There is debate as to whether the rest of the mantle, especially the lower mantle, has the same bulk composition. The pressure in the mantle increases from a few kbar at the Moho to kbar GPa at the core-mantle boundary .
Moon Dust and the Age of the Solar System Answers in Genesisthe leading young-earth creationist ministry, disowns cosmic dust arguments. The most amazing thing about the cosmic dust argument is that it is still being used! It has coasted along on obsolete evidence, and nothing but obsolete evidence, for the last 25 years!!
It nicely illustrates how creationists borrow from each other and never do any outside reading. The obsolescence of this argument has been brought out in numerous debates and published in countless books, journals, and newsletters. It can be discovered by anyone who exercises his or her library card.
It's not a state secret! What does it take to get through to the creationist brain??
The earliest use of the cosmic dust argument that Van Till Van Till et al, could find was in an article by Harold Slusher, which was published in the June issue of Creation Research Society Quarterly. Slusher made several blunders which are handed down in the "scientific" creationist literature to this very day.
In the cosmic dust argument received its big kick-off from Henry Morris' book, Scientific Creationism. Pettersson's upper estimate for the influx of cosmic dust, a figure he considered risky, was based on particles he collected from two filtration units in the Hawaiian Islands. One was located near the summit of Mauna Loa, Hawaii, and the other near the observatory on Haleakala, Maui.
Pettersson actually favored a figure about two-thirds less, and he warned his readers that the true figure could be much lower still. Further work was planned in Switzerland. This caution seems to have been lost on Henry Morris, who may have been relying on Slusher's work, and he ignored Pettersson's preferred value in favor of his highest estimate.
Again, we have echoes of Slusher's article. Of course, the sea of cosmic dust did not materialize, and the Impact article claimed a victory for creation science which supports a young moon without much cosmic dust.
Steven Shore shows that this entire scenario is wrongheaded. Let's get a proper perspective on history: In a conference held in lateon the Lunar Surface Layer, McCracken and Dublin state that "The lunar surface layer thus formed would, therefore, consist of a mixture of lunar material and interplanetary material primarily of cometary origin from 10 cm to 1 m thick.
The low value for the accretion rate for the small particles is not adequate to produce large scale dust erosion or to form deep layers of dust on the moon, for the flux has probably remained fairly constant during the past several billion years.
The basic conclusion of this conference was that both from the optical properties of the scattering of sunlight observed from the Earth, and from the early Ranger photographs, there was no evidence for an extensive dust layer.
Shore,p. Although direct confirmation was not yet at hand, thus allowing a few dissenting opinions, few scientists expected even as much as three feet of cosmic dust on the moon.
In May Surveyor I had landed on the moon, thus putting an end to any lingering doubts about a manned landing sinking in dust. The cosmic dust argument was already obsolete by the time Henry Morris included it in his book, Scientific Creationism.
It was already obsolete when Harold Slusher wrote his article three years earlier. Since the late s, much better and more direct measurements of the meteoritic influx to the Earth have been available from satellite penetration data. In a comprehensive review article, Dohnanyi [, Icarus Dalrymple,p.Port Manteaux churns out silly new words when you feed it an idea or two.
Enter a word (or two) above and you'll get back a bunch of portmanteaux created by jamming together words that are conceptually related to your inputs.. For example, enter "giraffe" and you'll get . The Earth's Layers Lesson #1. The Four Layers. The Earth is composed of four different layers.
Many geologists believe that as the Earth cooled the heavier, denser materials sank to the center and the lighter materials rose to the top. The crust and the upper layer of the mantle together make up a zone of rigid, brittle rock called the.
(Click here for bottom) P p p, P Momentum. Utility of the concept of momentum, and the fact of its conservation (in toto for a closed system) were discovered by . The Crust: The outer layer (Oceanic crust and Continental crust). The Mantle: The middle layer (Upper mantle and Lower mantle).
(Click here for bottom) P p p, P Momentum. Utility of the concept of momentum, and the fact of its conservation (in toto for a closed system) were discovered by . Layer from 50 to km thick that comprises the Earth’s crust and the solid part of the upper mantle; it is divided into tectonic plates. continental crust Layer varying in thickness from 30 to 70 km and composed mainly of granite. * The Scablands: The primary surface features of the Scablands, which cover thousands of square miles of eastern Washington, were long believed to have formed gradually.
The Core: The inner layer (Outer layer and Inner layer). The Crust. The outer layer of the Earth is called the crust. It is a thin layer and it is composed of rocks. The crust is further divided into two types: oceanic crust and .
Let’s explore some facts about the layers of the earth! Then, why not take a look at our question sheet in the activity section at the end to test what you have learned.
The Earth is made of three layers that are just like an onion – the crust, the mantle and the core. Structure of the Earth The internal structure of the Earth is layered in spherical shells: an outer silicate solid crust, a highly viscous asthenosphere and mantle, a liquid outer core that is much less viscous than the mantle, and a solid inner core.