Cherry Berry took the chalk in her mouth and scraped out an equation on the chalkboard.
Lift= CL ½ ρ V^2S
“Lift is equal to the coefficient of lift, a number dependent on the shape and direction of the wing, times half of rho, which is air pressure, times velocity squared times the surface area of the wing…See what this means?”
Thunderlane scratched his head.
"No, I don’t get it. What are you getting at?”
“Look, all I'm saying is, if the wings are right and if you throw it hard enough it will fly.
Thunderlane, I can make earth ponies fly anywhere they want, in any direction, without the use of magic.”
The balloon was great.
The mechanics of which had been discovered by accident many years ago when some pony had lost their bag on the updraft of some flame.
It could carry a good hoof-full of passengers great distances in a manageable length of time, not quite as fast as train, or pegasus chariot, but not bad for not needing any rails and only needing to be managed by one pony.
It was great for scouting, and for cartography missions… (Though honestly perhaps maps would have been drawn better by unicorns than earth ponies, less skewed for the mouth work.)
But there had to be more to flight.
There was so much that pegasi could manage that an earth pony in a balloon couldn't even come close to.
The light/sound barrier for one.
But even setting that aside it had to be something to swoop around in any direction, or to sweep towards the ground pulling up at just the last second.
Shucks, to even have the flight capability of the birds flying for miles and miles and could guide themselves not being always affected by the shift in breeze...
Now, this could be accomplished in the balloon with some slight unicorn magic… but these enhancements were expensive… and on most occasions were barely worth their going rate.
The copter experiment had worked out pretty well, just a simple large screw with a smaller one to balance for rotation, but it was tiring, and to try to use something like that to go long distances, never.
A flapping wing design might work in theory, but, again, an efficiency issue…
How does one go fast and far, and have maneuverability similar to even the least skilled pegasi?
How does one get thrust without flapping or magic?
Out of the corner of her eye, Cherry noticed some movement in a shop window.
Breezy had just put out a new display, a fan blowing a pony’s mane.
“Hmm”...
She stepped inside, several other ponies rushing in beside her, presumably for cosmetic reasons. She browsed for a bit as the crowd swelled and subsided within the small shop.
They were all too small, and none of them were powerful enough… but the workmanship of the blades were so fine, finessed perfectly to provide the best wind speed for a given mount, so efficient.
Manes were not wing-shaped by any means.
But perhaps (disregarding magic) they took to the air for similar reasons…
And perhaps for a similar reason to the balloon.
The balloon would go aloft because as heated the air inside having more energy would expand outward and up as hot air has the tendency to do.
After carefully examining pegasi at play Cherry had discovered a similar system at work on wings, even magically enhanced ones…
Wings fly because the angle at which they meet the air, and their shape forces the air pressure to be greater on the bottom side of the wing than the top. The wing and the air under it seeks to fill the vacuum created above.
A similar thing is happening to my mane, she thought.
When fluid flow in a system increases, the pressure must decrease.
She scratched out an equation on the ground with her hoof.
P + 1 2 ρ v 2 + ρ g h = c
She thought about it a bit more.
The wind hits my mane which is laying flat and vertical against my neck, the wind that fails to hit it blows over the top unobstructed, the wind that hits it is slowed down…. So therefore the wind going over the top of the mane has a lower pressure than the wind hitting the mane…
The wind in the low-pressure area wants to join the area of high pressure, and the fast spread out air particles makes for an opening, a vacuum that sucks the mane up with it…once the pressure exchange is resolved the mane is dropped a bit only to be picked up by a repeat in the cycle… which is why it must wave like that… …perhaps stabilization and control could be used in a similar system to keep the object from falling back down...
“Ms., Ms. Can I help you? I'm going to be closing up shop soon.”
At this point Cherry Berry was practically drooling in thought… about thrust and weight and drag, and what best wing shape would suit a large powerful fan blade.
“Um, um..”
She wiped the drool from her face hoping the kind handsome stallion hadn't noticed.
If he had, he didn't say anything.
“Sorry… lost in thought…
I don’t suppose you make custom fan blades?
“Ok class, settle down, settle down.’
There was a brief interlude of chaos, and yet as Ms. Cheerilee's voice rang through the room the young ones almost though not quite snapped to attention. There was still some fidgeting here and there, but it was as much if not more than what could be expected for a room filled with wide-eyed fillies and colts.
Today we have a very special guest.
As you know this is earth pony science appreciation week. I'm sure everypony enjoyed Dr. Hooves' presentation of The Future Present that is Now.. Or then... Or…
Hoof to the face, and a chuckle from the barely contained youth.
“ You know what I mean...
Today I'd like you to meet our new guest, everyone welcome Ms. Cherry Berry.
“Hi Ms. Cherry Berry” the class called out in staggered unison.
“Hello Colts and fillies, it's good to be here today, thank you for having me, class, Ms.Cheerilee”
“We are glad to have you Ms. Berry. I can’t wait to see what you have prepared to show the class”
Cherry smiled
“I'm excited too, in fact, I'm ecstatic…
Today, I wanted to show a model of my newest invention, in fact, we are all going to be making our own.”
Cherry turned to her bag and withdrew a large sheet of paper.
“I want everypony to grab a sheet of paper, not your homework mind you.
All right, everypony has their paper? Great. Now take it, and fold it in half, long as if you were making a carrot dog and crease”
As she spoke she folded the paper skillfully in her hooves, creasing along the edge.
“ All right, take your carrot dog and unfold it. Great!”
At this, there were some rolled eyes, many wondering why one would fold something just to unfold it.
“Alrighty then, now using that middle crease as a guide we are going to fold the corners in like this, and then again, we fold them in one more time, like this.
Great! Now, close your hot dog back up, now for the wing, fold them out like this.
And we are done.
Now, I want everypony to take their craft, and throw it.
Suddenly the classroom airspace was filled with over a dozen white and multicolored objects soaring, zooming and gliding. Many looping, and pirouetting gently around the room... Most headed directly for the chalkboard, for the teacher, and for cherry, both of which covered their eyes in an attempt to avoid penetration of the worst sort.
It was so simple.
Flight.
Author's Note
Be sure to check out the continuation in: Look Out!
In which Cherry discover something about her family and adventurous shenanigans enssue.
