The biggest moon in the solar system is Ganymede, the third large moon out from Jupiter. Larger than Mercury, Ganymede has a heterogeneous surface of dark and light areas (picture), grooved terrain, abrupt changes of landforms, and bright splashes where impacts have scarred its icy surface (gallery). What goes on inside, though, is more surprising: it has an intrinsic magnetic field. Researchers could only make it last for the assumed age of the solar system by appealing to “special conditions” that are not necessarily compatible with theories of its formation. Bland, Showman and Tobie, writing in Icarus Dec 2008,1 realized that an intrinsic magnetic field requires a liquid core in which convection can occur to drive a dynamo. A liquid core requires heat. If they could find ways to stop runaway cooling inside the moon, maybe it would stay hot enough to maintain the magnetic field for 4.5 billion years. They tried all kinds of things to keep the core hot. They modeled Ganymede’s orbit passing through a resonance that would increase tidal pumping. They varied the silicate rheology. They altered Jupiter’s tidal dissipation factor. They played with the size of the ice shell. They imagined partial melting in the silicate mantle. Nothing worked. “We find that, contrary to expectations, there are no physically plausible scenarios in which tidal heating in the silicates is sufficient to cause the thermal runaway necessary to prevent core cooling.” The only other possibility was if the amount of sulfur in the core was very low (less than 3%) or very high (greater than 21%). Neither of those options was palatable, but they were stuck: “we must appeal to the special conditions described above to explain the presence of the field.” At the end of the paper they tossed out one other possibility: late differentiation. If the core didn’t form until 1 billion years ago (about 1/5 the assumed age of the moon), then convection might last for a billion years. Either way requires invoking special conditions:We have shown that production of Ganymede’s magnetic field by secular cooling and chemical convection requires that a very specific set of conditions be met: the mass fraction of sulfur in the core must be low (or alternatively very high), the core must have formed hot, and the silicate mantle must be able to cool rapidly (i.e. it must have a viscosity consistent with wet olivine). If any of these criterion are not met magnetic field production fails. These results contrast with previous workers who find that compositional convection can drive a core dynamo under a broad range of conditions.2Speaking of Mercury, which is slightly smaller than Ganymede, Dr. D. Russell Humphreys celebrated a confirmed prediction in the current Journal of Creation:Mercury’s magnetic field matches the measurements from the MESSENGER spacecraft (07/09/2008). He adds this to his list of predictive successes for the magnetic fields of the outer planets. Humphreys’ model assumes that magnetic fields are young – thousands of years old, not billions.1. Bland, Showman and Tobie, “The production of Ganymede’s magnetic field,” Icarus 198 (Dec 2008), pp. 384�399, doi:10.1016/j.icarus.2008.07.011.2. reference cited by Bland et al: S.A. Hauck, J.M. Aurnou and A.J. Dombard, “Sulfur’s impact on core evolution and magnetic field generation on Ganymede,” J. Geophys. Res. 111 (2006) 10.1029/2005JE002557 E09008.And so another phenomenon doesn’t fit the consensus view of the age of the solar system. Creationists who think they are escaping difficulties by accepting the consensus age are merely trading one set of problems for another. Every view has problems; face it. But don’t think the long-age evolutionary naturalistic view is simple and straightforward. When they pile on miracles needed to get their physicalist scenarios to work, then the appeal to miracles becomes academic: do you want purposeful miracles, or miracles of chance? Like ketchup with fries, miracles go better with design. This paper does not support a view that Ganymede is a few thousand years old, of course, but neither does it rule it out. What it does, though, is put plausible upper limits on the age of Ganymede, beyond which appeals to highly contrived special conditions are required. Reconstructing the core history of Ganymede can only be done with scientific models. Being simulations with simplifying assumptions, models can only be judged by subjective criteria of plausibility. If you think that it is plausible to insert special conditions to form Mercury, Venus, Earth, the moon, Mars, Jupiter, Io, Europa, Ganymede, Callisto (which has an induced magnetic field), Jupiter’s gossamer rings, Saturn, the F-ring, the A-ring, the C-ring, the D-ring, Enceladus, Rhea, Titan, Hyperion, Iapetus, Uranus, the rings of Uranus, Miranda, Neptune, the rings of Neptune, Triton, comets, binary asteroids and the Sun-Earth diameter, then be our guest. Just admit that you are, in effect, applying your own intelligent design to imaginary models of reality, not to reality itself.(Visited 15 times, 1 visits today)FacebookTwitterPinterestSave分享0
Conveniently packaged in single-use sachets, DryBath saves up to 80 litres of water per use.(Image: HeadBoy Industries) A jubilant Marishane accepts the award which confirms his status as one of the world’s top young entrepreneurs.(Image: Global Student Entrepreneur Awards) MEDIA CONTACTS • Ludwick Marishane Founder, Headboy Industries RELATED ARTICLES • Meds on wheels for positive change • Meet a top social entrepreneur • Grooming future leaders: priceless • Young people: own your destiny! • Imbizo boost for entrepreneurs Bhekumuzi MdakaneImagine taking a bath anywhere at any time without using the traditional method of water. A young South African entrepreneur has developed a product that will allow people who have limited access to water to maintain their standards of hygiene.Ludwick Marishane hails originally from Motetema on the border of Limpopo and Mpumalanga, a town located not too far from the small Kwaggavoetpad Nature Reserve. He’s just completed his fourth year as a commerce student at the University of Cape Town.His product, called DryBath, is a clear germicidal and moisturising gel that’s applied to skin in the manner of waterless hand cleaners, although it has a sweet aroma rather than the distinctive alcohol smell of the latter.DryBath does the work of water and soap and it earned Marishane the 2011 Global Student Entrepreneur of the Year Award, with a US$10 000 (R86 000) prize to boot.The product has positive implications for millions of people in Africa and other parts of the developing world where lack of regular access to clean water leads to reduced basic hygiene and a lower quality of life. Children, for example, often have to walk for hours to fetch clean water, which detracts from the time they can spend at school, doing homework or just playing.To show solidarity for and raise awareness of the millions of affected people, Marishane is organising a no-bath weekend from 5 to 7 July, which will coincide with the fourth anniversary of the invention of DryBath. More details are available online.His main goal is to get 10-million people to hygienically skip a bath once a week during 2013, even if they don’t use DryBath, and save the precious resource of water.DryBath is manufactured by Western Cape-based gel cosmetic specialists BioEarth Labs for HeadBoy Industries, the company started by Marishane to develop and market the product. Laziness leads to inspirationMarishane grew up in rural Limpopo, where as a 17-year-old he was chatting one day with a close friends, discussing typical teenage topics and sunbathing in the winter sun.Full of imagination, the friend asked: “Why can’t they invent something that you can just apply to your skin so that you don’t have to take a bath nor shower?”Marishane felt the same way, and that planted the seed that would germinate into DryBath.“I came up with this idea all because I didn’t feel like taking a bath!” he joked.Although he only had high school science knowledge, Marishane got onto the internet via his mobile phone and researched statistics on water access, as well as the composition and manufacture of lotions and creams. He finally came up with a formula. Some months later and after much experimentation, he held a bottle of DryBath in his hand and went on to obtain a patent through his company.One 20ml DryBath sachet can do the work of one bath, and Marishane claims it saves about 80 litres of water on average with every use.Access to water is crucialDuring his research he found out that over 2.5-billion people in the world live without access to clean water – 450-millon of them are in Africa and five-million live in South Africa.Continued research revealed that sanitation-related diseases are often found within these poor areas and the lack of water is one of the main causes of the infections.Saving water is a job that everyone needs to focus on. But there are many areas around the world that have no access to safe water, or water at all, and people often have to walk long distances to get fresh water.Living without water can also lead to death, as waterborne diseases such as cholera, dysentery, typhoid and schistosomiasis are found in areas that lack clean water. Trachoma, a disease caused by dirt getting into the eye through agents such as flies or towels, affects 350-million people and leaves eight-million of them permanently blind through recurring infection.According to Water.org, nearly 10% of the global disease burden could be reduced through improved water supply, sanitation, hygiene, and water resource management. Getting the product out thereMarishane first approached charity organizations for support, but says he was turned back because of his age and because of doubt that his concept would ever work.Back at the drawing board, he put together a lengthy and detailed proposal – all done on his trusty Nokia.With paper in hand he approached the corporate world in search for sponsors, endorsements and investors. At the moment he has struck up partnerships with WaterAid and Oxfam.DryBath is now manufactured commercially for clients such as hotels, music festival organisers, major global airlines – one of which is British Airways – and governments for soldiers in the field. It’s not yet available for consumer use but Marishane says it will soon be sold online.
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Two militants and two soldiers were killed in an early morning operation in north Kashmir’s Bandipora area on Wednesday.A police official said security forces, comprising of army and local police, sealed off Rakh (Paribal), Hajin, around 5 a.m. The operation was launched after “follow up of inputs about the presence of a large group of armed militants in the area.”In the initial exchange of firing, two militants were killed. “However, two soldiers also sustained injuries, who succumbed later [sic],” said the official.Both militants are believed to be associated with the Lashkar-e-Taiba. The search operation is on as the firing from both sides have stopped. “It was an intense operation. Two members of the army’s Air Force Garud were killed,” army spokesperson told The Hindu. On September 27, a BSF jawan, who was home on a leave, was killed by militants in Hajin.
ATHENS — Panathinaikos has been docked three points and fined for the fan violence that forced the referee to abort a Greek league match against Olympiacos.Panathinaikos forfeited the game and was fined 190,000 euros ($200,000). The club will also have to play its next four home matches behind closed doors.The decision follows the violence of Nov. 22, when home fans clashed with police before the game and threw flares at Olympiacos players as they walked out onto the field, injuring two people.Panathinaikos is now fifth in the Greek league standings with 19 points from 12 games. Olympiacos leads with 36 points.TweetPinShare0 Shares