Scientists explain causes of abrupt rain storms
No two rain storms are alike. Dark clouds may form slowly throughout the day before a drop of rain falls, and sunny days can suddenly transform into thunderstorms. Different societies throughout history have held their own explanations for the behavior of weather – from human rituals to godly intervention – and now physicists from the U.K. and Sweden tackle one of the weirder weather phenomena: the abrupt rainfall often observed from cumulus clouds.
Michael Wilkinson, Bernhard Mehlig and Vlad Bezuglyy explain how quick showers can result from a dramatic increase in the collision rate of microscopic water droplets when the turbulence intensity in the atmosphere exceeds a threshold. Their theory, published in a recent issue of Physical Review Letters, suggests that the collision rate suddenly increases when the velocity of the water droplets as a function of position forms “caustics,” becoming a multi-valued function. When particles at the same position are moving with different velocities, the probability for collision is greatly enhanced.
Ok I admit that I had my own theories about what caused sudden rain storms and I’m big enough to admit I was wrong. One was that if it if we needed rain I would think real hard about rain and hope for rain, so when it did eventually rain I thought that it was simply a result of positive thinking. My second favorite theory was that at least temporarily the Cranky rain would take control over The Emperor of the Rain and wouldn’t let the Friendly rain come down for a visit, but eventually the Friendly rain would win back control and make all the trees, corn fields and frogs happy. – And on a serious note there is more at the link with a formula for the math geeks.
Updated CRS Report: The Cost of Iraq, Afghanistan, and Other Global War on Terror Operations Since 9/11
The $437 billion total does not include the $50 billion “placeholder” figure for FY2007 war costs that is listed in the FY2007 budget. Although the Administration has not formally submitted a request, both the House and Senate authorization (H.R. 5122/S. 2766) and appropriation bills (H.R. 5631) provide $50 billion for war costs in specific accounts. If that $50 billion is enacted, war appropriations would total about $487 billion, presumably covering part of FY2007′s costs.
Some folks are good at managing money and priorities and some are not.
