Posted on 12/18/2008 4:29:15 AM PST by Joiseydude
It may sound like a superstitious excuse for a poor day's swimming, but it is not uncommon for triathletes to complain that the water is behaving badly - even that it is "evil". Now a study suggests what they are feeling is real.
Leo Maas, a fluid dynamicist at the Royal Netherlands Institute for Sea Research, and colleagues found that "dead water" - an obstructive effect encountered by ships at sea - can strike swimmers too.
As ships sail over a layer of warm water sitting over saltier, or colder, layers, waves form in the boundary between the two layers. As these waves grow, they form a gulf beneath the ship, sucking away its speed. This effect can stall boats at sea, reducing their speed by up to 80%.
(Excerpt) Read more at newscientist.com ...
I’ve been genuinely scared three or four times in my adult life but that was the only time that was spooky too.
This scared me big time at first because I’d get tired of waiting and remove the cup of water thinking is just won’t boil and go ahead and put in a spoonful of instant coffee and it would go off like a volcano! I then saw it on one of those 20/20 dumb science segments. Thing is the container was super clean and smooth. They said that would happen in a saucepan on the stove, too, but no pan is that smooth. They advised stopping the microwave and stirring the water will jostle it up enough. I find that only cups and glass measuring cups washed in the dishwasher are likely to do that. Looks like anything I wash by hand is not that clean and therefore it boils like crazy.
Underwater CO2 disasters.
This is an interesting hypothesis (Bermuda triangle CO2). I wonder if underwater methane could do something similar? If it were massive enough, and lighter than air, could this effect cause pilots to pass out and dive? Several ifs, I realize.
The mechanism of the African Lake Nyos CO2 disaster is not known, although the people and cattle apparently died when the gas, slightly heavier than air, concentrated in depressed areas. When the victims walked down into these valleys, they suffocated. One possible mechanism might have been a small landslide down into the lake stirring up the stratified layers and releasing the gas.
Methane Hydrates can change the specific gravity of the seas locally and the air density. I’m wondering if rising methane clouds would cause magnetic disturbance in ships or planes? Ships won’t stay afloat in a methane cloud and when they sink, the eventual rush of water over the vessel sinks it. But the magnetic anomolies in some BT incidents are still unexplained.
Massive school of anchovies?
Internal standing waves on an interface is described in some hydrodynamics books (with equations). Even more interesting is knowing where it routinely occurs. I don’t.
______________________________________
Nope. Just a very eerie darkening of the water with the added aspect of eddies.
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.