WEBVTT 00:00:07.420 --> 00:00:10.429 What does it mean to be one in a million? 00:00:10.429 --> 00:00:12.779 Not in the greeting card sense, 00:00:12.779 --> 00:00:14.608 in the scientific sense, 00:00:14.608 --> 00:00:17.990 where one part per million is a unit of measurement. 00:00:17.990 --> 00:00:21.600 Parts per million counts the number of units of one substance 00:00:21.600 --> 00:00:24.260 per one million units of another. 00:00:24.260 --> 00:00:28.420 It can measure concentrations when a small amount makes a big difference. 00:00:28.420 --> 00:00:33.849 For example, a concentration of just 35 ppm of carbon monoxide in the air 00:00:33.849 --> 00:00:35.890 is poisonous to us. 00:00:35.890 --> 00:00:38.560 We encounter measurements like this pretty often, 00:00:38.560 --> 00:00:41.610 but because it's hard to conceptualize really large numbers, 00:00:41.610 --> 00:00:46.839 it's difficult to wrap our brain around what one part per million really means. 00:00:46.839 --> 00:00:50.050 So here are nine helpful ways to visualize it. 00:00:50.050 --> 00:00:55.482 If you had 11,363 pianos-worth of piano keys, 00:00:55.482 --> 00:01:00.611 one of those keys would be about one part per million. 00:01:00.611 --> 00:01:06.090 So would a single granule of sugar among 273 sugar cubes, 00:01:06.090 --> 00:01:10.441 one second in eleven and a half days, 00:01:10.441 --> 00:01:12.440 or four dots in the painting, 00:01:12.440 --> 00:01:17.322 "A Sunday Afternoon on the Island of La Grande Jatte." 00:01:17.322 --> 00:01:21.111 Your bath tub's capacity is about 60 gallons, 00:01:21.111 --> 00:01:25.021 so seven drops of ink would be one part per million. 00:01:25.021 --> 00:01:32.041 The English version of the Harry Potter series has 1,084,170 words, 00:01:32.041 --> 00:01:37.102 which makes "hippogriff" on page 221 of "The Prisoner of Azkaban" 00:01:37.102 --> 00:01:40.614 a little less than one part per million. 00:01:40.614 --> 00:01:44.832 A million kernels of corn is about 1,250 ears, 00:01:44.832 --> 00:01:49.393 so one kernel in that truckload would be one part per million. 00:01:49.393 --> 00:01:52.583 There are 10 million bricks in the Empire State Building, 00:01:52.583 --> 00:01:56.713 so one part per million would be a pile of just ten. 00:01:56.713 --> 00:02:01.803 And finally, 100 people worked together to animate this video. 00:02:01.803 --> 00:02:06.393 Collectively, they have about 10 million hairs on their heads. 00:02:06.393 --> 00:02:10.873 Pluck ten of those hairs, and you have one in a million.