soviet circumlunar flight during 1968 , due to the unreliability of the Zonds . The
History of the United States (1945–64)
A dramatic shock to Americans ' self - confidence and its technological superiority came in 1957 , when the Soviets beat the United States into outer space by launching Sputnik , the first earth satellite . The space race began , and by the early 1960s the United States had forged ahead , with President Kennedy promising to land a man on the moon by the end of the 1960s -- the landing indeed took place on July 20 , 1969 .
Geologic time scale
The first geologic time scale that included absolute dates was published in 1913 by the British geologist Arthur Holmes . He greatly furthered the newly created discipline of geochronology and published the world - renowned book The Age of the Earth in which he estimated Earth 's age to be at least 1.6 billion years .
Kuiper belt
Further evidence for the existence of the Kuiper belt later emerged from the study of comets . That comets have finite lifespans has been known for some time . As they approach the Sun , its heat causes their volatile surfaces to sublimate into space , gradually dispersing them . In order for comets to continue to be visible over the age of the Solar System , they must be replenished frequently . One such area of replenishment is the Oort cloud , a spherical swarm of comets extending beyond 50,000 AU from the Sun first hypothesised by Dutch astronomer Jan Oort in 1950 . The Oort cloud is thought to be the point of origin of long - period comets , which are those , like Hale -- Bopp , with orbits lasting thousands of years .
Moon landing
The Google Lunar X Prize competition offers a $20 million award for the first privately funded team to land a robotic probe on the Moon . Like the Ansari X Prize before it , the competition aims to advance the state of the art in private space exploration . Of the several competing teams , Puli Space Technologies at one time ( 2012 ) planned to launch in 2014 and Astrobotic Technology plans to launch in the second half of 2016 with their own rover plus another team 's lunar rovers from Hakuto .
Moon landing
Mission Mass ( kg ) Launch vehicle Launch date Goal Result Pioneer 0 38 Thor - Able 17 August 1958 Lunar orbit Failure -- first stage explosion ; destroyed Pioneer 1 34 Thor - Able 11 October 1958 Lunar orbit Failure -- software error ; reentry Pioneer 2 39 Thor - Able 8 November 1958 Lunar orbit Failure -- third stage misfire ; reentry Pioneer 3 6 Juno 6 December 1958 Flyby Failure -- first stage misfire , reentry Pioneer 4 6 Juno 3 March 1959 Flyby Partial success -- first US craft to reach escape velocity , lunar flyby too far to shoot photos due to targeting error ; solar orbit Pioneer P - 1 168 Atlas - Able 24 September 1959 Lunar orbit Failure -- pad explosion ; destroyed Pioneer P - 3 168 Atlas - Able 29 November 1959 Lunar orbit Failure -- payload shroud ; destroyed Pioneer P - 30 175 Atlas - Able 25 September 1960 Lunar orbit Failure -- second stage anomaly ; reentry Pioneer P - 31 175 Atlas - Able 15 December 1960 Lunar orbit Failure -- first stage explosion ; destroyed Ranger 1 306 Atlas -- Agena 23 August 1961 Prototype test Failure -- upper stage anomaly ; reentry Ranger 2 304 Atlas -- Agena 18 November 1961 Prototype test Failure -- upper stage anomaly ; reentry Ranger 3 330 Atlas -- Agena 26 January 1962 Landing Failure -- booster guidance ; solar orbit Ranger 4 331 Atlas -- Agena 23 April 1962 Landing Partial success -- first U.S. spacecraft to reach another celestial body ; crash impact -- no photos returned Ranger 5 342 Atlas -- Agena 18 October 1962 Landing Failure -- spacecraft power ; solar orbit Ranger 6 367 Atlas -- Agena 30 January 1964 Impact Failure -- spacecraft camera ; crash impact Ranger 7 367 Atlas -- Agena 28 July 1964 Impact Success -- returned 4308 photos , crash impact Ranger 8 367 Atlas -- Agena 17 February 1965 Impact Success -- returned 7137 photos , crash impact Ranger 9 367 Atlas -- Agena 21 March 1965 Impact Success -- returned 5814 photos , crash impact
Carbon
Carbon - 14 ( C ) is a naturally occurring radioisotope , created in the upper atmosphere ( lower stratosphere and upper troposphere ) by interaction of nitrogen with cosmic rays . It is found in trace amounts on Earth of 1 part per trillion ( 0.0000000001 % ) or more , mostly confined to the atmosphere and superficial deposits , particularly of peat and other organic materials . This isotope decays by 0.158 MeV β emission . Because of its relatively short half - life of 5730 years , C is virtually absent in ancient rocks . The amount of C in the atmosphere and in living organisms is almost constant , but decreases predictably in their bodies after death . This principle is used in radiocarbon dating , invented in 1949 , which has been used extensively to determine the age of carbonaceous materials with ages up to about 40,000 years .
Cancer (constellation)
The smaller , denser open cluster Messier 67 can also be found in Cancer , 2500 light - years from Earth . It has an area of approximately 0.5 square degrees , the size of the full Moon . It contains approximately 200 stars , the brightest of which are of the tenth magnitude .
Mars
Noachian period ( named after Noachis Terra ) : Formation of the oldest extant surfaces of Mars , 4.5 to 3.5 billion years ago . Noachian age surfaces are scarred by many large impact craters . The Tharsis bulge , a volcanic upland , is thought to have formed during this period , with extensive flooding by liquid water late in the period . Hesperian period ( named after Hesperia Planum ) : 3.5 to between 3.3 and 2.9 billion years ago . The Hesperian period is marked by the formation of extensive lava plains . Amazonian period ( named after Amazonis Planitia ) : between 3.3 and 2.9 billion years ago to the present . Amazonian regions have few meteorite impact craters , but are otherwise quite varied . Olympus Mons formed during this period , with lava flows elsewhere on Mars .
Alan Shepard
Shepard was designated as the commander of the first manned Project Gemini mission , but was grounded in 1963 due to Ménière 's disease , an inner - ear ailment that caused episodes of extreme dizziness and nausea . This was surgically corrected in 1969 , and in 1971 , Shepard commanded the Apollo 14 mission , piloting the Apollo Lunar Module Antares to the most accurate landing of the Apollo missions . At age 47 , he became the fifth , the oldest , and the earliest - born person to walk on the Moon , and the only one of the Mercury Seven astronauts to do so . During the mission , he hit two golf balls on the lunar surface . He was Chief of the Astronaut Office from November 1963 to July 1969 ( the approximate period of his grounding ) , and from June 1971 until his retirement from the United States Navy and NASA on August 1 , 1974 . He was promoted to rear admiral on August 25 , 1971 , the first astronaut to reach that rank .
Age of Enlightenment
There is little consensus on the precise beginning of the Age of Enlightenment , though the beginning of the 18th century ( 1701 ) or the middle of the 17th century ( 1650 ) are often used as epochs . French historians usually place the period , called the Siècle des Lumières ( `` Century of Enlightenments '' ) , between 1715 and 1789 , from the beginning of the reign of Louis XV until the French Revolution . If taken back to the mid-17th century , the Enlightenment would trace its origins to Descartes ' Discourse on the Method , published in 1637 . In France , many cited the publication of Isaac Newton 's Principia Mathematica in 1687 . It is argued by several historians and philosophers that the beginning of the Enlightenment is when Descartes shifted the epistemological basis from external authority to internal certainty by his cogito ergo sum published in 1637 . As to its end , most scholars use the last years of the century , often choosing the French Revolution of 1789 or the beginning of the Napoleonic Wars ( 1804 -- 1815 ) as a convenient point in time with which to date the end of the Enlightenment .
Satellite
In 1957 the Soviet Union launched the world 's first artificial satellite , Sputnik 1 . Since then , about 6,600 satellites from more than 40 countries have been launched . According to a 2013 estimate , 3,600 remained in orbit . Of those , about 1,000 were operational ; while the rest have lived out their useful lives and become space debris . Approximately 500 operational satellites are in low - Earth orbit , 50 are in medium - Earth orbit ( at 20,000 km ) , and the rest are in geostationary orbit ( at 36,000 km ) . A few large satellites have been launched in parts and assembled in orbit . Over a dozen space probes have been placed into orbit around other bodies and become artificial satellites to the Moon , Mercury , Venus , Mars , Jupiter , Saturn , a few asteroids , a comet and the Sun .
Space Race
On December 21 , 1968 , Frank Borman , James Lovell , and William Anders became the first humans to ride the Saturn V rocket into space on Apollo 8 . They also became the first to leave low - Earth orbit and go to another celestial body , and entered lunar orbit on December 24 . They made ten orbits in twenty hours , and transmitted one of the most watched TV broadcasts in history , with their Christmas Eve program from lunar orbit , that concluded with a reading from the biblical Book of Genesis . Two and a half hours after the broadcast , they fired their engine to perform the first trans - Earth injection to leave lunar orbit and return to the Earth . Apollo 8 safely landed in the Pacific Ocean on December 27 , in NASA 's first dawn splashdown and recovery .
Observable universe
13.8 billion light - years The age of the universe is estimated to be 13.8 billion years . While it is commonly understood that nothing can accelerate to velocities equal to or greater than that of light , it is a common misconception that the radius of the observable universe must therefore amount to only 13.8 billion light - years . This reasoning would only make sense if the flat , static Minkowski spacetime conception under special relativity were correct . In the real universe , spacetime is curved in a way that corresponds to the expansion of space , as evidenced by Hubble 's law . Distances obtained as the speed of light multiplied by a cosmological time interval have no direct physical significance .
Moon landing
Plans for manned Moon exploration originated during the Eisenhower administration . In a series of mid-1950s articles in Collier 's magazine , Wernher von Braun had popularized the idea of a manned expedition to the Moon to establish a lunar base . A manned Moon landing posed several daunting technical challenges to the US and USSR . Besides guidance and weight management , atmospheric re-entry without ablative overheating was a major hurdle . After the Soviet Union 's launch of Sputnik , von Braun promoted a plan for the United States Army to establish a military lunar outpost by 1965 .
Time dilation
Gravitational time dilation is at play e.g. for ISS astronauts . While the astronauts ' relative velocity slows down their time , the reduced gravitational influence at their location speeds it up , although at a lesser degree . Also , a climber 's time is theoretically passing slightly faster at the top of a mountain compared to people at sea level . It has also been calculated that due to time dilation , the core of the Earth is 2.5 years younger than the crust . Travel to regions of space where gravitational time dilation is taking place , such as within the gravitational field of a black hole , yet still outside the event horizon , perhaps on a hyperbolic trajectory exiting the field , could yield time - shifting results analogous to those of near - lightspeed space travel .
Moon landing
In early December 1968 the launch window to the Moon opened for the Soviet launch site in Baikonur , giving the USSR their final chance to beat the US to the Moon . Cosmonauts went on alert and asked to fly the Zond spacecraft then in final countdown at Baikonur on the first manned trip to the Moon . Ultimately , however , the Soviet Politburo decided the risk of crew death was unacceptable given the combined poor performance to that point of Zond / Proton and so scrubbed the launch of a manned Soviet lunar mission . Their decision proved to be a wise one , since this unnumbered Zond mission was destroyed in another unmanned test when it was finally launched several weeks later .
Moon landing
Mission Mass ( kg ) Launch vehicle Launch date Goal Result Semyorka -- 8K72 23 September 1958 Impact Failure -- booster malfunction at T+ 93 s Semyorka -- 8K72 12 October 1958 Impact Failure -- booster malfunction at T+ 104 s Semyorka -- 8K72 4 December 1958 Impact Failure -- booster malfunction at T+ 254 s Luna - 1 361 Semyorka -- 8K72 2 January 1959 Impact Partial success -- first spacecraft to reach escape velocity , lunar flyby , solar orbit ; missed the Moon Semyorka -- 8K72 18 June 1959 Impact Failure -- booster malfunction at T+ 153 s Luna - 2 390 Semyorka -- 8K72 12 September 1959 Impact Success -- first lunar impact Luna - 3 270 Semyorka -- 8K72 4 October 1959 Flyby Success -- first photos of lunar far side Semyorka -- 8K72 15 April 1960 Flyby Failure -- booster malfunction , failed to reach Earth orbit Semyorka -- 8K72 16 April 1960 Flyby Failure -- booster malfunction at T+ 1 s Sputnik - 25 Semyorka -- 8K78 4 January 1963 Landing
Halley's Comet
Halley 's orbital period has varied between 74 -- 79 years since 240 BC . Its orbit around the Sun is highly elliptical , with an orbital eccentricity of 0.967 ( with 0 being a circle and 1 being a parabolic trajectory ) . The perihelion , the point in the comet 's orbit when it is nearest the Sun , is just 0.6 AU . This is between the orbits of Mercury and Venus . Its aphelion , or farthest distance from the Sun , is 35 AU ( roughly the distance of Pluto ) . Unusual for an object in the Solar System , Halley 's orbit is retrograde ; it orbits the Sun in the opposite direction to the planets , or , clockwise from above the Sun 's north pole . The orbit is inclined by 18 ° to the ecliptic , with much of it lying south of the ecliptic . ( Because it is retrograde , the true inclination is 162 ° . ) Due to the retrograde orbit , it has one of the highest velocities relative to the Earth of any object in the Solar System . The 1910 passage was at a relative velocity of 70.56 km / s ( 157,838 mph or 254,016 km / h ) . Because its orbit comes close to Earth 's in two places , Halley is associated with two meteor showers : the Eta Aquariids in early May , and the Orionids in late October . Halley is the parent body to the Orionids . Observations conducted around the time of Halley 's appearance in 1986 suggested that the comet could additionally perturb the Eta Aquarid meteor shower , although it might not be the parent of that shower . Orionid
Cave painting
The oldest date given to an animal cave painting is now a pig that has a minimum age of 35,400 years old at Timpuseng cave in Sulawesi , an Indonesian island . Indonesian and Australian scientists have dated other non-figurative paintings on the walls to be approximately 40,000 years old . The method they used to confirm this was dating the age of the stalactites that formed over the top of the paintings . The art is similar in style and method to that of the Indonesian caves as there were also hand stencils and disks made by blowing paint onto the walls . Cave paintings in El Castillo cave were found to date back to at least 37,300 years old by researchers at Bristol University , making them the oldest known cave art in Europe , 5 -- 10,000 years older than previous examples from France . This date coincides with the earliest known evidence for Homo sapiens in Europe . Because of the cave art 's age , some scientists have conjectured that the paintings may have been made by Neanderthals .
History of calendars
The ancient Sumerian calendar divided a year into 12 lunar months of 29 or 30 days . Each month began with the sighting of a new moon . Sumerian months had no uniform name throughout Sumer because of the religious diversity . This resulted in scribes and scholars referring to them as `` the first month '' , `` the fifth month '' etc . To keep the lunar year of 354 days in step with the solar year of 365.242 days an extra month was added periodically , much like a Gregorian leap year . There were no weeks in the Sumerian calendar . Holy days and time off from work were usually celebrated on the first , seventh and fifteenth of each month . In addition to these holy days , there were also feast days which varied from city to city .
Muhammad Yunus
At 72 years old , he was 12 years beyond the legal retirement age for civil servants in Bangladesh in 2011 . Government spokespersons called for Yunus to step down and declared , `` We need to redefine the bank 's role and bring it under closer regulation . ''
Radioactive decay
If an artifact is found to have radioactivity of 4 dpm per gram of its present C , we can find the approximate age of the object using the above equation :