* Volatile Compounds: Rotten fish releases volatile organic compounds (VOCs), which are molecules that easily evaporate into the air. These compounds include trimethylamine (TMA), a pungent, fishy-smelling gas, and hydrogen sulfide (H2S), which has a characteristic rotten egg odor.
* Concentration and Dispersion: While TMA and H2S are present in smaller amounts in fresh fish, they build up as the fish decomposes. The concentration of these compounds increases significantly, making the odor stronger.
* Diffusion: The VOCs released from the decaying fish diffuse through the air, spreading the odor in all directions. This diffusion process is aided by wind and air currents.
* Olfactory Sensitivity: Humans have a strong sense of smell, particularly for certain compounds like TMA and H2S. Our olfactory receptors are very sensitive to these odors, allowing us to detect them even at low concentrations.
In summary: The combination of volatile compounds released in high concentrations, their diffusion through the air, and our sensitive olfactory system allows us to smell rotten fish from a distance.