this post was submitted on 14 Sep 2023
254 points (94.7% liked)

BeWowed

697 readers
1 users here now

A friendly place for people to share exceptionals videos and images that will leave other users ~~speechless~~ wowed!

Community Rules:

  1. No hate, be respectful
  2. No spam
  3. No self-promotion
  4. No Illegal Content
  5. No Porn/Sexually Explicit Content

founded 1 year ago
MODERATORS
 
you are viewing a single comment's thread
view the rest of the comments
[–] FooBarrington 4 points 1 year ago (1 children)

What we see is light being refracted in "weird" ways. It's similar to the way light above a very hot surface, like asphalt on a hot sunny day, appears to be warped.

Everything has a refractive index, meaning a number that determines how much light is warped. Air is usually very evenly distributed, so you don't see much (or any) warping. But the airplane moves so fast that it pushes the air in front of it to the side, which means around the airplane the air is denser. The refractive index of air changes with density. This makes the light appear so warped :)

Fun fact, the sonic boom also comes from the air being pushed to the side. Behind the airplane there is a pocket without air (or with very little). The higher density around the airplane is not stable, gases want to be evenly distributed. This makes the air crash violently into itself as it fills the pocket, which produces the sound! This also explains why you hear the sonic boom everywhere along the path of the airplane, and not just where it breaks the sound barrier.

[–] [email protected] 2 points 1 year ago (1 children)

But then that means what we see has nothing to do with breaking the speed of sound. So is the only relation between the distortion and breaking the sound barrier the fact that one needs to be quite fast for both?

[–] FooBarrington 3 points 1 year ago

Yes, in the sense that you already get a weaker version of this effect below the sound barrier. You don't need to break it to see them.