//------------------------------//
// Ditzy Doo and the Exploding Lake 
// Story: C̶o̶d̶a̶ Codex Equestria: Scientific Pony T̶a̶i̶l̶s̶ Tales 
// by Pineta 
//------------------------------//


Vectors: Derpy by TheJedyates, Pinkie by SuxtonHael

Rainbow Dash, Applejack, Pinkie Pie and Twilight Sparkle sat at a wooden table outside Sweet Apple Acres, enjoying the bright sunshine, and sipping last year’s cider out of glass bottles. They were joined by the mailmare Ditzy, who had just delivered the latest Daring Do book to Rainbow Dash, who was giving her friends an enthusiastic summary of the plot.

“So after Daring rescued the Dromedary prince from the fortified citadel in the heart of the Cameloonian jungle, she returned to her lodgings in the city of Hayrare, only to receive a threatening message from Ahuizotl. If she didn’t surrender the sacred magical flute of Limpolo, he would cause the lake Neighos to explode! The ponies and camels living along the shore were in terrible danger!”

“Ohmygosh!” cried Pinkie Pie, thrusting her pink forelegs into her mouth and biting the edge of her hooves. “What happened next? Was Daring Do able to stop him? Or did the lake explode? Or did the lake explode and Daring managed to put it back together? Or—”

“Please,” said Twilight. “No spoilers. I haven’t got to that part yet.”

Applejack gave a sceptical frown. “How the hay can you make a lake explode?”

“Well, you…” Rainbow paused, ensure how to answer that question. “That is Ahuizotl… I suppose…”

Always ready to help, Ditzy reached across the table and tapped a hoof sharply on the top of Rainbow’s cider bottle. A plume of cider foam erupted from the bottle neck.

“Argh!” cried Rainbow, dropping the bottle onto the table, shaking the foam off her hooves and rescuing her book from the fountain of cider bubbles flowing onto the wooden surface. This gave Pinkie a fit of giggles.

“The cider bottle tapping party prank! That’s an old favourite.” She grinned at Rainbow, her concern for the ponies of the shore of lake Neighos temporarily forgotten. Rainbow was not so amused and stared at the mailmare.

“How did you do that Derpy?” she asked. “Let me guess—you just don’t know what went wrong?”

“I do.” Ditzy looked upset. “I was only trying to answer the question.”

“What?”

“Hitting the top of the bottle sends a shock wave down through the glass,” she explained. “When it hits the bottom, it rebounds and sends an expansion wave up through the liquid. This causes a sudden drop in pressure. The wave rebounds from the top, compressing the liquid. The expansion and compression causes the large bubbles in the cider to break up into lots of little bubbles. These get bigger very quickly and rise upwards forming a plume, which pushes the cider out of the bottle.”

Rainbow Dash opened her mouth but couldn’t think of any words to say. She gaped at Ditzy for a moment.

“The same thing can happen to the lake,” continued the mailmare. “Lake Neighos is saturated with carbon dioxide gas produced by volcanic activity under the lake. If you get a sudden shock—maybe an earthquake or a landslide—it releases a huge cloud of gas, which can suffocate ponies.”

Rainbow Dash remained open mouthed. “How… you… know… that.” she stammered.

Ditzy shrugged her shoulders. “Bubbles are my special talent,” she explained.