This episode was proudly made possible by the all-new 2015 Subaru Legacy.
It's not just a sedan, it's a Subaru.
Movies in space are awesome, don't get me wrong, except when it comes to the sound.
But, if space is a vacuum, then there's no sound… but maybe space isn't a vacuum.
Can you hear me DNews fans?
Hey, it's Trace here and I'm not in space, and if you're not in space either, then you
should be able to hear me just fine.
As regular viewers already know, sound travels using a medium.
Sound is a mechanical, longitudinal wave of energy emanating from a vibration.
When a guitar string vibrates, the atoms of the metal string hit the atoms around it,
and that vibration is passed along to the next and next until it gets to your ear.
Once there, the tympanic membrane, or eardrum, vibrates at the same frequency, and the tiny
bones in your middle and inner ear translate the movement to energy that your brain can
interpret.
Because all atoms can vibrate like this, sound can travel through solids, liquids, and gases.
Outer space on the other hand, is thought of as a vacuum, the ABSENCE of matter; and
no matter means no sound.
But really, in space it more like, atom, atom… atom…
NASA says there's about one atom per cubic centimeter!
If you took all those free-floating atoms into account, you'd have 90 percent hydrogen,
9 percent helium and less than one percent of other stuff.
Which makes sense considering the makeup of everything we know in the universe, amirite?
Even though one atom per cubic centimeter might seem like more than you thought, it's
still fantastically thin.
With such low density, sound's energy waves cannot bounce from one atom to another.
No atoms, no waves, no sound.
So, George Lucas: you're wrong!!
Spaceships don't make noise - unless they’re flying within the atmosphere of a planet…
And not just ours!
You can hear sounds on certain other planets too.
For instance, sound travels FASTER on Venus than it does on Earth, because its atmosphere
is "thick and soupy," says Tim Leighton of the University of Southampton.
This means if you COULD talk on Venus, the sound would zoom through your vocal chords,
but deepen in pitch because of the makeup of the air.
Basically, you'd sound like a Bassy Smurf.
We get around this by building structures that contain pockets of air.
The atmosphere INSIDE the International Space Station sounds pretty normal.
But if an astronaut hit his helmet against something outside, he would hear the impact
because his helmet has air, but the people INSIDE wouldn't hear anything.
Purely hypothetically, if somehow, you could put your bare head against the outside of
the International Space Station you might be able to "hear" Chris Hadfield inside the
ISS playing his guitar.
See, that guitar vibration might travel through the air inside, to the walls of the ISS vibrating
them.
And then, if your bones were touching just right, that vibration MIGHT vibrate your BONES
and thus get directly to your inner ear.
This is called bone conduction, and it's used in some headphones and in tech like Google
Glass.
Because your bones conduct that vibration, it surpasses the need for air and doesn't
require the eardrum at all… but again, it would only work if your bone was touching
the ISS.
Plus, of course, you'd die pretty quickly…
There IS another way to to pull sound directly from space, not in an atmosphere, or in a
spacesuit…
can you guess it?
Tell me your guess in the comments!
If we get 7,000 likes, I'll release a follow-up with the answer!
We wanna extend a quick thank you to Subaru, for making this episode possible.
And especially the all-new 2015 Subaru Legacy.
Every sedan has its benefits, but only one combines them all.
It’s not just a sedan.
It’s a Subaru.
Thanks for watching DNews everyone, and please subscribe.