If a rotten fish was in a vacuum, would it still be smelly?

Question

If there was no air to circulate the pong, and no-one to smell it, would a stink still be emitted?

It has been put there AFTER the bacteria have got to work on it.

Answer 1

The question breaks into two parts.

'If there was no air to circulate the pong' - even in completely still air the molecules which we detect as smell still diffuse through a room (or other sealed container). So the carrier of smell (so to speak) doesn't require air movement to spread.

Although, as someone else has mentioned, the vacuum would kill some bacteria (but probably not all), since the bacteria have already been at work on the fish, the volatile parts which dissipate and are perceived by us as smell would already have been partially created. They would dissipate into a vacuum at a greater rate than in air - nothing to inhibit their physical tendency to expand. (I'm assuming that all this is being done at something like room temperature - if we were talking about the vacuum of interstellar space, the fish would be deep frozen and much less volatile).

I guess strictly speaking if the fish was in a closed container it would never be in a vacuum because of the volatile parts evaporating from the fish and thus creating a very thin, smelly atmosphere.

As for the 'no-one to smell it' - this is a variant on does a falling tree in an unihabited forest make a sound, but one with an easier resolution. Unlike sounds, which simply pass away as their energy is absorbed, smells depend on the existence of molecules and molecules are much more enduring than sounds. So one could test whether the fish had a smell by closing it off from the rest of the sealed vacuum, then allowing purified air (ie air that is guaranteed not to smell like rotting fish) into the part of the container which is no longer open to the fish. When it has reached a pressure safe enough to stick your nose in, you could find out if there was a pong. (Yes there would be).

Answer 2

Depends on the size your vacuum occupies. It it is really large the molecules emitted by the fish will soon be so diluted that they are probably below the smelling capability of most inhabitants of this planet. Unless there happens to be a lifeform which can perceive single molecules of the particular smell. And the vacuum will not be strictly a vacuum any more (by definition there is no air in a vacuum!), but the difference will not really be measurable.
If your vacuum is kind of small, it won't be a vacuum any more after you put your rotting fish any more. It will be more or less rotted fish stink, whatever molecules this is composed out of.

the rest of your question depends if you look at it from a physical or perceptual viewpoint.

Answer 3

Let's tackle this from first principles. Fish would go rotten in the absence of air. You have to consider the inherent chemical breakdown of the fish and the action of bacteria that do not require oxygen. So, whilst the chemical changes might not be the same as those that would occur if oxygen was present, the decomposition of the fish would probably be enough to generate 'smelly' molecules. That's the biology/chemistry bit, now to physics. Once produced the 'smelly' molecules would certainly have some kinetic energy and be moving. By Newton's laws of motion the 'smelly' molecules would continue to travel in a straight line with the same speed (i.e velocity) until acted upon by an external force. Now back to biology/chemistry, if somebody was in the path of the 'smelly' molecules and these molecules were free to impinge on the olfactory senses of a human then that person would smell them. QED

Answer 4

Yes, the volitile chemicals would still evaporate from the fish.

It's these volitile chemicals that cause the stink.

The vacuum would soon be a partial vacuum as the volitiles formed (smelly) gases.

In fact the volitile chemicals would be encouraged to evaporate as there would be no air pressure to resist. Same way water boils more easily at a lower pressure.

Good question, I like your thinking.

Answer 5

Stink/smelly are subjective terms and, as we would die if we entered the vacuum to assess the smell, we could never find out the answer.

Answer 6

If it was in a total vacuum it would pretty much instantly freeze at a tiny fraction above 0 degrees kelvin - so no molecular processes would be running and hence no stink.

Answer 7

Yes it does I vacuumed up a fish finger (child dropped after lunch) and every time my vacuum was switched on I could smell fish. I have now replaced my vacuum and I use vacuum fresheners.

Answer 8

It wouldn't rot because the bacteria that break it down and cause it to smell would not survive.

Answer 9

Ah, the old "vacuum" question?
No matter what the question is the answer is always the same!!

Answer 10

I think theres a dead mouse in my vacuum - smells like it anyway.