Sound in Space
Law of Sonic Amplification, First Law of Anime Acoustics– or Sound in Space, where loud sounds, like explosions, are even louder because there is no air to get in the way. (Darrin Bright and Ryan Shellito)
Alright class who wants to tell me what is wrong with that clip…… and no its not Gundam Seed Denstiny, Kira Yamato, or sparkly gundam BS. Still didn’t get it…. Well it is something that almost every science fiction movie gets wrong……. There is no sound in space. Yes you heard me, there is no sound in space, so all those bad ass sounds you hear in your favorite space battles, sadly they are there to just make things more bad ass.
So why is there no sound in space
Well, first things first; we need to define what sound actually is. At the most basic level sound is a mechanical wave traveling through physical media either solid or liquid. A mechanical wave is a wave cause by the movement of a material.
As we can see in the picture above the wave begins when the object is hit. The vibrations in the object are then transmitted to the air. The vibrations then travel through the air until then hit another object, die off, or are detected by our ears, creating the sounds we detect.
Outer Space is a vacuum
A vacuum is defined as a space that does not contain any matter. Outer space is commonly referred to as a vacuum; however, it is a bit more nuanced than that. For the sake of this discussion we can consider space a vacuum, but in reality it does contain a tiny degree of matter that is so spread out that it has no effect on transmitting vibrations.
Not that simple
But I thought you just said that sound can’t travel through outer space, so it’s the end of the story, right? Well, not exactly, there are some situations that deserve to be explored. Clearly Kira shouldn’t hear anything when he is blasting away at all the mobile suits and battleships attacking the Eternal. And that is completely correct, he can’t hear anything as there is no way for the vibrations from the explosions he is causing, due to being in outer space. What about the people he is blasting?
Will a particle beam, plasma beam, or railgun bolt cause the ship to vibrate? Yes, of course it will. These vibrations will travel through the hull of the ship as transverse waves. Transverse waves travel 90 degrees to the direction that the energy is traveling.
When the waves traveling along the hull of the ship reach the interior, the vibrations will be transferred to the air inside the hull. After this transfer the vibration is now a longitudinal wave, where the waves and energy travel in the same direction.
Now that the vibration is traveling through the air, people inside the ship will be able to hear a sound when the ship is hit by weapons fire. The same would go for individuals inside fighters, and mobile suits as long as the vehicles contains some degree of air.
Sadly, there is no sound in space, so real life space battles will be nowhere near as cool as their anime counterparts. Oh, and if you were in a real life space battle and did hear sound effects then it would be really bad since the enemy is now in the process of blowing the crap out of you.
Here is a nice video if anyone has heard of and is interested in noise cancellation.