generic image
Processing...
  • Games
  • Catalog
  • Develop
  • Robux
  • Search in Players
  • Search in Games
  • Search in Catalog
  • Search in Groups
  • Search in Library
  • Log In
  • Sign Up
  • Games
  • Catalog
  • Develop
  • Robux
   
ROBLOX Forum » Club Houses » Off Topic
Home Search
 

Re: About Earth

Previous Thread :: Next Thread 
FlameingBird545 is not online. FlameingBird545
Joined: 26 Jul 2013
Total Posts: 345
03 Sep 2013 01:33 AM
Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets. It is sometimes referred to as the world or the Blue Planet.[22]
Earth formed approximately 4.54 billion years ago, and life appeared on its surface within its first billion years.[23] Earth's biosphere then significantly altered the atmospheric and other basic physical conditions, which enabled the proliferation of organisms as well as the formation of the ozone layer, which together with Earth's magnetic field blocked harmful solar radiation, and permitted formerly ocean-confined life to move safely to land.[24] The physical properties of the Earth, as well as its geological history and orbit, have allowed life to persist. Estimates on how much longer the planet will be able to continue to support life range from 500 million years (myr), to as long as 2.3 billion years (byr).[25][26][27]
Earth's lithosphere is divided into several rigid segments, or tectonic plates, that migrate across the surface over periods of many millions of years. About 71% of the surface is covered by salt water oceans, with the remainder consisting of continents and islands which together have many lakes and other sources of water that contribute to the hydrosphere. Earth's poles are mostly covered with ice that is the solid ice of the Antarctic ice sheet and the sea ice that is the polar ice packs. The planet's interior remains active, with a solid iron inner core, a liquid outer core that generates the magnetic field, and a thick layer of relatively solid mantle.
Earth gravitationally interacts with other objects in space, especially the Sun and the Moon. During one orbit around the Sun, the Earth rotates about its own axis 366.26 times, creating 365.26 solar days, or one sidereal year.[note 7] The Earth's axis of rotation is tilted 23.4° away from the perpendicular of its orbital plane, producing seasonal variations on the planet's surface with a period of one tropical year (365.24 solar days).[28] The Moon is Earth's only natural satellite. It began orbiting the Earth about 4.53 billion years ago (bya). The Moon's gravitational interaction with Earth stimulates ocean tides, stabilizes the axial tilt, and gradually slows the planet's rotation.
The planet is home to millions of species of life, including humans.[29] Both the mineral resources of the planet and the products of the biosphere contribute resources that are used to support a global human population.[30] These inhabitants are grouped into about 200 independent sovereign states, which interact through diplomacy, travel, trade, and military action. Human cultures have developed many views of the planet, including its personification as a planetary deity, its shape as flat, its position as the center of the universe, and in the modern Gaia Principle, as a single, self-regulating organism in its own right.
Name and etymology

The modern English noun earth developed from Middle English erthe (recorded in 1137), itself from Old English eorthe (dating from before 725), deriving from Proto-Germanic *erthō. Earth has cognates in all other Germanic languages, including Dutch aarde, German Erde, and Swedish, Norwegian, and Danish jord.[31] The Earth is personified as a goddess in Germanic paganism (appearing as Jörð in Norse mythology, mother of the god Thor).[32]
In general English usage, the name earth can be capitalized or spelled in lowercase interchangeably, either when used absolutely or prefixed with "the" (i.e. "Earth", "the Earth", "earth", or "the earth"). Many deliberately spell the name of the planet with a capital, both as "Earth" or "the Earth". This is to distinguish it as a proper noun, distinct from the senses of the term as a mass noun or verb (e.g. referring to soil, the ground, earthing in the electrical sense, etc.). Oxford spelling recognizes the lowercase form as the most common, with the capitalized form as a variant of it. Another common convention is to spell the name with a capital when occurring absolutely (e.g. Earth's atmosphere) and lowercase when preceded by "the" (e.g. the atmosphere of the earth). The term almost exclusively exists in lowercase when appearing in common phrases, even without "the" preceding it (e.g. "It does not cost the earth.", "What on earth are you doing?").[33]
Chronology

Formation
Main article: History of the Earth


Artist's impression of the birth of the Solar System
The earliest material found in the Solar System is dated to 4.5672±0.0006 bya;[34] therefore, it is inferred that the Earth must have been formed by accretion around this time. By 4.54±0.04 bya[23] the primordial Earth had formed. The formation and evolution of the Solar System bodies occurred in tandem 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 in tandem with the star. A nebula contains gas, ice grains and dust (including primordial nuclides). In nebular theory planetesimals commence forming as particulate accrues by cohesive clumping and then by gravity. The assembly of the primordial Earth proceeded for 10–20 myr.[35] The Moon formed shortly thereafter, about 4.53 bya.[36]
The Moon's formation remains debated. The working hypothesis is that it formed by accretion from material loosed from the Earth after a Mars-sized object dubbed Theia impacted with Earth.[37] The model, however, is not self-consistent. In this scenario, the mass of Theia is 10% of the Earth's mass,[38] it impacts with the Earth in a glancing blow,[39] and some of its mass merges with the Earth. Between approximately 3.8 and 4.1 bya, numerous asteroid impacts during the Late Heavy Bombardment caused significant changes to the greater surface environment of the Moon, and by inference, to the Earth.
Geological history
Main article: Geological history of Earth
Earth's atmosphere and oceans formed by volcanic activity and outgassing that included water vapor. The origin of the world's oceans was condensation augmented by water and ice delivered by asteroids, proto-planets, and comets.[40] In this model, atmospheric "greenhouse gases" kept the oceans from freezing while the newly forming Sun was only at 70% luminosity.[41] By 3.5 bya, the Earth's magnetic field was established, which helped prevent the atmosphere from being stripped away by the solar wind.[42]
A crust formed when the molten outer layer of the planet Earth cooled to form a solid as the accumulated water vapor began to act in the atmosphere. The two models[43] that explain land mass propose either a steady growth to the present-day forms[44] or, more likely, a rapid growth[45] early in Earth history[46] followed by a long-term steady continental area.[47][48][49] Continents formed by plate tectonics, a process ultimately driven by the continuous loss of heat from the earth's interior. On time scales lasting hundreds of millions of years, the supercontinents have formed and broken up three times. Roughly 750 mya (million years ago), one of the earliest known supercontinents, Rodinia, began to break apart. The continents later recombined to form Pannotia, 600–540 mya, then finally Pangaea, which also broke apart 180 mya.[50]
The present pattern of ice ages began about 40 mya and then intensified during the Pleistocene about 3 mya. High-latitude regions have since undergone repeated cycles of glaciation and thaw, repeating every 40–100,000 years. The last continental glaciation ended 10,000 years ago.[51]
Evolution of life
Main article: Evolutionary history of life


Stratocumulus clouds over the Pacific, viewed from orbit. Over 70% percent of Earth's surface is covered with water, which contains about half of the planet's species.[52]
Highly energetic chemistry is thought to have produced a self-replicating molecule around 4 bya and half a billion years later the last common ancestor of all life existed.[53] The development of photosynthesis allowed the Sun's energy to be harvested directly by life forms; the resultant oxygen accumulated in the atmosphere and formed a layer of ozone (a form of molecular oxygen [O3]) in the upper atmosphere. The incorporation of smaller cells within larger ones resulted in the development of complex cells called eukaryotes.[54] True multicellular organisms formed as cells within colonies became increasingly specialized. Aided by the absorption of harmful ultraviolet radiation by the ozone layer, life colonized the surface of Earth.[55]
Since the 1960s, it has been hypothesized that severe glacial action between 750 and 580 mya, during the Neoproterozoic, covered much of the planet in a sheet of ice. This hypothesis has been termed "Snowball Earth", and is of particular interest because it preceded the Cambrian explosion, when multicellular life forms began to proliferate.[56]
Following the Cambrian explosion, about 535 mya, there have been five major mass extinctions.[57] The most recent such event was 66 mya, when an asteroid impact triggered the extinction of the (non-avian) dinosaurs and other large reptiles, but spared some small animals such as mammals, which then resembled shrews. Over the past 66 myr, mammalian life has diversified, and several million years ago an African ape-like animal such as Orrorin tugenensis gained the ability to stand upright.[58] This enabled tool use and encouraged communication that provided the nutrition and stimulation needed for a larger brain, which allowed the evolution of the human race. The development of agriculture, and then civilization, allowed humans to influence the Earth in a short time span as no other life form had,[59] affecting both the nature and quantity of other life forms.
Future
Main article: Future of the Earth
See also: Risks to civilization, humans, and planet Earth
14 billion year timeline showing Sun's present age at 4.6 byr; from 6 byr Sun gradually warming, becoming a red dwarf at 10 byr, "soon" followed by its transformation into a white dwarf star

The life cycle of the Sun
The future of the planet is closely tied to that of the Sun. As a result of the steady accumulation of helium at the Sun's core, the star's total luminosity will slowly increase. The luminosity of the Sun will grow by 10% over the next 1.1 byr and by 40% over the next 3.5 byr.[60] Climate models indicate that the rise in radiation reaching the Earth is likely to have dire consequences, including the loss of the planet's oceans.[61]
The Earth's increasing surface temperature will accelerate the inorganic CO2 cycle, reducing its concentration to levels lethally low for plants (10 ppm for C4 photosynthesis) in approximately 500-900 myr.[25] The lack of vegetation will result in the loss of oxygen in the atmosphere, so animal life will become extinct within several million more years.[62] After another billion years all surface water will have disappeared[26] and the mean global temperature will reach 70 °C[62] (158 °F). The Earth is expected to be effectively habitable for about another 500 myr from that point,[25] although this may be extended up to 2.3 byr if the nitrogen is removed from the atmosphere.[27] Even if the Sun were eternal and stable, 27% of the water in the modern oceans will descend to the mantle in one billion years, due to reduced steam venting from mid-ocean ridges.[63]
The Sun, as part of its evolution, will become a red giant in about 5 byr. Models predict that the Sun will expand out to about 250 times its present radius, roughly 1 AU (150,000,000 km).[60][64] Earth's fate is less clear. As a red giant, the Sun will lose roughly 30% of its mass, so, without tidal effects, the Earth will move to an orbit 1.7 AU (250,000,000 km) from the Sun, when the star reaches its maximum radius. The planet was, therefore, initially expected to escape envelopment by the expanded Sun's sparse outer atmosphere, though most, if not all, remaining life would have been destroyed by the Sun's increased luminosity (peaking at about 5,000 times its present level).[60] A 2008 simulation indicates that the Earth's orbit will decay due to tidal effects and drag, causing it to enter the red giant Sun's atmosphere and be vaporized.[64] After that, the Sun's core will collapse into a white dwarf, as its outer layers are ejected into space as a planetary nebula. The matter that once made up the Earth will be released into interstellar space, where it may one day become incorporated into a new generation of planets and other celestial bodies.
Composition and structure



Size comparison of inner planets (left to right): Mercury, Venus, Earth and Mars in true-color.
Main article: Earth science
Further information: Earth physical characteristics tables
Earth is a terrestrial planet, meaning that it is a rocky body, rather than a gas giant like Jupiter. It is the largest of the four terrestrial planets in size and mass. Of these four planets, Earth also has the highest density, the highest surface gravity, the strongest magnetic field, and fastest rotation,[65] and is probably the only one with active plate tectonics.[66]
Shape
Main article: Figure of the Earth


Chimborazo, Ecuador. The furthermost point on the Earth's surface from its center.[67]
The shape of the Earth approximates an oblate spheroid, a sphere flattened along the axis from pole to pole such that there is a bulge around the equator.[68] This bulge results from the rotation of the Earth, and causes the diameter at the equator to be 43 km (kilometer) larger than the pole-to-pole diameter.[69] For this reason the furthest point on the surface from the Earth's center of mass is the Chimborazo volcano in Ecuador.[70] The average diameter of the reference spheroid is about 12,742 km, which is approximately 40,000 km/π, as the meter was originally defined as 1/10,000,000 of the distance from the equator to the North Pole through Paris, France.[71]
Local topography deviates from this idealized spheroid, although on a global scale, these deviations are small: Earth has a tolerance of about one part in about 584, or 0.17%, from the reference spheroid, which is less than the 0.22% tolerance allowed in billiard balls.[72] The largest local deviations in the rocky surface of the Earth are Mount Everest (8,848 m above local sea level) and the Mariana Trench (10,911 m below local sea level). Due to the equatorial bulge, the surface locations farthest from the center of the Earth are the summits of Mount Chimborazo in Ecuador and Huascarán in Peru.[73][74][75]
Chemical composition of the crust[76]
Compound Formula Composition
Continental Oceanic
silica SiO2 60.2% 48.6%
alumina Al2O3 15.2% 16.5%
lime CaO 5.5% 12.3%
magnesia MgO 3.1% 6.8%
iron(II) oxide FeO 3.8% 6.2%
sodium oxide Na2O 3.0% 2.6%
potassium oxide K2O 2.8% 0.4%
iron(III) oxide Fe2O3 2.5% 2.3%
water H2O 1.4% 1.1%
carbon dioxide CO2 1.2% 1.4%
titanium dioxide TiO2 0.7% 1.4%
phosphorus pentoxide P2O5 0.2% 0.3%
Total 99.6% 99.9%
Chemical composition
See also: Abundance of elements on Earth
The mass of the Earth is approximately 5.98×1024 kg. It is composed mostly of iron (32.1%), oxygen (30.1%), silicon (15.1%), magnesium (13.9%), sulfur (2.9%), nickel (1.8%), calcium (1.5%), and aluminium (1.4%); with the remaining 1.2% consisting of trace amounts of other elements. Due to mass segregation, the core region is believed to be primarily composed of iron (88.8%), with smaller amounts of nickel (5.8%), sulfur (4.5%), and less than 1% trace elements.[77]
The geochemist F. W. Clarke calculated that a little more than 47% of the Earth's crust consists of oxygen. The more common rock constituents of the Earth's crust are nearly all oxides; chlorine, sulfur and fluorine are the only important exceptions to this and their total amount in any rock is usually much less than 1%. The principal oxides are silica, alumina, iron oxides, lime, magnesia, potash and soda. The silica functions principally as an acid, forming silicates, and all the commonest minerals of igneous rocks are of this nature. From a computation based on 1,672 analyses of all kinds of rocks, Clarke deduced that 99.22% were composed of 11 oxides (see the table at right), with the other constituents occurring in minute quantities.[78]
Internal structure
Main article: Structure of the Earth
The interior of the Earth, like that of the other terrestrial planets, is divided into layers by their chemical or physical (rheological) properties, but unlike the other terrestrial planets, it has a distinct outer and inner core. The outer layer of the Earth is a chemically distinct silicate solid crust, which is underlain by a highly viscous solid mantle. The crust is separated from the mantle by the Mohorovičić discontinuity, and the thickness of the crust varies: averaging 6 km (kilometers) under the oceans and 30-50 km on the continents. The crust and the cold, rigid, top of the upper mantle are collectively known as the lithosphere, and it is of the lithosphere that the tectonic plates are comprised. Beneath the lithosphere is the asthenosphere, a relatively low-viscosity layer on which the lithosphere rides. Important changes in crystal structure within the mantle occur at 410 and 660 km below the surface, spanning a transition zone that separates the upper and lower mantle. Beneath the mantle, an extremely low viscosity liquid outer core lies above a solid inner core.[79] The inner core may rotate at a slightly higher angular velocity than the remainder of the planet, advancing by 0.1–0.5° per year.[80]
Geologic layers of the Earth[81]
Earth-crust-cutaway-english.svg

Earth cutaway from core to exosphere. Not to scale. Depth[82]
km Component Layer Density
g/cm3
0–60 Lithosphere[note 8] —
0–35 Crust[note 9] 2.2–2.9
35–60 Upper mantle 3.4–4.4
35–2890 Mantle 3.4–5.6
100–700 Asthenosphere —
2890–5100 Outer core 9.9–12.2
5100–6378 Inner core 12.8–13.1
Report Abuse
BobafrigginFeet is not online. BobafrigginFeet
Joined: 12 Nov 2011
Total Posts: 26012
03 Sep 2013 01:34 AM
http://www.youtube.com/watch?v=7-Y4JI_VpTE

k.
Report Abuse
BaconSoap is not online. BaconSoap
Joined: 12 Sep 2010
Total Posts: 1882
03 Sep 2013 01:34 AM
To sum it up, Earth is a rock floating in a void populated by carbon-based sausage creatures.
Report Abuse
FlameingBird545 is not online. FlameingBird545
Joined: 26 Jul 2013
Total Posts: 345
03 Sep 2013 01:35 AM
@bacon
LOL
Report Abuse
FlameingBird545 is not online. FlameingBird545
Joined: 26 Jul 2013
Total Posts: 345
03 Sep 2013 01:36 AM
@Boba
Nice video
Report Abuse
Xedra is not online. Xedra
Joined: 14 Sep 2007
Total Posts: 2163
03 Sep 2013 01:37 AM
eltontechnologies
Report Abuse
leates is not online. leates
Joined: 16 Jan 2009
Total Posts: 5650
03 Sep 2013 01:48 AM
It is obvious that this was copied off of the Internet, from a website such as Wikipedia. Do you know why?

A lot of Wikipedia's images are *.svg files, and if you look closely, you have copied a whole section of the page, including where the images are supposed to be. So you can see some image file names in there! :)
Report Abuse
FlameingBird545 is not online. FlameingBird545
Joined: 26 Jul 2013
Total Posts: 345
03 Sep 2013 01:49 AM
@leates
Oh no....
Report Abuse
simplebond1 is not online. simplebond1
Joined: 02 Apr 2011
Total Posts: 13440
03 Sep 2013 01:49 AM
@leates umg u so smrt
Report Abuse
FlameingBird545 is not online. FlameingBird545
Joined: 26 Jul 2013
Total Posts: 345
03 Sep 2013 01:52 AM
@simple
Yep he's so smart :D
Report Abuse
leates is not online. leates
Joined: 16 Jan 2009
Total Posts: 5650
03 Sep 2013 01:55 AM
Haha.
Report Abuse
leates is not online. leates
Joined: 16 Jan 2009
Total Posts: 5650
03 Sep 2013 01:56 AM
Thanks!
Report Abuse
Moristhecat is not online. Moristhecat
Joined: 02 Oct 2008
Total Posts: 30294
03 Sep 2013 01:57 AM
Apparently I was the only one to think he was referring to the OT'er, Earth.
Report Abuse
FlameingBird545 is not online. FlameingBird545
Joined: 26 Jul 2013
Total Posts: 345
03 Sep 2013 02:00 AM
@leates
No worries
Report Abuse
goof333 is not online. goof333
Joined: 27 Aug 2008
Total Posts: 16615
03 Sep 2013 02:01 AM
HNNNGGGGGGGG...!

That wall of text damaged my tired brain.
Report Abuse
FlameingBird545 is not online. FlameingBird545
Joined: 26 Jul 2013
Total Posts: 345
03 Sep 2013 02:04 AM
@goof
NICE BRAIN YOU HAVE THERE.
Report Abuse
XxepicpupxX is not online. XxepicpupxX
Joined: 30 Jan 2011
Total Posts: 8096
03 Sep 2013 02:04 AM
tl;dr

- the chicken crossed the road to get away from you -
Report Abuse
xxTeddyAveryxx is not online. xxTeddyAveryxx
Joined: 01 Mar 2013
Total Posts: 1462
03 Sep 2013 02:05 AM
Copy and pasted?


Looks like it.
Report Abuse
FlameingBird545 is not online. FlameingBird545
Joined: 26 Jul 2013
Total Posts: 345
03 Sep 2013 02:11 AM
@Teddy
Yea i'm beginning to stop copy pasting now :D
Report Abuse
trainboy1249 is not online. trainboy1249
Joined: 25 Dec 2012
Total Posts: 432
03 Sep 2013 02:32 AM
NICE COPING AND PASTING *claps* found this wiki...
Report Abuse
FlameingBird545 is not online. FlameingBird545
Joined: 26 Jul 2013
Total Posts: 345
03 Sep 2013 02:33 AM
@Train
Thanks dude
Report Abuse
friendofaryxsaber is not online. friendofaryxsaber
Joined: 06 Jul 2012
Total Posts: 692
03 Sep 2013 02:35 AM
tl;dr



this ain't science class so get the hell out.
Report Abuse
Previous Thread :: Next Thread 
Page 1 of 1
 
 
ROBLOX Forum » Club Houses » Off Topic
   
 
   
  • About Us
  • Jobs
  • Blog
  • Parents
  • Help
  • Terms
  • Privacy

©2017 Roblox Corporation. Roblox, the Roblox logo, Robux, Bloxy, and Powering Imagination are among our registered and unregistered trademarks in the U.S. and other countries.



Progress
Starting Roblox...
Connecting to Players...
R R

Roblox is now loading. Get ready to play!

R R

You're moments away from getting into the game!

Click here for help

Check Remember my choice and click Launch Application in the dialog box above to join games faster in the future!

Gameplay sponsored by:
Loading 0% - Starting game...
Get more with Builders Club! Join Builders Club
Choose Your Avatar
I have an account
generic image