rocket taking off with visible sound waves

Watch a rocket literally shred a rainbow with sound waves

Contributed by
Jul 16, 2018

You only need to watch the first 15 seconds of this video to understand why it recently went viral on Reddit.

The footage of a rocket’s sound waves shredding a rainbow during the launch of NASA’s Solar Dynamics Observatory really blasted into the stratosphere of the r/space forum because, you know, that’s just not something you see every day even if you check the NASA Twitter feed so often you might as well be in mission control.

Rockets are way more intense than rock concerts when it comes to how loud they can get. The human threshold for pain — sound actually can reach levels high enough to put you in agony — is 120 decibels. A jet engine takes off at 150. Roaring at up to 200 decibels, which means they vibrate a superfast 600 times per second, rocket engines are capable of everything from setting your hair on fire to serious bodily harm with sound alone.

With that kind of sonic power, decimating a rainbow was obviously no problem. This rainbow, a phenomenon called a sundog, appeared as a watercolor smudge because it was behind a sheet of ice crystals with a certain alignment. The rocket’s sound waves smashed into the semisolid medium as it shot through the air, not only shattering the rainbow but creating visible ripples in the sky. Watch the right corner of your screen and prepare for your mind to be blown.

"When the rocket penetrated the cirrus, shock waves rippled through the cloud and destroyed the alignment of the ice crystals," atmospheric optics expert Les Cowley told NASA after the launch. "This extinguished the sundog."  

While this rocket hadn’t actually accelerated faster than the speed of sound, because otherwise its sound waves would be falling behind in something of a cone instead of rippling in front, it was obviously loud enough to do visible damage. Rocket engines could actually kill someone standing near the launchpad. Even as the hulking piece of metal shoots through the atmosphere, the aerodynamic noise caused by rushing air is loud enough to hear with your car window down.

NASA is nervous enough about Mars and obviously doesn’t need any casualties on Earth, which is why sound waves that issue from rockets get the volume turned down by drenching the launchpad in hundreds of thousands of gallons of water post-liftoff, which keeps the high-pressure waves left in its wake from bouncing back and smashing the spacecraft.

Lethal noises aside, you have to admit that totally deserved the double replay it got, because what other force could possibly be capable of this? Maybe Superman.

(via LiveScience)