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Old Mar 8th 2014, 01:26 PM   #1
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thermodynamic bumble bees

Physics in general is a grey area for me, as the same people who clearly state that perpetual motion is an impossibility, come from the same group of people that would have you believe that a bumble bee can not fly, due to its wings being far too small for its body.
Did the humble bumble bee drink a can of red bull or am i missing something here...?
And while on the subject, is there a difference between perpetual motion and perpetual propulsion? Only PM is possible if you take an object into outer space and throw it towards the edge of the universe, as it will in theory keep going, which would put it into a state of perpetual motion.
This i find insane, as such a thing would serve no purpose, as you would not be ale to harness anything from it... the instant you try, you would create friction, and thus end its motion.
Has anybody seen the youtube video of the man who built a device that has a large ball bearing perpetually traveling around a circuit ring? Again, what is the point? as you could never gain any energy from said ball bearing.
Leo Szilard likes traffic lights... i like Leo Szilard.
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Old Mar 10th 2014, 09:41 AM   #2
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The comments in your post indicate you are aware of the key issue of perpetual motion, the inability to extract energy.

It could (almost) be argued that the orbits of the planets is an example of perpetual motion.
The key is that the rate of extraction of energy from this system is very low,
so the change of the motion is very slight.

As you indicate, perpetual propulsion implies a perpetual supply of additional energy.

The Bumble-Bee idea was down to a "simple" analysis of the problem,
a more detailed analysis showed that the initial study had ignored some important factors.
At first glance these details had been assumed trivial, but they turned out to be vital.

The way I heard the story, the missing assumption was something to do with the very precise shape of folds in the wing.
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