Geology gives insight into the history of the Earth by providing the primary evidence for plate tectonics, the evolutionary history of life, and past climates. In modern times, geology is commercially important for mineral and hydrocarbon exploration / exploitation as well as for evaluating water resources. It is publicly important for the prediction and understanding of natural hazards, the remediation of environmental problems, and for providing insights into past climate change. Geologic time Geological time put in a diagram called a geological clock, showing the relative lengths of the eons of the Earth's history. The geologic time scale encompasses the history of the Earth. It is bracketed at the old end by the dates of the earliest solar system material at 4.567 Ga, (gigaannum: billion years ago) and the age of the Earth at 4.54 Ga at the beginning of the informally recognized Hadean eon. Important milestones Brief time scale Millions of Years Rock
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Geologic time scaleThe geologic time scale (GTS) is a system of chronological measurement that relates stratigraphy to time, and is used by geologists, paleontologists, and other earth scientists to describe the timing and relationships between events that have occurred throughout Earth's history. The table of geologic time spans presented here agrees with the nomenclature, dates and standard color codes set forth by the International Commission on Stratigraphy. Evidence from radiometric dating indicates that the Earth is about 4.54 billion years old. The geology or deep time of Earth's past has been organized into various units according to events which took place in each period. Different spans of time on the GTS are usually delimited by changes in the composition of strata which correspond to them, indicating major geological or paleontological events, such as mass extinctions. Terminology History and nomenclature of the time scale Graphical representation of Earth's history as a spiral
50,000 year old woman's toe reveals Neanderthals had sex with everyoneAccording to an international team of anthropologists and geneticists at the University of California, Berkeley, our ancient Neanderthal cousins were a randy and apparently not very picky conglomerate of sexual deviants. Thanks to their remarkable research, in which DNA was extracted from a 50,000-year-old woman's toe, the team at Berkeley discovered Neanderthals had a long history of interbreeding among at least four different types of early humans living in Europe and Asia at the time. The team compared the Neanderthal genomes with those of modern humans and a recently recognised group of early humans called Denisovans, discovering that Neanderthals and Denisovans are very closely related, with their common ancestor splitting off from the ancestors of modern humans around 400,000 years ago. The research team estimates that between 1.5 and 2.1 percent of the genomes of modern non-Africans can be traced to Neanderthals.
WeatherWeather is driven by air pressure (temperature and moisture) differences between one place and another. These pressure and temperature differences can occur due to the sun angle at any particular spot, which varies by latitude from the tropics. The strong temperature contrast between polar and tropical air gives rise to the jet stream. Weather systems in the mid-latitudes, such as extratropical cyclones, are caused by instabilities of the jet stream flow. Surface temperature differences in turn cause pressure differences. Studying how the weather works on other planets has been helpful in understanding how weather works on Earth. Cause On Earth, common weather phenomena include wind, cloud, rain, snow, fog and dust storms. Weather occurs primarily due to air pressure (temperature and moisture) differences between one place to another. Because the Earth's axis is tilted relative to its orbital plane, sunlight is incident at different angles at different times of the year.
Rock (geology)Rocks have been used by mankind throughout history. From the Stone Age rocks have been used for tools. The minerals and metals we find in rocks have been essential to human civilization. Three major groups of rocks are defined: igneous, sedimentary, and metamorphic. Classification The three classes of rocks are subdivided into many groups. Igneous Sedimentary Sedimentary sandstone with iron oxide bands Before being deposited, sediments are formed by weathering or earlier rocks by erosion in a source area, and then transported to the place of deposition by water, wind, ice, mass movement or glaciers (agents of denudation). Metamorphic banded gneiss The three major classes of metamorphic rock are based upon the formation mechanism. Human use The use of rocks has had a huge impact on the cultural and technological development of the human race. Mining Mining of stone and metal has been done since pre-historic times. See also References
10 More Common Faults in Human ThoughtHumans This list is a follow up to Top 10 Common Faults in Human Thought. Thanks for everyone’s comments and feedback; you have inspired this second list! It is amazing that with all these biases, people are able to actually have a rational thought every now and then. There is no end to the mistakes we make when we process information, so here are 10 more common errors to be aware of. The confirmation bias is the tendency to look for or interpret information in a way that confirms beliefs. The Availability heuristic is gauging what is more likely based on vivid memories. Illusion of Control is the tendency for individuals to believe they can control or at least influence outcomes that they clearly have no influence on. Interesting Fact: when playing craps in a casino, people will throw the dice hard when they need a high number and soft when they need a low number. The Planning fallacy is the tendency to underestimate the time needed to complete tasks. Bonus Attribute Substitution
EarthEarth is the third planet from the Sun. It is the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets. It is sometimes referred to as the world or the Blue Planet. Earth formed approximately 4.54 billion years ago, and life appeared on its surface within its first billion years. Earth's biosphere then significantly altered the atmospheric and other basic physical conditions, which enabled the proliferation of organisms as well as the formation of the ozone layer, which together with Earth's magnetic field blocked harmful solar radiation, and permitted formerly ocean-confined life to move safely to land. The physical properties of the Earth, as well as its geological history and orbit, have allowed life to persist. Name and etymology In general English usage, the name earth can be capitalized or spelled in lowercase interchangeably, either when used absolutely or prefixed with "the" (i.e. Heat
Rock cycleHistorical development The original concept of the rock cycle is usually attributed to James Hutton, from the eighteenth century Father of Geology. The rock cycle was a part of Hutton's uniformitarianism and his famous quote: no vestige of a beginning, and no prospect of an end, applied in particular to the rock cycle and the envisioned cyclical nature of geologic processes. This concept of a repetitive non-evolutionary rock cycle remained dominant until the plate tectonics revolution of the 1960s. With the developing understanding of the driving engine of plate tectonics, the rock cycle changed from endlessly repetitive to a gradually evolving process. The Wilson cycle (a plate tectonics based rock cycle) was developed by J. The cycle Transition to igneous When rocks are pushed deep under the Earth's surface, they may melt into magma. Secondary changes  Transition to sedimentary Forces that drive the rock cycle Plate tectonics In 1967, J.
Scientists Are Beginning To Figure Out Why Conservatives Are…ConservativeScientists are using eye-tracking devices to detect automatic response differences between liberals and conservatives.University of Nebraska-Lincoln You could be forgiven for not having browsed yet through the latest issue of the journal Behavioral and Brain Sciences. If you care about politics, though, you'll find a punchline therein that is pretty extraordinary. Click here to read more from Mooney on the science of why people don't believe in science. Behavioral and Brain Sciences employs a rather unique practice called "Open Peer Commentary": An article of major significance is published, a large number of fellow scholars comment on it, and then the original author responds to all of them. The approach has many virtues, one of which being that it lets you see where a community of scholars and thinkers stand with respect to a controversial or provocative scientific idea. That's a big deal. The authors go on to speculate that this ultimately reflects an evolutionary imperative.