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nebular hypothesis

Definition of nebular hypothesis

Examples of nebular hypothesis in a sentence.

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'nebular hypothesis.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History

1833, in the meaning defined above

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“Nebular hypothesis.” Merriam-Webster.com Dictionary , Merriam-Webster, https://www.merriam-webster.com/dictionary/nebular%20hypothesis. Accessed 10 Apr. 2024.

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8 The Rise and Fall of the Nebular Hypothesis

• Published: August 2023
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The first to explain the origin of the planets and moons was Pierre-Simon Laplace in his 1796 book, Exposition for the System of the World . His theory would dominate science throughout the next century and come to be accepted as a given. He held that the solar system had begun as a hot, rotating gas cloud. As it spun, centrifugal force threw off blobs of gas that coagulated into planets. The planets then repeated the process to create their moons. By the last few decades of the eighteenth century, enough evidence had come to light to call the nebular hypothesis into question, if not to falsify it. This opened the way for three different theories for the origin of the Moon. The fission theory resembled the nebular hypothesis in holding that the gravity of the Sun had pulled off a bulge in the proto-Earth which became the Moon. The co-accretion theory held that the Moon and the Earth had formed near each other and thus were like sister planets. The capture theory imagined that the Moon had started out in some distant region of the solar system but drew near enough to be captured into orbit by the Earth’s gravity.

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Nebular Theory Might Explain How Our Solar System Formed

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Our solar system contains the sun, inner rocky planets, the gas giants , or the outer planets, and other celestial bodies, but how they all formed is something that scientists have debated over time.

The nebular theory , also known as nebular hypothesis , presents one explanation of how the solar system formed. Pierre-Simon, Marquis de Laplace proposed the theory in 1796, stating that solar systems originate from vast clouds of gas and dust, known as solar nebula, within interstellar space.

Learn more about this solar system formation theory and some of the criticism it faced.

What Is the Nebular Theory?

Criticisms of the nebular theory, solar nebular disk model.

Laplace said the material from which the solar system and Earth derived was once a slowly rotating cloud, or nebula, of extremely hot gas. The gas cooled and the nebula began to shrink. As the nebula became smaller, it rotated more rapidly, becoming somewhat flattened at the poles.

A combination of centrifugal force, produced by the nebula's rotation, and gravitational force, from the mass of the nebula, left behind rings of gas as the nebula shrank. These rings condensed into planets and their satellites, while the remaining part of the nebula formed the sun.

The planet formation hypothesis, widely accepted for about a hundred years, has several serious flaws. The most serious concern is the speed of rotation of the sun.

When calculated mathematically on the basis of the known orbital momentum, of the planets, the nebular hypothesis predicts that the sun must rotate about 50 times more rapidly than it actually does. There is also some doubt that the rings pictured by Laplace would ever condense into planets.

In the early 20th century, scientists rejected the nebular hypothesis for the planetesimal hypothesis, which proposes that planets formed from material drawn out of the sun. This theory, too, proved unsatisfactory.

Later theories have revived the concept of a nebular origin for the planets. An educational NASA website states: "You might have heard before that a cloud of gas and dust in space is also called a 'nebula,' so the scientific theory for how stars and planets form from molecular clouds is also sometimes called the Nebular Theory. Nebular Theory tells us that a process known as 'gravitational contraction' occurred, causing parts of the cloud to clump together, which would allow for the Sun and planets to form from it."

Victor Safronov , a Russian astronomer, helped lay the groundwork for the modern understanding of the Solar Nebular Disk Model. His work, particularly in the 1960s and 1970s, was instrumental in shaping our comprehension of how planets form from a protoplanetary disk.

At a time when others did not want to focus on the planetary formation process, Safronov used math to try to explain how the giant planets, inner planets and more came to be. A decade after his research, he published a book presenting his work.

George Wetherill's research also contributed to this area, specifically on the dynamics of planetesimal growth and planetary accretion.

This article was updated in conjunction with AI technology, then fact-checked and edited by a HowStuffWorks editor.

Please copy/paste the following text to properly cite this HowStuffWorks.com article:

e-LUMINESCIENCES: the blog of Jean-Pierre Luminet

Cosmogenesis (8) : The Nebular Hypothesis

Sequel of the preceding post Cosmogenesis (7) : The Date of the Creation

The Nebular Hypothesis

The ancient Babylonians had a different idea of how the world began. They believed that it had evolved rather than being created instantaneously. Assyrian inscriptions have been found which suggest that the cosmos evolved after the Great Flood and that the animal kingdom originated from earth and water. This idea was at least partially incorporated into a monotheist doctrine and found its way into the sacred texts of the Jews, neighbors and disciples of the Babylonians. It was also taken up by the early Ionian philosophers, including Anaximander and Anaximenes, and by the Stoics and atomists.

Democritus developed a theory that the world had originated from the void, a vast region in which atoms were swirling in a whirlpool or vortex. The heaviest matter was sucked into the center of the vortex and condensed to form the earth. The lightest matter was thrown to the outside where it revolved so rapidly that it eventually ignited to form the stars and planets. These celestial bodies, as well as the earth itself, were kept in position by centrifugal force. This concept admitted the possibility that the universe contained an infinite number of objects. It also anticipated the 19th century theory of the origin of the solar system, known as the nebular hypothesis, according to which a “primitive nebula” condensed to form the sun and planets.

The idea of universal evolution had a strong influence on classical thought and developed in various directions during Greek and Roman times. In the first century BC Lucretius extended the theories of atomism and evolution to cover every natural phenomenon [i] and argued that all living things originated from earth. Two centuries later, in his medical treatise On the Use of the Parts of the Body [ii] , the Greek physician Galen (Claudius Galenus) expressed the essentially Stoic view that matter is eternal and that even God is subject to the laws of nature: contrary to the literal interpretation of the Genesis story, he could not have “formed man from the dust of the ground”; he could only have shaped the dust according to the laws governing the behaviour of matter. The Church Fathers, who insisted that the Creation was instantaneous, rejected any sort of evolutionary theory; to them the ideas of the Stoics and atomists were heretical.

In the second half of the 16th century the idea of universal evolution began to be incorporated into the new system of scientific thought resulting from the work of Copernicus, Kepler, Galileo, Descartes and Newton. According to Descartes, for example, space consisted of “whirlpools” of matter whose motion was governed by the laws of physics. Newton, with his theory of universal attraction, was accused of having substituted gravitation for providence, for having replaced God’s spiritual influence on the cosmos by a material mechanism [iii] . A new view of the world had nevertheless been established, whereby the workings of the universe were subject not to the whim of the Almighty but to the laws of physics – it was an irreversible step.

The Descartes system of whirlpools.

In the 18th century Newtonian theory came to dominate astronomical theory. The scriptures could no longer account for the origin of the world but Newton’s “uncreated” universe was no more satisfactory from a philosophical point of view. Moreover, since the earth no longer had a privileged position in relation to other celestial bodies (as it had in a geocentric universe), why should it have been created first? Science had established a new order of creation: first the stars, then the sun and finally the earth.

In the mid-18th century it began to be assumed that the early universe had been filled with some elementary fluid, a primeval substance from which the various celestial bodies had progressively emerged – an idea deriving largely from the Swedish mystic Emanuel Swedenborg. In his Prodromus Principiorum Rerum Naturalium (On the Principles of Natural Things), published in Germany in 1734, Swedenborg made the hypothesis that the planets, including the earth, had once been part of the sun and had separated themselves from it long ago; the solar system as a whole had originally been a nebula – like those we can now see in space – and the sun and the planets had only emerged as separate entities after a long period of evolution. It was therefore Swedenborg who first postulated what we now call the “nebular hypothesis”, although it is often attributed to Buffon.

In 1745, independently of Swedenborg, the French scientist had suggested ways in which celestial objects might have been formed and attempted to explain why all the planets orbited the sun in the same direction. According to Buffon the force that had created the solar system was the impact of a comet; this had thrown lumps of matter, which had been in the process of fusing with the sun, far enough from it not to be drawn back by its gravitational pull (this idea would be taken up again in the early 20th century by the English physicist James Jeans, but unsuccessfully). It is interesting to note that Buffon’s concept of opposing forces – centrifugal and gravitational – supports a myth which dates back to Heraclitus and parts of which are to be found in the Vedas: that of a great “pulsation”, a constant alternation in the balance between attraction and repulsion. Today’s astrophysicists reckon that these two forces coexist, in permanent opposition, in the solar system as well as in every galaxy.

The English scientist Thomas Wright published his major work, An Original Theory or New Hypothesis of the Universe, in 1750 and five years later completed his Universal Architecture (not published in his lifetime). His aim was nothing less than to reveal the Creator’s plan. Astronomy shows us what the universe looks like and determines our position within it but only religion, Wright argued, can give us a true picture of the Creation itself. He wanted to unify what we see through a telescope and what we know of the divine world of the Holy Trinity. The universe must therefore comprise a central region (the kingdom of God and the angels), a sphere surrounding that central kingdom (housing the sun and all the stars with their entourages of planets and living things) and a nebulous outer zone (the realm of the damned).

Despite its intention to reconcile science and religion, Wright’s work influenced rationalists like Herschel, Laplace and the German philosopher Immanuel Kant, whose Theory of the Heavens expressed a number of original ideas on cosmology. Kant applied the principles of Newtonian physics to the nebular hypothesis, giving it a consistency it had previously lacked. As far as the formation of the solar system (and of all other star systems) was concerned Kant had a grandiose vision of a primordial age when the infinite reaches of space were filled with matter, from which the planets and stars were formed. Dark and silent this veil of matter contained the seeds of the universe as we know it. Diderot’s Lettre sur les aveugles à l’usage de ceux qui voient (Note on the Blind for Those who See) of 1749 is a literary presentiment of this primeval state: “How many disfigured, misshapen worlds must have disintegrated and were perhaps being reformed and disintegrating again every second far away in space… where matter swirls and will continue to swirl in great masses until it has achieved a form in which it may survive.”

The French mathematician and astronomer, Pierre Simon, marquis de Laplace, defended the nebular hypothesis even more strongly than Kant, supporting it with mathematical reasoning as well as with reference to celestial mechanics. He proved that our solar system and other planetary and lunar systems were the result of nebulous masses acting in accordance with natural laws, as were the movements of those planets and moons and their relative sizes and distances from each other. Laplace derived his concept of a “primitive nebula” from the observations of astronomers such as Charles Messier and William Herschel, who had used the latest telescopes to catalogue hundreds of nebulous bodies. Some of these appeared to consist not of masses of stars but of clouds of opaque matter, which Laplace concluded must condense into stars. A man who constantly proclaimed, “I do not make hypotheses”, Laplace went on to make the most sensational hypothesis of the century: that the solar system had originated from a primitive nebulosity, a flat disc of slowly rotating matter, which had coalesced into lumps as it contracted and cooled. First its core had formed into a fireball (the infant sun) from which “wisps” of gas had escaped and quickly formed into rings surrounding the core; these rings, initially revolving in ellipses, then broke up into lumps, which condensed into young planets, emerging shining from their misty cocoon.

To believers in the Creation Laplace’s hypothesis was just another form of atheism, since it displaced God from His position as Creator of the stars, and opponents of the theory were delighted when telescopes revealed that some nebulosities were in fact clusters of stars: surely the same was true of all nebulae and it was only a matter of time before more powerful telescopes would prove the fact. The nebular hypothesis therefore remained unsubstantiated until the advent of spectroscopy, which allowed the light emitted by stars to be analyzed. In 1814 the German physicist Joseph von Fraunhofer discovered that the spectrum of a hot gas was broken up by dark lines (now known as Fraunhofer’s lines), caused by chemical elements in the gas. During the 1860s astronomers like Angelo Secchi in Italy and William Huggins in England undertook a systematic study of star spectra, thereby founding the discipline of astrochemistry. Like for the spectra of terrestrial objects, those of celestial objects reveal not only the presence of chemical elements, but also whether the object is solid or gaseous.

Many nebulae were thus proven to be enormous clouds of gas: no telescope, however powerful, would ever show them to consist of stars. Some of them even had a bright central point, indicating that a star was in the process of formation. The publication in the late 19th century of observations by the Irish astronomer William Parsons and by the Dane Heinrich Louis d’Arrest, accompanied by detailed drawings of nebulae, finally confirmed Laplace’s theory and established the nebular hypothesis as part of accepted cosmogony. It also proved to be a major contribution to physics, since it explained a number of the processes of star formation in terms of thermodynamics.

Scientists in various other fields of research dealt further blows to the traditional Creation myth: Darwin, of course, with his theory of evolution, but also archaeologists and philologists, who were studying ancient monuments and hieroglyphs. Historians such as Oppert, Rawlinson and Smith [iv] had succeeded in deciphering the inscriptions found in the great library of Assurbanipal (Sardanapalus) at Nineveh and an account of a deluge in the Epic of Gilgamesh appeared to be the source not only of the Babylonian myths but also of the story of the Great Flood in the bible. Genesis could therefore no longer be considered a reliable account of the Creation, as revealed to Moses by God Himself; it had become just one of many stories about the origin of the world, all of which had been influenced by various cultures and reflected the scientific knowledge of the people who had first conceived and recounted them.

[i] De Natura Rerum, book V.

[ii] De UsuPartium Corporis Humani, 11.14.

[iii] On this controversy see for example McCosh, The Religious Aspect of Evolution, New York, 1890, pp. 103-04.

[iv] George Smith, Chaldean Account of Genesis, New York, 1876, pp. 74-75.

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I felt dizzy and wept, for my eyes had seen that secret and conjectured object whose name is common to all men but which no man has looked upon — the unimaginable universe. Jorge luis Borges, The Aleph (1949)

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Evolution of Astronomy

"There is grandeur in this view of life...  Whilst this planet has been cycling on according to the fixed law of gravity, from so simple a beginning, forms most wonderful have been, and are being, evolved." – On The Origin of Species

• Is There a Chemical Origin of the Species? — Anthony Remijan
• Evolution: A Starry Archetype — David DeVorkin
• The Heavenly Origin of Evolution — Ron Numbers

Is There a Chemical Origin of the Species? — Astrochemists search for precursors to DNA in outer space By Anthony Remijan

Charles Darwin teaches us that by natural selection, the most fit and robust species survive and this leads to a complex chain of events—the formation and evolution of the complex organic systems present on the Earth.

"On the Origin of Species" opened up a new realm of scientific knowledge, arguing that all life-forms seen on the planet today developed through natural selection and evolution.  However, even the simplest of organisms must have had a more humble and fundamental beginning.  Before life ever organized into a single cell, it first needed proteins; and to assemble proteins, it needed to assemble the correct types and number of amino acids. RNA and DNA, the genetic instructions used to create amino acids, are also critical in the development and functioning of all living organisms.

But to truly understand "On the Origin of Species" and the formation of the organic molecules that lie at the heart of life, an even more basic question must be asked: was there a similar "evolution" from smaller, more robust molecules that eventually lead to the molecules that we now call RNA and DNA?  Searching for answers has some scientists looking in a most atypical place: outer space. 

Researchers in a discipline called astrochemistry—the study of chemical elements and molecules in space—are using the most powerful telescopes ever built to search for our molecular origins, led there by a fascinating scientific accomplishment—the famous Miller-Urey experiment of 1953.  Miller-Urey showed that large, organic molecules that form the basis of life on Earth can be formed in an atmosphere of little or no free oxygen.  The result presents an interesting dilemma because it is becoming more evident that the early Earth did not have the low oxygen environment necessary to synthesize these biologically important molecules. 

Unlike the oxidizing atmosphere of primitive Earth, interstellar space is a highly reducing environment, one that is rich in hydrogen and is conducive to the formation of large, organic species that may be the chemical precursors to RNA and DNA.  Evidence of this comes from infrared views of the space dust around newly forming stars.  Looking at these sources of material, we find the most complex of interstellar molecules.  In parts of the Orion nebula, as well as regions of high-mass star formation in our own Milky Way Galaxy, lies a chemistry that is producing molecules from vinegar (acetic acid) to antifreeze (ethylene glycol).

From spectroscopic research conducted via remote sensing at radio telescopes, we now know that interstellar space—the space between stars—which only a few decades ago was widely believed to be hostile to organic chemistry and chemical bonding, contains an astonishingly rich inventory of both familiar and exotic molecules. Furthermore, these molecules are found throughout the universe in giant gas clouds relatively close to Earth in our own Milky Way galaxy, and in external galaxies billions of light years away.

The inventory of interstellar molecules currently stands at 154.  Many are common terrestrial compounds such as water and ammonia, and larger species including alcohols, aldehydes, ethers, carboxylic acids, amines and nitriles.  But an equally large number are exotic by terrestrial standards, generally unknown or unfamiliar to chemists, including both positively and negatively charged molecular ions, radicals, carbenes and their energetic isomers, unusual metal-bearing species, and highly unsaturated organic species, including bare carbon clusters.

It is apparent there is a complex chemistry in space leading to a suite of organic material.  However, the question remains: how do larger, organic species that are the possible precursors to amino acids, or even amino acids themselves, assemble into a self-replicating molecule like RNA?  Is there a preferred "natural selection" that will not only lead to the formation of larger molecules but also eliminate smaller, less robust molecules that cannot survive the harsh environments of interstellar space?

For example, did the first polyatomic molecule detected in space, formaldehyde, evolve into acetone—the main solvent in household nail polish removers or urea (found in the excretion of all terrestrial vertebrates) via the principles of evolution outlined by Darwin?  As intricate as these species seem, they are exceedingly simple compared to a strand of RNA.

One idea, called the "RNA world hypothesis," proposes that life in our world first was based on RNA, which evolved into current life based on DNA.  It argues that RNA is the evolutionary remnant of the RNA world.  DNA, through its greater chemical stability, took over the role of data storage and proteins became the specialized catalytic molecules that fuel the development of life.  Yet there are nearly infinite possibilities of arranging atoms, then molecules, before a species resembling RNA is ever formed.  So while advances in astrochemistry continue to find even more molecular complexity in the universe, we still may never determine how these benign and humble beginnings to organic chemistry manifested themselves into the complex biological systems of today.  However, we continue to search for the answers to our molecular origins by looking out into the universe.

Anthony J. Remijan is an assistant scientist at the National Radio Astronomy Observatory in Charlottesville, Va.  He is a commissioning scientist who helps devise procedures to test and verify the Atacama Large Millimeter/submillimeter Array, a system of 66 radio telescopes that combine their signals to simulate a single, expansive telescope, located on the Chajnantor plateau in the Atacama Desert of northern Chile.  The project is the most ambitious ground-based telescope currently under construction.  Remijan has taught in several educational settings, including the University of Maryland-University College, Prince George's Community College, Parkland College and Illinois State University.  He promotes the sciences of astrochemistry and astrobiology through frequent public speaking and holds a Ph.D. in astronomy from the University of Illinois at Urbana-Champaign.

Please see the Resources section for the Bibliography/Additional Reading list for this essay.

Evolution A Starry Archetype Astronomers adapted Darwinism to create organizational framework that describes cosmic evolution

By Dr. David DeVorkin

Strictly speaking, mainstream 19th and early 20th century astronomers were less influenced by Darwinism than they were a part of a larger movement to think in terms of evolutionary change or "universal evolution."  For astronomers, this meant that systems of planets and stars, and stars and planets themselves, were not static over time, but changed through gravitational processes, the conversion of gravitational potential into motion, light and heat.  It was French mathematician and astronomer Pièrre Simon Laplace's Nebular Hypothesis that galvanized 19th-century thinking, especially in the United States, where the term evolution was quickly appropriated to mean evidence of change in the heavens: of planets, stars and systems of stars.  If Darwinism was linked to astronomical progress, it was more than not derided; in 1871 one writer scoffed at the very idea that life existed on the Earth at a time when, according to Laplace, the Earth was still in nebular condensation. Objections to Darwinism then and for the next few decades, indeed dealt with time scales more than anything else as Joe D. Burchfield and others have examined.

By the late 19th Century, it was George Darwin, not Charles, who offered inspiration to American astronomers. Darwin's second son and fifth child explored tidal evolution of rotating fluid masses, i.e. stars and planets. His teachings regarding the high and low tides of the Earth's solid body, which are very similar to the oceans' high and low tides, informed all subsequent generations about the planet's dynamism. Princeton University astronomer Charles A. Young observed in 1884 that George Darwin's theory of tidal evolution "opened a new field of research, and shown the way to new dominions." Not only did it shed light on the dynamical history of the Earth-Moon system, but, Young implied, it offered a new way to organize research.

For Young, and contemporary Victorian astronomers like Norman Lockyer, the English scientist and astronomer who discovered helium and founded the science journal Nature, universal evolution included studying how the very elements of physical existence formed and grew and could be destroyed during the life cycles of stars. Young encouraged his most illustrious student, Henry Norris Russell, to think in evolutionary terms and hold a naturalistic view of the universe, one of continuous development, presently acting and not confined to original cause. These elements indicate Darwinian thinking. Russell's research, leading to the Hertzsprung-Russell Diagram, the primary descriptive playing field for 20th century stellar astrophysics, was indeed stimulated by a neo-Lockyerian theory of stellar evolution.

A contemporary of Russell's who played possibly the most visible role in America establishing evolutionary thought as the organizing principle for research in astronomy was George Ellery Hale. The driving force behind the establishment of Yerkes Observatory, operated by the University of Chicago in Williams Bay, Wis., one of his first major programs there was to study red stars in the hope that they would lead finally to a "systematic scheme of stellar evolution on spectroscopic observations…" Hale made the observation in Yerkes's Decennial Publications in 1903.

Evolution as Hale understood and expressed it was not Darwinian, but he appropriated Darwinism as a symbol and as an organizing principle. In 1902, he told a popular audience that: "It would be difficult to overestimate the effect which the doctrine of evolution has wrought. The principle of orderly and harmonious development which it embodies has found application, not only in explaining the wide diversity of organic species, but in unifying the events of history, in elucidating the origin of language, and in throwing light on difficult questions in every department of human knowledge."

Over the next decade, Hale used the National Academy of Sciences as a platform to explore what all the sciences could say about the evolution of matter, stars, planets, life, man and society. Among Americans of the intellectual generation following Hale and Russell, leading into the mid-twentieth century, possibly the most ardent proponent of Darwinism—in the manner Hale expressed it—was Russell's former student, Harvard College Observatory director Harlow Shapley, who, unlike the majority of his contemporaries, included biological thinking in his essays on cosmic evolution. As historians have noted, Shapley's 1958 book "Of Stars and Men," a collection of earlier essays and lectures, set the stage for modern American writers—from Sagan to Chaisson—to explore the rich rhetorical landscape made so compelling by Charles Darwin, indeed a popular symbol and organizing principle of modern astronomy.

Dr. David DeVorkin is senior curator of history of astronomy and space sciences at the Smithsonian National Air and Space Museum in Washington, D.C. He is the author/editor/compiler of nine books and more than 100 scholarly and popular articles including "Hubble: Imaging Space and Time" (2008); "Beyond Earth: Mapping the Universe"; "Henry Norris Russell: Dean of American Astronomers"; and "The American Astronomical Society's First Century."

The Heavenly Origin of Evolution Natural selection viewed as logical extension of widely-accepted nebular hypothesis

By Ron Numbers

At the risk of oversimplifying a complex historical narrative, I would like to argue that the history of evolution did not begin in 1859 with Charles Darwin's "Origin of Species," but with the publication in 1796 of Pierre Simon Laplace's so-called nebular hypothesis. In 1798, Laplace, a distinguished French mathematician and astronomer, first suggested that the planets were created from the atmosphere of the sun, which, because of its heat, originally extended beyond the orbit of the most distant planet. As this atmosphere condensed, it abandoned a succession of rings—similar to those of Saturn—in the plane of the sun's equator. These rings then coalesced to form the various planets, similar to the way satellites or moons developed from planetary atmospheres.

Later, after William Herschel, a German-born British astronomer discovered interstellar clouds of dust and gas, called nebulae, Laplace argued that the primitive condition of the solar system resembled a slowly rotating hot nebula. This speculation attracted little attention in the English-speaking world before the 1830s, when several books brought it to the attention of the reading public.  It featured significantly as the beginning of the evolutionary account in the sensational "Vestiges of the Natural History of Creation" (1844), an anonymous work that introduced the idea of evolution, inorganic and organic, to tens of thousands of readers.

By the 1840s and 1850s, the nebular hypothesis was being taught in American colleges and embraced by leading biblical scholars as describing God's method of creating the solar system. Charles Hodge of Princeton Theological Seminary, arguably the most influential American theologian in the middle third of the century, concluded the first verses of Genesis "clearly intimated that the universe, when first created, was in a state of chaos, and that by the life-giving, organizing power of the spirit of God, it was gradually moulded into the wonderful cosmos which we now behold." For him, development from preexisting material clearly fell "within the Scriptural idea of creating." The solar system may have been created by natural laws, but they were God's laws.

By 1859, large segments of American Christians—one contemporary estimated a half—accepted the scientific evidence for an evolved solar system, as well as the great antiquity of life on earth. They had come to think of creation not in six days but over immense periods of time. And, just as important, they had become convinced that science required explaining natural phenomena naturally, not miraculously.

Not surprisingly, a number of the early proponents of Darwinism appealed to the successful accommodation of the nebular hypothesis to justifying accepting organic evolution. Brown University biologist A. S. Packard, for example, noted that the acceptance of the nebular hypothesis led almost directly to the question of "whether plants and animals share in their process of evolution." Numerous others, scientists and clergy alike, made much the same point. For such people, as geologist Clarence King observed, Darwinism was simply the last link in the chain of evolution that began with the nebular hypothesis.

Ron Numbers is a prominent scholar on the history and relationship of science and religion, having co-edited two anthologies on the subject. He is a 2008 recipient of the History of Science Society's George Sarton Medal. Numbers currently is Hilldale and William Coleman Professor of the History of Science and Medicine at the University of Wisconsin-Madison.

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Biology Forums Dictionary

Definition for Nebular theory

From Biology Forums Dictionary

In cosmogony, the nebular hypothesis is the most widely accepted model explaining the formation and evolution of the Solar System. There is evidence that it was first proposed in 1734 by Emanuel Swedenborg. Originally applied only to our own Solar System, this method of planetary system formation is now thought to be at work throughout the universe. The widely accepted modern variant of the nebular hypothesis is Solar Nebular Disk Model (SNDM) or simply Solar Nebular Model.

According to the nebular hypothesis, stars form in massive and dense clouds of molecular hydrogen—giant molecular clouds (GMC). They are gravitationally unstable, and matter coalesces to smaller denser clumps within, which then proceed to collapse and form stars. Star formation is a complex process, which always produces a gaseous protoplanetary disk around the young star. This may give birth to planets in certain circumstances, which are not well known. Thus the formation of planetary systems is thought to be a natural result of star formation. A sun-like star usually takes around 100 million years to form.

The protoplanetary disk is an accretion disk which continues to feed the central star. Initially very hot, the disk later cools in what is known as the T tauri star stage; here, formation of small dust grains made of rocks and ices is possible. The grains may eventually coagulate into kilometer-sized planetesimals. If the disk is massive enough the runaway accretions begin, resulting in the rapid—100,000 to 300,000 years—formation of Moon- to Mars-sized planetary embryos. Near the star, the planetary embryos go through a stage of violent mergers, producing a few terrestrial planets. The last stage takes around 100 million to a billion years.

The formation of giant planets is a more complicated process. It is thought to occur beyond the so-called snow line, where planetary embryos are mainly made of various ices. As a result they are several times more massive than in the inner part of the protoplanetary disk. What follows after the embryo formation is not completely clear. However, some embryos appear to continue to grow and eventually reach 5–10 Earth masses—the threshold value, which is necessary to begin accretion of the hydrogen–helium gas from the disk. The accumulation of gas by the core is initially a slow process, which continues for several million years, but after the forming protoplanet reaches about 30 Earth masses it accelerates and proceeds in a runaway manner. The Jupiter and Saturn–like planets are thought to accumulate the bulk of their mass during only 10,000 years. The accretion stops when the gas is exhausted. The formed planets can migrate over long distances during or after their formation. The ice giants like Uranus and Neptune are thought to be failed cores, which formed too late when the disk had almost disappeared.

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15 intriguing facts about nebular hypothesis.

Written by Vivyanne Lussier

Modified & Updated: 02 Mar 2024

Reviewed by Sherman Smith

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The Nebular Hypothesis is a fascinating concept that attempts to explain the formation of our solar system. Proposed in the 18th century by Immanuel Kant and further developed by Pierre-Simon Laplace, this theory suggests that our solar system originated from a massive rotating cloud of gas and dust known as a nebula.

In this article, we will delve into the intricacies of the Nebular Hypothesis and uncover 15 intriguing facts that shed light on our understanding of how our solar system came into existence. From the creation of the sun and planets to the formation of asteroids and comets , each fact presents a unique perspective on the inner workings of the nebular theory.

So, buckle up and prepare to embark on a cosmic journey as we explore the mysteries of the universe and unravel the secrets hidden within the Nebular Hypothesis.

Key Takeaways:

• The Nebular Hypothesis explains how our solar system formed from a spinning cloud of gas and dust, giving rise to the planets and the sun. It also helps us understand planet formation in other star systems.
• This fascinating theory has shaped our understanding of the universe and continues to inspire scientists to explore the origins of solar systems, pushing the boundaries of our knowledge.

The Nebular Hypothesis is a widely accepted explanation for the formation of the solar system.

The Nebular Hypothesis suggests that the solar system originated from a cloud of gas and dust, known as the solar nebula.

It was first proposed by philosopher Immanuel Kant in the 18th century.

Kant hypothesized that a rotating, flattened disk of gas and dust gradually formed the planets and the sun .

The Nebular Hypothesis was further developed by French mathematician and astronomer Pierre-Simon Laplace in the late 18th century.

Laplace expanded on Kant’s idea, suggesting that the solar nebula contracted due to gravitational forces, causing it to spin faster and flatten into a disk.

According to the Nebular Hypothesis, the sun and planets formed from the collapse of a rotating cloud of gas and dust.

As the solar nebula contracted, it began to spin faster, and the majority of the material collected at the center, forming the sun.

The remaining material in the disk gradually accumulated to form protoplanetary bodies, known as planetesimals.

These planetesimals collided and merged over time, eventually forming the planets we see today.

The Nebular Hypothesis explains why the planets in our solar system orbit the sun in the same direction and roughly in the same plane.

The rotation of the original cloud of gas and dust determined the direction and orientation of the planetary orbits.

It also accounts for the fact that the inner planets (Mercury, Venus, Earth, and Mars) are rocky, while the outer planets (Jupiter, Saturn, Uranus, and Neptune) are composed mostly of gas.

As the solar nebula cooled, volatile compounds accumulated further from the sun, allowing the gas giants to form in the outer regions.

The Nebular Hypothesis suggests that the moon formed from the debris left over after a giant impact between Earth and another celestial body.

This collision ejected material into space , which eventually coalesced to form the moon.

The concept of the Nebular Hypothesis is not restricted to our solar system.

Astronomers have observed similar disk formations around other stars, providing evidence that the process of planet formation is common in the universe.

The Nebular Hypothesis has evolved over time and is continually refined as new observations and data become available.

Advancements in technology and space missions have allowed scientists to gather more information about the formation of planets and the evolution of solar systems.

This hypothesis has gained support from various scientific disciplines, including astronomy, astrophysics, and planetary science.

The wealth of evidence collected from telescopic observations, meteorite analysis, and computer simulations have bolstered the credibility of the Nebular Hypothesis.

The Nebular Hypothesis provides insights into the early stages of planet formation, helping scientists understand the conditions necessary for life to exist.

By studying how planets form within a solar nebula, researchers can better grasp the potential habitability of exoplanets in other star systems.

It can also explain the presence of asteroids and comets in our solar system.

These celestial objects are remnants from the early stages of planetary formation and have been preserved in their original forms.

The Nebular Hypothesis has been instrumental in shaping our understanding of the universe and our place within it.

By providing a framework for how solar systems form, it has laid the foundation for further investigations into planetary science and exoplanet research.

The Nebular Hypothesis continues to spark curiosity and drive scientific inquiry, pushing the boundaries of our knowledge about the origins of the universe.

As technology advances and our understanding deepens, we can expect further advancements and refinements to this intriguing theory.

In conclusion, the Nebular Hypothesis has revolutionized our understanding of the formation and evolution of our universe. Through extensive research and observation, scientists have unraveled the mysteries of planetary systems, including our own solar system . The Nebular Hypothesis proposes that the solar system originated from a giant rotating cloud of gas and dust called the nebula. Over time, gravity caused this nebula to collapse, giving birth to the Sun and forming a rotating disk of material around it. Within this disk, planets, moons, and other celestial objects formed.The study of the Nebular Hypothesis has provided us with intriguing facts about the origins of our solar system and beyond. From the formation of planetary rings to the presence of exoplanets, the Nebular Hypothesis continues to shape our understanding of the vast universe we inhabit.As we delve deeper into the mysteries of the universe, the Nebular Hypothesis serves as a guiding principle, shedding light on the intricate mechanisms that govern the formation and evolution of galaxies , stars, and celestial bodies. Through ongoing research and exploration, we continue to uncover new insights and expand our knowledge of the mesmerizing cosmos.

Q: What is the Nebular Hypothesis?

A: The Nebular Hypothesis is a scientific theory that proposes the formation of our solar system from a giant rotating cloud of gas and dust called the nebula.

Q: Who proposed the Nebular Hypothesis?

A: The Nebular Hypothesis was first proposed by the French mathematician and astronomer Pierre-Simon Laplace in the late 18th century.

Q: How does the Nebular Hypothesis explain the formation of planets?

A: According to the Nebular Hypothesis, as the nebula collapses under gravity, it forms a rotating disk of material around a central protostar, known as the Sun. Within this disk, planetesimals, small rocky bodies, gradually merge and accrete to form planets.

Q: Does the Nebular Hypothesis apply to other planetary systems?

A: Yes , the Nebular Hypothesis is a widely accepted explanation for the formation of planetary systems beyond our own solar system, known as exoplanetary systems.

Q: What evidence supports the Nebular Hypothesis?

A: There is substantial evidence supporting the Nebular Hypothesis, including the observations of protoplanetary disks around young stars, the presence of exoplanetary systems with similar characteristics to our own, and the isotopic composition of meteorites that aligns with predictions made by the hypothesis.

Q: Can the Nebular Hypothesis explain the formation of other celestial objects?

A: Yes, in addition to planets, the Nebular Hypothesis can also explain the formation of moons, asteroids, comets, and other celestial bodies within our solar system and beyond.

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nebular hypothesis

The nebular hypothesis is the idea first put forward in general terms by Immanuel Kant in 1775, and then more specifically by LaPlace in 1796, that the Solar System formed through the progressive condensation of a gassy nebula which once encircled the Sun . It was suggested that as this nebula rotated and contracted, rings of gas were cast off at various stages from which the planets subsequently condensed. Accordingly, the outer planets would have formed first, followed by Mars , Earth , Venus , and Mercury .

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Hypothesis n., plural: hypotheses [/haɪˈpɑːθəsɪs/] Definition: Testable scientific prediction

Table of Contents

What Is Hypothesis?

A scientific hypothesis is a foundational element of the scientific method . It’s a testable statement proposing a potential explanation for natural phenomena. The term hypothesis means “little theory” . A hypothesis is a short statement that can be tested and gives a possible reason for a phenomenon or a possible link between two variables . In the setting of scientific research, a hypothesis is a tentative explanation or statement that can be proven wrong and is used to guide experiments and empirical research.

It is an important part of the scientific method because it gives a basis for planning tests, gathering data, and judging evidence to see if it is true and could help us understand how natural things work. Several hypotheses can be tested in the real world, and the results of careful and systematic observation and analysis can be used to support, reject, or improve them.

Researchers and scientists often use the word hypothesis to refer to this educated guess . These hypotheses are firmly established based on scientific principles and the rigorous testing of new technology and experiments .

For example, in astrophysics, the Big Bang Theory is a working hypothesis that explains the origins of the universe and considers it as a natural phenomenon. It is among the most prominent scientific hypotheses in the field.

“The scientific method: steps, terms, and examples” by Scishow:

Biology definition: A hypothesis  is a supposition or tentative explanation for (a group of) phenomena, (a set of) facts, or a scientific inquiry that may be tested, verified or answered by further investigation or methodological experiment. It is like a scientific guess . It’s an idea or prediction that scientists make before they do experiments. They use it to guess what might happen and then test it to see if they were right. It’s like a smart guess that helps them learn new things. A scientific hypothesis that has been verified through scientific experiment and research may well be considered a scientific theory .

Etymology: The word “hypothesis” comes from the Greek word “hupothesis,” which means “a basis” or “a supposition.” It combines “hupo” (under) and “thesis” (placing). Synonym:   proposition; assumption; conjecture; postulate Compare:   theory See also: null hypothesis

Characteristics Of Hypothesis

A useful hypothesis must have the following qualities:

• It should never be written as a question.
• You should be able to test it in the real world to see if it’s right or wrong.
• It needs to be clear and exact.
• It should list the factors that will be used to figure out the relationship.
• It should only talk about one thing. You can make a theory in either a descriptive or form of relationship.
• It shouldn’t go against any natural rule that everyone knows is true. Verification will be done well with the tools and methods that are available.
• It should be written in as simple a way as possible so that everyone can understand it.
• It must explain what happened to make an answer necessary.
• It should be testable in a fair amount of time.
• It shouldn’t say different things.

Sources Of Hypothesis

Sources of hypothesis are:

• Patterns of similarity between the phenomenon under investigation and existing hypotheses.
• Insights derived from prior research, concurrent observations, and insights from opposing perspectives.
• The formulations are derived from accepted scientific theories and proposed by researchers.
• In research, it’s essential to consider hypothesis as different subject areas may require various hypotheses (plural form of hypothesis). Researchers also establish a significance level to determine the strength of evidence supporting a hypothesis.
• Individual cognitive processes also contribute to the formation of hypotheses.

One hypothesis is a tentative explanation for an observation or phenomenon. It is based on prior knowledge and understanding of the world, and it can be tested by gathering and analyzing data. Observed facts are the data that are collected to test a hypothesis. They can support or refute the hypothesis.

For example, the hypothesis that “eating more fruits and vegetables will improve your health” can be tested by gathering data on the health of people who eat different amounts of fruits and vegetables. If the people who eat more fruits and vegetables are healthier than those who eat less fruits and vegetables, then the hypothesis is supported.

Hypotheses are essential for scientific inquiry. They help scientists to focus their research, to design experiments, and to interpret their results. They are also essential for the development of scientific theories.

Types Of Hypothesis

In research, you typically encounter two types of hypothesis: the alternative hypothesis (which proposes a relationship between variables) and the null hypothesis (which suggests no relationship).

Simple Hypothesis

It illustrates the association between one dependent variable and one independent variable. For instance, if you consume more vegetables, you will lose weight more quickly. Here, increasing vegetable consumption is the independent variable, while weight loss is the dependent variable.

Complex Hypothesis

It exhibits the relationship between at least two dependent variables and at least two independent variables. Eating more vegetables and fruits results in weight loss, radiant skin, and a decreased risk of numerous diseases, including heart disease.

Directional Hypothesis

It shows that a researcher wants to reach a certain goal. The way the factors are related can also tell us about their nature. For example, four-year-old children who eat well over a time of five years have a higher IQ than children who don’t eat well. This shows what happened and how it happened.

Non-directional Hypothesis

When there is no theory involved, it is used. It is a statement that there is a connection between two variables, but it doesn’t say what that relationship is or which way it goes.

Null Hypothesis

It says something that goes against the theory. It’s a statement that says something is not true, and there is no link between the independent and dependent factors. “H 0 ” represents the null hypothesis.

Associative and Causal Hypothesis

When a change in one variable causes a change in the other variable, this is called the associative hypothesis . The causal hypothesis, on the other hand, says that there is a cause-and-effect relationship between two or more factors.

Examples Of Hypothesis

Examples of simple hypotheses:

• Students who consume breakfast before taking a math test will have a better overall performance than students who do not consume breakfast.
• Students who experience test anxiety before an English examination will get lower scores than students who do not experience test anxiety.
• Motorists who talk on the phone while driving will be more likely to make errors on a driving course than those who do not talk on the phone, is a statement that suggests that drivers who talk on the phone while driving are more likely to make mistakes.

Examples of a complex hypothesis:

• Individuals who consume a lot of sugar and don’t get much exercise are at an increased risk of developing depression.
• Younger people who are routinely exposed to green, outdoor areas have better subjective well-being than older adults who have limited exposure to green spaces, according to a new study.
• Increased levels of air pollution led to higher rates of respiratory illnesses, which in turn resulted in increased costs for healthcare for the affected communities.

Examples of Directional Hypothesis:

• The crop yield will go up a lot if the amount of fertilizer is increased.
• Patients who have surgery and are exposed to more stress will need more time to get better.
• Increasing the frequency of brand advertising on social media will lead to a significant increase in brand awareness among the target audience.

Examples of Non-Directional Hypothesis (or Two-Tailed Hypothesis):

• The test scores of two groups of students are very different from each other.
• There is a link between gender and being happy at work.
• There is a correlation between the amount of caffeine an individual consumes and the speed with which they react.

Examples of a null hypothesis:

• Children who receive a new reading intervention will have scores that are different than students who do not receive the intervention.
• The results of a memory recall test will not reveal any significant gap in performance between children and adults.
• There is not a significant relationship between the number of hours spent playing video games and academic performance.

Examples of Associative Hypothesis:

• There is a link between how many hours you spend studying and how well you do in school.
• Drinking sugary drinks is bad for your health as a whole.
• There is an association between socioeconomic status and access to quality healthcare services in urban neighborhoods.

Functions Of Hypothesis

The research issue can be understood better with the help of a hypothesis, which is why developing one is crucial. The following are some of the specific roles that a hypothesis plays: (Rashid, Apr 20, 2022)

• A hypothesis gives a study a point of concentration. It enlightens us as to the specific characteristics of a study subject we need to look into.
• It instructs us on what data to acquire as well as what data we should not collect, giving the study a focal point .
• The development of a hypothesis improves objectivity since it enables the establishment of a focal point.
• A hypothesis makes it possible for us to contribute to the development of the theory. Because of this, we are in a position to definitively determine what is true and what is untrue .

How will Hypothesis help in the Scientific Method?

• The scientific method begins with observation and inquiry about the natural world when formulating research questions. Researchers can refine their observations and queries into specific, testable research questions with the aid of hypothesis. They provide an investigation with a focused starting point.
• Hypothesis generate specific predictions regarding the expected outcomes of experiments or observations. These forecasts are founded on the researcher’s current knowledge of the subject. They elucidate what researchers anticipate observing if the hypothesis is true.
• Hypothesis direct the design of experiments and data collection techniques. Researchers can use them to determine which variables to measure or manipulate, which data to obtain, and how to conduct systematic and controlled research.
• Following the formulation of a hypothesis and the design of an experiment, researchers collect data through observation, measurement, or experimentation. The collected data is used to verify the hypothesis’s predictions.
• Hypothesis establish the criteria for evaluating experiment results. The observed data are compared to the predictions generated by the hypothesis. This analysis helps determine whether empirical evidence supports or refutes the hypothesis.
• The results of experiments or observations are used to derive conclusions regarding the hypothesis. If the data support the predictions, then the hypothesis is supported. If this is not the case, the hypothesis may be revised or rejected, leading to the formulation of new queries and hypothesis.
• The scientific approach is iterative, resulting in new hypothesis and research issues from previous trials. This cycle of hypothesis generation, testing, and refining drives scientific progress.

Importance Of Hypothesis

• Hypothesis are testable statements that enable scientists to determine if their predictions are accurate. This assessment is essential to the scientific method, which is based on empirical evidence.
• Hypothesis serve as the foundation for designing experiments or data collection techniques. They can be used by researchers to develop protocols and procedures that will produce meaningful results.
• Hypothesis hold scientists accountable for their assertions. They establish expectations for what the research should reveal and enable others to assess the validity of the findings.
• Hypothesis aid in identifying the most important variables of a study. The variables can then be measured, manipulated, or analyzed to determine their relationships.
• Hypothesis assist researchers in allocating their resources efficiently. They ensure that time, money, and effort are spent investigating specific concerns, as opposed to exploring random concepts.
• Testing hypothesis contribute to the scientific body of knowledge. Whether or not a hypothesis is supported, the results contribute to our understanding of a phenomenon.
• Hypothesis can result in the creation of theories. When supported by substantive evidence, hypothesis can serve as the foundation for larger theoretical frameworks that explain complex phenomena.
• Beyond scientific research, hypothesis play a role in the solution of problems in a variety of domains. They enable professionals to make educated assumptions about the causes of problems and to devise solutions.

Research Hypotheses: Did you know that a hypothesis refers to an educated guess or prediction about the outcome of a research study?

It’s like a roadmap guiding researchers towards their destination of knowledge. Just like a compass points north, a well-crafted hypothesis points the way to valuable discoveries in the world of science and inquiry.

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Further Reading

• RNA-DNA World Hypothesis
• BYJU’S. (2023). Hypothesis. Retrieved 01 Septermber 2023, from https://byjus.com/physics/hypothesis/#sources-of-hypothesis
• Collegedunia. (2023). Hypothesis. Retrieved 1 September 2023, from https://collegedunia.com/exams/hypothesis-science-articleid-7026#d
• Hussain, D. J. (2022). Hypothesis. Retrieved 01 September 2023, from https://mmhapu.ac.in/doc/eContent/Management/JamesHusain/Research%20Hypothesis%20-Meaning,%20Nature%20&%20Importance-Characteristics%20of%20Good%20%20Hypothesis%20Sem2.pdf
• Media, D. (2023). Hypothesis in the Scientific Method. Retrieved 01 September 2023, from https://www.verywellmind.com/what-is-a-hypothesis-2795239#toc-hypotheses-examples
• Rashid, M. H. A. (Apr 20, 2022). Research Methodology. Retrieved 01 September 2023, from https://limbd.org/hypothesis-definitions-functions-characteristics-types-errors-the-process-of-testing-a-hypothesis-hypotheses-in-qualitative-research/#:~:text=Functions%20of%20a%20Hypothesis%3A&text=Specifically%2C%20a%20hypothesis%20serves%20the,providing%20focus%20to%20the%20study.

©BiologyOnline.com. Content provided and moderated by Biology Online Editors.

Last updated on September 8th, 2023

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16: (Case Study) Nebular theory and the formation of the solar system

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• Page ID 22679
• 16.1: In the beginning...
• 16.2: Nebular theory
• 16.3: A star is born
• 16.4: Age of the solar system
• 16.5: The implications of meteorites
• 16.6: Further reading
• 16.S: Summary

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What Is Nebular Hypothesis Geology

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Nebular theory . Definition, Synonyms, Translations of Nebular theory by The Free Dictionary.

neb·u·lar hypothesis – nebular hypothesisn. A hypothesis concerning the formation of stars and planets, and therefore the origin of the solar system, according to which a rotating nebula underwent gravitational collapse into a star with an accretion disk, from which planets condensed or formed by coagulation of dust particles into increasingly larger bodies. American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved. nebular hypothesis n (Astronomy) the theory that the solar system evolved from the gravitational collapse of nebular matter Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014neb′ular hypoth′esis n. the theory that the solar system evolved from a mass of nebular matter. (1830–40) Random House Kernerman Webster’s College Dictionary, © 2010 K Dictionaries Ltd.

Video advice: NEBULAR HYPOTHESIS

In this Introductory video I have explained the theories of Origin of Earth, i.e, Nebular Hypothesis of Kant and Laplace.

Nebular hypothesis

The nebular hypothesis is the most widely accepted model in the field of cosmogony to explain the formation and evolution of the Solar System (as well as other planetary systems). It suggests the Solar System is formed from gas and dust orbiting the Sun. The theory was developed by Immanuel Kant and published in his Universal Natural History and Theory of the Heavens (1755) and then modified in 1796 by Pierre Laplace. Originally applied to the Solar System, the process of planetary system formation is now thought to be at work throughout the universe. The widely accepted modern variant of the nebular theory is the solar nebular disk model (SNDM) or solar nebular model. It offered explanations for a variety of properties of the Solar System, including the nearly circular and coplanar orbits of the planets, and their motion in the same direction as the Sun’s rotation. Some elements of the original nebular theory are echoed in modern theories of planetary formation, but most elements have been superseded.

Johansen, A. Jacquet, E. Cuzzi, J.N. Morbidelli, A. Gounelle, M. . “New Paradigms For Asteroid Formation”. In Michel, P. DeMeo, F. Bottke, W. (eds. ). Asteroids IV. Space Science Series. College of Arizona Press. p. 471. arXiv:1505. 02941. Bibcode:2015aste. book. . 471J. doi:10. 2458/azu_uapress_9780816532131-ch025. ISBN 978--8165-3213-1. S2CID 118709894.

8.2: Origin of the Solar System—The Nebular Hypothesis

References – Our solar system formed at the same time as our Sun as described in the nebular hypothesis. The nebular hypothesis is the idea that a spinning cloud of dust made of mostly light elements, called a nebula, flattened into a protoplanetary disk, and became a solar system consisting of a star with orbiting planets (12). The spinning nebula collected the vast majority of material in its center, which is why the sun Accounts for over 99% of the mass in our solar system.

Video advice: The nebular theory

Nebular Hypothesis, an explanation of how the solar system was formed, proposed by Pierre Simon de Laplace in 1796. Laplace said that the material from which the solar system was formed was once a slowly rotating cloud, or nebula, of extremely hot gas. The gas cooled and the nebula began to shrink. As the nebula became smaller, it rotated more rapidly, becoming somewhat flattened at the poles. A combination of centrifugal force, produced by the nebula’s rotation, and gravitational force, from the mass of the nebula, caused rings of gas to be left behind as the nebula shrank. These rings condensed into planets and their satellites, while the remaining part of the nebula formed the sun. The nebular hypothesis, widely accepted for about a hundred years, has several serious flaws. The most serious concerns the speed of rotation of the sun. When the nebular hypothesis is worked out mathematically on the basis of the known orbital momentum of the planets, it predicts that the sun must rotate about 50 times more rapidly than it actually does.

Time Traveller’s Guide—The Nebular Hypothesis

Travelling back through time with Dr Richard Smith’s imaginary time machine on the ABC program Australia: The Time Traveller’s Guide, we reach the nebular hypothesis at about 7 min. This was first proposed by the French mathematician, astronomer and atheist Pierre-Simon Laplace to explain how our solar system came into existence by natural processes. The idea is that the sun and the planets condensed from a swirling cloud of dust and gas, said to have occurred some 4.5 billion years ago.

At 7 min 30 sec within the video we have seen glowing red chunks of rock orbiting wide and crashing together. But it’s cold wide. The chunks that the planets created could have been cold and black. Once the earth’s formation once the iron core differentiated did the earth are a molten blob—according towards the story.

Travelling back through time with Dr Richard Smith’s imaginary time machine on the ABC program Australia: The Time Traveller’s Guide, we reach the nebular hypothesis at about 7 min. This was first proposed by the French mathematician, astronomer and atheist Pierre-Simon Laplace to explain how our solar system came into existence by natural processes. The idea is that the sun and the planets condensed from a swirling cloud of dust and gas, said to have occurred some 4. 5 billion years ago.

Definition of nebular hypothesis

Definition of nebular hypothesis from Dictionary.com, the world’s leading online source for English definitions, pronunciations, word origins, idioms, Word of the Day, and more.

Top Definitions Quiz Examples British Scientific This shows grade level in line with the word’s complexity. This shows grade level in line with the word’s complexity. noun Astronomy. the idea the solar system started out scores of nebular matter: prominent within the 1800s following its precise formulation by Laplace. QUIZQUIZ Your Self On AFFECT Versus. EFFECT! Essentially, this quiz will prove whether you will find the skills to understand the main difference between “affect” and “effect. ” The wet weather couldn’t ________ my elated spirits on my small graduation day. Origin of nebular hypothesisFirst recorded in 1830–40Words nearby nebular hypothesisNebraska, Nebraskan, nebris, Nebuchadnezzar, nebula, nebular hypothesis, nebulated, nebulium, nebulize, nebulizer, nebuloseDictionary.

Video advice: Nebular Hypothesis – Origin of the Earth Solar system

In this video we will learn about Immanuel Kant and Laplace theory on Nebular Hypothesis on the origin of Earth. It is also the early theories of the origin of the earth.

What is the best definition of nebular hypothesis?

Definition of nebular hypothesis : a hypothesis in astronomy: the solar system has evolved from a hot gaseous nebula .

What is solar nebular hypothesis?

solar nebula, gaseous cloud from which, in the so-called nebular hypothesis of the origin of the solar system, the Sun and planets formed by condensation . Swedish philosopher Emanuel Swedenborg in 1734 proposed that the planets formed out of a nebular crust that had surrounded the Sun and then broken apart.

What is an example of nebular hypothesis?

For example, we would not expect to find a planet with a large moon, specifically Earth and the Moon . Uranus is tilted on its side and 'rolls' around the Sun. And Venus rotates in retrograde (backwards) as it orbits the Sun, contrary to the other planets in the solar system.

What are the 4 steps of the nebular hypothesis?

Terms in this set (5)

• step one(4) -The solar nebula consisted of. -hydrogen, ...
• step two(2) -A disturbance. ...
• step three(2) -The solar nebula assumed a flat, disk shape. ...
• step four(2) -Inner planets began to form from metallic. ...
• step five(2) -Larger outer planets began forming from fragments.

What are Jovian or gas giant planets?

The gas giants of our solar system are Jupiter, Saturn, Uranus and Neptune . These four large planets, also called jovian planets after Jupiter, reside in the outer part of the solar system past the orbits of Mars and the asteroid belt.

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