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To: cymbeline

Maybe this related example will help explain it better.

Take a child’s pinwheel. Hold it in a 20 mph breeze. Now live it 20 mph in still air. The reaction and effect on the air are the same, very minor heating by friction. The velocity was only relative to the ground as to which was moving and not part of the interaction equation.

For what you claim to work would require “still” air to drop in temperature aa you move the pinwheel through it.


53 posted on 05/02/2012 7:34:36 AM PDT by thackney (life is fragile, handle with prayer)
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To: thackney

“For what you claim to work would require “still” air to drop in temperature aa you move the pinwheel through it.”

Not true, because since you’re moving the pinwheel through the air (assuming it’s not freewheeling and therefore having no effect on the air), the pinwheel blades are speeding up the air molecules. By ‘speeding up’ I mean the molecules are moving faster coming out of the blades than going into the blades.

So the temperature of the air coming out of the blades is higher than the temperature going into the blades. This is the case when the blades are moved through the air, as opposed to the air moving against stationary blades.

When moving air is deflected by stationary blades, the air is slowed down.


55 posted on 05/02/2012 10:25:02 AM PDT by cymbeline
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