Popular Science - USA (2019-10)

USUAL SUSPECTS

imagine your

voice on

other planets

ACOUSTICIANS SOMETIMES

speculate about how conversations might

carry on alien worlds. Of course, you’d have

no time to chat if you stood in the open air on

Mars: Your blood would boil you to death in

seconds. But what about those final screams?

No matter where you are, your voice is a

product of how swiftly pressure waves move

through your larynx and the frequency at

which your vocal cords vibrate. But when

shouted into different gases of varying

densities, the same noises take on new forms.

Here’s how a few extraterrestrial atmo-

spheres could change your tune.

Saturn

Jupiter

Uranus

Earth: Human vocal

cords quiver at fre-

quencies adapted to a

Goldilocks atmosphere—

not especially dense or

light. Our air’s plenti-

ful nitrogen and scant

carbon- dioxide molecules

don’t absorb many vi-

brations, so sound also

happens to carry well.

Mars:You’d struggle to be

heard on the Red Planet:

Its atmosphere is 95 per-

cent carbon dioxide— the

molecular bonds of which

absorb vibrations ex-

tremely well— so even

speakers blasting at full

volume would barely be

audible 30 feet away. The

chilly air’s chemistry also

makes audio move slug-

gishly, slowing down your

croons to a husky bass.

Other worlds: The rest

of the rocky bodies orbit-

ing our sun are virtually

silent, as is the case in

open space. There isn’t

enough gas in their thin

or nonexistent atmo-

spheres to carry sound

waves at all. A few locales

might manage to pro-

ject the ruckus of, say, a

sci-fi movie explosion, but

squeaks on the scale of a

human voice would falter.

Venus:These thick, chow-

derlike climes would drop

your pitch about half

an octave because the

heaviness slows your vo-

cal folds’ wiggling. At the

same time, though, waves

move quickly through the

fog, simultaneously giv-

ing you a sort of squawky

quality—sometimes com-

pared to Donald Duck.

Titan:Saturn’s moon is

the most Earth- like world

we’ve studied, but its gas

mix is about 50 percent

denser than ours. Thick,

cold air would slow the

tremor of vocal cords and

the speed of sound itself,

deepening your voice and

giving it a rasp. The sultry

tones would travel far

thanks to abundant nitro-

gen gas, which doesn’t do

much dampening.

16 WINTER 2019 • POPSCI.COM by Sara Chodosh / illustration by Giacomo Gambineri

Neptune