How do you think the Sonic Rainboom is achieved?

[Guest]

This kid explains it all...

GG, sirs.

[Zerul 555]

She's never been able to do it off raw skill or speed. she's done it twice in her life and both times were for here friends.

 

1-For fluttershy's honor in flight school

2- To save Rarity's life

FRIENDSHIP IS MAGIC

[DashPony 359]

Heh, right, more on-topic, though, there must be something like unicorn magic at work propelling her forward.

 

Remember, the Sonic Rainboom is just a legend, nobody's done it for a huge amount of time (decades, centuries, millenia?) until she did it as a filly, which is undoubtably due to her connection with the Elements of Harmony. Kyronea wrote quiet a bit about that in her psychological analysis', in every one of the characters' analysis, IIRC.

 

This is backed up by two things...

 

1:The fastest any bird can fly, is about 110 mph, record-setting. A human has a maximum terminal speed of about 200 mph. (the balance-point of drag slowing you down and gravity pulling you down) Together, this will give a maximum dive speed of ~230 mph. (aerodynamc drag goes by the square of the velocity, so you don't add the speeds together, you use a pythagorean form of (v_t² = v₁² + v₂²) Pegasus are smaller and lighter than humans, meaning their terminal speed would be much slower. And even with a 200 mph level-flight speed, we still only get ~280 mph max dive speed.

 

A far cry from 770 mph (give or take a few, depending on the weather and altitude).

 

2:Call it a hunch, but something tells me it's impossible to go faster than sound without a brayton cycle (a jet engine, which compresses air and has combustion) or a rocket. In other words, it's impossible to go faster than sound just by pushing on air with wings.

 

 

So there has to be something else propelling Rainbow Dash. We know unicorns have telekenisis, a magic that can exert a force, so a similar magic must be at work for RD.

 

Luckily, she put her strong hooves forward to act as a drag-resistant aerospike. See, the powerful shockwaves form on her hooves instead of her face. If she lowers both her hooves, it's possible the shockwave could do some nasty things to her face...

 

(Well, aside from causing her to tumble and doing some other grotesque things to her body... There's some really serious force at those speeds. I'll calculate the pressure in a jiffy.)

 

EDIT: Excuse-moi. Turns out dynamic pressure at mach 1 with supersonic flow is only about 3/4ths of an atmosphere, so about 10.4 pounds per square inch of pressure. Oh, it'll hurt and deform things, but won't do anything permanent. But if she tries to extend wings at full brake at that speed, she could break one. In fact, as she goes trans-sonic, the pressure would significantly increase, and she definitely would break a wing if she did that, at least.

(where I got my numbers)

 

I guess I was just thinking of dynamic pressure that rockets go into at launch, up to 10,000 pounds per square inch! But I guess mach 1 is so much slower it isn't anything like that at all... /EDIT

 

 

By the way, I don't agree with the guy that says she goes mach 5.

#1, it's just artistic rendition, canon is she went mach 1

#2, in the lower atmosphere (troposphere, 30,000 feet or lower, anywhere anything can breathe) you begin to have serious heating issues in-between mach 2 and 3. She would be incinerated at mach 4, never mind anything higher. Heck, titanium aircraft would be incinerated at mach 3 below 70,000 feet, and at 50,000 feet you'd might as well be in space, in terms of being able to breathe. And there's this revolutionary type of jet engine, a scramjet, that they're having serious issues with because it needs a minimum speed of mach 4 to work, and they haven't built anything that can go that fast that low without melting.

#3, She goes at the rainbow speed for 10 seconds. Mach 5 is 5,575 feet/second. She'd have to have done it at 55,600 feet or so, and if Cloudsdale was as much as 28,000 feet, nopony would be able to breathe except the pegasi, assuming they have eagle-like lungs.

 

I agree with everything you just said. I don't know a whole lot about physics, but that makes the most sense. I also read a theory somewhere that she isn't really breaking the sound barrier, she is breaking the magic barrier. Hence the rainbow effect. In a world controlled by magic, that actually sounds plausible

 

Emotion probably plays a small part in her being able to perform the Rainboom, but I think Pegasus magic is what actually allows it to happen. I'm also going to assume that some kind of protective barrier activates at the start of the Rainboom to keep her safe. Travelling at those speeds is probably quite painful/deadly. Assuming that she is really breaking the sound barrier.

[Comet Tail 809]

I agree with everything you just said. I don't know a whole lot about physics, but that makes the most sense. I also read a theory somewhere that she isn't really breaking the sound barrier, she is breaking the magic barrier. Hence the rainbow effect. In a world controlled by magic, that actually sounds plausible

 

Emotion probably plays a small part in her being able to perform the Rainboom, but I think Pegasus magic is what actually allows it to happen. I'm also going to assume that some kind of protective barrier activates at the start of the Rainboom to keep her safe. Travelling at those speeds is probably quite painful/deadly. Assuming that she is really breaking the sound barrier.

 

All that pressure is only on the mach cone. Or, mostly, anyways.

 

[i guess I should add, "dynamic pressure" is the term for how hard a fluid pushes on your when you're traveling through it. In this case, the "fluid" is air. "Fluid Dynamics" uses the term "fluid" to mean anything that flows.]

 

I worked the math for those speeds, and it appears that it's not really that bad, actually (the dynamic pressure stuff). Well, actually, I'm no medical specialist, so I don't know what 10.4 pounds per square inch does, but basically that means the same pressure as a 10.4 pound weight sitting on an area the size of your big toenail. If that's on your face, it will definitely deform it quiet a bit (as we see RD's cheeks flying back, exactly what I mean), but I really don't know if it'd cause permanent damage. Good luck keeping your eyes open at those speeds, though, lol. The eyes watering was a great effect they animators added.

 

But anyways, she wouldn't feel all that pressure because of the shock cone, behind the shock cone, the air is moving a lot slower relative to RD, and is also at a lower pressure, resulting in a much lower dynamic pressure.

 

Luckily, her hooves are all that feel the full supersonic pressure.

 

 

Now, alternatively, there's breaking the magic barrier. That sounds interesting... It would mean magic is literally a fluid that fills their world like an atmosphere. Very interesting concept...

Edited July 9, 2012 by EASA - Matt

[NavelColt 22,883]

Imaginaaaaaaation.

 

 

I'm not even gonna attempt to delve into physics, so I'll say something like this: It needs a specific velocity, and another factor, perhaps emotional state like confidence, to both be at a specific level, and then it is achieved, thusly breaking the sound barrier and shattering the visual light spectrum. Emotional state makes the most sense to me, because it's the only variable that has changed over time with Rainbow. She's always been ludicrously fast, but her confidence with the rainboom has changed over time.

 

-When she was a filly, she was absolutely determined to win the race, and was so focused on proving something for her friend Fluttershy, that she achieved it easily.

 

-In Sonic Rainboom, while practicing, Fluttershy's weak ability to truly root her on resulted in Dash not being able to get herself in the mental state to accomplish it, thusly, it backfired. But then later on, even though Dash had thousands of spectators watching her every move, she pulled it off in order to save both her friend Rarity, and the Wonderbolts.

 

-It is now shown that she has *apparently* mastered the ability to do a rainboom on demand, as she did an apparent nameless one in Lesson Zero to demolish AJ's barn, and did another one instantaneously at the Royal Wedding. Though I suppose if someone absolutely wants to play Devil's Advocate they can say that her confidence came easily due to AJ counting on her, and then the princess, and everyone at the wedding counting on her to do one.

 

So yeah. Emotion *confidence, most likely* and maximum required velocity.

Edited July 9, 2012 by ~Chaotic Discord~

[discorded 234]

watch on youtube: deathbattle rainbowdash vs starcream. explains it all

[The Awesome One 1,316]

It's like breaking the sound barrier in our world. You may have noticed that fighter jets sometimes have this smokey disk around them.

 

Well, the same thing applies to Rainbow Dash...except for the fact that the 'disc' is rainbow coloured and much bigger and looks like some sort of orbital cannon being fired.

[spas-ticShotty 3,588]

How to achieve a sonic rainboom; fly at supersonic speed (Above 735 mph, I believe, at least on ground level)

 

Damn, if that's true, RD was flying at over 700 mph

[Darker 1,352]

Breaking the sound barrier. But RD just had the motivation and needs to do it, since he never showed to reach near Mach speeds.

[Pastel 7,630]

The answer is here...I guess

http://en.wikipedia.org/wiki/Sound_barrier

Edited August 26, 2014 by Blobulle

[Fractured 2,684]

>comparing a magical effect to a scientific principle, and using the latter to explain the former
>using it to justify Rainbow Dash going barely over mach 1
I'll let Jackie take this one: