Spherical Earth - Wikipedia
Earth Is Round We Will Meet Again quotes - 1. If it's apart of gods plan than we will meet again Read more quotes and sayings about Earth Is Round We Will. Of all the lessons in friendship, there are two lessons that I think are “A friend is the one who comes in when the whole world has gone out.” George Washington . When they meet again after many years apart, Their friendship is as true as ever.” . You reminded me of an old saying, “Friends make the world go round.”. A farewell is necessary before you can meet again. The world is round and the place which may seem like the end may also be the beginning. ~George Granville, Lord Lansdowne (–), Heroick Love,
Earth's shape is also slightly lumpy because it is composed of different materials of different densities that exert slightly different amounts of gravitational force per volume. The liquidity of a hot, newly formed planet allows heavier elements to sink down to the middle and forces lighter elements closer to the surface, a process known as planetary differentiation. This event is known as the iron catastrophe ; the most abundant heavier elements were iron and nickelwhich now form the Earth's core.
History of Earth Later shape changes and effects[ edit ] Though the surface rocks of the Earth have cooled enough to solidify, the outer core of the planet is still hot enough to remain liquid. Energy is still being released; volcanic and tectonic activity has pushed rocks into hills and mountains and blown them out of calderas. Meteors also create impact craters and surrounding ridges. However, if the energy release ceases from these processes, then they tend to erode away over time and return toward the lowest potential-energy curve of the ellipsoid.
Weather powered by solar energy can also move water, rock, and soil to make the Earth slightly out of round. Earth undulates as the shape of its lowest potential energy changes daily due to the gravity of the Sun and Moon as they move around with respect to the Earth. This is what causes tides in the oceans ' water, which can flow freely along the changing potential.
The same spheroidal shape can be seen from smaller rocky planets like Mars to gas giants like Jupiter. These come in many non-spherical shapes which are lumpy masses accreted haphazardly by in-falling dust and rock; not enough mass falls in to generate the heat needed to complete the rounding. Some SSSBs are just collections of relatively small rocks that are weakly held next to each other by gravity but are not actually fused into a single big bedrock. Some larger SSSBs are nearly round but have not reached hydrostatic equilibrium.
The small Solar System body 4 Vesta is large enough to have undergone at least partial planetary differentiation. Stars like the Sun are also spheroidal due to gravity's effects on their plasmawhich is a free-flowing fluid. Ongoing stellar fusion is a much greater source of heat for stars compared to the initial heat released during formation.
Effects and empirical confirmation[ edit ] The roughly spherical shape of the Earth can be confirmed by many different types of observation from ground level, aircraft, and spacecraft. The shape causes a number of phenomena that a flat Earth would not.
Some of these phenomena and observations would be possible on other shapes, such as a curved disc or torusbut no other shape would explain all of them. Spacecraft[ edit ] Many pictures have been taken of the entire Earth by satellites launched by a variety of governments and private organizations.
Goodbye Quotes - QuoteAuthors | Popular Quotes from Famous Authors
From high orbits, where half the planet can be seen at once, it is plainly spherical. The only way to piece together all the pictures taken of the ground from lower orbits so that all the surface features line up seamlessly and without distortion is to put them on an approximately spherical surface. Astronauts in low Earth orbit can personally see the curvature of the planet, and travel all the way around several times a day.
The astronauts who travelled to the Moon have seen the entire Moon-facing half at once, and can watch the sphere rotate once a day approximately; the Moon is also moving with respect to the Earth.
Aircraft[ edit ] People in high-flying aircraft or skydiving from high-altitude balloons can plainly see the curvature of the Earth. Trying to measure the curvature of the horizon by taking a picture is complicated by the fact that camera lenses can produce distorted images depending on the angle used.
An extreme version of this effect can be seen in the fisheye lens. Scientific measurements would require a carefully calibrated lens. The fastest way for an airplane to travel between two distant cities is a great circle route, which deviates significantly from what would be the fastest straight-line travel path on a flat Earth. Photos of the ground taken from airplanes over a large enough area also do not fit seamlessly together on a flat surface, but do fit on a roughly spherical surface.
Aerial photographs of large areas must be corrected to account for curvature. A spherical surface has a horizon which is closer when viewed from a lower altitude. If the degree of curvature was determined to be the same everywhere on the Earth's surface, and that surface was determined to be large enough, it would show that the Earth is spherical. In practice, this turns out to be an unreliable method of measurement, due to variations in atmospheric refraction.
This additional effect can give the impression that the earth's surface is flat, curved more convexly than it is, or even that it is concaveby bending light travelling near the surface of the earth as happened in various trials of the famous Bedford Level experiment. The phenomenon of variable atmospheric bending can be empirically confirmed by noting that sometimes the refractive layers of air can cause the image of a distant object to be broken into pieces or even turned upside down.
This is commonly seen at sunset, when the sun's shape is distorted, but has also been photographed happening for ships, and has caused the city of Chicago to appear normally, upside down, and broken into pieces from across Lake Michigan from where it is normally below the horizon.
When the atmosphere is relatively well-mixed, the visual effects generally expected of a spherical Earth can be observed. For example, ships travelling on large bodies of water such as the ocean disappear over the horizon progressively, such that the highest part of the ship can still be seen even when lower parts cannot, proportional to distance from the observer.
Goodbye Quotes – The Quote Garden
The same is true of the coastline or mountain when viewed from a ship or from across a large lake or flat terrain. This could be produced by a flat disc that always faces the Moon head-on during the eclipse, but this is inconsistent with the fact that the Moon is only rarely directly overhead during an eclipse.
For each eclipse, the local surface of the Earth is pointed in a somewhat different direction. The shadow of a circular disc held at an angle is an oval, not a circle as is seen during the eclipse. The idea of the Earth being a flat disc is also inconsistent with the fact that a given lunar eclipse is only visible from half of the Earth at a time.
The only shape that casts a round shadow no matter which direction it is pointed is a sphere, and the ancient Greeks deduced that this must mean the Earth is spherical. Moving away from the surface of the Earth means that the ground blocks less and less of the sky.
- We'll Meet Again
- Flat Earth
- The world is small. The earth is round. We’ll meet someday
For example, when viewed from the Moon, the Earth blocks only a small portion of the sky, because it is so distant.
The rate of change in the angle blocked by the sky as altitude increases is different for a disc than a sphere, and values observed show that the Earth is locally convex. The angles blocked would also be different for a mountain close to the edge of a flat Earth compared to a mountain in the middle of a flat Earth, and this is not observed. In theory, measurements of this type from all around the Earth would confirm that it is a complete sphere as opposed to some other shape with convex areas though actually taking all those measurements would be very expensive.
Using other evidence to hypothesize a spherical shape, the medieval Iranian scholar Al-Biruni used this phenomenon to calculate the Earth's circumference to within Unlike the Sun, Moon, and planets, they do not change position with respect to one another at least not perceptibly over the span of a human lifetime ; the shapes of the constellations are always the same. This makes them a convenient reference background for determining the shape of the Earth.
Adding distance measurements on the ground allows calculation of the Earth's size. The fact that different stars are visible from different locations on the Earth was noticed in ancient times. Aristotle wrote that some stars are visible from Egypt which are not visible from Europe. The star Polaris the "North Star" is almost at the center of this rotation which is directly overhead.
The other six months of the year, it is continuously daytime and the light from the Sun mostly blots out the stars. The location of the poles can be defined by these phenomena, which only occur there; more than 24 hours of continuous daylight can occur north of the Arctic Circle and south of the Antarctic Circle.
At the South Polea completely non-overlapping set of constellations are visible during the six months of continuous nighttime, including OrionCruxand Centaurus. The fact that the stars visible from the north and south poles do not overlap must mean that the two observation spots are on opposite sides of the Earth, which is not possible if the Earth is a single-sided disc, but is possible for other shapes like a sphere, but also any other convex shape like a donut or dumbbell.
When facing east, the stars visible from the north pole are on the left, and the stars visible from the south pole are on the right. The direction any intermediate spot on the Earth is facing can also be calculated by measuring the angles of the fixed stars and determining how much of the sky is visible. So for example, both Orion and the Big Dipper are visible during at least part of the year.
Making stellar observations from a representative set of points across the Earth, combined with knowing the shortest on-the-ground distance between any two given points makes an approximate sphere the only possible shape for the Earth.
Knowing the difference in angle between two points on the Earth's surface and the surface distance between them allows a calculation of the Earth's size. Surface circumnavigation[ edit ] Since the s, many people have sailed or flown completely around the world in all directions, and none have discovered an edge or impenetrable barrier. See CircumnavigationArctic explorationand History of Antarctica. Some flat Earth theories that propose the world is a north-pole-centered disc, conceive of Antarctica as an impenetrable ice wall that encircles the planet and hides any edges.
East-west paths form a circle in both disc and spherical geometry. It is possible in this model to traverse the North Pole, but it is not possible to perform a circumnavigation that includes the South Pole which it posits does not exist. Explorers, government researchers, commercial pilots, and tourists have been to Antarctica and found that it is not a large ring that encircles the entire world, but actually a roughly disc-shaped continent smaller than South America but larger than Australia, with an interior that can in fact be traversed in order to take a shorter path from e.
The first land crossing of the entirety of Antarctica was the Commonwealth Trans-Antarctic Expedition inand many exploratory airplanes have since passed over the continent in various directions. With a spherical Earth, half the planet is in daylight at any given time the hemisphere facing the Sun and the other half is experiencing nighttime.
When a given location on the spherical Earth is in sunlight, its antipode - the location exactly on the opposite side of the Earth - is always experiencing nighttime. The spherical shape of the Earth causes the Sun to rise and set at different times in different places, and different locations get different amounts of sunlight each day. In order to explain day and night, time zones, and the seasons, some flat Earth theorists propose that the Sun does not emit light in all directions, but acts more like a spotlight, only illuminating part of the flat Earth at a time.
A spotlight Sun would also appear at different angles in the sky with respect to a flat ground than it does with respect to a curved ground. It has neither upper nor lower regions, nor front nor back.
For whatever is round and bounded on every side by the circumference of a solid sphere, has no beginning or end But as to the fable that there are Antipodes, that is to say, men on the opposite side of the Earth, where the sun rises when it sets to us, men who walk with their feet opposite ours that is on no ground credible.
And, indeed, it is not affirmed that this has been learned by historical knowledge, but by scientific conjecture, on the ground that the Earth is suspended within the concavity of the sky, and that it has as much room on the one side of it as on the other: But they do not remark that, although it be supposed or scientifically demonstrated that the world is of a round and spherical form, yet it does not follow that the other side of the Earth is bare of water; nor even, though it be bare, does it immediately follow that it is peopled.
For Scripture, which proves the truth of its historical statements by the accomplishment of its prophecies, gives no false information; and it is too absurd to say, that some men might have taken ship and traversed the whole wide ocean, and crossed from this side of the world to the other, and that thus even the inhabitants of that distant region are descended from that one first man.
Apparently Augustine saw this picture as more useful for scriptural exegesis than the global Earth at the centre of an immense universe. In it, the author repeatedly expounds the doctrine that the universe consists of only two places, the Earth below the firmament and heaven above it. Carefully drawing on arguments from scripture, he describes the Earth as a rectangle, days' journey long by wide, surrounded by four oceans and enclosed by four massive walls which support the firmament.
The spherical Earth theory is contemptuously dismissed as "pagan". Early Middle Ages Early medieval Christian writers in the early Middle Ages felt little urge to assume flatness of the Earth, though they had fuzzy impressions of the writings of Ptolemy and Aristotle, relying more on Pliny.
Most scientific treatises of classical antiquity in Greek were unavailable, leaving only simplified summaries and compilations. In contrast, the Eastern Roman Empire did not fall, and it preserved the learning. In the Carolingian erascholars discussed Macrobius's view of the antipodes. One of them, the Irish monk Dungalasserted that the tropical gap between our habitable region and the other habitable region to the south was smaller than Macrobius had believed.
This was widely interpreted as referring to a disc-shaped Earth. Some have concluded that he thought the Arctic and Antarctic zones were adjacent to each other. At the same time, Isidore's works also gave the views of sphericity, for example, in chapter 28 of De Natura Rerum, Isidore claims that the sun orbits the Earth and illuminates the other side when it is night on this side.
See French translation of De Natura Rerum. It became an essential part of European medieval culture. Soon after the invention of typography it appeared many times in print. Early medieval writers often had fuzzy and imprecise impressions of both Ptolemy and Aristotle and relied more on Pliny, but they felt with one exceptionlittle urge to assume flatness.
It is, in fact, set like a sphere in the middle of the whole universe. The large number of surviving manuscripts of The Reckoning of Time, copied to meet the Carolingian requirement that all priests should study the computus, indicates that many, if not most, priests were exposed to the idea of the sphericity of the Earth. The only surviving record of the incident is contained in Zachary's reply, datedwhere he wrote: He was later appointed bishop of Salzburgand was canonised in the 13th century.
However the word 'orbis' means 'circle' and there is no record of a globe as a representation of the Earth since ancient times in the west until that of Martin Behaim in Additionally it could well be a representation of the entire 'world' or cosmos. Late Middle Ages Picture from a edition of On the Sphere of the Worldthe most influential astronomy textbook of 13th-century Europe Hermannus Contractus — was among the earliest Christian scholars to estimate the circumference of Earth with Eratosthenes ' method.
Thomas Aquinas —the most important and widely taught theologian of the Middle Ages, believed in a spherical Earth; and he even took for granted his readers also knew the Earth is round.
In Summa Theologiae he wrote: In these explorations, the sun's position moved more northward the further south the explorers travel. Its position directly overhead at noon gave evidence for crossing the equator.
These apparent solar motions in detail were more consistent with north-south curvature and a distant sun, than with any flat-Earth explanation. The ultimate demonstration came when Ferdinand Magellan's expedition completed the first global circumnavigation in Antonio Pigafettaone of the few survivors of the voyage, recorded the loss of a day in the course of the voyage, giving evidence for east-west curvature. No flat-Earth theory could reconcile the daily apparent motions of the sun with the ability to sail around the world, and the loss of a day could make no sense, either.
Islamic scholars Further information: Muslim scholars of the past believed in a spherical Earth. Do the words 'And the Earth We spread out' indicate that it is flat? Yes, because the Earth, even though it is round, is an enormous sphere, and each little part of this enormous sphere, when it is looked at, appears to be flat.
As that is the case, this will dispel what they mentioned of confusion. The evidence for that is the verse in which Allah says interpretation of the meaning: He called them awtaad pegs even though these mountains may have large flat surfaces.
And the same is true in this case. And we have not received anything indicates a denial, not even a single word. He stated that the Arabic word falak Arabic: Ibn Abbas said it is like that of a spinning wheel. The scholar Al-Suyuti stated that the belief in a flat Earth is a deviation.
Beijing in by the Persian astronomer Jamal ad-Dinbut it is not known to have made an impact on the traditional Chinese conception of the shape of the Earth. Myth of the Flat Earth Beginning in the 19th century, a historical myth arose which held that the predominant cosmological doctrine during the Middle Ages was that the Earth was flat.
An early proponent of this myth was the American writer Washington Irvingwho maintained that Christopher Columbus had to overcome the opposition of churchmen to gain sponsorship for his voyage of exploration. Later significant advocates of this view were John William Draper and Andrew Dickson Whitewho used it as a major element in their advocacy of the thesis  that there was a long lasting and essential conflict between science and religion.
Modern flat Earth societies In the modern era, the pseudoscientific belief in a flat Earth has been expressed by a variety of individuals and groups: English writer Samuel Rowbotham —writing under the pseudonym "Parallax", produced a pamphlet, "Zetetic Astronomy", in arguing for a flat Earth and published results of many experiments that tested the curvatures of water over a long drainage ditch, followed by another called The inconsistency of Modern Astronomy and its Opposition to the Scripture.
William Carpentera printer originally from GreenwichEngland home of the Royal Observatory and central to the study of astronomywas a supporter of Rowbotham.