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Nebula theory

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Artist conception of a Solar Nebula. Watch animated video.

The nebula theory is the most generally accepted evolutionary model for formation of the solar system from a cloud of gas and dust particles known as a nebula.

In short, the process starts with a rotating cloud of gas and dust that contracts and flattens to form a disk around a star forming at its center. Planets grow from the dust and gas in the disk and are left behind when the disk clears.[1]

Contents

Process

According to this theory, the nebula begins to collapse because of its own gravity. Some astronomers speculate that a nearby supernova (exploding star) triggered the collapse. (Of course, this would not be available for the first generation of stars.) As the nebula contracts, it spins faster and flattens into a disk. The nebular theory indicates that particles within the flattened disk then collide and stick together to form asteroid-sized objects called planetesimals. Some of these planetesimals combine to become planets. Other planetesimals form moons, asteroids, and comets. The planets and asteroids all revolve around the sun in the same direction, and in more or less the same plane, because they originally formed from the same rotating flattened disk.

Most of the material in the nebula, however, is pulled toward the center and forms the star. According to the theory, the pressure at the center becomes great enough to trigger nuclear fusion reactions that power the sun. Eventually, eruptions occur, producing a stellar wind. In the inner solar system, the wind sweeps away most of the lighter elements -- hydrogen and helium. In the outer regions of the solar system, however, the solar wind was much weaker. As a result, much more hydrogen and helium remains on the outer planets. This process explains why, in our solar system, the inner planets are small, rocky worlds and the outer planets, except for Pluto, are giant balls composed almost entirely of hydrogen and helium.[2]

Supporting evidence

Disk1.jpg

Disks in the Orion Nebula

The image at right is a Hubble Space Telescope picture of a disk of dust seen edge-on in the Orion nebula, located 1,500 light-years away. Such disks are believed to be a protoplanetary systems. Because the disk is edge-on, the star is largely hidden inside. At 17 times the diameter of our own solar system, this disk is the largest of several discovered in the Orion nebula in the mid-1990s.[3]

Disk2.jpg

The images at left are other Hubble Space Telescope images of four disks around stars in the Orion nebula, located 1,500 light-years away. Gas and dust disks, long suspected by astronomers to be an early stage of planetary formation, can be directly seen in visible light by Hubble.[4]

Spectrographic Evidence of Discs Around Stars

Spectrograph.jpg
Disk5.jpg

Using the technique of spectroscopy, scientists can deduce the temperature and chemical composition of material around a star, even if they cannot see the disc itself. Spectroscopy involves spreading the light from a star into a spectrum (in visible light, we are familiar with white light being spread out into a rainbow when it passes through a prism), and then measuring exactly how much light is present in each wavelength.

In these diagrams, we see the spectrum of a star with a disc of dust and gas around it. In the case of a star, most of the light is produced at shorter wavelengths (the left side of the diagram), due to the high temperature of the star's surface. Moving to the right-hand side of the diagram, the wavelengths increase to lower energies (indicating lower temperatures) and, the starlight drops off.

The warm dust and gas disc around the star produces its own infrared light, which changes the shape of the spectrum. The circumstellar material is cooler than the surface of the star, so it emits most of its light at longer infrared wavelengths, closer to the right-hand side of the diagram. Now, there is an excess of infrared emission, which can not be coming from the star itself. The disc is revealed.[5]

While this does not show the motion of the material around a star, it does suggest the presence of a disk of material around stars, even when such disks can not be seen optically. Sometimes this data seems to suggest dust and gas while other times debris such as asteroids. It should be noted that there is no evidence of planet formation in this data.

HD141569.jpg

HD141569

The image at right is another alleged protoplanetary disk. In this case, however, the structure is strongly suggestive that matter is moving away from the mass. It should once again be noted that there is no evidence of planet formation in this image.

Problems for the nebula theory

Theoretically, this process should always result in the same basic pattern, with the heated inner disk forming terrestrial planets and the cold outer disk forming gas giants. It should also leave each planet revolving around the sun, and rotating about its axis, in the same direction as the rest, and all objects moving in the same or almost the same plane, with little or no orbital or axial inclination. Similarly, the moons of any planet should each revolve around the primary, and rotate about its axis, in the same direction and in the same plane. Finally, the orbital planes of any moons should be the same as the common orbital plane of the planets.

The Sun and Planets

The sun rotates too slowly for this model to explain. The sun contains 99.9% of the mass of the solar system, but the planets contain 98% of the angular momentum.[1] Thus the planets have 50 times the sun's angular momentum while the sun should have 700 times the planets' combined angular momentum. So according to the nebula model, the sun should spin much faster than it does.

Evolutionists understand the problem, so they propose that the sun has slowed over time and dissipated its angular momentum in the solar wind.[6] But this fails to consider the true scope of the problem. To make the sun have as much angular momentum as the planets, it would have to rotate 50 times faster than actual. To satisfy the conservation of angular momentum, it would have started rotating 700 times faster than this. Thus the sun's initial rotation rate should have been 35,000 times its present rate. Now the sun is presently pivoting at one rotation per 25.38 da609.12 h (Earth days)[7] A rotation rate that is 35,000 times faster than present conditions produces an initial period of rotation of 1 minute and 2.65 seconds.

According to the CRC Handbook of Chemistry and Physics, the sun's equatorial rotational speed is 2.0578 km/s. Thus the initial equatorial rotational speed would have to be 72,023 km/s or nearly a quarter of the speed of light.

Another problem is that the sun's surface escape speed is 617.7 km/s2,223,720 km/h
383.821 mi/s
1,381,755.548 mph
which is 116.7 times smaller than the initial equatorial rotational speed of 72,023 km/s. If the sun were ever to spin as fast initially as the nebula theory demands, then it would literally fly apart, if it could form to begin with.

Other astronomers attempt to deny the angular momentum problem completely by suggesting that a star yields its angular momentum to its planets.[8] This statement utterly fails to account for the tremendous differences in mass between the star and all its planets.

Still others assert that the Sun is in a binary orbit with another object with an orbital period of 24,000 years. This object, they say, must have eight percent of the Sun's mass. As further evidence, they cite the abrupt "edge" of the Kuiper belt and scattered disk beyond which no other matter seems to be in orbit around the Sun. They admit that no astronomer has yet seen any such object, but then declare that the object might be a black hole, a brown dwarf star, or even a neutron star. (They also briefly mention the Nemesis hypothesis.)[9]

Orbital and axial inclinations of the sun and planets

The sun is inclined with respect to the ecliptic and indeed the orbits of all its planets. If the sun and planets all formed from a spinning accretion disk, then the sun should not be so inclined.

Moreover, the axes of rotation of most of the planets are also inclined with respect to their own orbits. Some of these inclinations are quite extreme.


Note that the orbital inclinations of the planets and dwarf planets listed above differ significantly. This is true even of those objects that lie inside the Kuiper belt (about 30 AU or closer).

Of greater import is that these satellites also differ in their axial tilts. By convention, an axial tilt of or near 180 degrees is consistent with retrograde motion (see below). But an axial tilt of or near 90 degrees signifies an axis within or near the plane of the orbit. Uranus has an axial tilt of 97.86 degrees, which signifies retrograde rotation that is nearly perpendicular to the ecliptic. This is an extraordinary inclination that no astronomer has yet been able to explain.

Retrograde motion

Rotation

As the above table shows, three of the listed satellites of the sun have negative sidereal days. By convention, a negative sidereal day means a period of rotation of a body rotating retrograde to the regular direction of orbit and rotation in the solar system.

Orbits

None of the planets have retrograde orbits. But many of their moons orbit retrograde with respect to their primaries.

The following table lists moons that orbit retrograde to their primaries:
Name Primary Semi-major axis Eccentricity Sidereal month Inclination Axial tilt Sidereal day
Triton Neptune 3547600000.00237 AU354,760 km
220,437.644 mi
1.6E-51.6e-5 -5.876854-5.877 da-0.0161 a 2.74618831155157.345 °2.746 rad
174.828 grad
00 °0 rad
0 grad
-507760.1856-141.044 h-5.877 da


Extrasolar Planets

Over two hundred extrasolar planets have been detected to date. Most are large, with the smallest about five times the size of Earth.[10] The largest are many times the size of Jupiter while some are larger still, enough to be classified as brown dwarfs. They are usually detected by indirect means, like their effect on their parent star.

Recently one was confirmed orbiting the star HD 209458 as was observed by the effect on the star's light during transit. Astronomers also detected spectral evidence of sodium in the planet's atmosphere. A larger one has actually been photographed near Gliese 229 and likewise is classified as a brown dwarf. One possible planet called SOri70 is located 36,000 times farther from its star than Jupiter is from our Sun.

Many of these planets are extremely close to their respective stars, sometimes surprisingly close. One planet orbits around HD 209458 at 4 million miles. Upsilon Andromedae has three gas giants, all of which are too close to their sun for gas giants to form under the nebula theory. These planets are so close to their stars that they defy evolutionary models of planet formation. The star would sweep up too much mass and the temperatures are too high. Evolutionists have invented a number of mechanisms to cause planets to migrate closer to their star, but they all require assuming unrealistic gas and dust densities.

Another interesting observation is that seen with the Hubble Space Telescope. It found a giant gaseous object orbiting two burned out stars. Many astronomers believed this to be the oldest planet found yet and they dated it around 12.7 billion years. However, this creates a problem for the Big Bang and it’s theories of planet formation because during this time in cosmic evolution, 12.7 billion years ago assuming the Big Bang is true, there weren't enough heavy elements at that time.[11]

Conclusion

It remains questionable whether this dust and debris represent forming planets or destroyed planets.

Massive Coronal Mass Ejections (CME) called superflares have been observed that are 10 million times more powerful than any CME from the sun.[12] A superflare that is powerful and concentrated enough could theoretically destroy planets.

Other forms of stellar outgassing could theoretically destroy planets as well.

Planets with above average amounts of radioactive nuclei could have large amounts of nuclear fission. If powerful enough this could cause their demise, particularly with large amounts of relatively short-lived nuclei.

The dust and other debris from such planets would remain in orbit around the star forming a disk. Some of the matter ejected from the star would be brought into orbit by planetary material. The speed and location of ejected material would be highly important. This would also explain so-called protostars, since if any of these stars ejected too much material, their nuclear fusion reactions would shut down.

In no case is there any evidence of planet formation. Stars shoot out gas all the time and they can pass through nebulae, so none of the observations can be legitimately considered evidence for the Nebula Theory. As shown above there is no real evidence supporting the theory, but plenty of evidence against it.

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References

  1. 1.0 1.1 Britto, Angela. "Historic and Current Theories on the Origins of the Solar System." University of Toronto, February 13, 2006. Accessed June 28, 2008.
  2. Worldbook at NASA: Solar System by the U.S. National Aeronautic and Space Administration
  3. Edge-on Protoplanetary Disk in the Orion Nebula, November 20, 1995, Space Telescope Science Institute (STScI), News Release Number: STScI-1995-45, Image "c". (Image credit: Mark McCaughrean (Max-Planck-Institute for Astronomy), C. Robert O'Dell (Rice University), and NASA)
  4. Planetary Systems in the Making: Dust and Gas Disks Around Young Stars in Orion Nebula, November 20, 1995, Space Telescope Science Institute (STScI), News Release Number: STScI-1995-45, Image "b". (Image credit: Mark McCaughrean (Max-Planck-Institute for Astronomy), C. Robert O'Dell (Rice University), and NASA)
  5. Spectra Show Protoplanetary Disc Structures, 05.27.04, NASA/JPL-Caltech/D. Watson (University of Rochester).
  6. "Solar system." Encyclopædia Britannica. 2008. Encyclopædia Britannica Online. 29 June 2008.
  7. Harvey, Samantha. "Sun: Facts and Figures." NASA, June 11, 2008. Accessed June 28, 2008.
  8. Imamura, James N. "The Angular Momentum Problem." University of Oregon, October 19, 2001. Accessed June 29, 2008.
  9. "Evidence: Angular Momentum." Binary Research Institute, n.d. Accessed June 29, 2008.
  10. Alexander, Amir. "Discovery of Small Distant Planet Suggests Many 'Earths' Not Far Behind." The Planetary Society, January 26, 2006. Accessed June 29, 2008.
  11. Lisle, Jason. "New Planet Challenges Evolutionary Models." Answers, July 18, 2003. Accessed June 28, 2008.
  12. Sun-like stars said to emit superflares, 9-Jan-1999, CNN (dead link)

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