Free Republic

An abrupt shutdown of Atlantic Ocean currents that could put large parts of Europe in a deep freeze is looking a bit more likely and closer than before as a new complex computer simulation finds a "cliff-like" tipping point looming in the future. A long-worried nightmare scenario, triggered by Greenland's ice sheet melting from global warming, still is at least decades away if not longer, but maybe not the centuries that it once seemed, a new study in Friday's Science Advances finds. The study, the first to use complex simulations and include multiple factors, uses a key measurement to track...

Iran, N.Korea 'Run Joint Nuclear Research Center' A Japanese daily claims that Iran and North Korea run a joint nuclear research center to carry out computer simulations of nuclear tests. Japan's Sankei Shimbun on Thursday said Iran has three secret research centers across the country. And a dozen North Korean researchers and experts have visited the facilities this year to share information about nuclear technology. The report goes on to say that the two countries are running the tests to develop starting devices for nuclear bombs. Iran and North Korea are both under international sanctions due to their uranium enrichment...

Garbage In, Money Out Warren Meyer, 07.23.10, 02:03 PM EDT How much money are taxpayers willing to bet on computer models? Wall Street firms, which have made substantial investments based on complex computer models, are rethinking the limits of these models as they have watched a number of their peers sink into bankruptcy. Most experienced CEOs of non-financial firms would not invest $2 based solely on computer models prepared by one of their divisions seeking funding. The seasoned executive has seen too many hockey-stick market forecasts that oversimplify complex market dynamics to be anything but skeptical of such models. Unfortunately,...

U.S. scientists say they have created an automated program designed to "debug" the nation's nuclear test computer simulations. Purdue University researchers, working with scientists at the Lawrence Livermore National Laboratory, said their program, called AutomaDeD (pronounced like automated), finds errors in computer code for complex "parallel" programs. Because international treaties forbid the detonation of nuclear test weapons, certification is done using complex simulations. The researchers said such simulations, which may contain as many as 100,000 lines of computer code, must accurately show reactions taking place on the scale of milliseconds, or thousandths of a second. "The simulations take several weeks...