So what is smell exactly? I'm sorry if this is really basic but I'm

[Versus]

So what is smell exactly? I'm sorry if this is really basic but I'm quite confused by it. Does our brain produce the smell and it is a bi-product of chemicals? Or is it a wave like sound? Or is it something else? I'm just curious as I know what Photons and Sound is but I've never really heard about smell.

 

[Drakkith]

Your nose has receptors inside it that molecules in the air latch on to when you breathe. Different molecules latch onto different receptors in your nose. These receptors send a signal to your brain and gives you the sense of smell. Different receptors send different signals resulting in many different smells you can perceive.

Note that you must have molecules physically latch onto these receptors to smell. This isn't like a sound wave that simply vibrates your eardrum.

 

[JesseM]

As Drakkith said it's definitely about receptors picking up types of molecules and triggering nerves, but interestingly there's still some controversy about how the receptors actually work, whether they're just responding to the shape of odor molecules or if they also respond to ways different odor molecules vibrate. See this article:

http://news.sciencemag.org/sciencenow/2011/02/do-vibrating-molecules-give-us-o.html