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Earth and Neptune were both on stage this week with stories of impacts. How do scientists know when they occurred?Neptune: A comet struck Neptune 200 years ago. That’s what planetary scientists are claiming, according to National Geographic. The data only “suggests” this explanation, according to Space.com. Since nobody witnessed the impact in 1810 (Neptune had not even been discovered yet), how do they know? The data consists of elevated carbon monoxide levels in the outer atmospheric layers of Neptune compared with the lower layers, as measured by the Herschel spacecraft. According to one of the authors of a paper on the hypothesis, “The higher concentration of carbon monoxide in the stratosphere can only be explained by an external origin,” Another author added, “From the distribution of carbon monoxide we can therefore derive the approximate time, when the impact took place.” According to the articles, similar techniques were used on Saturn to suspect an impact about 300 years ago. The only impacts on gas giants witnessed by humans have been on Jupiter. Scientists estimate the one that hit Neptune was twice as big as the first fragment of Comet Shoemaker-Levy 9 that struck Jupiter in 1994.Earth: A new impact crater was found in the deserts of Egypt, according to Space.com – one of the most pristine ever found. National Geographic has a good picture of it. Because of its lack of erosion, they estimated the crater formed within the last 2,000 years. Called Kamil Crater, it is 147 feet in diameter and 52 feet deep. This leads astrophysicists to estimate the characteristics of the impactor: “Based on their calculations, the team thinks that a 4.2-foot-wide (1.3-meter-wide) solid iron meteor weighing 11,023 to 22,046 pounds (5,000 to 10,000 kilograms) smashed into the desert—nearly intact—at speeds exceeding 2.1 miles (3.5 kilometers) a second.” Based on estimates of the number of impactors orbiting our region of the solar system, the scientists estimate that 1,000 to 10,000 such impactors should strike earth each million years. Why are more not found? An Italian scientist explained, “The reason why they are rare, however, is that, on Earth, weathering rates are high—small craters are usually easily eroded or buried.”For more on crater count dating methods, see this list of search bar results.Which is easier: (1) to make up a story about something in the past that was not observed, or (2) to predict when something will happen? If planetary scientists can tell us when and where a meteor will strike and form a crater, that would be very impressive. “Too many variables!” they would rightly complain. But those same variables are time-independent. When you see them predicting 1,000 to 10,000 impacts each million years, that would be 4.5 to 45 million craters over the assumed age of the earth. It smells like a theory-rescuing device to say they were all eroded and weathered away. Not all portions of the earth erode at the same rate. Geologists tell us there are some rock outcrops 3.8 billion years old. Surely some evidence, direct or indirect, of 45 million craters should be detectable beyond the 176 National Geographic said have been discovered. It appears there is some potential for testing deep time here. Take the assumed flux of material, the assumed age of the earth, the compositional content of the impacting material, the geological column, reasonable erosion rates, and research the question: is there evidence for this much meteoritic or cometary material in the rock record of our planet? Let’s not just take the secular geologists’ word for it. They are wedded to deep time. It would never occur to them to doubt their spouse: besides, it would be in bad taste. It’s up to the untied to ask such questions.(Visited 14 times, 1 visits today)FacebookTwitterPinterestSave分享0
With local government elections set for next year, Minister of Cooperative Governance and Traditional Affairs Pravin Gordhan discusses the importance of reforming municipal structure to ensure optimal governance and service delivery.South Africans queue to vote in the 2014 national elections. (Image: The Presidency) Minister of Cooperative Governance and Traditional Affairs Pravin GordhanSouth Africans are no doubt looking forward to the local government elections next year. They are an important because municipalities form the first line of contact between citizens and government.Since 1994 our nation has undergone many changes. But for all our success we are still plagued by issues from our past.Among them is the need to review governance structures, including municipal structures. There are municipalities that struggle to deliver services because of insufficient revenue and inadequate governance.The Back-to-Basics programme analysed municipalities across the country and found about a third to be dysfunctional. This was determined by measuring economic and financial viability, tax sustainability and dependence on inter-governmental transfers.Measures to address these challenges are aimed at ensuring sustainability and viability. The measures include direct interventions in cases where laws have been flouted or municipalities lack the capacity to deliver services. They also include strengthening district municipalities so that they deliver services. In certain cases there is a need to disestablish and amalgamate local municipalities to improve governance and functionality.The eagle-eyed would by now have noticed that the changes tend to coincide with municipal elections. There is a small window to make changes between local government election cycles. Having consulted all MECs responsible for local government in the provinces, the Ministry for Cooperative Governance and Traditional Affairs requested the Municipal Demarcation Board in terms of section 22(2) of the Local Government: Municipal Demarcation Act of 1998 to determine/re-determine the boundaries of various municipalities based on assessments conducted by the Department of Cooperative Governance.There were 25 specific requests in respect of seven provinces, with a total of 61 municipalities affected. There are also another 15 municipalities in KwaZulu-Natal where the request to the Board requires adjustments to municipal boundaries to align traditional rural communities.Historically, these changes have been met with only limited opposition. The process is open and transparent and any proposed change must pass legislative muster.Proposed changes are first scrutinised by the Board, which is an independent body that derives its mandate from the Constitution, the Municipal Demarcation Act, and the Local Government: Municipal Structures Act of 1998.In 1993, provincial boundaries were formed using the erstwhile magisterial districts and 843 municipalities were created. This was not sustainable as municipal areas were based on skewed settlement patterns, great spatial separations and disparities between towns, townships and urban areas.After the 2000 municipal elections, the number of municipalities was reduced to 284. There were also 16 cross-boundary municipalities that were created affecting five provinces.After a further review in 2006 the number of municipalities was reduced from 284 to 283. Further change was implemented in 2011 when 283 municipalities were reduced to 278.The proposal to establish 267 municipalities post the 2016 municipal elections demonstrates the continuous evolution of our system of local government, and should be seen within the context to build a capable state. It should be seen as the first phase towards addressing non-viable municipalities.The latest round of proposed demarcations will, no doubt, illicit strong responses from various quarters. Robust debate is part of our democracy and is welcomed. Nonetheless, we believe that the proposed changes will lead to better governance and stronger functioning municipalities.These changes are part of our Back-to-Basics approach to serve communities better. It prioritises the delivery of basic services, good governance, sound financial management and building capabilities.The Board will determine whether the identified municipalities meet the objectives of demarcation, and the factors that must be taken into account when the boundaries are determined. In considering the request by the Minister, certain legislated requirements will be followed.It must publish a notice in a newspaper circulating in the area concerned stating the intention to consider the matter and to also invite written representations from the public within a specified period, which may not be shorter than 21 days.After this, the Board must consider all submissions, and may hold a public meeting, or conduct a formal investigation, or do both.Thereafter, it must publish its determination or redetermination of a municipal boundary in the relevant Provincial Gazette, and any person aggrieved by a determination of a municipal boundary may within 30 days of publication of that determination submit objections in writing to the Board. Objections are then considered, and the Board must either confirm, vary or withdraw its determination. After having complied with the above requirements, the Board then publishes its decision in the relevant Provincial Gazette.It is clear that the determination of municipal boundaries may only be undertaken by the Board, an independent institution which finds its origins in the Constitution. No politician, including myself, may determine boundaries.This article was first published in the Sowetan on 24 March 2015.
On July 16, the United States National Institutes of Health (NIH) in Bethesda, Maryland will welcome a handful of Wikimedia Foundation’s staff and volunteers. Some of the nation’s top health, science, and medical minds will take a one day course on the mechanics and formatting of Wikipedia. Said Sue Gardner, executive director of the Wikimedia Foundation, “With the broad range of experts from the National Institutes of Health, we see a great opportunity for increasing the quality of all health-related information on Wikipedia.”This is a significant event, not only because the Wikipedia Academy training will be the first of its kind in the US, but also because Wikipedia is often at the top of results when the general public searches for online health information. According to the Wikipedia blog, the 2009 swine flu pandemic page “got about 16,000 page hits on April 23, and this number increased to a dizzying 2.86 million page hits only a week later.” The article began as a mere stub and has since expanded to a 21 page article with multiple iterations and discussions. The NIH is the U.S. Department of Health and Human Services’ primary agency for conducting and supporting medical research. Contributions from the group will likely help dispel myth from fact and increase awareness for early detection and preventative health. In the past, a number of media stories from the American Medical News, Reuters Health and Seattle’s KOMO TV News have criticized Wikipedia for its lack of credibility. There have also been a number of breakaway efforts to recreate the Wikipedia experience amongst subject experts including Toxipedia, Medpedia and Citizendium. Nevertheless, with Wikipedia’s monthly unique traffic of 300 million visitors, it simply makes more sense for medical experts to travel to an information epicenter rather than asking millions to modify their behavior. While no responsible medical professional would ever suggest Wikipedia as the sole information source for self-diagnosis and treatment, the NIH’s recognition of Wikipedia’s value might spur on other agencies to consider the site in health outreach strategies. 8 Best WordPress Hosting Solutions on the Market Top Reasons to Go With Managed WordPress Hosting dana oshiro Tags:#health#web Why Tech Companies Need Simpler Terms of Servic… A Web Developer’s New Best Friend is the AI Wai… Related Posts
Explore further This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only. As Chini notes, huge strides have been made over the past few decades in using light to convey information, while at the same time, electronic devices have continued to be limited by the upper frequency limits at which electric currents can be driven. As he also notes, prior research has shown that it is possible to use light in the form of laser pulses to drive electrons through a bulk insulator at much higher than normal frequencies, but until now, there was no way to measure the oscillations of those electrons, a necessary part of applying them in a high-speed device.In this new effort, the researchers took advantage of the fact that when electrons speed up, they emit what are known as high-order harmonics, which just happen to be a direct reflection of the motion of those electrons. They used an attosecond streak camera to measure these harmonics in a silica nanofilm and noted that the light was emitted in bursts lasting less than 500 attoseconds. These findings suggest that it should be possible to build devices that use lasers to push the oscillating frequency of electrons up to 100 times that of devices currently used to test the limit (into the multi-petahertz range). Currently, Chini notes, more work still needs to be done—subtle variations that occur in the process will have to be removed, for example, and testing will have to be done to see if the same results can be obtained with materials other than silica. Also, it is still not clear if the laser-pulsed approach causes any negative impact on current production. Citation: Researchers demonstrate extension of electronic metrology to the multi-petahertz frequency range (2016, October 20) retrieved 18 August 2019 from https://phys.org/news/2016-10-extension-electronic-metrology-multi-petahertz-frequency.html (Phys.org)—A team of researchers with the Max-Planck-Institut für Quantenoptik has found a way to link previously demonstrated laser light-induced high-speed switching of an insulator between conducting states and high-frequency light emissions from insulators blasted with laser pulses. In their paper published in the journal Nature, the team describes the techniques they used to pull off this feat. Michael Chini with the University of Central Florida offers a News & Views piece on the work done by the team in the same journal issue, and explains what hurdles still need to be overcome before devices making use of the technology can be developed. © 2016 Phys.org