Why airplanes fly? [Fun alternative explanation]

Well, two years ago, when I started learning about airplanes I was a bit scared that I didn't know a right explanation as to why airfoils work. Everyone told me, low pressure on top, high pressure on the bottom yada yada.. but there was a professor of flight mechanics and he has been flying for more than 30 years and during his first class he told us jokingly "No one knows the exact reason why airfoils work".

Now, let's get into the fun alternative explanation.

[* Disclaimer : this is a fun reasoning, not to be taken scientifically or seriously. Please don't cite this blog post ]

So, let's say you have a closed domain with liquid (say water). Simply put, imagine a bowl with water or coffee (or better yet, a pint of beer). When you dip your finger into it and begin to drag it across, you can see two vortices being created, mathematical the two vortices are equal and opposite and they cancel each other out. When you drag your finger across, the fluid moves around your finger, this is called circulation and if the circulation above your finger and below are equal the vortex shredded behind will be equal and opposite to each other (I imagine you have a beautiful circular cylindrical fingers). This phenomenon was studied by a famous scientist Kelvin and they came up with a theorem called
Kelvin's circulation theorem, which states that, "in a closed domain of fluid the total circulation is zero".
And we all know, the circulation around the finger is directly related to the two vortices left behind.

Now, let's imagine airfoil shape, we all know the shape of the airfoil isn't symmetrical and when you do the same and drag it across fluid, the circulation on the top and bottom are not same, which in turn creates two unequal vortices behind.
Wait a minute, we just agreed that the total circulation in a closed domain must be zero and we can relate the vortex to the circulation and if the vortices are unequal there supposed to be another vortex somewhere which should cancel the inequality, isn't it?. Well Dr. Watson, you are right. When an airfoil accelerates from 0 to V m/s, it's shreds two unequal vortices and during the flight, there is a still vorticity in the fluid behind the airfoil because of difference in velocity but as long as it maintains the same V, there is no vortex shredding and this gives the circulation around the airfoils to be non-zero.

But when it decelerates from V to 0, it shreds another two unequal vortices but now they are equal and opposite to the first two.

Ergo, the airfoil when it's moving has a non-zero circulation, because of the first two unequal vortices and stops flying when this inequality is cancelled. In many numerical and experimental studies (PIV etc), this phenomenon can be seen.
Earth's atmosphere can be seen as a closed domain between ground to 400km (more on this, in the future).
When it comes to flying from Paris to Beijing, the vortex shredded in Paris are not cancelling each other, and this gives the circulation around airfoil to be non-zero and the plane starts flying, and when it comes to halt at Beijing, the other vortices are shred making everything add up to zero.
And this is why airplanes fly ?!!.. not exactly, but hey it's a fun explanation nonetheless.

Cheers
Dhanush