Cathemeral Thinking

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Tuesday, July 30, 2002 Cosmic rays linked to global warming Last week, I brought you the news that ice ages seem to correlate with cosmic ray levels on long timescales. Now some new research shows a link between cosmic rays and short term warming. The process is a bit complicated but essentially what happens is that cosmic rays affect cloud cover and that cloud cover affects warming. One key aspect of the new work is that it shows a height dependence in how the cosmic rays affect clouds. The end result is that this process may explain why the ground-level temperatures on Earth can rise but the upper atmosphere stays at about the same temperature, as experimentally confirmed. Before people go rushing off to say that this means global warming is not caused by human activities, they should realise that the cosmic ray process only partially explains the amount of gloabl warming that has been measured. Check out the full press release for some more information. Permalink  7:17:23 PM  Your views [] Quantum tweezers for atoms Physicists may be able to pluck an exact number of atoms out of a collection using a newly proposed technique. Currently, it is difficult to obtain an exact number of neutral atoms in a trap with any guarantee of results. The new technique should achieve this. Dragging laser tweezers across a Bose-Einstein condensate will pull out a specific number of atoms depending on the speed of the tweezers. News reports APS Physics tip sheet (item #4) Nature Science Update Permalink  2:40:09 PM  Your views [] Cultural diversity brings biodiversity? "Areas with the most animal species also contain the greatest number of human languages, say researchers." reports John Whitfield at Nature Science Update. Although causal relationships are not clear, this article suggests that preserving cultural diversity in a geographical area may also preserve biodiversity. Permalink  2:29:14 PM  Your views [] World first successful scramjet test An Australian team has finally launched a scramjest without the test vehicle being destroyed in the process. Past scramjet tests by the Australian group and a separate NASA group have been plagued by problems with each previous attempt resulting in a rocket or missile carrying the scramjet going out of control before the scramjet itself could be tested. However, the Tuesday HyShot test (Australian time) resulted in full data collection over the duration of the ten minute rocket flight with the last few minutes testing the scramjet itself. Although the data obtained has not yet been analysed, at least the scramjet survived the test! The scramjet was tested at the Woomera rocket range in the Australian desert, battling a small launch window due to other recent testing and the imminent end of an insurance policy which the low-budget group could not afford to renew. For comparison, the Australian project had a budget of AU$1.5 million whereas the NASA project had AU$185 million Pictures of the test HyShot experiment significance Milestones in the history of scramjets [Added since initial report] News reports Australians Launch Hypersonic Scramjet Engine Hypersonic jet launch raises hopes Scramjet shoots across Australia's sky Outback supersonic test flight a world first Aussie Rocket Scientists Fly Successful ScramJet Test Permalink  7:47:26 AM  Your views []

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