Pressure waves in --- whatever the medium is --- air.
In a vacuum (real empty space), there is no sound.
(See the old gag line for the original Alien movie (in space they can't hear you scream).)
he discovered the atom was mostly made up of empty space
D: Empty space.
He discovered that the atom was mostly made up of empty space.
A vacuum is composed of empty space.
empty space
Empty space
In space
it was just an empty space but then the creators made something of that space
Sound cannot travel in a vacuum (empty space) because there is no medium through which soundwaves can travel upon. This is why if you were to scream in space no sound would be made (well except maybe in your mind! ha!) well anyways, that is also why the Star Wars movies, and some other sci-fi movies that have laser fights in space are innaccurate because no sound would be made from the lasers (also because there is no gravity in empty space the vehicles would move much differently...but that is a whole new concept!) Anyways, so sound needs a medium to travel and so far, no medium has been found.... THAT IS LEFT TO BE DISCOVERED!!!! YEAH!!!!
The emergency sound made by ambulances is produced by a siren.
The emptiness of space is made of nothing -- absolutely nothing. There are various particles, chunks of rock, dust and gases, but they are made of matter. The space itself is just space. Lots and lots of space.
The body is made of bones,fat,cells,blood,and atoms. Because of atoms your body is mostly empty space The body is made of bones,fat,cells,blood,and atoms. Because of atoms your body is mostly empty space The body is made of bones,fat,cells,blood,and atoms. Because of atoms your body is mostly empty space