All comets would have disintegrated after 10, years. Jupiter and Saturn wreak havoc to the comet orbits. Some long-period comets are perturbed into short period orbits, others are permanently ejected. Comets are believed to have a short lifetime after being perturbed to short periods.
Actually, the Oort cometary cloud hypothesis published by Jan H. Oort in was originally proposed in order to explain "the rate of appearance of long-period comets" i. It really didn't have anything to do with the age of short-period comets which the note above refers to. Each time a comet passes close to the sun, some of its matter is driven off into space by the sun's energy forming its "tail". However, the fact that a comet cannot have occupied its present orbit for very long does not automatically imply that it is young.
The Oort hypothesis does explain this problem as well, in that long-period comets -- if frequent enough -- will be moved into short-period orbits by a relatively near approach to a planet comet loses momentum, planet gains it, comet is now in a vastly shorter orbit, planet is now in a very slightly longer orbit.
In fact, of the short-period comets, roughly half orbit pretty much between the sun and jupiter, leading astronomers to believe that jupiter "captured" them into their current orbits. Statistically, we would expect the largest planet -- the best "capturer" -- to have captured the most short-period comets. Finally, nobody really knows about the Oort cloud. Astronomers like the way it explains the frequency of long-period comets, and there is much support for it amongst them.
It apparently also explains the youth of the short-period comets, quite nicely. However, until we see a comet get sucked into a short-period orbit apparently this must happen every years or so , or until we send something out to 10, A. But we aren't very sure that it's true, either.
Actually the premise is false. The Sino-Tibetan family of languages is distinct from the Indo-European family of languages, which English seems to have been derived from.
Considering how long ago the 50 arguments were written was it around ? Ever heard of plate tectonics? Your county Soil Conservation Board will be happy to tell you why your topsoil is getting shallower, and what you can do to curb the problem.
Mississippi delta would have formed in years. You have given a steady-state system which it is NOT identified a possible geographic feature less than 5k years old.
That's neat - and the steady-state assumptions are? And how did you get the "original precipice" without deciding up front how old you wanted it? Before that, the whole area was under glacial ice! And it some millenia after the ice retreated for the land to reach its present level and the drainage paths to reach their present alignment. I'd love to see what happens in the year the falls erode back to Lake Erie!
Not enough dissolved minerals in oceans. Dissolved minerals - the stuff moves in cycles, and as such most of the minerals are very close to their balance levels. The same general idea holds for everything else.
Remember the space shuttle? Except for the last time, it has been landing on salt. Like from the oceans, remember? Other "geological clocks" that suggest a "young" earth- juvenile water from volcanoes , oil deposit pressure, Stalactite Growth limestone Juvenile water is covered in those same computer models, and again nothing tricky is involved at all.
Oil deposits themselves require a time well over years to exist, so try again. Stalactite growth - of some, perhaps. You are still identifying merely temporary features Please read: Gentry's work is of particular importance because it involves actual field and laboratory work followed up by papers appearing in refereed scientific journals, offering some credibility to the field of "creation research.
It has been devoted almost entirely to the physics of the polonium halos, thereby neglecting the geological setting of the samples in which the halos are found.
Because of this neglect, Gentry makes unwarranted generalizations about the nature of the world's Precambrian rocks. As an alpha particle nears the end of its path and slows, it causes disruption of the crystal structure leaving a small damage track. Over time, repeated decays from the parent isotope will leave a spherical halo of discoloration. The distance that an alpha particle travels depends upon the energy of the decay and that, in turn, is a function of the particular nuclide that decays.
Theoretically, then, the radii of a series of halos that surround a radioactive inclusion permit identification of the specific decaying nuclides. Gentry has claimed that certain of these halos indicate that the granite "basement rocks" of the earth are "the primordial Genesis rocks" and were created instantaneously about six thousand years ago. Essentially, Gentry has found that in certain samples of Precambrian biotite a mica the inner ring halos for uranium and other nuclides in the decay chain which should be producing Polonium , Po and Po are missing; only the polonium rings for these three isotopes are present.
In addition, Gentry observed little or no uranium in the radioactive inclusion. His conclusion is that the polonium must have been primordial and, because of the short half-lives of the polonium isotopes His book, however, leaves no doubt on his position: Could it be that the Precambrian granites were the Genesis rocks of our planet? This misunderstanding came about because Gentry is annoyingly vague on exact sites in his book. One mine, the Silver Crater Mine, is mentioned specifically, while the remaining sites are described only as being in Madagascar, New Hampshire and Norway.
This tendency towards vagueness also occurs in his Medical Opinion and Review article, in which he refers to "the Wolsendorf Bavaria fluorite. Regarding the first site, the Fission Mine, it appeared to Wakefield that this was where Gentry obtained his fluorite samples and some of his biotite.
Gentry denied this, saying they had come from Germany, but Louis Moyd of the National Museum in Ottawa indicated that samples from the Fission Mine were in fact sent to Gentry. I will break tradition briefly and quote Wakefield exactly, "it is clear we are dealing with intrusive calcite vein dikes rocks containing mostly the mineral calcite and other minerals, such as mica that are small in length and width and cut metasedimentary rocks which still retain bedding planes.
Radioactive minerals abound in this locality. Percolating water from the hill the deposit occupies is strongly radioactive and was sold in the s for therapeutic purposes. Neither of these mines are in fact granites, a fact Gentry gets wrong.
In addition, while Gentry claims that "halos occur in many mica samples which have not undergone metamorphism of any kind," the micas of the Silver Crater were indeed formed during metamorphism under the load of moderate-depthed overburden, whch has since been eroded off.
Gentry's primordial biotite was in fact metamorphically derived. The third site, the Faraday mine, I will touch on only briefly.
Gentry emphasizes that the oddity of the halos is that there is no uranium or thorium in the nucleus at the center of the polonium halos. Unfortunately for him, the Faraday pegmatite was mined for uranium -- a total of some four million tons of U 3 O 8 ore were mined for a total of 7.
The most common radioactive mineral was uranothorite, hence lots of uranium and thorium. Gentry's case rests heavily on a "God-of-the-gaps" approach to the halos; that is, it requires that there be no acceptable naturalistic explanation for the halos.
Once such an explanation is found, Gentry's case crumbles. One paper that proposes such a naturalistic explanation is by N. I make no pretense about being able to understand the model they present; perhaps those with the necessary background will help out here. Gentry also has problems with accuracy in his quotation of other scientific sources. In one case, Gentry p. Feather , saying that Feather discusses "clear mica without any conduits ," but there is no reference to this in Feather's paper.
In another instance, Gentry quotes Steven Talbott for scientific support and provides a copy of Talbott's article in the appendices of his book, but Talbott himself states that he has relied on two sources for HIS information: What Gentry has in essence done is to reference himself and attempt to pass this off as independent corroboration.
Feather, "The unsolved problem of the Po-halos in Precambrian biotite and other old minerals," Comm. And for a more recent: The abstract and first two-and-a-half and last one paragraphs of the report, giving a summary of the problem and the authors' conclusion: ABSTRACT "The radii of radiation-induced color halos RICHs surrounding radioactive mineral inclusions in mica generally correspond closely to the calculated range of common uranogenic and thorogenic alpha particles in mica.
Many exceptions are known, however, and these variants have led investigators to some rather exotic interpretations. Three RICHs found in quartz are identified as aluminum hole-trapping centers. Whereas the inner radii of these RICHs closely match the predicted range of the most energetic common alphas 39 micrometers , the color centers observed extend to micrometers.
Migration of valence-band holes down a radiation-induced charge potential might account for these enigmatic RICHs. Such RICHs provide natural experiments in ultraslow charge diffusion. Shortly afterwards, Rutherford noted a close correspondence between the radial size of halos and the energies of the alpha particles.
A number of workers have described and measured these radiation-induced color halos RICHs and, from their sizes, have tried to match them with specific radionuclides in the inclusions.
Although it seems possible to relate the sizes of most of the described halos to alpha emitters in the U and Th decay chains, there are many exceptions. Particularly controversial have been two perhaps artificial classes of RICHs referred to as Po halos and giant halos. Significantly, rings that can be attributed to the other five alpha decays in the U seroes seem to be lacking.
That the half-life of Po is 3 min has not deterred some investigators from proposing separation of Po from its radioactive progenitors before its inclusion in minerals. Indeed, Po halos have even been offered as possible evidence of an instantaneous creation.