Sonic rainboom (event)

"The Sonic Rainboom is legendary! When a pegasus like Rainbow Dash is going so fast... BOOM! A sonic boom and a rainbow can happen all at once!"

- Pinkie Pie

''This article is about the event. For the episode, see Sonic Rainboom.''

A Sonic Rainboom is an event that a Pegasus Pony can cause in My Little Pony: Friendship is Magic. There are two known occurances of the event, both caused by Rainbow Dash.

How to Perform
When a Pegasus Pony travels fast enough, a sonic boom and a rainbow can happen at the same time. This results in a rainbow-coloured sonic boom, if the pony can break the sound barrier. Following the event, a rainbow will follow the pony for a short time.

First Sonic Rainboom
In a flashback shown in The Cutie Mark Chronicles, Rainbow Dash, as a filly, saves Fluttershy from a group of bullies by challenging them to a race. In order to win, Rainbow Dash breaks the sound barrier, causing a Sonic Rainboom.

Effects of the Rainboom
As a result of the Sonic Rainboom, several young fillies had their lives altered:


 * Applejack, who had fled to Manehattan, saw the Sonic Rainboom and followed the resulting Rainbow back to Sweet Apple Acres. As a result of discovering where she belonged, she earned a cutie mark.


 * Fluttershy, who had been knocked to the ground out of Cloudsdale, had befriended several animals. The Sonic Rainboom caused those animals to get scared. Fluttershy calmed the animals, and earned a cutie mark.


 * Rarity had been led to a rock by means of magic. When the Sonic Rainboom occurred, the rock was shattered, revealing gem stones inside. Rarity would go on to use these gem stones in her fashion design and earn a cutie mark as a result.


 * Twilight Sparkle was struggling with the Entrance Exam at Celestia's School for Gifted Unicorns. The Sonic Rainboom allowed her to use more powerful magic than she would have been able to under ordinary circumstances, causing the birth of Spike, as well as throwing the entire room into chaos and disarray. Princess Celestia saw what had happened and quickly remedied the situation, as well as taking Twilight under her wing. As a result, Twilight, Celestia, and Spike all became friends. Twilight Sparkle also earned a cutie mark for her powerful magic.


 * Pinkie Pie drew inspiration from the Sonic Rainboom, and stopped farming rocks, instead deciding to throw parties. Her realization caused her to earn a cutie mark.


 * Rainbow Dash was nicknamed "Rainbow Crash" by the bullies. Despite this, she earned a cutie mark for her Sonic Rainboom.

Second Sonic Rainboom
In Sonic Rainboom, Rainbow Dash had planned a Sonic Rainboom as Phase Three of her act to be performed in the Best Young Flyer competition. Despite a lot of practice, she was unable to perform the feat in any rehearsals.

When the actual contest occured, unexpected events unfolded and Rarity was stripped of her wings, and fell to the ground. The Wonderbolts had tried to save her, but Rarity's panic reaction had knocked them out and rendered them unconscious.

Rainbow Dash, who was too high up at the time, could not reach Rarity without breaking the sound barrier. Despite her struggles, she managed to finally overcome the sound barrier and perform another Sonic Rainboom.

Effects of the Rainboom
As a result of the Sonic Rainboom, Rarity's life was saved, and The Wonderbolts were saved by Rainbow Dash as well. This drew Rainbow Dash to The Wonderbolts' attention, which they remembered even until The Best Night Ever.

Princess Celestia crowned Rainbow Dash as the winner of the Best Young Flyer competition. She was awarded the grand prize, spending a day with The Wonderbolts.

Trivia

 * Pinkie Pie mentions in Sonic Rainboom that she has never seen a Sonic Rainboom before in her life. This is contradictory, as she did see one in a flashback in The Cutie Mark Chronicles. Of course, Pinkie says a lot of things that don't make complete sense, and in any case she may not have known what the Sonic Rainboom was as a foal.


 * In the Equestria Girls promo video released by The Hub, Pinkie Pie mentions that once you party with ponies, you'll be seeing Rainbooms. At that time, Rainbow Dash performs the Sonic Rainboom from the episode The Cutie Mark Chronicles.
 * The name Sonic Rainboom is of course a portmanteau of the words 'rainbow' and 'Sonic Boom' the sound made when an object breaks the sound barrier. It can therefore be assumed that Rainbow Dash is capable of flying beyond Mach 1.
 * Rainbow Dash is the only pony seen and heard of in the show who has the ability to execute Sonic Rainbooms. However, it isn't explained directly that her rainbow-colored mane could have probably contributed in the formation of colors, nor is it stated that other ponies have done a simple Sonic Boom. With this said, other ponies of the past may have reached the same height of speed as Rainbow Dash did, but did not probably display the same colorful bursts.
 * Aircraft breaking the sound barrier are typically accompanied by a 'cone' or 'halo' of water vapor. The rainbow effect of the Sonic Rainboom may have been caused by light filtering through condensed water, as it does in real rainbows, or possibly by a pony passing through Equestria's innate magical field - who knows?