Sound can kill you.
That’s the message from a science writer to a five-year old who said she wanted to hear “the loudest sound in the world.”
Despite what we may think, sound isn’t just a “glitter rainbow floating around with no connection to the physical world,” Maggie Koerth-Baker writes in FiveThirtyEight. Sound is mechanical; a push. A shove.
Most of the time it’s a tiny one – like a tap on the membrane of your eardrum. But the louder the sound, the larger the tap.
Loud enough and it cap rip your eardrum to pieces. Even louder yet and it can knock you over. And if it’s really, really loud, it can kill you.
A bomb is essentially massive sound waves. They can level a brick home, sending glass and debris flying.
Consider this piece of history: On the morning of Aug. 27, 1883, ranchers on a sheep camp outside Alice Springs, Australia, heard a sound like two shots from a rifle. At that very moment, the Indonesian volcanic island of Krakatoa was blowing itself to bits 2,233 miles away. Scientists think this is probably the loudest sound humans have ever accurately measured. Not only are there records of people hearing the sound of Krakatoa thousands of miles away, there is also physical evidence that the sound of the volcano’s explosion traveled all the way around the globe multiple times.
Koreth-Baker asks you to imagine the world is like being in a crowded train car. “If you were to hip check the person standing next to you — which I do not recommend — they would tense up and scoot away from you,” she explains. “In the process, they’d probably bump into the next person, who would tense up and shimmy away from them. (There would also be words exchanged, but that is neither germane to our thought experiment nor child friendly.) Meanwhile, though, that original person you bumped into has now relaxed. The pattern travels through the crowd — bump-tense-wiggle-sigh, bump-tense-wiggle-sigh.”
And that’s what a sound wave is like.
Some sounds are incredibly loud, we just don’t hear them. A sperm whale’s noises is about 200 decibels. By comparison, the loudest sound NASA has ever recorded was the first stage of the Saturn V rocket, which clocked in at 204 decibels. You don’t hear the whale’s sound because it’s in the water, which is denser than air and doesn’t travel outside the water.
So the author was reluctant to tell the five-year-old what the loudest sound ever was – because it would kill her if she was close enough. But, from her calculations, it was the explosion of the Chelyabinsh meteor, which exploded in the sky over southern Russia, near the border between Europe and Asia, on Feb. 15, 2013. Test-Ban Treaty sensors picked up the infrasound more than 9,000 miles from the source and the sound waves circled the globe. The nearest sensor was 435 miles away, Garces told me, and even at that distance the infrasound decibel level reached 90. Turns out, things don’t have to say “boom” to go boom.
When my dad used to yell at me, I knew the louder he got, the more likely it was he was going to kill me.
In a way, that was right.