How fast is Rainbow Dash’s Sonic Rainboom?

[MLPForLife 55]

I always wondered how fast is the Sonic Rainboom that Rainbow Dash made? 

[Jeric 46,835]

2 minutes ago, MLPForLife said:

I always wondered how fast is the Sonic Rainboom that Rainbow Dash made? 

The Rainboom was probably going normal speed for rapid displacement of sound and air (particularly air droplets). Dash on the other hand was going much faster.

[Meson Bolt 2,647]

Spoiler

 

Uhm... I did a calculation about this a looong time ago. Don't really feel like digging it up, but I do remember the conclusion.

Some people are convinced that Dash flew at Mach 10 (10 times the speed of sound, about 7,600 mph) because of the animation and the mach cone that forms in front of her. I disagree; if she was flying that fast straight down from Cloudsdale, that'd make Cloudsdale like 32 miles in the air. It's clearly not, because we see several establishing shots of Cloudsdale and it's evident that the ground is still in sight (plus the clouds that Cloudsdale is made up of are most likely cumulonimbus, which don't form at those altitudes).

I'm more convinced that she simply broke the speed of sound, 760 mph, hence the name "Sonic Rainboom", derived from the term "sonic boom".

Fun fact though, she actually travels more than twice as fast coming back from Cloudsdale, even with the weight of the Wonderbolts she's carrying. Her "exit trip" takes about 11 seconds after the Sonic Rainboom, but her "return trip" from ground level is only 5 seconds. So about 1500ish mph.

Still not mach 10, but still really fast.

EDIT:

 

Ok, I actually dug up the old theory, and while I don't really wanna go too much into detail, here's the meat and potatoes.

I calculated the height of Cloudsdale Stadium to be just shy of 20,000 feet above the ground, based on the maximum tolerable altitude for humans. Yes, they're ponies and not humans, and yes, this might not be earth, but just... shut up, this is the best I could come up with.

It took her 30 seconds to reach the ground from the stadium, giving her an average speed of 666 (lel) feet per second, or 454 mph (mach 0.59). Granted, that's her average speed; she was obviously accelerating for a good portion of that time. It's very likely that she did break the sound barrier on her way down.

But she actually travels the same distance of 20,000 feet on her return trip, this time in only 5 seconds. Don't believe me? Here's the clip. It's really noticeable if you're looking for it.

Spoiler

Her "departing" trip, 2:58 to 3:28.

Her "return" trip, 3:32 to 3:37.

Using the same theory, 20,000 divided by 5 gives us 4,000 feet per second, 2727 mph, or mach 3.5.

So yes, she's going faster than the speed of sound, but not mach 10 or anything stupid like that.

Also SCREW Flex Tape, I want whatever kind of tape that kept the number 15 card stuck to her butt!

Edited August 30, 2019 by Meson Bolt

[Splashee 28,537]

The question is, how fast is Rainbow Dash brain activity when moving that fast? If she is a slow thinker, it is easy to speed up, and crash. The reaction time of her flying that fast required almost super fast thinking compared to the rest (includes power up in Eqeustria Girls, to navigate at super speed)

[EpicEnergy 22,082]

Faster than the speed of light! 

[H10Scratch 0]

Considering a Sonic Rainboom is similar to a Sonic Boom, when an object (in this case, rainbow dash) goes faster than the speed of sound. I can't remember the episode but there is one when Rarity goes up to the sky with her butterfly wings, and the sun burns them. Depends on a lot of things but assuming it was a really hot day, the speed of sound is faster in warmer air, so that makes the speed of sound faster on that day. It can't really be told what number the speed of sound was at, but it was probably over 761 mph, the speed of sound on the average day. To save time, let's call the speed of sound on that day 'S'. Rainbow Dash would have to go faster than S, again, probably over 761 mph! When she was going down, she was starting to do the sonic rainboom at that point, but Rarity was falling FAST, and she noticed that, and I don't know if it was luck, but I'm guessing 'adrenaline' kicked in and that made her REALLY fast, able to save Rarity. I can't remember the end but I do believe she pulled off a sonic rainboom, meaning she went faster than 761 mph, again bringing us back to the very beginning, considering a Sonic Rainboom is similar to a Sonic Boom. In conclusion, on the average warm day, she has to go over 760 mph to pull off a sonic rainboom! Doesn't surprise me that her cheeks flap-  Hope this helped!

[DubWolf 16,619]

At least the speed of sound at the given conditions (it is based on temperature, primarily).

 

If you want to go further yes, animation should give you a good solid number, although IRL going that fast will definitely shatter a lot of windows if she was going Mach 10.

Also it must be stated that IRL a sonic boom is not a one-time event, but rather it is the sound you hear as you are passed by the shock wave of the moving object. It is a continuous shock wave, and hence, the boom is heard where the shock is heard.

 

(the faster you go, the narrower the sonic boom shock wave cone gets as the sound wave gets more “condensed“).

Edited June 16, 2021 by WWolf

[BornAgainBrony 2,395]

Why would anyone think it was something other than Mach 1?

Even the lore surrounding the rainboom before Dash pulls it off, shares a lot of common threads with the sound barrier we deal with on Earth. Many believed the sound barrier was unbreakable until Chuck Yeager did it.

[Reality Check 627]

If I have to guess, it's probably faster than the speed of sound, especially if she's able to do it plenty of times like it's no problem. Though I'm actually curious if it's really something that only she can perform if that's the case.

[BornAgainBrony 2,395]

32 minutes ago, Dusky Wings said:

If I have to guess, it's probably faster than the speed of sound, especially if she's able to do it plenty of times like it's no problem. Though I'm actually curious if it's really something that only she can perform if that's the case.

I never thought only she could do it. Only she was the only one that has. So far. I really expected to see another Pegasus execute a sonic boom before the show was over. Lightning Dust, maybe? Kinda disappointing it never happened. That could've made for a pretty interesting Dash episode; having that thing that was strictly her own personal domain for so long, and then suddenly having to share it.

[Courageous Thunder Dash 7,809]

A sonic boom alone makes someone travel faster than the speed of sound, which is around 767 mph (according to sources). From a physics standpoint, the only way for Rainbow to do this was to fly downward and break the terminal velocity limit. With her cutie mark (talent boost), this enables her to reach those speeds. 

[BornAgainBrony 2,395]

1 hour ago, Courageous Thunder Dash said:

A sonic boom alone makes someone travel faster than the speed of sound, which is around 767 mph (according to sources). From a physics standpoint, the only way for Rainbow to do this was to fly downward and break the terminal velocity limit. With her cutie mark (talent boost), this enables her to reach those speeds. 

Well, if we're going to bring those kind of physics into it, Pegusi must have some kind of alien flying-saucer level of resistance to inertia.

Plugging the Fluttershy-saving maneuver into a G-force equation...

I'm being generous with the rate of acceleration because it sure as heck looks like she turns 90 degrees on a dime. This also assumes that she didn't continue to speed up beyond the speed of sound. So we'll assume 0.5 seconds for her to complete the turn. Since a turn is scientifically "acceleration" the same way starting up from being motionless, that means she's going from zero to Mach 1 in half a second. That's 150 G's!

For comparison's sake, the most astronauts usually experience is around 4 G's. NASA tries to keep it around 2 - 3. Most people risk passing out at 5. With a flight suit, a fighter pilot might be able to handle 9. Anything above that is reasonably considered lethal.