Archeological research, as generally practiced, shares with the rest of anthropology and the other social sciences a concern for the recurrent, patterned aspects of human behavior rather than with the isolation of the unique. It is historical in the sense that it deals with human behavior viewed through time and supplements written sources with the documentation provided by artifactual evidence from the past. During the century or so of its existence as a recognizable scholarly discipline, archeology has come more and more to apply scientific procedures to the collection and analysis of its data, even when its subject matter could be considered humanistic as well as scientific. Archeology can also be properly regarded as a set of specialized techniques for obtaining cultural data from the past, data that may be used by anthropologists, historians, art critics, economists, or any others interested in man and his activities. This view has the advantage of eliminating the argument whether archeology is anthropology or history and allows for recognition of the varied, sometimes incompatible, purposes for which archeological data and conclusions are used. There is no reason to regard the archeology of Beazley, who analyzes Greek black-figure vases, as identical with the archeology of MacNeish, who has excavated plant remains of the earliest Mexican farmers. No other reliable means is available to extend backward our knowledge of culture, since traditional histories, orally transmitted, are not only shallow in their time depth but subject to many distortions with the passage of time. It has provided an essential check on theories of cultural evolution and is substituting fact for fancy in such matters as the origins of plant and animal domestication and the beginnings of writing, urbanization, and other crucial steps toward civilization. Although scientific archeology—in contrast to antiquarian studies and the collection of curios—is less than a century old, it has already provided a comprehensive and fairly detailed view of human activities in all parts of the world from the very beginnings of mankind Clark At the same time that archeology is fundamental to a scientific understanding of man, it is also a subject of tremendous popular interest, albeit too often of a superficial and sensational kind.
Crystals and Gemstones
Chemically pure silica has been prepared in at least 35 crystalline forms with density varying by more than a factor of 2 17 to 43 SiO2 units per cubic Angstroms. Chemical properties such as hygroscopicity tendency to react with ambient water vary tremendously depending on the structure. Devine, Plenum NY ] I’ve seen a lot of work using the refractive index at optical frequencies to characterize silica.
Then there is fire, which may be considered as eating its fuel, breaking it down to simpler substances, converting it into its own flaming structure, and eliminating the ash which it can’t use.
Radioactive decay[ edit ] Example of a radioactive decay chain from lead Pb to lead Pb. The final decay product, lead Pb , is stable and can no longer undergo spontaneous radioactive decay. All ordinary matter is made up of combinations of chemical elements , each with its own atomic number , indicating the number of protons in the atomic nucleus. Additionally, elements may exist in different isotopes , with each isotope of an element differing in the number of neutrons in the nucleus. A particular isotope of a particular element is called a nuclide.
Some nuclides are inherently unstable. That is, at some point in time, an atom of such a nuclide will undergo radioactive decay and spontaneously transform into a different nuclide. This transformation may be accomplished in a number of different ways, including alpha decay emission of alpha particles and beta decay electron emission, positron emission, or electron capture.
Another possibility is spontaneous fission into two or more nuclides. While the moment in time at which a particular nucleus decays is unpredictable, a collection of atoms of a radioactive nuclide decays exponentially at a rate described by a parameter known as the half-life , usually given in units of years when discussing dating techniques.
After one half-life has elapsed, one half of the atoms of the nuclide in question will have decayed into a “daughter” nuclide or decay product.
Potential of abundant, environmentally harmless energy technology , which already exists My strategy for manifesting that energy event for humanity’s and the planet’s benefit. I w as born in In that same year, I had my cultural and mystical awakenings.
Chemistry Interaction with hydrogen and water are important in semiconductor applications of silicon dioxide.
For more examples, see my article: Yet it’s a vacuum there. The thing is that of course it was a sunny day for the astronauts – you tend to forget when you see the black sky. On Earth some of the light comes to the landscape from the sun and some reaches us indirectly from the blue sky and the clouds. On the Moon, much of the light comes from the sun, but a lot of light also comes indirectly from the landscape itself. That’s why you can see detail in the shadows, and why they aren’t completely black on the Moon.
So – it’s not quite so surprising as you’d think, but fun. You can make the photos look even more like Earth by reducing the contrast – shadows are not quite so contrasty on Earth. I tried that and it worked. You could also fuzz the edges of the shadows as they are never so sharp edged on Earth, and you’d need to do something about the black sky reflected in astronaut’s helmets. However I’m not trying to simulate an Earth illumination on the Moon. I don’t have the skills anyway, there are graphics designers, artists, 3D modelers etc who could do a much better job.
But that wasn’t my aim here. The aim was to show how the Moon is as Earth like as Mars in photographs, and indeed more so, with minimal processing, not even the white balancing they use for Mars photos.
Astrology and natal chart of Robert Pattinson, born on /05/13
Driving to Villarrica felt like coming home. A few years back, several TBF members spent a month here studying the behaviour of its lava lake. Back then we had to face a series of storms and found ourselves working under the snow and having to dig out our instruments from piles of ice every other morning. The lake level was very low, the gas emissions barely above detection limit and the resulting data not amazing.
This time we were welcomed with a pure blue sky, little wind and a beautiful high stand of the lava lake! Spattering could be seen from the rim.
This idea has been rebutted by those who claim there is no known scientific mechanism to produce such a change, see for example Tim-Thompson:
This age is obtained from radiometric dating and is assumed by evolutionists to provide a sufficiently long time-frame for Darwinian evolution. And OE Christians theistic evolutionists see no problem with this dating whilst still accepting biblical creation, see Radiometric Dating – A Christian Perspective. This is the crucial point: Some claim Genesis in particular, and the Bible in general looks mythical from this standpoint. A full discussion of the topic must therefore include the current scientific challenge to the OE concept.
This challenge is mainly headed by Creationism which teaches a young-earth YE theory. A young earth is considered to be typically just 6, years old since this fits the creation account and some dating deductions from Genesis. The crucial point here is: Accepted Dating Methods Here we outline some dating methods , both absolute and relative, that are widely accepted and used by the scientific community.
Absolute dating supplies a numerical date whilst relative dating places events in time-sequence; both are scientifically useful. Radiometric Dating This is based upon the spontaneous breakdown or decay of atomic nuclei. Radioactive parent P atoms decay to stable daughter D atoms e. The time required for half the original number of parent atoms to decay is called the half life.
In this context of changing and challenging market requirements, Gas Insulated Substation GIS has found a broad range of applications in power systems for more than two decades because of its high reliability, easy maintenance and small ground space requirement etc. SF6 has been of considerable technological interest as an insulation medium in GIS because of its superior insulating properties, high dielectric strength at relatively low pressure and its thermal and chemical stability.
SF6 is generally found to be very sensitive to field perturbations such as those caused by conductor surface imperfections and by conducting particle contaminants. The presence of contamination can therefore be a problem with gas insulated substations operating at high fields. If the effects of these particles could be eliminated, then this would improve the reliability of compressed gas insulated substation.
It would also offer the possibility of operating at higher fields to affect a potential reduction in the GIS size with subsequent savings in the cost of manufacture and installation.
Sound waves short enough to have that kind of resolving power would demand a good deal of energy to produce, would have very poor range in air, and would incidentally be decidedly dangerous to human explorers.
Bring fact-checked results to the top of your browser search. Nonradiometric dating In addition to radioactive decay , many other processes have been investigated for their potential usefulness in absolute dating. Unfortunately, they all occur at rates that lack the universal consistency of radioactive decay. Sometimes human observation can be maintained long enough to measure present rates of change, but it is not at all certain on a priori grounds whether such rates are representative of the past.
This is where radioactive methods frequently supply information that may serve to calibrate nonradioactive processes so that they become useful chronometers. Nonradioactive absolute chronometers may conveniently be classified in terms of the broad areas in which changes occur—namely, geologic and biological processes, which will be treated here. Geologic processes as absolute chronometers Weathering processes During the first third of the 20th century, several presently obsolete weathering chronometers were explored.
Most famous was the attempt to estimate the duration of Pleistocene interglacial intervals through depths of soil development. In the American Midwest, thicknesses of gumbotil and carbonate-leached zones were measured in the glacial deposits tills laid down during each of the four glacial stages. Based on a direct proportion between thickness and time, the three interglacial intervals were determined to be longer than postglacial time by factors of 3, 6, and 8.
To convert these relative factors into absolute ages required an estimate in years of the length of postglacial time. When certain evidence suggested 25, years to be an appropriate figure, factors became years—namely, 75, , , , and , years. And, if glacial time and nonglacial time are assumed approximately equal, the Pleistocene Epoch lasted about 1, , years.
In casual encounters with the material universe, we rarely feel any difficulty here, since we usually deal with things that are clearly alive, such as a dog or a rattlesnake; or with things that are clearly nonalive, such as a brick or a typewriter. Nevertheless, the task of defining “life” is both difficult and subtle; something that at once becomes evident if we stop to think. Consider a caterpillar crawling over a rock.
The caterpillar is alive, but the rock is not; as you guess at once, since the caterpillar is moving and the rock is not. Yet what if the caterpillar were crawling over the trunk of a tree? The trunk isn’t moving, yet it is as alive as the caterpillar.
The important thing is, that none of these would make Earth less habitable than Mars.
Las Posadas Geochemical distribution of the elements Knowledge of the geochemical distribution of elements involves elucidation of the relative and absolute abundances of the chemical elements in the Earth and in its various parts—the crust, interior, atmosphere, and hydrosphere. This comprises a major part of the science of geochemistry , which is the study of the distribution of the chemical elements in space and time and the laws governing this distribution.
Basic knowledge in this area was largely accumulated during the 19th century. As noted above, the concept of a limited number of chemical elements had been established by , and the appearance of the periodic table , in , provided a new insight into the limitations on the number of elements. The output from North America was materially increased following the establishment of the United States Geological Survey in and the appointment of Frank W.
Clarke as chief chemist in In Clarke wrote the first of his many publications on the geochemical distribution of the elements. He assembled many chemical analyses of rocks from different continents, calculated average values, and showed that the overall chemical compositions of continental areas are remarkably similar. By combining these averages he obtained values for the abundances of the commoner elements in the continental crust of the Earth, values that have not been materially changed in spite of the vast increase of available data since that time.
He also estimated abundances for many of the less common elements; these estimates were based in many instances on very limited and imprecise data and subsequently have been improved. A further development of great significance was the assemblage of comprehensive data on the abundances of individual elements in terrestrial materials and in the Cosmos based on solar and meteorite abundances by the Norwegian geochemist Victor Moritz Goldschmidt during the s. Goldschmidt also contributed to the understanding of elemental distribution within the Earth through his geochemical classification of the elements into lithophile, siderophile, chalcophile, and atmophile.
Lithophile elements are those with a strong affinity for oxygen; they are concentrated in the crust or lithosphere as silicate and oxide minerals.
Back to the Top 2. A group, or family of elements, is a vertical column of the periodic table. Elements are placed into families due to their similar properties, characteristics, and reactivities. For example, all of the elements in group 1 except for hydrogen, which has unique properties are very reactive and form compounds in the same ratios and with similar properties as other 1 elements.
Due to the similarities in their chemical properties, Mendeleev put these elements into the same group and they came to be known as the alkali metals. The alkali metals include:
In a restricted locality where there is uniformity of climate and soil, the extent of fluorine addition is at least a measure of relative age and has been so used with notable success in dating certain hominid remains.
The burial of these organisms also meant the burial of the carbon that they contained, leading to formation of our coal, oil and natural gas deposits. As the rate of C14 formation is independent from the levels of normal carbon, the drop in available C12 would not have reduced the rate of C14 production. Even if the rate of C14 formation had not increased after the Flood, there would have been a fundamental shift in the ratio towards a relatively higher radiocarbon content.
The amount of C14 present in the pre-flood environment is also limited by the relatively short time less than years which had elapsed between Creation and the Flood. Even if one is generous and allows for the current rate of C14 production to have ocurred throughout this period, the maximum amount of C14 in existence then is less than a fourth of the amount present today. The last years have seen this effect occur in reverse. Our massive consumption of fossil fuels is releasing the carbon which has been locked up in the Earth’s crust for the last four or five millennia.
The effect has been complicated by the addition of manmade radioactive carbon to the biosphere because of nuclear explosions and experimentation. And God said, Let there be a space in the midst of the waters, and let it divide the waters from the waters. And God made the space, and divided the waters which [were] under the space from the waters which [were] above the space: And God called the space Heaven. And there was evening and there was morning – Day Two. The water vapour layer had many significant effects.
It increased atmospheric pressure, making absorption of oxygen by living creatures a much easier process than it is today.