19 Dec

Water Can Get Hotter than the Sun

first_imgWhen vacuum bubbles form in turbulent water, they can collapse violently in a process called cavitation.  Scientists reporting in Nature1,2 March 3 showed that the energy of cavitation can heat the plasma in the bubble to 15,000 degrees Kelvin – hotter than the surface of the brightest stars.  The resulting flash can sometimes be seen by the naked eye.  Science News reports that some believe thermonuclear fusion might take place in plasma within the collapsing bubbles under such high temperatures; imagine that happening in cold flowing water.  See also the explanations on Physics Web, Science Now, and Science News. 1Flannigan and Suslick, “Plasma formation and temperature measurement during single-bubble cavitation,” Nature 434, 52 – 55 (03 March 2005); doi:10.1038/nature03361. 2Detlef Lohse, “Sonoluminescence: Cavitation hots up,” Nature 434, 33 – 34 (03 March 2005); doi:10.1038/434033a. This is the kind of amazing scientific fact that can inspire a youngster to take an interest in science.  Cavitation can produce such violence in water that it can rip apart steel propellers and erode through solid concrete in dam channels, such as happened at Glen Canyon Dam in 1983 (see videos at Open Video Project).  Cavitation may have been one of several effects in a worldwide flood that could have made mincemeat of solid rock with no trouble at all (see CRS article).(Visited 38 times, 1 visits today)FacebookTwitterPinterestSave分享0last_img read more

19 Dec

Victory for press freedom

first_imgNewspaper editor Gasant Abarder will notbe prosecuted for contempt of court in theCounty Fair defamation case. This ishailed as a victory for media freedom.(Image: stock.xchng)Janine ErasmusPress freedom and credibility have won the day in Cape Town. Newspaper editor Gasant Abarder, who refused to compromise his ethics by testifying in a defamation case, has escaped prosecution and possible incarceration for contempt of court, as the case has been settled out of court.The South African National Editors’ Forum (Sanef), who stood by Abarder right from the start, has applauded the development.Abarder, the executive editor of the Cape Argus, has been battling the courts since 2006, when he was first summoned to give evidence in a case brought by poultry processors County Fair against a representative of the Associated Trade Unions of South African Workers (ATUSAW).In 2005 ATUSAW’s Grant Twigg attended a protest gathering by County Fair employees following the death of a colleague, where they raised concerns about working conditions. Here, it was alleged, he made defamatory statements against the company – statements reported by Abarder, then news editor of the tabloid publication Daily Voice.Defamation suitThe chicken processor subsequently brought a defamation suit against Twigg. Abarder and Aziz Hartley of the Cape Times were subpoenaed to give evidence.Hartley yielded to the summons, but Abarder took the stand only to state on record his refusal to testify, on the grounds that it would compromise his professional ethics and strike a blow against media freedom.A statement released at the time by South Africa’s Freedom of Expression Institute (FXI), in support of Abarder, described the sole role of journalists as that of gathering information for the purpose of news-making – not as courtroom evidence.In the mind of the public there should be no confusion regarding the function of a journalist, but cases such as County Fair would blur this clear-cut definition. In future, journalists might be treated with suspicion and harassed, or barred from important gatherings. Interviewees might become wary of giving statements to the press. The principle of freedom of expression would be the ultimate loser.“In this case the freedom of expression must take precedence over the right to dignity and reputation of County Fair,” said the FXI. “If it does not, then all journalists may be affected.”In February 1999 Sanef and the South African government signed a memorandum of understanding giving journalists the right to protect their sources without fear of prosecution, and to rest assured that they would only be called upon to testify in court as a last resort.Present at the signing were then justice minister, the late Dullah Omar, Azalia Cachalia on behalf of the minister of safety and security, former director of public prosecutions Bulelani Nquka, and Sanef vice-chair Moegsien Williams, then Cape Argus editor.With the backing of this important document, Abarder argued that because he had been carrying out his journalistic duties he had a right to protect his relationship with his sources.Alternative sourcesAbarder was adamant that the information sought from him could be obtained elsewhere, as there were around 100 people at the gathering, most of them County Fair employees. It was possible to identify many of them, he said, from a photo published in the paper, and to track them down.The magistrate hearing the case dismissed his reasoning, saying it did not constitute a lawful excuse.Abarder was now in danger of being hit with charges of contempt of court and an accompanying jail term, but his stance did not waver. He asked for leave to appeal, only to be turned down by the Cape Town High Court, which decided that as Abarder was not one of the main parties in the case, he had no right to appeal.The High Court later granted Abarder leave to appeal, saying that another court might see things differently. The journalist lost the appeal and was served with a new subpoena. However, before further action could be taken the two litigants decided to settle out of court and the subpoena became invalid.Abarder said in a statement that he had been fully prepared to go to jail for his principles, despite the pain and inconvenience for him and his family. “It is in the interest of press freedom, credibility and independence that this subpoena be challenged.”Do you have queries or comments about this article? Contact Janine Erasmus at [email protected] articlesPress freedom on Sanef agendaUseful linksSouth African National Editors’ ForumRecord of Understanding – SanefFreedom of Expression Institutelast_img read more

15 Dec

Apple Just Set Itself Up For A Big Spring Product Launch: Finally, A TV?

first_imgWhat does Apple’s new iPad tell us about Apple’s future new product launch plans? Maybe a little.Over the past few years years, Apple has scheduled its gadget launches in fairly regular, annual cycles. That is: New iPad in the spring, new OS X in the summer, new iPhone and iOS in the summer or fall, new iPods in the fall. (New Macs whenever.)But with today’s big iPad launch — including the iPad mini and a new, fourth-generation iPad — Apple leaves a big question mark for next spring: What’s it going to announce between January and June?Will Apple move the iPad to a six-month update cycle, unveiling new iPads annually in both the spring and fall?Probably not — an annual update still seems frequent enough. People aren’t likely to buy new iPads more often than every couple of years, and component breakthroughs aren’t always going to happen every six months. Plus, it’s not like competitors are breaking through the market with regular updates.But it does make sense to move Apple’s iPad updates to the fall, in time for the big holiday shopping season. With rivals like Amazon and Google (and soon Microsoft) finally starting to catch up in the tablet market, it no longer makes sense for Apple to sell half-year-old tablets as Christmas presents.So what will Apple do in the Spring? Something, right? Going six months before another launch seems unlikely.It’s probably not going to be another iPhone or iPod. This really sounds like an opportunity for something new.One possibility: Finally, an Apple television set. Spring isn’t necessarily the ideal time to start selling a TV — right after Christmas and the Super Bowl — but slowly rolling out a TV might be a decent idea, anyway.Or something else? Perhaps a new fitness device in time for warm weather? Or an entirely new gadget that we haven’t even considered yet?Either way, there’s now room for something.Photo: Grey Clayman Related Posts A Web Developer’s New Best Friend is the AI Wai… Tags:#Apple#iPad#iPad mini#Mysteries#TV Why Tech Companies Need Simpler Terms of Servic…center_img dan frommer 8 Best WordPress Hosting Solutions on the Market Top Reasons to Go With Managed WordPress Hostinglast_img read more