“Odorless” and “tasteless”

If you read anything science related you’ll see the terms odorless and tasteless used to describe certain liquids or gases. It just occurred to me the reason many things are odorless or tasteless to humans is that we don’t need to smell or taste them.

If we desperately needed to find nitrogen gas it’s a safe bet we would have evolved an olfactory system to detect it. As it is the Earth’s atmosphere is mostly made of nitrogen, so it’s probably best that we can’t smell it. Else we’d be able to smell almost nothing else. If water had a strong taste it would drown out every other flavor, pardon the pun. We only need to smell and taste things that are unusual, life-sustaining, dangerous, or difficult to identify with our other senses.

4 Comments to “Odorless” and “tasteless”

Paul Simer
December 9, 2008

You say we evolved to smell only the really important things, I say we were designed that way.

Either way, though, it’s pretty nifty, and I’m glad it is the way it is.

BobG
December 9, 2008

“It just occurred to me the reason many things are odorless or tasteless to humans is that we don’t need to smell or taste them.”

There might also be another reason. Air and water, which are essential for life, are tasteless in order that we are able to taste any impurities in them that could be detrimental to health. Bad tasting water means Don’t drink!, and bad smelling air means you need to leave the area.
Just my opinion.

Les Jones
December 9, 2008

Bob: Agreed. I don’t think we’re saying different things.

Mikee
December 11, 2008

There is also a simpler, non evolutionary explanation: Nitrogen, N2 in the atmosphere, is odorless because it does not react at all readily with anything else, and is essentially inert. Sure, that O2 reacts like a mutha, but it does that reacting primarily in the red blood cells, not in the taste buds.

Water - boring. Same thing.

Smells and tastes occur when there are interesting chemical bits hanging off the molecule - like ketones, or esters, or carboxylic acids. These make the molecules both more reactive than N2 and indicate specific properties of the molecules themselves.

Chemistry is the simple explanation for a lot of complex evolutionary (or Intelligent Design) questions. And when Chemistry won’t work, baffle them with Physics.