Atom Rubbing Sounds: Wood vs Glass

[Drbazz]

What makes the noise when atoms rub each other. E.g a different noise is made from scratching wood than a noise from scratching glass.

 

[Perillux]

well noise is just an illusion created by your brain. All 'noise' is, is atoms in the air vibrating against each other. These atoms vibrations reach your eardrums which convert them into signals your brain can interpret.

If you were in a vacuum (no air) I could yell at the top of my lungs and you would not hear a thing.

Now, if you are having trouble understanding what makes sounds different, or how we are able to interpret one sound from another and why everything doesn't sound the same...
Then just think of speakers. All speakers are is basically a wall that vibrates. It has a magnet on the speaker and an electromagnet attached to some wires. When an electrical signal passes through the electromagnet it attracts the speaker and then it let's go causing the speaker to "push" the air.
How is it that a speaker then, if all it can do is push, create soooo many different sounds?

It's the patterns of vibrations that are created that give rise to all the different possible sounds.

 

[madmike159]

The mediums the sound in also has an effect. In water every thing sounds different because sound moves at a different speed.

 

[Freyster98]

This brings up the question "If a tree falls in the forest and nobody is there to hear it, does it make a sound?"

no eardrums=nothing to interpret the compression wave created=no sound

 

[madmike159]

I never thought of that. Logically it would, but if you define sound as how your brain interpretaties wave compressions then there is no sound... still compressions though.

 

[atyy]

Sound is just mechanical vibrations. So in a sense, "touch" is "very low frequency sound" - the lowest frequency vibrations in a rock concert or organ recital are felt with your body. Scratching wood and glass produces different sounds because you cannot scratch them in the same way.