[Script Info]
Title: 
[Events]
Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text
Dialogue: 0,0:00:06.98,0:00:10.68,Default,,0000,0000,0000,,As the story goes, \Nthe legendary marksman William Tell
Dialogue: 0,0:00:10.68,0:00:15.43,Default,,0000,0000,0000,,was forced into a cruel challenge\Nby a corrupt lord.
Dialogue: 0,0:00:15.43,0:00:17.65,Default,,0000,0000,0000,,William's son was to be executed\N
Dialogue: 0,0:00:17.65,0:00:21.96,Default,,0000,0000,0000,,unless William could shoot \Nan apple off his head.
Dialogue: 0,0:00:21.96,0:00:26.93,Default,,0000,0000,0000,,William succeeded, but let's imagine\Ntwo variations on the tale.
Dialogue: 0,0:00:26.93,0:00:28.57,Default,,0000,0000,0000,,In the first variation,
Dialogue: 0,0:00:28.57,0:00:33.07,Default,,0000,0000,0000,,the lord hires a bandit to steal\NWilliam's trusty crossbow,
Dialogue: 0,0:00:33.07,0:00:37.34,Default,,0000,0000,0000,,so he is forced to borrow\Nan inferior one from a peasant.
Dialogue: 0,0:00:37.34,0:00:41.36,Default,,0000,0000,0000,,However, the borrowed crossbow\Nisn't adjusted perfectly,
Dialogue: 0,0:00:41.36,0:00:43.45,Default,,0000,0000,0000,,and William finds that his practice shots
Dialogue: 0,0:00:43.45,0:00:47.75,Default,,0000,0000,0000,,cluster in a tight spread \Nbeneath the bullseye.
Dialogue: 0,0:00:47.75,0:00:52.61,Default,,0000,0000,0000,,Fortunately, he has time \Nto correct for it before it's too late.
Dialogue: 0,0:00:52.61,0:00:54.37,Default,,0000,0000,0000,,Variation two:
Dialogue: 0,0:00:54.37,0:00:58.80,Default,,0000,0000,0000,,William begins to doubt his skills\Nin the long hours before the challenge
Dialogue: 0,0:00:58.80,0:01:01.50,Default,,0000,0000,0000,,and his hand develops a tremor.
Dialogue: 0,0:01:01.50,0:01:04.62,Default,,0000,0000,0000,,His practice shots still cluster\Naround the apple
Dialogue: 0,0:01:04.62,0:01:06.68,Default,,0000,0000,0000,,but in a random pattern.
Dialogue: 0,0:01:06.68,0:01:08.73,Default,,0000,0000,0000,,Occasionally, he hits the apple,
Dialogue: 0,0:01:08.73,0:01:12.62,Default,,0000,0000,0000,,but with the wobble,\Nthere is no guarantee of a bullseye.
Dialogue: 0,0:01:12.62,0:01:14.51,Default,,0000,0000,0000,,He must settle his nervous hand\N
Dialogue: 0,0:01:14.51,0:01:19.20,Default,,0000,0000,0000,,and restore the certainty in his aim\Nto save his son.
Dialogue: 0,0:01:19.20,0:01:23.64,Default,,0000,0000,0000,,At the heart of these variations\Nare two terms often used interchangeably:
Dialogue: 0,0:01:23.64,0:01:26.37,Default,,0000,0000,0000,,accuracy and precision.
Dialogue: 0,0:01:26.37,0:01:27.94,Default,,0000,0000,0000,,The distinction between the two
Dialogue: 0,0:01:27.94,0:01:31.52,Default,,0000,0000,0000,,is actually critical \Nfor many scientific endeavours.
Dialogue: 0,0:01:31.52,0:01:35.50,Default,,0000,0000,0000,,Accuracy involves how close you come\Nto the correct result.
Dialogue: 0,0:01:35.50,0:01:39.64,Default,,0000,0000,0000,,Your accuracy improves with tools\Nthat are calibrated correctly
Dialogue: 0,0:01:39.64,0:01:42.01,Default,,0000,0000,0000,,and that you're well-trained on.
Dialogue: 0,0:01:42.01,0:01:43.71,Default,,0000,0000,0000,,Precision, on the other hand,
Dialogue: 0,0:01:43.71,0:01:48.21,Default,,0000,0000,0000,,is how consistently you can get \Nthat result using the same method.
Dialogue: 0,0:01:48.21,0:01:52.03,Default,,0000,0000,0000,,Your precision improves \Nwith more finely incremented tools
Dialogue: 0,0:01:52.03,0:01:54.51,Default,,0000,0000,0000,,that require less estimation.
Dialogue: 0,0:01:54.51,0:01:59.33,Default,,0000,0000,0000,,The story of the stolen crossbow\Nwas one of precision without accuracy.
Dialogue: 0,0:01:59.33,0:02:02.89,Default,,0000,0000,0000,,William got the same wrong result\Neach time he fired.
Dialogue: 0,0:02:02.89,0:02:08.06,Default,,0000,0000,0000,,The variation with the shaky hand\Nwas one of accuracy without precision.
Dialogue: 0,0:02:08.06,0:02:11.24,Default,,0000,0000,0000,,William's bolts clustered \Naround the correct result,
Dialogue: 0,0:02:11.24,0:02:15.45,Default,,0000,0000,0000,,but without certainty of a bullseye\Nfor any given shot.
Dialogue: 0,0:02:15.45,0:02:18.18,Default,,0000,0000,0000,,You can probably get away \Nwith low accuracy
Dialogue: 0,0:02:18.18,0:02:21.08,Default,,0000,0000,0000,,or low precision in everyday tasks.
Dialogue: 0,0:02:21.08,0:02:24.58,Default,,0000,0000,0000,,But engineers and researchers\Noften require accuracy
Dialogue: 0,0:02:24.58,0:02:30.26,Default,,0000,0000,0000,,on microscopic levels with \Na high certainty of being right every time.
Dialogue: 0,0:02:30.26,0:02:32.77,Default,,0000,0000,0000,,Factories and labs increase precision
Dialogue: 0,0:02:32.77,0:02:36.33,Default,,0000,0000,0000,,through better equipment \Nand more detailed procedures.
Dialogue: 0,0:02:36.33,0:02:39.17,Default,,0000,0000,0000,,These improvements can be expensive,\Nso managers must decide
Dialogue: 0,0:02:39.17,0:02:44.01,Default,,0000,0000,0000,,what the acceptable uncertainty \Nfor each project is.
Dialogue: 0,0:02:44.01,0:02:46.10,Default,,0000,0000,0000,,However, investments in precision
Dialogue: 0,0:02:46.10,0:02:49.32,Default,,0000,0000,0000,,can take us beyond \Nwhat was previously possible,
Dialogue: 0,0:02:49.32,0:02:51.53,Default,,0000,0000,0000,,even as far as Mars.
Dialogue: 0,0:02:51.53,0:02:54.55,Default,,0000,0000,0000,,It may surprise you that NASA\Ndoes not know exactly where
Dialogue: 0,0:02:54.55,0:02:58.54,Default,,0000,0000,0000,,their probes are going to touch down\Non another planet.
Dialogue: 0,0:02:58.54,0:03:02.48,Default,,0000,0000,0000,,Predicting where they will land\Nrequires extensive calculations
Dialogue: 0,0:03:02.48,0:03:06.25,Default,,0000,0000,0000,,fed by measurements \Nthat don't always have a precise answer.
Dialogue: 0,0:03:06.25,0:03:11.25,Default,,0000,0000,0000,,How does the Martian atmosphere's density\Nchange at different elevations?
Dialogue: 0,0:03:11.25,0:03:14.05,Default,,0000,0000,0000,,What angle will the probe\Nhit the atmosphere at?
Dialogue: 0,0:03:14.05,0:03:17.23,Default,,0000,0000,0000,,What will be the speed \Nof the probe upon entry?
Dialogue: 0,0:03:17.23,0:03:20.76,Default,,0000,0000,0000,,Computer simulators run thousands\Nof different landing scenarios,
Dialogue: 0,0:03:20.76,0:03:24.39,Default,,0000,0000,0000,,mixing and matching values\Nfor all of the variables.
Dialogue: 0,0:03:24.39,0:03:26.06,Default,,0000,0000,0000,,Weighing all the possibilities,
Dialogue: 0,0:03:26.06,0:03:29.44,Default,,0000,0000,0000,,the computer spits out \Nthe potential area of impact
Dialogue: 0,0:03:29.44,0:03:32.84,Default,,0000,0000,0000,,in the form of a landing ellipse.
Dialogue: 0,0:03:32.84,0:03:37.53,Default,,0000,0000,0000,,In 1976, the landing ellipse\Nfor the Mars Viking Lander
Dialogue: 0,0:03:37.53,0:03:44.34,Default,,0000,0000,0000,,was 62 x 174 miles,\Nnearly the area of New Jersey.
Dialogue: 0,0:03:44.34,0:03:45.92,Default,,0000,0000,0000,,With such a limitation,
Dialogue: 0,0:03:45.92,0:03:50.61,Default,,0000,0000,0000,,NASA had to ignore many interesting\Nbut risky landing areas.
Dialogue: 0,0:03:50.61,0:03:53.98,Default,,0000,0000,0000,,Since then, new information \Nabout the Martian atmosphere,
Dialogue: 0,0:03:53.98,0:03:56.45,Default,,0000,0000,0000,,improved spacecraft technology,
Dialogue: 0,0:03:56.45,0:04:02.33,Default,,0000,0000,0000,,and more powerful computer simulations\Nhave drastically reduced uncertainty.
Dialogue: 0,0:04:02.33,0:04:06.19,Default,,0000,0000,0000,,In 2012, the landing ellipse \Nfor the Curiosity Lander
Dialogue: 0,0:04:06.19,0:04:10.05,Default,,0000,0000,0000,,was only 4 miles wide by 12 miles long,
Dialogue: 0,0:04:10.05,0:04:14.25,Default,,0000,0000,0000,,an area more than 200 times \Nsmaller than Viking's.
Dialogue: 0,0:04:14.25,0:04:18.49,Default,,0000,0000,0000,,This allowed NASA to target \Na specific spot in Gale Crater,
Dialogue: 0,0:04:18.49,0:04:23.34,Default,,0000,0000,0000,,a previously un-landable area \Nof high scientific interest.
Dialogue: 0,0:04:23.34,0:04:26.20,Default,,0000,0000,0000,,While we ultimately strive for accuracy,
Dialogue: 0,0:04:26.20,0:04:30.48,Default,,0000,0000,0000,,precision reflects our certainty\Nof reliably achieving it.
Dialogue: 0,0:04:30.48,0:04:32.50,Default,,0000,0000,0000,,With these two principles in mind,
Dialogue: 0,0:04:32.50,0:04:34.20,Default,,0000,0000,0000,,we can shoot for the stars
Dialogue: 0,0:04:34.20,0:04:37.12,Default,,0000,0000,0000,,and be confident \Nof hitting them every time.