We used to have a very nice vacation home on Lake Vostok. We let it go after a bunch of foreigners moved in and started drilling. They totally ruined the neighborhood and drove down property values. We took a bath when we sold that place. The upside is that we are now much cleaner after the bath got rid of all the contamination.
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Of course it's always easy to over-interpret dolphin actions in human terms. But there are very few creatures - and no domesticated ones I know of - that would behave in that fashion.
They are fascinating and incredibly intelligent but they also make me quite sad if only because of the cruelty and the rape.
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They're amazing creatures. It's sad we're driving them to extinction in many parts of the world.
Maybe, but it certainly cuts down on the dolphin rape.
I'm not sure how you go from, not related to anything else, to just a contaminant. Unless, they stated results before they had done sequencing. Once they had a sequence though it should have been trivially easy to compare to known genomes.
The similar shapes are not accidental at all, of course -- that's streamlining. If you're moving through a fluid (whether air or water), and you want to minimize resistance and drag-inducing turbulence, then you had better be shaped in such a way that the fluid flows over your surfaces as smoothly as possible, with minimal resistance and turbulence.
It's a really neat illustration of how function dictates form, isn't it?
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The similar shapes are not accidental at all, of course -- that's streamlining. If you're moving through a fluid (whether air or water), and you want to minimize resistance and drag-inducing turbulence, then you had better be shaped in such a way that the fluid flows over your surfaces as smoothly as possible, with minimal resistance and turbulence.
It's a really neat illustration of how function dictates form, isn't it?
You didn't note the speed of the air or fluid involved, but those figures would corrospond to about 140 MPH in air, probably different with other fluids like water, according the the research I had done many years ago. The % of drag would vary at different speeds and at very low speeds there would not be much difference. At higher speeds Laminar flow and turbulance come into play with different effects than in these illustrations.
Also in the top left picture that plank is, like, flying with the flat bit forward. TLR, you failed to note that nobody throws a board that way, according to some board throwing I used to do.
Wind resistance (the drag in air flow) increases up to the speed of aproximately 140 MPH, and up to this speed a rough surface gives less drag than a smooth polished surface. This is due to the trubulence at the surface acting like tiny ball berrings to allow the air to pass over more smothly. At aprox. 140 MPH the drag drops off as the flow becomes Laminar and turbulence creates more drag. Laminar flow continues as speed and drag increase.
You should not look at this video either. Its title is "Giant Kidney Worm," and it's about the surgical removal of a giant kidney worm. (There is a happy ending, though.)
http://www.youtube.com/watch?v=5ob6S_EqR1c
Forgot to add:
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Last edited by specious_reasons; 03-21-2013 at 05:17 PM.
The similar shapes are not accidental at all, of course -- that's streamlining. If you're moving through a fluid (whether air or water), and you want to minimize resistance and drag-inducing turbulence, then you had better be shaped in such a way that the fluid flows over your surfaces as smoothly as possible, with minimal resistance and turbulence.
It's a really neat illustration of how function dictates form, isn't it?
The 1914 Alfa Aerodynamica was not only streamlined, it took advantage of skin-dimpling, which has been proven by Mythbusters to be more aerodynamic than smooth surfaces.
You can't get much more drive-by sciency than that.
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From my understanding skin dimpling, and shape are both trying to solve the same basic problem, laminar boundary separation. Dimpling helps by creating small vortexes above the object skin, producing a low pressure space between it and the laminar flow, causing it to be pushed against the skin longer creating a smaller wake. The effects of dimpling are most seen in fluids with high flow and low viscosity.
In just another look to nature moments, you will notice birds have rather rough surfaces with feathers covering their bodies, on the other hand many water dwelling creatures have smooth bodies covered in scales.
From my understanding skin dimpling, and shape are both trying to solve the same basic problem, laminar boundary separation. Dimpling helps by creating small vortexes above the object skin, producing a low pressure space between it and the laminar flow, causing it to be pushed against the skin longer creating a smaller wake. The effects of dimpling are most seen in fluids with high flow and low viscosity.
In just another look to nature moments, you will notice birds have rather rough surfaces with feathers covering their bodies, on the other hand many water dwelling creatures have smooth bodies covered in scales.
It's all relative to viscosity and speed. In air a rough surface is better up to about 140 MPH. This is going to be different in other fluids. An engineer once related a study that indicated that at very high presures the resistance of hydraulic fluid in a pipe went down, but I was not present for the presentation of the study and it was many years ago that I heard about it.
A good, and common, example of skin dimpling is the golf ball,
From my understanding skin dimpling, and shape are both trying to solve the same basic problem, laminar boundary separation. Dimpling helps by creating small vortexes above the object skin, producing a low pressure space between it and the laminar flow, causing it to be pushed against the skin longer creating a smaller wake. The effects of dimpling are most seen in fluids with high flow and low viscosity.
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I have often wondered how the 'vortex generators' on the Iowa class Battleships affected their speed. They were supposed to be to enhance maneuverability. And if that technology has been encorporated in other classes of US Navy ships?
At the speeds one swings a 39 ounce bat (~20 mph), the aerodynamics of said bat makes only a small difference in swing speed, but I know which one would make a better canoe paddle.
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Re: Drive by science
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