The "rare Earth hypothesis" holds that ..
Do you consider the Copernican Principle to be in conflict with the Rare Earth hypothesis?
evidence for the Earth’s collision with a rare swarm of ..
Causes and Mechanisms
While the absolute cause of the initiation of the Snowball Earth event is not known, many theories have been proposed. These theories include a solar output decrease, the Earth passing through rare space clouds, or even a runaway cooling effect due to a decrease in greenhouse gases. However, many scientists believe that a combination of these factors could be the real reason the Earth became covered in ice.
The newest of these theories proposes the Earth became covered in ice while passing through a rare space cloud. The support for this theory is limited; however it states that the dense space clouds would have allowed charged particles to enter the Earth’s atmosphere and destroy the ozone layer (25). Pavlov suggests that in combination with dust that would collect in the atmosphere as a result of this event, solar radiation would scatter and not be absorbed, allowing heat to escape into space. This would eventually cause a runaway ice effect and possible global glaciation (25). By assessing levels of uranium 235, geologists can test this hypothesis. Uranium 235 is not produced naturally on Earth, or anywhere else in the solar system, but is very readily produced in exploding stars called supernovae. These supernovae are found in space clouds. A higher level of uranium 235 during the Snowball Earth period would support this hypothesis. However, opponents to this theory argue that it would take the solar system 500,000 years to completely pass through a space cloud, the Earth’s magnetic fields would likely switch during this time, allowing the sun’s charged cosmic rays and ultraviolet radiation into the atmosphere.
The path to developing FE technology for public use outlined above I believe work, but there are also other ways that the Fifth Epochal Event can manifest. If I had to bet on how it will manifest, I would put my money on the struggle between the , and on their beginning to release some of their sequestered technologies. The reason why their organized suppression efforts have been so successful is that they know if of it makes it to the public, it will only be a matter of time before the dam breaks, which would probably include ETs openly interacting with humanity. The GCs know that if any of that happens, their days of ruling humanity will quickly end. That is partly why this hump has been so hard to get over. But I am not going to wait for something to happen at that level to save us all, and what I am attempting will also help form a nucleus of awareness that can greatly help with an enlightened and harmless implementation of FE. If FE makes its appearance, its implementation will need to be led by as many enlightened and informed people as possible. Some need to be ahead of the curve to lead the way, if only by promoting an enlightened awareness. Once people can see FE with their own eyes, preferably by having it delivered to their home (anything less, and ; they will not be talked into an abundance-based mentality; they must experience it), the should be pretty rapid, especially if there is already a choir singing the song of abundance.
The Scientific Method: Hypothesis to Theory
The Oligocene ended with a sudden global warming that continued into the (c. 23 to 5.3 mya). The Miocene was also the first epoch of the (c. 23 to 2.6 mya). Although the Miocene was , England had palm trees again, Antarctic ice sheets melted, and oceans rose. The Miocene is also called the Golden Age of Mammals. Scientists still wrestle with why Earth’s temperature increased in the late Oligocene, but there is no doubt that it did. As the has demonstrated, many dynamics impact Earth’s climate, and positive and negative feedbacks can produce dramatic changes. For the several million year warm period, carbon dioxide levels do not appear to have been elevated. That data has been seized on by as evidence that carbon dioxide levels have nothing to do with Earth’s temperature, but climate scientists not rarely think that way. Carbon dioxide is only one greenhouse gas, and . But as clouds demonstrate, water is notoriously ephemeral, constantly evaporating and precipitating, and some land can get a lot (rainforests), and some can get very little (deserts). Icehouse Earth temperatures are more variable than Greenhouse Earth temperatures, particularly during the transitions between states, and an Icehouse Earth atmosphere contains less water vapor than a Greenhouse Earth atmosphere.
A has challenged The Expensive-Tissue Hypothesis, at least as far as robbing energy from the digestive system to fuel the brain. The study compared brain and intestinal size in mammals and found no strong correlation, but there was an inverse correlation between brain size and body fat. But since human fat does not impede our locomotion much, humans have combined both strategies for reducing the risk of starvation. Whales have bucked the trend, also because being fatter does not impede their locomotion and provides energy-conserving insulation. A human infant’s brain uses about 75% of its energy, and baby fat seems to be brain protection, so that it does not easily run out of fuel. However, the rapid evolutionary growth of an energy-demanding organ like the human brain seems unique or nearly so in the history of life on Earth, and comparative anatomy studies may have limited explanatory utility. There are great debates today on how fast the human brain grew, what coevolutionary constraints may have limited the brain’s development (, , ), and scientific investigations are in their early days.
Earth Science THE SCIENTIFIC METHOD
In recent years, many in the geology community have voiced increased support for the Slushball Earth hypothesis, developed by Richard Cowen (9). The Slushball Earth hypothesis is less extreme than the Snowball Earth hypothesis. The Slushball hypothesis acknowledges that ice sheets covered large parts of the earth, but asserts that a skeletal layer of ice covered oceans near the equator, enabling photosynthetic organisms to acquire sunlight and survive during these extreme temperatures.
Evidence and Counterevidence
Proponents of the Snowball Earth model postulate that the presence of diamictite deposits on every continent points to the fact that a global glaciation had once occurred (10). Lindsay et al. (1996) claim that diamictities with glacial origin from the neoproterozoic have been widespread, and this distribution points to the development of ice sheets. The synchronization of these events strengthens their claim (11). Global distribution of Sturtian and Marinoan (and to a lesser extent the Gaskiers) glacial deposits, and the widespread synchronicity of those in the Marinoan has led some scientists to conclude that glaciers had once covered the entire earth. This widespread distribution of glacial deposits is seen in Figure 2. However, Hoffman and Schrag argue that Neoproterozoic glacial strata do not fit with Phanerozoic stereotypes (14). This argument calls into question the diamicite hypothesis because if the glacial strata do not fit across time period there must be some other reason for the diamicite deposits. Eyles and Januszczak also dispute the diamicite evidence, arguing that the global distribution of diamicite is incorrect because it assumes that deposits are glacially and chronostratigraphically equivalent (18). Due to the increased knowledge of the various ways poorly sorted diamictite can be produced, Eyles and Janusczczak conclude that most Neoproterozoic diamictites are products of deepwater debris flows caused by large-scale continental “unzippings” and are not correlated with global ice ages (18).
It is known that anaerobic bacteria survive and flourish near hydrothermal vents deep within the Earth’s oceans, so it is likely bacteria could survive in the same location during a global glaciation event. Adaptations required for living in such an environment include the ability to convert heat into energy. However, photosynthesis is not possible at these locations because light does not penetrate that deep in the ocean. It was previously believed that thin ice or cracks in the ice during the Snowball event would allow for photosynthesizers to survive and produce trace amounts of oxygen that could be used by oxygen-dependent organisms (depicted in Figure 7). While this is still a possibility, a concurrent hypothesis for survival has been proposed. After analyzing samples of phytoplankters from different geothermal waters, Costas et al. concluded that geothermal waters were very hazardous to cyanobacteria and microalgae because growth in these waters was not detected (28). However, by looking for rare variants that flourished under these conditions, they found this response was due to a single, spontaneous mutation. While there is no way to be certain if algae during the late Neoproterozoic had a similar mutation, it is possible they may have survived in ice-free geothermal waters by using a similar mutation mechanism (28).
Rare, ancient maps show how thousands of years ago, …
Last Word Archive | New Scientist
Abiogenesis - Wikipedia
Feature Stories Archives - Astrobiology Magazine
Rare, ancient maps show how thousands of years ago, an advanced civilization mapped the Earth
The Great Mystery: Current Arguments
Earth began to receive water from space even before our planet had fully formed.
Komatiites and the Plume Debate - Mantle plume
In short, hypothesis testers are accused of forcing anunrealistic and idealized view of the scientific method into a setting which is utterlyinconsistent with the paradigm.The Matlon and Cross survey reveals that much of the theory is translated intopractice: hypo-testers do not require a negative policy, rarely make on-balancejudgements, support well-defined conditional arguments and do require proof of a coremotive; however, they neither accept contradictions nor vote on presumption morefrequently than their colleagues who accept other paradigms. Tabula Rasa ParadigmNature of the Tabula Rasa ParadigmTabula rasa (Latin for "blank slate") means that a judge enters a round withno personal preferences or prejudgments; supposedly he or she will vote for whateverparadigm the debaters establish in the round.
A few elements of ideas proposed by Cascales-Miñana et al
Part of the hypothesis for skyrocketing oxygen levels during the late Proterozoic was that high carbon dioxide levels, combined with a continent that had been ground down by glaciers, and the resumption of the hydrological cycle, which would have vanished during the Snowball Earth events, would have created conditions of dramatically increased erosion, which would have buried carbon (the cap carbonates are part of that evidence) and thus helped oxygenate the atmosphere. Evidence for that increased erosion also came in the form of strontium isotope analysis. Two of strontium’s stable isotopes are . Earth’s mantle is enriched in strontium-86 while the crust is enriched in strontium-87, so basalts exposed to the ocean in the oceanic volcanic ridges are enriched in strontium-86 while continental rocks are enriched in strontium-87. If erosion is higher than normal, then ocean sediments will be enriched in strontium-87, which analysis of Ediacaran sediments confirmed. That evidence, combined with carbon isotope ratios, provides a strong indication of high erosion and high carbon burial, which would have increased atmospheric oxygen levels. There is other evidence of increasing atmospheric oxygen content during the late Proterozoic, such as an increase in rare earth elements in Ediacaran sediments. Although there is still plenty of controversy, today's consensus is that the Cryogenian is when , where they have largely stayed, although as this essay will later discuss, oxygen levels have varied widely since the late Proterozoic (from perhaps only a few percent to 35%).
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