The human nose can detect at least 1 trillion different smells
For decades scientists thought humans could only detect about 10,000 distinct odours. A 2014 study in Science revised that to at least 1 trillion — and possibly far more. The olfactory system uses approximately 400 different types of smell receptors that combine in different patterns to produce an almost limitless range of perceived odours. Dogs have about 300 million olfactory receptor cells compared to humans' 6 million, yet humans can still distinguish an extraordinary range of scents.
We consistently underestimate human smell. Compared to vision and hearing, we treat it as a minor sense — yet the numbers reveal it may be the most discriminating of all our senses in raw detection capacity.
“The human nose can detect at least 1 trillion different smells. Scientists once thought the limit was 10,000 — they were off by a factor of 100 million. 👃 #OddlyHuman”