Thales was interested in almost everything, investigating almost all areas of knowledge, philosophy, history, science, mathematics, engineering, geography, and politics. He proposed theories to explain many of the events of nature, the primary substance, the support of the earth, and the cause of change. Thales was much involved in the problems of astronomy and provided a number of explanations of cosmological events which traditionally involved supernatural entities. His questioning approach to the understanding of heavenly phenomena was the beginning of Greek astronomy. He founded the Milesian school of natural philosophy, developed the scientific method, and initiated the first western enlightenment. When considered in association with his hypotheses they take on added meaning and are most enlightening. Thales was highly esteemed in ancient times, and a letter cited by Diogenes Laertius, and purporting to be from Anaximenes to Pythagoras, advised that all our discourse should begin with a reference to Thales D. Doubts have always existed about whether Thales wrote anything, but a number of ancient reports credit him with writings. Simplicius Diels, Dox. Lobon of Argus asserted that the writings of Thales amounted to two hundred lines D.
How Does Carbon Dating Work
Obviously scientists have determined some dates more accurately than others, but the consistency of different dating techniques applied to the same event gives confidence in the overall chronology.
According to this theory, the ocean formed from the escape of water vapor and other gases from the molten rocks of the Earth to the atmosphere surrounding the.
You may know the story. The planet shuddered with magnitude earthquakes, loosing tsunamis across the Gulf of Mexico. Some of the ejected debris condensed in orbit and plunged back to Earth as searing spheres of molten glass, which torched the land and turned forests into firestorms. By the time it was over, about 75 percent of all species on Earth had died, including all nonavian dinosaurs. Since , when the K-T impact hypothesis was first proposed , the Day the Dinosaurs Died has attained almost mythic significance.
But questions remain about the theory. Why did this one end the million-year reign of the dinosaurs? A new paper , published this week in the Proceedings of the National Academy of Sciences , offers a possible answer: The impact changed the chemical content of the ocean, rendering seawater more acidic and inhospitable to the tiny plankton that form the base of the marine food chain. Combined with the other effects of the asteroid—darkened skies and a snap of global cooling—this ecologic disruption doomed much of life on Earth.
The finding may be satisfying for asteroid fans, but it is an ominous one. Read: Caring for the last member of a doomed species. How does an asteroid prompt an extinction? It chooses the right location.
An Essay on Radiometric Dating. Radiometric dating methods are the strongest direct evidence that geologists have for the age of the Earth. All these methods point to Earth being very, very old — several billions of years old. Young-Earth creationists — that is, creationists who believe that Earth is no more than 10, years old — are fond of attacking radiometric dating methods as being full of inaccuracies and riddled with sources of error.
When I first became interested in the creation-evolution debate, in late , I looked around for sources that clearly and simply explained what radiometric dating is and why young-Earth creationists are driven to discredit it. I found several good sources, but none that seemed both complete enough to stand alone and simple enough for a non-geologist to understand them.
Dinosaurs roamed the earth for million years until their sudden One early theory was that small mammals ate dinosaur eggs, thereby of the earth–trace amounts of radiation dating back to the Cretaceous Period.
There are three major types of creationism espoused by fundamentalist antievolutionists, each with variants, plus a few less popular types. This type aims to employ the most literal and direct interpretation of Genesis, and the strictest fundamentalists tend to insist upon it: fiat ex nihilo “out of nothing” creation in six, twenty-four-hour days about six thousand or so years ago.
Because of the obvious difficulties of the extreme young-Earth Flood geology position, many creationists hold one of the two other main positions: “day-age” or “gap theory” creationism. Each also involves critical compromises with the plainest, most literal reading of the Bible in order to force scripture into concordance with scientific evidence regarding the age of Earth. There are various means of reconciling this interpretation with the biblical account which need not concern us here.
And this latter point does involve some stubborn difficulties. The “gap theory,” also known as the “ruin-restitution” theory, preserves the literal, recent six twenty-four-hour-day creation but assumes that the vast ages so well attested to by science occurred prior to this set of events. This exegesis is accomplished by postulating a tremendous “gap” between the very first two verses of Genesis, into which go all the geological ages:.
But this world perhaps just Earth and not the entire universe grew to be evil, and God destroyed it in a gigantic cataclysm. Earth became “without form and void” as a result of this destruction. Gap theorists hold that the verb in the second verse is more accurately translated as became or had become rather than as was. Gap theory advocates, by this maneuver, are able to reconcile the scientific evidence for an old Earth and universe and for life itself.
Universe is created, according to Kepler
He works for the University of Toronto. In , J. Known as plate tectonics , the theory describes the large-scale motion of the outer layer of the Earth. It explains tectonic activity things like earthquakes and the building of mountain ranges at the edges of continental landmasses for instance, the San Andreas Fault in California and the Andes in South America.
Although the widespread acceptance of the theory of plate tectonics is younger than Barack Obama, German scientist Alfred Wegener first advanced the hypothesis back in After analyzing fossil records that showed similar species once lived in now geographically remote locations, meteorologist Wegener proposed that the continents had once been fused.
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Earth is estimated to be about 4. Indeed, some scientists think life appeared the moment our planet’s environment was stable enough to support it. The earliest evidence for life on Earth comes from fossilized mats of cyanobacteria called stromatolites in Greenland that are about 3. Ancient as their origins are, these bacteria which are still around today are already biologically complex—they have cell walls protecting their protein-producing DNA, so scientists think life must have begun much earlier.
In fact, there are hints of life in even more primeval rocks: 4. But despite knowing approximately when life first appeared on Earth, scientists are still far from answering how it appeared. The answer to this question would not only fill one of the largest gaps in scientists’ understanding of nature, but also would have important implications for the likelihood of finding life elsewhere in the universe.
Today, there are several competing theories for how life arose on Earth. Some question whether life began on Earth at all, asserting instead that it came from a distant world or the heart of a fallen comet or asteroid. Some even say life might have arisen here more than once. Most scientists agree that life went through a period when RNA was the head-honcho molecule, guiding life through its nascent stages. RNA is very similar to DNA, and today carries out numerous important functions in each of our cells, including acting as a transitional-molecule between DNA and protein synthesis, and functioning as an on-and-off switch for some genes.
Like DNA, RNA is a complex molecule made of repeating units of thousands of smaller molecules called nucleotides that link together in very specific, patterned ways. While there are scientists who think RNA could have arisen spontaneously on early Earth, others say the odds of such a thing happening are astronomical.
Age of Earth
Hutton was the son of a merchant and city officeholder. Although already interested in chemistry , he entered the legal profession. He, along with his friend James Davie, was also deeply interested in investigating the manufacture of sal ammoniac from coal soot. As a result, he was released from law apprenticeship before his first year was out, and he turned to the study of medicine, as it was most closely related to chemistry.
He spent three years at the University of Edinburgh, then two in Paris, and finally was granted an M.
Willard Libby’s concept of radiocarbon dating; Predictions about carbon order to prove the idea Libby would have to understand the earth’s carbon system. It was here that he developed his theory and method of radiocarbon dating, for.
When asked for your age, it’s likely you won’t slip with the exception of a recent birthday mistake. But for the sprawling sphere we call home, age is a much trickier matter. Before so-called radiometric dating, Earth’s age was anybody’s guess. Our planet was pegged at a youthful few thousand years old by Bible readers by counting all the “begats” since Adam as late as the end of the 19th century, with physicist Lord Kelvin providing another nascent estimate of million years.
Kelvin defended this calculation throughout his life, even disputing Darwin’s explanations of evolution as impossible in that time period. In , Marie Curie discovered the phenomenon of radioactivity, in which unstable atoms lose energy, or decay, by emitting radiation in the form of particles or electromagnetic waves.
Subscriber Account active since. Thankfully, no conspiracy theories or predictions about how and when the world would end have proven true so far, though many have caught our attention worldwide. But many people still find doomsday predictions intriguing, even if they don’t really believe that a hidden alien planet is going to crash into Earth and herald the apocaplyse. Here are seven times that theories about the world ending became the subject of public fascination and pop culture.
The Library of Congress reports that mass hysteria branded Halley’s Comet ” the evil eye of the sky ” in , prompting the sales of anti-comet pills and gas masks in the event that it hit the planet and triggered an apocalyptic explosion. It harmlessly passed between Earth and the sun in May of that year.
This theory suggests that the characteristics of tne earth’s interior can be so the old iron-nickel theory of the earth’s core, developed to explain the earth’s.
Pre-Darwinian Theories. T he acceptance of biological evolution is an essential part of the modern scientific explanation of the natural world. Most scientists and major religions in the Western World have long since incorporated it into their understanding of nature and humanity. However, some churches still maintain that there was a special and independent creation of every species and that life forms do not change through time from generation to generation. These “creationists” often share beliefs about the Judeo-Christian Bible that were widely held, even by scientists, during the early 19th century and before.
By counting the generations of the Bible and adding them to modern history, he fixed the date of creation at October 23, B.
The Worst Day in Earth’s History Contains an Ominous Warning
Taking the necessary measures to maintain employees’ safety, we continue to operate and accept samples for analysis. Radiocarbon dating is a method that provides objective age estimates for carbon-based materials that originated from living organisms. The impact of the radiocarbon dating technique on modern man has made it one of the most significant discoveries of the 20th century. Archaeology and other human sciences use radiocarbon dating to prove or disprove theories.
Over the years, carbon 14 dating has also found applications in geology, hydrology, geophysics, atmospheric science, oceanography, paleoclimatology and even biomedicine. Radiocarbon carbon 14 is an isotope of the element carbon that is unstable and weakly radioactive.
Stromatolites have been found that date back to about billion years ago. Today, there are several competing theories for how life arose on Earth.
The Earth is 4,54 billion years old. This age has been determined with the radioactive dating technique. The precise decay rate of radioactive elements is used as a clock: the number of daughter products in one rock indicates its age. The oldest meteorites ever dated in the Solar System are 4,56 billion years old, the oldest minerals on Earth are 4,4 billion years old, and the oldest rocks on Earth are 4 billion years old.
These ages are very consistent because the meteorites had to form before the accretion of our planet, and the Earth had to cool down before the first minerals could crystallise. The Solar System was formed around 4. Dating meteorites thus allows us to give a lower age to the Solar System 4,56 billion years old. Lead isotope isochron that Clair Patterson used to determine the age of the solar system and Earth Patterson, C.
The animation shows progressive growth over million years Myr of the lead isotope ratios for two stony meteorites Nuevo Laredo and Forest City from initial lead isotope ratios matching those of the Canyon Diablo iron meteorite. Courtesy of Wikipedia.
Scientific Evidence for an Old Earth
The Cretaceous-Tertiary extinction event, or the K-T event, is the name given to the die-off of the dinosaurs and other species that took place some However, in the s, father-and-son scientists Luis and Walter Alvarez discovered in the geological record a distinct layer of iridium—an element found in abundance only in space—that corresponds to the precise time the dinosaurs died. This suggests that a comet, asteroid or meteor impact event may have caused the extinction of the dinosaurs.
Dinosaurs roamed the earth for million years until their sudden demise some Over the years, paleontologists have proposed several theories for this extensive die-off.
After studying thousands of rocks samples dating at least billion years old, Kamber & Tomlinson determined the Earth’s upper mantle was.
This theory suggests that the characteristics of tne earth’s interior can be described on the basis of variations in condition rather than composition. Assuming a temperature-gradient of one degree for every 90 ft. The pressure at the centre of the earth is calculated at 50 million pounds per square inch, and in such circumstances anounce of hydrogen would be compressed into to of a cubic foot. The gas would be ionized and compounds would produce much higher densities than the known average of for the earth.
He thinks that iron would lose its magnetic properties under the intense heat at the earth’s centre, so the old iron-nickel theory of the earth’s core, developed to explain the earth’s magnetic properties, cannot be sustained, and in any event is unnecessary if rotating bodies develop magnetism, as has been recently found for stars.