jm + water + science   3

NASA's Sound Suppression Water System
If you’ve ever watched a rocket launch, you’ve probably noticed the billowing clouds around the launch pad during lift-off. What you’re seeing is not actually the rocket’s exhaust but the result of a launch pad and vehicle protection system known in NASA parlance as the Sound Suppression Water System. Exhaust gases from a rocket typically exit at a pressure higher than the ambient atmosphere, which generates shock waves and lots of turbulent mixing between the exhaust and the air. Put differently, launch ignition is incredibly loud, loud enough to cause structural damage to the launchpad and, via reflection, the vehicle and its contents. To mitigate this problem, launch operators use a massive water injection system that pours about 3.5 times as much water as rocket propellant per second. This significantly reduces the noise levels on the launchpad and vehicle and also helps protect the infrastructure from heat damage.
water  rockets  launch  nasa  space  sound-suppression  sound  science 
august 2017 by jm
Inside the Mind of an anti-fluoridationist
An exceptionally well-researched and thorough disassembly of 'Public Health Investigation of Epidemiological data on Disease and Mortality in Ireland related to Water Fluoridation and Fluoride Exposure' by Declan Waugh, which appears to be going around currently
declan-waugh  debunking  flouride  flouridation  science  mortality  health  ireland  water 
march 2014 by jm
Pruney fingers grip better : Nature News
The hypothesis, from Mark Changizi, an evolutionary neurobiologist at 2AI Labs in Boise, Idaho, and his colleagues goes against the common belief that fingers turn prune-like simply because they absorb water. Changizi thinks that the wrinkles act like rain treads on tyres. They create channels that allow water to drain away as we press our fingertips on to wet surfaces. This allows the fingers to make greater contact with a wet surface, giving them a better grip.'
science  anatomy  grip  evolution  water  biology  from delicious
july 2011 by jm

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