Supplemental Materials: Passages

Galaxy (easy version)

Agalaxyis a massive system bound by gravity. It consists ofstars,stellar remnants, aninterstellar mediumof gas anddust, anddark matter. Dark matter is an important but poorly understood component. The word galaxy is derived from the Greek galaxias (γαλαξίας). It literally means "milky", a reference to theMilky Way. Examples of galaxies range fromdwarfs with as few as ten million stars to giants with one hundredtrillion stars. Each orbits their galaxy's owncenter of mass. Galaxies contain varying numbers ofplanets,star systems,star clustersand types ofinterstellar clouds. In between these objects is a sparseinterstellar mediumof gas, dust, andcosmic rays.

Supermassive black holesreside at the center of most galaxies. They are thought to be the primary driver ofactive galactic nucleifound at the core of some galaxies. The Milky Way galaxy is known to harbor at least one such object. The first attempt to describe the shape of the Milky Way and the position of theSunin it was carried out byWilliam Herschel.Herschel carefully counted the number of stars in different regions of the sky. He made a diagram of the shape of the galaxy. The solar system was close to the center of his diagram.There are probably more than 170billion galaxies in theobservable universe. Most are 1,000 to 100,000parsecs in diameter. They are usually separated by distances on the order of millions of parsecs (or megaparsecs).Intergalactic spaceis the space between galaxies. It is filled with a tenuous gas of an average density less than oneatomper cubic meter.

Most galaxies are arranged into a family of associations known asgalaxy groupsandclusters. These, in turn, tend to form largersuperclusters. At thelargest scale, these groups and clusters are arranged intosheets and filaments, around which are largevoids. Galaxies have been historically group based on their shape. Their shape is usually referred to as their visual morphology. A common form is theelliptical galaxy. It has anellipse-shaped light profile.Spiral galaxiesare disk-shaped with dusty, curving arms. Those with unusual shapes are known asirregular galaxies.They tend to originate from disruption by the gravitational pull of neighboring galaxies. Such interactions between nearby galaxies may finally result in a merger. This can induce much increased incidents ofstar formation leading tostarburst galaxies. Smaller galaxies lacking a clear structure are calledirregular galaxies.

In October 2013,z8 GND 5296was confirmed to be the most distant galaxy yet found. It is around 13.1 billionlight-yearsfrom Earth. The galaxy appears to astronomers as it was just 700 million years after theBig Bang. At that time, the universe was only about 5 percent of its current age of 13.8 billion years. z8 GND 5296 produces starsat a rate of about 300sunsper year in mass. Tens of thousands of these galaxies have now been catalogued. Only a few have been given a well-known name. These include the Andromeda Galaxy, theMagellanic clouds, theWhirlpool Galaxyand theSombrero Galaxy.

Galaxy (hard version)

Agalaxyis a massive,gravitationally boundsystem consisting ofstars,stellar remnants, aninterstellar mediumof gas anddust, anddark matter, an important but poorly understood component. The word galaxy is derived from theGreekgalaxias(γαλαξίας), literally "milky", which is a reference to theMilky Way. Examples of galaxies range fromdwarfs with as few as ten million stars to giants with one hundredtrillionstars, each orbiting their galaxy's particularcenter of mass. Galaxies contain varying numbers ofplanets,star systems,star clustersand types ofinterstellar clouds, and in between these objects is a sparseinterstellar mediumof gas, dust, andcosmic rays.

Supermassive black holesreside at the center of most galaxies, and black holes are thought to be the primary driver ofactive galactic nucleifound at the core of some galaxies (the Milky Way galaxy has been identified as harboring a minimum of one such object). The first attempt to describe the shape of the Milky Way and the position of theSunin it was carried out byWilliam Herschelin 1785 by carefully counting the number of stars in different regions of the sky and producing a diagram of the shape of the galaxy with the solar system close to the center. There are undoubtedly more than 170billion galaxies in theobservable universe, the majority of which are 1,000 to 100,000parsecs in diameter and usually separated by distances on the order of millions of parsecs (or megaparsecs).Intergalactic space(the space between galaxies) is occupied with a tenuous gas of an average density less than oneatomper cubic meter.

The majority of galaxies are organized into a hierarchy of associations known asgalaxy groupsandclusters, which, in turn usually form largersuperclusters. At thelargest scale, these associations are generally arranged intosheets and filaments, which are surrounded by immensevoids. Galaxies have been historically categorized according to their apparent shape, usually referred to as their visual morphology. A typical form is theelliptical galaxy, having anellipse-shaped light profile.Spiral galaxiesare disk-shaped with dusty, curving arms, and those with irregular or unusual shapes are known asirregular galaxiesand typically originate from disruption by the gravitational pull of neighboring galaxies. Such interactions between nearby galaxies, which may ultimately result in a merger, sometimes induce significantly increased incidents ofstar formation leading tostarburst galaxies. Smaller galaxies lacking a coherent structure are referred to asirregular galaxies.

In October 2013,z8 GND 5296was confirmed to be the most distant galaxy yet discovered, at a distance of approximately 13.1 billionlight-yearsfrom Earth. The galaxy appears to astronomers as it was "just 700 million years after theBig Bang, when the universe was only about 5 percent of its current age of 13.8 billion years,” and it produces starsat a phenomenal rate of about 300sunsper year in mass. Tens of thousands of these galaxies have now been catalogued, although only a few galaxies have been given a well-established name, such as theAndromeda Galaxy, theMagellanic clouds, theWhirlpool Galaxyand theSombrero Galaxy.

Pompeii (easy)

By the 1st century AD, Pompeii was one of a number of towns located near the base of the volcano, Mount Vesuvius. The area had a large population. It grew wealthy from the region'sagricultural fertility. Many of Pompeii's neighboring communities also suffered damage or destruction during the eruption. The eruption occurred on August 24. This was one day afterVulcanalia. Vulcanalia was the festival of the Roman god offire, including that from volcanoes.A multidisciplinary volcanological and bio-anthropological studyexamined the cause of people’s deaths. This study was merged with numerical simulations and experiments. The research showed that heatwas the main cause of death. Previously it was thought that they died by ashsuffocation. The results of the 2010 study showed that exposure to at least 250°C (482°F) hot surges at a distance of 10 km (6 miles) from the vent was enough to cause instant death. Even if people were sheltered in buildings.

The people and buildings of Pompeii were covered in up to twelve different layers of tephra. The tephra was 25 meters deep and rained down for about 6 hours.Pliny the Youngerprovided a first-hand account of the eruption of Mount Vesuvius. He was across theBay of NaplesatMisenum. The account was written 25 years after the event. His uncle,Pliny the Elder, with whom he had a close relationship, died while attempting to rescue stranded victims. Pliny the Elder was an Admiral of the fleet. He had ordered the ships of the Imperial Navy stationed at Misenum to cross the bay to assist evacuation attempts.

Volcanologists have recognised the importance of Pliny the Younger's account of the eruption. They call similar events "Plinian".The eruption was documented by contemporary historians. It is accepted as having started on 24 August 79. This date is based on one version of the text of Pliny's letter. However the archeological excavations of Pompeii suggest that the city was buried about three months later. This is supported by another version of the letterwhich gives the date of the eruption as November 23.People buried in the ash appear to be wearing warmer clothing than the light summer clothes that would be expected in August. The fresh fruit and vegetables in the shops are typical of October. Conversely, the summer fruit that would have been typical of August was already being sold in dried, or conserved form. Wine fermenting jars had been sealed over. This would have happened around the end of October. Coins were found in the purse of a woman buried in the ash. They include one which features a fifteenth imperatorial acclamation among the emperor's titles. These cannot have been minted before the second week of September. So far there is no definitive theory as to why there should be such a discrepancy.

Pompeii has been a tourist destination for over 250 years. Today it hasUNESCOWorld Heritage Sitestatus. It is one of the most popular tourist attractions of Italy. About 2.5 million people visit every year.

Pompeii (hard)

By the 1st century AD, Pompeii was one numerous towns located near the base of the volcano, Mount Vesuvius, an area that had a substantial population which grew prosperous from the region's renowned agricultural fertility. Many of Pompeii's neighboring communities also suffered damage or destruction during the eruption. It occurred on August 24, just one day afterVulcanalia, the festival of the Roman god offire, including that from volcanoes. A multidisciplinaryvolcanologicalandbio-anthropologicalstudy of the eruption products and victims, merged with numerical simulations and experiments, indicate that heatwas the main cause of death of people, previously believed to have died by ashsuffocation. The results of the study, published in 2010, show that exposure to at least 250°C (482°F) hot surges at a distance of 10 kilometres (6 miles) from the vent was sufficient to cause instant death, even if people were sheltered within buildings.

The people and buildings of Pompeii were covered in up to twelve different layers of tephra, in total 25 meters deep, which rained down for about 6 hours.Pliny the Youngerprovided a first-hand account of the eruption of Mount Vesuvius from his position across theBay of NaplesatMisenum, in a version which was written 25 years after the event. His uncle,Pliny the Elder, with whom he had a close relationship, died while attempting to rescue stranded victims (as Admiral of the fleet, Pliny the Elder had ordered the ships of the Imperial Navy stationed at Misenum to cross the bay to assist evacuation attempts).

Volcanologists have recognised the importance of Pliny the Younger's account of the eruption by calling comparable events "Plinian". The eruption was documented by contemporary historians and is generally accepted as having started on 24 August 79, based on one version of Pliny's letter—however, the archeological excavations of Pompeii suggest that the city was buried approximately three months later, a timeframe that is supported by another version of the letterwhich gives the date of the eruption as November 23. People buried in the ash appear to be wearing warmer clothing than the light summer clothes that would be expected in August. The fresh fruit and vegetables in the shops are typical of October, and conversely the summer fruit that would have been typical of August was already being sold in dried, or conserved form. Wine fermenting jars had been sealed over which would have happened around the end of October, and coins found in the purse of a woman buried in the ash include one which features a fifteenth imperatorial acclamation among the emperor's titles, suggesting that the coins cannot have been minted before the second week of September. So far there is no definitive theory as to why there should be such an apparent discrepancy.

Pompeii has been a tourist destination for over 250 years, and today it hasUNESCOWorld Heritage Sitestatus. It is one of the most popular tourist attractions of Italy, with approximately 2.5 million visitors every year.

Satre (easy)

Jean-Paul Sartre was born in Paris.He was the only child of Jean-Baptiste Sartre, an officer of the French Navy. His mother was Anne-Marie Schweitzer. She was of Alsatian origin and the first cousin of Nobel Prize laureate Albert Schweitzer. (Her father, Charles Schweitzer, was the older brother of Albert Schweitzer's father, Louis Théophile.) When Sartre was two years old, his father died of a fever. Anne-Marie moved back to her parents' house in Meudon. She raised Sartre there with help from her father, a teacher of German. Her father taught Sartre mathematics and introduced him to classical literature at a very early age. When he was twelve, Sartre's mother remarried, and the family moved to La Rochelle, where he was often bullied.

As a teen in the 1920s, Sartre was drawn to philosophy. This occurred after he read Henri Bergson's essay Time and Free Will: An Essay on the Immediate Data of Consciousness. Satre studied and earned a degree in philosophy in Paris. He went tothe École Normale Supérieure, an institute of higher education. It was the alma mater for many well known French thinkers and intellectuals. It was at ENS that Sartre began his lifelong, at times fractious, friendship with Raymond Aron. Sartre was influenced by many aspects of Western philosophy. He adopted ideas from Immanuel Kant, Georg Wilhelm Friedrich Hegel, and Martin Heidegger, among others. Perhaps the biggest influence on Sartre's philosophical growth was his weekly attendanceat Alexandre Kojève's seminars. He went to them for many years.

From his first years in the École Normale, Sartre was one of its fiercest pranksters. In 1927, his antimilitarist satirical cartoon in the revue of the school, coauthored with Georges Canguilhem, upset the director Gustave Lanson. That year, with his comrades Nizan, Larroutis, Baillou and Herland, he organized a media prank. The prank occurred after Charles Lindbergh's successful New York-Paris flight. Sartre and Co. called the newspapers.He told them that Lindbergh was going to be awarded an honorary École degree. Many newspapers, including Le Petit Parisien, announced the event on 25 May. Thousands, including journalists and curious spectators, showed up.They were unaware that what they were witnessing was a stunt involving a Lindbergh look-alike. The public's outcry forced Lanson to resign.

In 1929 at the École Normale, he met Simone de Beauvoir. She studied at the Sorbonne. Simone later went on to become a noted philosopher, writer, and feminist. The two became attached and lifelong companions. They initiated a romantic relationship, though they were not monogamous. The first time Sartre took the exam to become a college instructor, he failed. But he took it a second time and was first in his class. Beauvoir was second.Sartre was drafted into the French Army from 1929 to 1931. He served as a meteorologist for some time. He later argued in 1959 that each French person was responsible for the collective crimes during the Algerian War of Independence. Together, Sartre and de Beauvoir challenged the cultural and social assumptions and expectations of their upbringings. They considered them bourgeois, in both lifestyle and thought.

Satre (hard)

Jean-Paul Sartre was born in Paris as the only child of Jean-Baptiste Sartre, an officer of the French Navy, and Anne-Marie Schweitzer, who was of Alsatian origin and the first cousin of Nobel Prize laureate Albert Schweitzer (her father, Charles Schweitzer, was the older brother of Albert Schweitzer's father, Louis Théophile). When Sartre was two years old, his father died of a fever, and Anne-Marie moved back to her parents' house in Meudon, where she raised Sartre with help from her father, a teacher of German who taught Sartre mathematics and introduced him to classical literature at a very early age. When he was twelve, Sartre's mother remarried, and the family moved to La Rochelle, where he was frequently bullied.

As a teenager in the 1920s, Sartre became attracted to philosophy upon reading Henri Bergson's essay titled Time and Free Will: An Essay on the Immediate Data of Consciousness. Satre studied and earned a degree in philosophy in Paris at the École Normale Supérieure, an institution of higher education that was the alma mater for several prominent French thinkers and intellectuals. It was at ENS that Sartre began his lifelong, sometimes fractious, friendship with Raymond Aron. Sartre was influenced by several aspects of Western philosophy, adopting ideas from Immanuel Kant, Georg Wilhelm Friedrich Hegel, and Martin Heidegger, among others. Perhaps the most decisive influence on Sartre's philosophical development was his weekly attendance at Alexandre Kojève's seminars, which continued for several years.

From his first years in the École Normale, Sartre was one of its fiercest pranksters. In 1927, his antimilitarist satirical cartoon in the revue of the school, coauthored with Georges Canguilhem, particularly upset the director Gustave Lanson, and in the same year, with his comrades Nizan, Larroutis, Baillou and Herland, he organized a media prank following Charles Lindbergh's successful New York-Paris flight. Sartre & Co. called newspapers and informed them that Lindbergh was going to be awarded an honorary École degree, leading many newspapers, including Le Petit Parisien, to announce the event on 25 May. Thousands, including journalists and curious spectators, showed up, unaware that what they were witnessing was a stunt involving a Lindbergh look-alike, and the public's resultant outcry forced Lanson’s resignation.