Saturday, March 22, 2014

Humans Can Distinguish One Trillion Odors

Scientists have determined that humans are capable of distinguishing at least one trillion different odors.  Since the 1920's, people have believed that we could only smell about 10,000 different smells, but this was never tested.  So, fueled by curiosity, scientists from Howard Hughes Medical Institute began to test this theory.  They used 128 different odorant molecules to create mixtures.  After the mixtures were created, the scientists would let the subject smell three odors, two of them being the same.  The subject was then tollied on how many times they were correctly able identify the different odor.  In doing this, they were able to determine that a human can distinguish between at least one trillion different odors.

Themes of the Nature of Science
  • Role of skepticism- The scientists did not believe what was said to be true, so they tested it themselves.
  • Role of motivation and curiosity- The scientists were curious about how many odors a human could distinguish, so they tested it.
http://www.sciencedaily.com/releases/2014/03/140320140738.htm

4 comments:

  1. Wow, so how precise can we really smell? I mean can we smell the difference between two amounts of an odor, like more butter and less butter or what about the difference between a synthetic smell and a real smell?

    http://news.nationalgeographic.com/news/2014/03/140321-nose-human-smell-odors-trillion-science/

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  2. It is really suprising that the previous number of 10,000 was so far off from what it actually is. Our nose like our tongue has different groups to classify each type of smell. The four smell groups that were thought to be detected by our nose are ragrant, acid, burnt and caprylic. This experiment proved that there ar way more then these four groups and suggests that this number is actually tons higher. Average things like a cup of coffee have 400+ different oder molecules. Proving that our noses have a much higher range then we previously thought.

    -Tyler Welder
    http://www.washingtonpost.com/national/health-science/human-nose-can-detect-at-least-1-trillion-odors--far-more-than-thought-says-study-of-smell/2014/03/20/ffb8644a-af95-11e3-95e8-39bef8e9a48b_story.html

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  3. I think that this is very interesting, and also quite amazing. I think that it is amazing that we are able to distinguish between so many different odors. I thought it was very surprising that they used to think that it was ten thousand different smells but it actually turned out that it was so much more, and that they were way off. How many different types of odors can we smell? How many odors are there? Are there any odors that we cannot smell? I think that it is truly incredible that our nose can distinguish between so many different odors.

    Link:
    http://www.csmonitor.com/Science/2014/0320/Human-nose-can-sniff-out-one-trillion-distinct-odors-say-scientists

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  4. I thought this was very fascinating because I have never thought of my sense of smell being that sensitive. Scientists estimate that we can discriminate between several million colors and half a million different sounds, but these numbers don't compare to the one trillion scents our nose can pick up.
    My link: http://www.cnn.com/2014/03/21/health/time-nose-scents/

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