Believe it or not, scientists still don't know how the sense of smell works. But they're looking at how powerful it is - dogs can actually sniff out cancer and many other diseases - and they're trying to figure out how to reverse engineer it. In fact, one MIT scientist may have built a robot nose ... without completely understanding how his invention works. For further reading, sign up for our newsletter here: http://vox.com/unexplainable-newsletter Show transcript and articles at: http://vox.com/unexplainable Article on quantum nose theory: https://bit.ly/3clurfs Email us! unexplainable@vox.com We read every email. Learn more about your ad choices. Visit podcastchoices.com/adchoices