A planet or moon covered with craters just looks old, doesn’t it? Planetary geologists have long relied on crater counts to estimate the absolute ages of surfaces, such as on the moon, Mars, Europa, and every other solid body. Lots of craters meant old. Few craters meant young. Presumably, impacting bodies came in like clockwork and left their marks over the eons. An uncomfortable fact has come to light that disturbs this simple picture like a bolide: most of the craters are secondary impacts. Picture a big meteor hitting Mars. Did you know that it could toss up enough debris to create 10 million more craters – all from a single event? That’s one of several shocking facts presented by Clark R. Chapman and two colleagues in a Letter to Nature.1 (see also summary on Space.com). Believe it or not, they calculate that some 95% of small craters (1 km in diameter and under) are secondaries, and many of the moderate size craters probably are, too. This means that only a few impactors could quickly saturate a body with craters. It also means that estimating surface ages via crater counts is a lost art, because it just lost its credibility:Surface ages can be derived from the spatial density of craters, but this association presumes that the craters are made by interplanetary impactors, arriving randomly in time and location across the surface. Secondary craters cause confusion because they contaminate the primary cratering record by emplacing large numbers of craters, episodically, in random and non-random locations on the surface. The number and spatial extent of secondary craters generated by a primary impact has been a significant research issue. If many or most small craters on a surface are secondaries, but are mistakenly identified as primaries, derived surface ages or characteristics of the impacting population size-frequency distribution (SFD) will be in error. (Emphasis added in all quotes.)Their mathematical analysis yielded the 95% figure for secondaries. The production of secondary craters on Europa, they found, was “unexpectedly efficient.” Although secondary crater formation on icy bodies was so, they feel that similar secondary crater production occurs on rocky bodies like the Moon and Mars, and granted that, has a ripple effect casting the entire method into doubt:Our work raises doubts regarding methods that use the lunar small-crater distribution to calibrate other inner Solar System surface ages (for example, Mars). If, as on Europa, lunar and martian secondaries are 95% of the small crater (less than a few kilometres) population, the error bars (and thus derived surface ages) on any residual primary crater population become large (uncertainties are 20 times the measured density value). This uncertainty applies to both the measured population on a martian surface unit and the lunar SFD that supposedly represents absolute age. We emphasize that traditional age-dating analyses still derive robust ages when using large craters (greater than a few kilometres diameter), which are less likely to be secondaries. However, the technique becomes increasingly unreliable when applied to dating tiny geographical units using small craters, which may be mostly secondaries.As a result, they conclude that “any attempt” to age-date surfaces or characterize the population of impactors may suffer “a significant and perhaps uncorrectable bias” due to the contribution from secondaries. They ended with that case of the single Martian impact that generated 10 million secondaries from 10 to 100 meters in diameter. Speaking of Mars, the Mars Global Surveyor recently took a sharp image captioned “secondary craters.” Click here for a look.1Bierhaus, Chapman and Merline, “Secondary craters on Europa and implications for cratered surfaces,” Nature 437, 1125-1127 (20 October 2005) | doi: 10.1038/nature04069.Things are not always what they seem. This announcement must hurt like a rock to Darwinists, who really need those long periods of uniformitarian processes. Imagine ten million craters forming in one day! If crater counts say nothing about age, why could not all the observed cratering have occurred quickly, in relatively recent times?(Visited 17 times, 1 visits today)FacebookTwitterPinterestSave分享0
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Share Facebook Twitter Google + LinkedIn Pinterest The National Milk Producers Federation (NMPF) expressed its support for new bipartisan legislation introduced in the House of Representatives that would clarify the exemption of dairy farms and other livestock producers from being subject to the Resource Conversation and Recovery Act (RCRA), which governs the safe disposal of solid waste.The Farm Regulatory Certainty Act (H.R. 5685), sponsored by Rep. Dan Newhouse (R-WA), would spell out that the RCRA law, enacted in 1976 to govern solid wastes in landfills, is not intended to regulate agricultural operations like dairy farms. Tin the past, NMPF feels the RCRA statute has been used to inappropriately target agriculture, specifically dairy and livestock producers, even if they have demonstrated that they have been following approved plans for using manure as a fertilizer. The Farm Regulatory Certainty Act will also protect farmers from citizen suits if they are undergoing efforts to comply with federal orders.The new measure comes in response to a federal court ruling last year in lawsuits brought against several dairies in Washington state. The litigation claimed that farms had inappropriately handled and stored animal manure under the RCRA law, even though RCRA was not intended to focus on farming practices or the management of livestock manure. The U.S. District Court for the Eastern District of Washington determined the amount of manure deposited exceeded approved limits and constituted environmental and human endangerment.“This legislation would help end the confusion among farmers about environmental regulations, especially those who practice responsible waste management,” said Jim Mulhern, president and CEO of NMPF. “The RCRA law was not intended to govern farms, and Congress needs to enact this bipartisan legislation to reinforce that point.”NMPF supports the use of safe and efficient environmental practices — such as anaerobic digesters and nutrient recovery — to help dairy operations remain stewards of a healthy ecosystem.
The Asian Football Confederations wants to give the country a big push in order to develop the game in all its citiesChinese president Xi Jinping has put football growth as the main objective in sports in the country.And the Asian Football Confederation (AFC) is happy to help.AFC president Shaikh Salman bin Ebrahim Al Khalifa got together with Gou Zhongwen, Minister of General Administration of Sport of the People’s Republic of China and President of the National Olympic Committee to discuss the future of the sport.“The meeting with H.E. Gou Zhongwen was important to hear his thoughts on the direction for football in China PR,” Shaikh Salman told the AFC’s official website.“The country has stated its ambition to host and win the FIFA World Cup and the AFC is ready to support those aims.”Lippi turned down the Spurs because of his English Manuel R. Medina – September 7, 2019 The China national team manager, Marcello Lippi, had a chance to join Tottenham Hotspur in the past but he feared his English was not good enough.“We have established a Task Force to work closely with the CFA, particularly in the areas of regional development and technical improvement and I look forward to seeing this assistance bring about some excellent results.”“China PR have also qualified for the AFC Asian Cup to be held in the United Arab Emirates in January next year and I am sure that the hundreds of millions of football fans in the country will be tuning in to follow their fortunes,” he added.“We are also grateful to China PR for hosting many AFC competitions in recent years including the AFC U-23 Championships earlier this year and the AFC Women’s U-19 Championships last year.”“We hope that China PR continues to put its impressive stadia forward as hosts of other major AFC competitions in the years to come,” he continued.“We thank you for all the support the CFA continues to receive and look forward to achieving our common goals together.”
(Phys.org)—At a cryptography gathering in Leuven, Belgium, on Tuesday, Cambridge University researchers made it known that they do not like what they see in chip and pin systems. Banks rely on customer confidence in their word that chip and pin systems are safe, but the researchers tell quite a different story. Part of the problem has to do with the number generators, which the researchers give a failing grade. Each time a customer is involved in a chip and pin transaction, withdrawing cash or buying goods, a unique unpredictable number is created to authenticate the transaction. The unpredictable number, generated by software, is supposed to be chosen at random. But researchers say the number is highly predictable, because dates or timestamps had been used. www.lightbluetouchpaper.org/20 … the-pre-play-attack/www.cl.cam.ac.uk/~rja14/Papers/unattack.pdf Explore further © 2012 Phys.org More information: Their paper, “Chip and Skim: Cloning EMV Cards with the Pre-play Attack” presents the troubling details of weaknesses in protocol and random number generation which leave customers in the cold as fraud victims. “EMV” is the name given to the system from its original developers Europay, MasterCard and Visa. The system is also known as chip and pin, and is the leading system for card payments, in Europe, much of Asia, and starting to be used in North America. Payment cards contain a chip so they can execute an authentication protocol. POS terminals or ATMs generate the unpredictable number, for each transaction to ensure it is fresh. Some EMV implementers have merely used counters, timestamps or home-grown algorithms to supply this number. This exposes them to a pre-play attack, say the Cambridge team. The researchers find it shocking that many ATMs and point-of-sale terminals have “seriously defective” random number generators, often “just counters.”The study authors also point to a key shortcoming at the protocol level where “the party depending upon freshness in the protocol is not the party responsible for generating it.” Although the issuing bank is depending on the merchant for transaction freshness, they said, the merchant “may not be incentivised to provide it, may not be able to deliver it correctly due to lack of end-to-end authentication with the issuer, and might even be collusive (directly or indirectly).”The study team’s harshest words are for those banks that “suppress information about known vulnerabilities, with the result that fraud victims continue to be denied refunds.” The researchers argue the lack of fairness when any customer who complains of fraud may be told by the bank that since EMVs are secure, the victim is mistaken “or lying when they dispute card transactions.” And yet, said the study, “again and again, the banks have turned out to be wrong.” One vulnerability after another has been discovered and exploited by criminals. They said it has mostly been left to independent security researchers to identify what is happening and to spread the word.The researchers said that, in looking for solutions, it would not be practical to turn to what is a slow and complex negotiation process between merchants, banks and vendors. “It is time for bank regulators to take an interest,” they said. “It’s welcome that the US Federal Reserve is now paying attention, and time for European regulators to follow suit.” 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. Cambridge researchers show Chip and PIN system vulnerable to fraud Citation: Cambridge team exposes EMV card vulnerabilities (2012, September 13) retrieved 18 August 2019 from https://phys.org/news/2012-09-cambridge-team-exposes-emv-card.html