Wednesday, February 6, 2013

Geophysics

I have posted material on websites and Youtube channel on Geophysics.

 

http://www.youtube.com/watch?v=6nzYkJnqudc

http://scienceray.com/earth-sciences/geology/geophysics-for-beginners/

http://gscim.com/phy/Geophysics/Geophysics.html

http://genesismission.4t.com/Physics/Geophysics/Geophysics.html

http://creationsciencetalk.blogspot.com/2013/02/geophysics-and-creation.html

 

Geophysics is the study in physics of the Earth and its environment in space. Geophysics mainly includes studies of the Earth's shape; gravitational field, magnetic field, internal structure, internal composition, plate tectonics, generation of magmas, volcanism and rock formation. Some times it includes the hydrological cycle; fluid dynamics of the oceans and the atmosphere; electricity and magnetism in the ionosphere and magnetosphere; solar-terrestrial interaction; and similar problems on the Moon and other planets. Geophysics is at its hart the application of the principles of physics to the Earth and in more recent years other planetary bodies. As we expand our knowledge of worlds other than the Earth this expansion is natural. It is really only cultural inertia with in the scientific community that keeps it from being changed to planetary physics. There are four areas of geophysics that are of importance to origins, in particular they show problems with the idea of an old Earth.

Radioactivity

Radioactivity is the phenomenon where by an unstable atomic nucleus emits ionizing radiation causing the nucleus to loses energy and rest mass. Radioactivity causes about 80% of the Earth's internal heat, with the main isotopes being potassium40, uranium238, uranium235, and thorium232. While there are many types of nuclear decay there are two main ones found in nature, Alpha decay and Negative Bata decay.  In alpha decay the nucleus ejects an alpha particle. An alpha particle is a helium atomic nucleus consisting of 2 protons and 2 neutrons. The process reduces the atomic number of atom by 2 changing the element. In negative Beta decay a neutron emits a Beta particle and an electron anti-neutrino to become a proton. Beta particles are actually negatively charged electrons. This process increases the atomic number of the nucleus by one.

For collections of radioactive nuclei there is a characteristic decay rate which is usually designated by the isotopes half-life which is the time needed for half of the isotope to decay. This half-life is independent of the amount of the present isotope because the more atoms of the parent isotope there are the more nuclei will decay in a given unit of time. Nuclear decay is often used in determining the age of a sample however there are assumptions involved in the process. It is especially assumed that the half-life of an isotope is constant.

Accelerated Nuclear Decay is the process by which nuclear decay proceeds at a faster rate than normal. Now small amounts of accelerated nuclear decay have been observed in Bata-decay under some circumstances. While accelerated alpha decay has never been directly observed evidence for it exists in the retention of radiogenic helium by zircon crystals. Accelerated Nuclear Decay would look identical to normal decay but faster. The main argument against the hypothesis that the retention of radiogenic helium by zircon crystals shows substantial accelerated alpha decay is heat. The other common argument is the lack of an observed cause of accelerated alpha decay. However there are theoretical answers to both objections. The real reason for resistance to the hypothesis that the retention of radiogenic helium by zircon crystals shows substantial accelerated alpha decay is the fact that it would drastically reduce radiometric ages. However none of these arguments change the fact that measured helium diffusion rates in zircon crystals are a perfect match to a model showing accelerated alpha decay about six thousand years ago.

Plate Tectonics

The Earth’s crust is divided into segments called plates. These plates are not fixed but they slowly move over the mantel. Where the plates meet they interact in three main ways sliding, spreading and subduction. Subduction is seen as the driving mechanism of Plate Tectonics. When these plates interact the results are Earth quakes and volcanoes.

Plate Tectonics got its start in a book published by Antonio Snider-Pellegrini in 1859 called La Création et ses mystères dévoilés (The Creation and its Mysteries Unveiled). He proposed that all of the continents were once connected together based discovering the same plant fossils in both Europe and the United States. He then found this matching of fossils on all of the continents. He proposed that the super continent catastrophically broke up resulting in the Flood described in Genesis the first book of the Bible. The catastrophic nature of the process went against uniformitarianism and this early version of plate tectonics got little support at the time.

The idea of Plate Tectonics was later picked up by Alfred Wegener around 1910. He slowed down Antonio Snider's Catastrophic Plate Tectonics to make it fit evolutionary time scales producing continual drift. This slowed down version of Plate Tectonics became an establishment theory around 1963. Catastrophic Plate Tectonics was revived by Dr. John R. Baumgardner in the 1990's with support from computer modeling of the Earth's interior.The result is a Scientific description of the Genesis Flood. Modern Catastrophic Plate Tectonics is basically plate tectonics on over drive.

Geomagnetism

Geomagnetism is the study of the Earth’s magnetic field. It includes the study of the magnetic fields of other planetary bodies as well. The Earth magnetic field is tilted about 11 degrees relative to its rotational axis. At present the magnitude of the Earth magnetic field at the Earth's surface ranges from 0.25 to 0.65 gauss. The Earth’s magnetic field is produced by an electric current in the core. However measurements since 1900 have shown a net loss of field energy of about 5% which is equivalent to a half-life of 1465 years.

The dominant model used to solve this problem called the dynamo theory. The idea is that the current that produces planetary magnetic fields is generated by a self sustaining dynamo, powered by the planet's spin. The result is complex currents in the planets core that causes the field to fluctuate from time to time, and reversing itself. In the case of the Earth this is thought to occur about every 500 - 700 thousand years.

Most illustrations of magnetic reversals show nice neat strips across the ocean floor, as produced by the theory. In Reality the pattern is not so neat and regular, in fact the tendency is for the positive and negative areas to be mixed up and this is the case all over the world. It gets worse when you look vertically where negative and positive are one on top of the other. Actual data seem to be inconsistent with uniformitarian theory, but is consistent with: a rapid spreading coupled with rapid magnetic reversals, a stretching with cracking and a single reversal, temporary local magnetic reversals, and reversals resulting from stress in the rocks.

There are other problems with the dynamo theory. Life would periodically be exposed to deadly solar radiation. It can not explain the existence of the magnetic field of Mercury. It rotates too slowly to have a self sustaining dynamo and so it should not have a magnetic field. Furthermore Mercury’s magnetic field is decaying and quit rapidly. It can not explain the orientation of the magnetic fields of, Uranus and Neptune. The magnetic axis of each planet is tilted about 60 degrees, with respect to the rotation axis, so that the magnetic poles are near the equator. Further more the source of each planet's field is offset from the center, by about one third of a planetary radius. According to the dynamo theory, the magnetic and rotation axes should nearly always be closely aligned.

Dynamic Decay Theory was developed by Dr. Russell Humphreys; a physicist with the Institute for Creation Research. It uses an alignment of the magnetic fields of the planet's molecules, to jump start the planets magnetic field. It includes fluctuations and possibly even reversals during and shortly after the Genesis Flood thus explaining the mixed up magnetic patterns. Projecting back in time based on magnetic field energy, gives a maximum age for the Earth of 8,700 years. Dynamic Decay Theory explains the origin of planetary and stellar magnetic fields. The orientation of the magnetic fields of. Uranus and Neptune, both the tilted of about 60 degrees with respect to the rotation axis and the field's source being about one third of a planetary radius offset from the center. The existence of the magnetic field of Mercury, since the field's source is a decaying and the current in its core can not related to spin. Measurements by the Messenger space craft have confirmed that Mercury’s magnetic field is decaying as predicted by Dynamic Decay. The residual magnetism on the Moon and Mars, despite the lack of a planetary magnetic fields. The strength for the magnetic fields of Uranus, Neptune, and the 4 large moons of Jupiter; all fall with in the range predicted by Dynamic Decay Theory.

Lunar Recession

One aspect of Geophysics that gets little attention for its degree of importance is the recession of moon. That’s right moon is slowly getting farther away and slowing the Earth’s rotation in the process. It was first discovered following the Apollo moon landings by bouncing laser off reflectors left behind by astronauts. These reflectors were designed to accurately measure the Earth / Moon distance. The results showed that the moon is getting further away at a rate of 1.5 inches or 3.82 cm per year. Furthermore a day is getting longer by 1.7 milliseconds per day per century.

A backwards projection of the observed slowing of the Earth's rotation and lunar recession data and when this data is plugged into the laws of physics. The result is that the Moon would have been locked in Geosynchronous orbit around the Earth 1.25 billion years ago. This is far short of the 4.533 billion years commonly given for the age of the Earths suggesting that the Earth-Moon system can not be any where near 4.533 billion years old.

The problem is understood by the proponents of a 4.533 billion year old Earth and several solution have been proposed. The problem is that paleontological data claimed as evidence for longer days in the past does not fit with any possible model that allows 4.533 billion years The ultimate response seems to be that the Earth-Moon system is too complicated to get accurate results form such calculations. This is essentially admitting that the problem can not be solve for an Earth-Moon system that is 4.533 billion years old. Which is exactly what would be the case if the Earth-Moon system were indeed much younger than 4.533 billion years.

 

------ Charles Creager Jr.

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