The Last Stoic

Life’s a Drag

Posted in Uncategorized by munty13 on March 8, 2009


The remarkable observation that all free falling objects fall at the same rate was first proposed by Galileo, nearly 400 years ago. For all falling objects gravitational acceleration is 9.8 metres per square second. In a vacuum, a falling object is subjected to only one external force, the gravitational force, expressed as the weight of the object. If the object falls through the atmosphere, there is an additional drag force acting on the object.

Drag is a mechanical force. It is generated by the interaction and contact of a solid body with a fluid (liquid or gas). We can think of drag as aerodynamic friction, and one of the sources of drag is the skin friction between the molecules of the air, and the solid surface of our falling object. Drag opposes the motion of the object. When the drag is equal to weight , acceleration is zero.

A falling body stops accelerating when it achieves terminal velocity. When the force of gravity which attracts the object, and the drag which slows it down are equal, terminal velocity is achieved. Interestingly, all objects falling on Earth have different terminal velocities due to density, mass, air friction, and other factors.

Drag interests me, because, in its own funny way, it opposes ‘gravity’ (or perhaps more directly the aether) by imposing a limitation to an object’s speed. I can’t help but make the comparison to the way the Earth imposes a restriction on the speed of light. Further still, it coincides with the manner in which optical density (and physical density?) appear to slow down the speed of light.

If there is no fluid, there is no drag. Drag is generated by the difference in velocity between the solid object and the fluid. There must be motion between the object and the fluid. If there is no motion, there is no drag. It makes no difference whether the object moves through a static fluid, or whether the fluid moves past a static solid object. In the same way, perhaps, we could say that if there is no changing magnetic field, then there is no electric field (and vice versa).

We are taught that air resistance is a friction force, and the energy taken out of the falling object will appear in the form of heat in the air immediately surrounding the object. Except the energy taken to produce heat is not taken from the object – it is taken from the aether. Some of this heat will cause a rise in the temperature of the object itself. The aether is warming up the object.

Previously, I have discussed heat as being part of magnetic friction. Foucault’s copper disc generated heat when in motion through an electromagnet’s magnetic field. It must be remembered that Foucault was using a battery to power the electromagnet; a DC supply. If the disc is stationary then a steady flux passes through the disc, but if no movement occurs then no force is developed. When the disc rotates , it moves through this damping flux, and those special eddy currents known as ‘Foucault currents’ are set up. The EMF induced is proportional to speed, and so are the current strengths. The currents interact with the damping flux itself, and thus produce a drag or damping torque proportional to speed.

I think of the magnetic flux as fluid, but when generated by a DC supply, the lines of force appear stagnant; a stagnant pool whose vibrations are imperceptible. On the copper disc we can imagine atomic-sized pegs, or bollards, which stand erect on the surface of the disc. As the copper disc is turned (by hand on Foucault’s machine), the pegs move through the fluid, and each one creates a drag force. This force could appear in much the same way as a rock in the middle of a stream is affected by the flow of water, or a falling rock is affected by the air resistance.

I doubt though, we are really looking at upright pegs on the conductor. Judging by the shape of electromagnetic sine waves, and assuming matter is the high end of EMR, then maybe what we are actually looking at are vortices, or parabolas. Molecular vortices were once suggested by Maxwell. A parabola shape would help explain how the aether is sucked-in, or induced, to flow with more force if the disk is made to spin faster. The aether no longer flows smoothly across a plain, but now flows across the conductor, rotating from one vortex to another; whirlpool after whirlpool. If you picture it all, it goes some way to explain how these currents derived the name ‘eddies’ from their counterparts in water.

It is supposed that eddy currents create an opposing magnetic field to the applied magnetic field. Is Foucault’s wheel condensing the aether field into two opposing forces? In doing so we create friction and heat. A falling body’s terminal velocity succumbs to the exact same thing – friction and heat. Heat appears to be a cut-off point for inducing the aether efficiently. Terminal velocity stops any further aether from being sucked-in, so that the object continues to fall without further acceleration. It’s almost as if the aether is stretched to a point where it folds in on itself to produce heat. This has a parallel with Foucault’s wheel, in that the greater the velocity of the disk, then the greater the amount of heat generated.

What’s interesting is that if the applied magnetic field is induced by an AC supply, and it is strong enough, then the electromagnet can be rotated to move a stationary disc. The electromagnet sticks to the wheel. The next comparison, I guess, would be my feet being stuck to the floor.

Many thanks:

http://deepblue.lib.umich.edu/bitstream/2027.42/6685/4/bad0220.0001.001.txt

http://www.physlink.com/Education/AskExperts/ae572.cfm
http://www2.cddc.vt.edu/gutenberg/etext05/8041710h.htm
http://physics.kenyon.edu/EarlyApparatus/Electricity/Foucaults_Disk/Foucaults_Disk.html
http://books.google.co.uk/books?id=DojwZzKAvN8C&pg=PA309&lpg=PA309&dq=electromagnet+turns+the+disk&source=web&ots=P8QgW-qtD4&sig=MWb1cCJGRymU2jUXgbvAYyD2RNk&hl=en&ei=s6mNScPvC8yp-gashKGuCw&sa=X&oi=book_result&resnum=8&ct=result
http://www.thecore.nus.edu.sg/landow/victorian/science/maxwell1.html
Dame Edna Everage Photo: CHANNEL 4

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