John Freestone
Graduate Poster
Wheeeeeee! Off we go! Another new tangent! What fun this is, like some weird acid-induced sci-fi B-movie! Invasion of the Non-Newtonian Fluids.
Firstly, in order to demand that the cart can't possibly do what they say it does, and the treadmill is "false", you refuse to accept the equivalence of inertial frames as regards a simple flow of air over a surface.
When that line of argument begins to wear so thin that you sound like some flat-earth throwback, you dodge to a new line of, er, "reasoning", that even if that were so, the boundary layer is going in the wrong direction! Shock horror.
When we bare that argument down to its bones and pose questions over and over to make it obvious that this is wrong, and you can't have the gradient simultaneously inverted (the 9s and 1s) and simply mirrored (the 6s), then the word 'turbulence' is thrown in weakly, hoping that is enough to get off that hook.
When that's so bizarre that people press you on it, suddenly we're off to see the wizard again, this time about how the leading edge of a fluid is going to have accelerated for longer than the mass behind it, and there will be different pressures - just think what happens when you pour water down a slope! Yeah? No.
I think you'll find that yes, in general a fluid flowing over a surface is slowed down (that's the friction), the result being the gradient of velocities we have been discussing all month under the name of 'boundary layer'. In the case of a wide open space with wind blowing over it, or a treadmill with or without small animals, that assumes a reasonably laminar flow, as we have been discussing all month, arguing over which way it changes.
If someone goes to the trouble of demolishing the new arguments (sorry, non-arguments), what will it be next? Rubbery treadmill surfaces have different static electrical properties from tarmac? Air in a room has fewer negative ions, which is the staple diet of negative dragons?
I can't wait to find out, but I can't be bothered to argue about stupid imaginary differences in turbulence or "mass/time". It's sometimes fun to engage with - I decided to push you to admit that the velocity layers are inverted measured from the ground, and that clinches the issue utterly and entirely. You're busted. No need to dig your hole even deeper.
But carry on. Do let's hear more about the front part of the wind going faster, and the pressure and mass/time differentials. I guess that means that the wind over a certain point must be slowing down, since the first part of it has had more time to accelerate.
And you know, folks, when you stand outside in the wind for any length of time, you find it's true, the wind does indeed slow down. It even stops eventually. So there you have it. Treadmills are false.
