[Script Info]
Title: 
[Events]
Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text
Dialogue: 0,0:00:15.04,0:00:17.64,Default,,0000,0000,0000,,Take a series of still, sequential images.
Dialogue: 0,0:00:18.36,0:00:19.80,Default,,0000,0000,0000,,Let's look at them one by one.
Dialogue: 0,0:00:23.76,0:00:24.96,Default,,0000,0000,0000,,Faster.
Dialogue: 0,0:00:28.44,0:00:30.26,Default,,0000,0000,0000,,Now, let's remove the gaps,
Dialogue: 0,0:00:30.28,0:00:31.48,Default,,0000,0000,0000,,go faster still.
Dialogue: 0,0:00:32.92,0:00:34.44,Default,,0000,0000,0000,,Wait for it ...
Dialogue: 0,0:00:36.16,0:00:37.58,Default,,0000,0000,0000,,Bam!
Dialogue: 0,0:00:37.60,0:00:38.80,Default,,0000,0000,0000,,Motion!
Dialogue: 0,0:00:39.52,0:00:40.98,Default,,0000,0000,0000,,Why is that?
Dialogue: 0,0:00:41.00,0:00:44.54,Default,,0000,0000,0000,,Intellectually, we know we're just looking\Nat a series of still images,
Dialogue: 0,0:00:44.56,0:00:46.50,Default,,0000,0000,0000,,but when we see them change fast enough,
Dialogue: 0,0:00:46.52,0:00:50.10,Default,,0000,0000,0000,,they produce the optical illusion\Nof appearing as a single, persistent image
Dialogue: 0,0:00:50.12,0:00:52.36,Default,,0000,0000,0000,,that's gradually changing\Nform and position.
Dialogue: 0,0:00:53.00,0:00:56.46,Default,,0000,0000,0000,,This effect is the basis\Nfor all motion picture technology,
Dialogue: 0,0:00:56.48,0:00:58.18,Default,,0000,0000,0000,,from our LED screens of today
Dialogue: 0,0:00:58.20,0:01:01.06,Default,,0000,0000,0000,,to their 20th-century\Ncathode ray forebearers,
Dialogue: 0,0:01:01.08,0:01:04.22,Default,,0000,0000,0000,,from cinematic film projection\Nto the novelty toy,
Dialogue: 0,0:01:04.24,0:01:07.10,Default,,0000,0000,0000,,even, it's been suggested,\Nall the way back to the Stone Age
Dialogue: 0,0:01:07.12,0:01:09.12,Default,,0000,0000,0000,,when humans began painting on cave walls.
Dialogue: 0,0:01:09.76,0:01:13.02,Default,,0000,0000,0000,,This phenomenon of perceiving\Napparent motion in successive images
Dialogue: 0,0:01:13.04,0:01:15.42,Default,,0000,0000,0000,,is due to a characteristic\Nof human perception
Dialogue: 0,0:01:15.44,0:01:18.58,Default,,0000,0000,0000,,historically referred\Nto as "persistence of vision."
Dialogue: 0,0:01:18.60,0:01:19.82,Default,,0000,0000,0000,,The term is attributed
Dialogue: 0,0:01:19.84,0:01:22.82,Default,,0000,0000,0000,,to the English-Swiss physicist\NPeter Mark Roget,
Dialogue: 0,0:01:22.84,0:01:24.46,Default,,0000,0000,0000,,who, in the early 19th century,
Dialogue: 0,0:01:24.48,0:01:27.38,Default,,0000,0000,0000,,used it to describe\Na particular defect of the eye
Dialogue: 0,0:01:27.40,0:01:28.98,Default,,0000,0000,0000,,that resulted in a moving object
Dialogue: 0,0:01:29.00,0:01:31.68,Default,,0000,0000,0000,,appearing to be still\Nwhen it reached a certain speed.
Dialogue: 0,0:01:32.40,0:01:35.70,Default,,0000,0000,0000,,Not long after, the term\Nwas applied to describe the opposite,
Dialogue: 0,0:01:35.72,0:01:37.74,Default,,0000,0000,0000,,the apparent motion of still images,
Dialogue: 0,0:01:37.76,0:01:41.52,Default,,0000,0000,0000,,by Belgian physicist Joseph Plateau,\Ninventor of the phenakistoscope.
Dialogue: 0,0:01:42.28,0:01:46.46,Default,,0000,0000,0000,,He defined persistence of vision\Nas the result of successive afterimages,
Dialogue: 0,0:01:46.48,0:01:49.22,Default,,0000,0000,0000,,which were retained\Nand then combined in the retina,
Dialogue: 0,0:01:49.24,0:01:52.94,Default,,0000,0000,0000,,making us believe that what we were seeing\Nis a single object in motion.
Dialogue: 0,0:01:52.96,0:01:55.86,Default,,0000,0000,0000,,This explanation was widely accepted\Nin the decades to follow
Dialogue: 0,0:01:55.88,0:01:57.98,Default,,0000,0000,0000,,and up through the turn\Nof the 20th century,
Dialogue: 0,0:01:58.00,0:02:01.30,Default,,0000,0000,0000,,when some began to question\Nwhat was physiologically going on.
Dialogue: 0,0:02:01.32,0:02:04.34,Default,,0000,0000,0000,,In 1912, German psychologist\NMax Wertheimer
Dialogue: 0,0:02:04.36,0:02:06.98,Default,,0000,0000,0000,,outlined the basic primary stages\Nof apparent motion
Dialogue: 0,0:02:07.00,0:02:09.26,Default,,0000,0000,0000,,using simple optical illusions.
Dialogue: 0,0:02:09.28,0:02:11.10,Default,,0000,0000,0000,,These experiments led him to conclude
Dialogue: 0,0:02:11.12,0:02:14.92,Default,,0000,0000,0000,,the phenomenon was due to processes\Nwhich lie behind the retina.
Dialogue: 0,0:02:15.64,0:02:17.62,Default,,0000,0000,0000,,In 1915, Hugo Münsterberg,
Dialogue: 0,0:02:17.64,0:02:20.06,Default,,0000,0000,0000,,a German-American pioneer\Nin applied psychology,
Dialogue: 0,0:02:20.08,0:02:22.94,Default,,0000,0000,0000,,also suggested that the apparent motion\Nof successive images
Dialogue: 0,0:02:22.96,0:02:25.50,Default,,0000,0000,0000,,is not due to their being\Nretained in the eye,
Dialogue: 0,0:02:25.52,0:02:28.44,Default,,0000,0000,0000,,but is superadded\Nby the action of the mind.
Dialogue: 0,0:02:29.52,0:02:32.10,Default,,0000,0000,0000,,In the century to follow,\Nexperiments by physiologists
Dialogue: 0,0:02:32.12,0:02:34.50,Default,,0000,0000,0000,,have pretty much confirmed\Ntheir conclusions.
Dialogue: 0,0:02:34.52,0:02:36.86,Default,,0000,0000,0000,,As it relates to the illusion\Nof motion pictures,
Dialogue: 0,0:02:36.88,0:02:39.58,Default,,0000,0000,0000,,persistence of vision\Nhas less to do with vision itself
Dialogue: 0,0:02:39.60,0:02:41.86,Default,,0000,0000,0000,,than how it's interpreted in the brain.
Dialogue: 0,0:02:41.88,0:02:45.42,Default,,0000,0000,0000,,Research has shown that different aspects\Nof what the eye sees,
Dialogue: 0,0:02:45.44,0:02:48.70,Default,,0000,0000,0000,,like form, color, depth, and motion,
Dialogue: 0,0:02:48.72,0:02:51.30,Default,,0000,0000,0000,,are transmitted to different areas\Nof the visual cortex
Dialogue: 0,0:02:51.32,0:02:53.22,Default,,0000,0000,0000,,via different pathways from the retina.
Dialogue: 0,0:02:53.24,0:02:54.74,Default,,0000,0000,0000,,It's the continuous interaction
Dialogue: 0,0:02:54.76,0:02:56.86,Default,,0000,0000,0000,,of various computations\Nin the visual cortex
Dialogue: 0,0:02:56.88,0:02:59.14,Default,,0000,0000,0000,,that stitch those different\Naspects together
Dialogue: 0,0:02:59.16,0:03:01.06,Default,,0000,0000,0000,,and culminate in the perception.
Dialogue: 0,0:03:01.08,0:03:02.94,Default,,0000,0000,0000,,Our brains are constantly working,
Dialogue: 0,0:03:02.96,0:03:05.70,Default,,0000,0000,0000,,synchronizing what we see,\Nhear, smell, and touch
Dialogue: 0,0:03:05.72,0:03:07.02,Default,,0000,0000,0000,,into meaningful experience
Dialogue: 0,0:03:07.04,0:03:09.62,Default,,0000,0000,0000,,in the moment-to-moment\Nflow of the present.
Dialogue: 0,0:03:09.64,0:03:12.82,Default,,0000,0000,0000,,So, in order to create the illusion\Nof motion in successive images,
Dialogue: 0,0:03:12.84,0:03:14.86,Default,,0000,0000,0000,,we need to get the timing of our intervals
Dialogue: 0,0:03:14.88,0:03:17.72,Default,,0000,0000,0000,,close to the speed at which our brains\Nprocess the present.
Dialogue: 0,0:03:18.80,0:03:21.94,Default,,0000,0000,0000,,So, how fast is the present\Nhappening according to our brains?
Dialogue: 0,0:03:21.96,0:03:23.18,Default,,0000,0000,0000,,Well, we can get an idea
Dialogue: 0,0:03:23.20,0:03:25.66,Default,,0000,0000,0000,,by measuring how fast\Nthe images need to be changing
Dialogue: 0,0:03:25.68,0:03:26.90,Default,,0000,0000,0000,,for the illusion to work.
Dialogue: 0,0:03:26.92,0:03:29.90,Default,,0000,0000,0000,,Let's see if we can figure it out\Nby repeating our experiment.
Dialogue: 0,0:03:29.92,0:03:33.98,Default,,0000,0000,0000,,Here's the sequence presented\Nat a rate of one frame per two seconds
Dialogue: 0,0:03:34.00,0:03:36.42,Default,,0000,0000,0000,,with one second of black in between.
Dialogue: 0,0:03:36.44,0:03:37.66,Default,,0000,0000,0000,,At this rate of change,
Dialogue: 0,0:03:37.68,0:03:39.78,Default,,0000,0000,0000,,with the blank space\Nseparating the images,
Dialogue: 0,0:03:39.80,0:03:41.94,Default,,0000,0000,0000,,there's no real motion perceptible.
Dialogue: 0,0:03:41.96,0:03:44.26,Default,,0000,0000,0000,,As we lessen the duration of blank space,
Dialogue: 0,0:03:44.28,0:03:47.02,Default,,0000,0000,0000,,a slight change in position\Nbecomes more apparent,
Dialogue: 0,0:03:47.04,0:03:49.50,Default,,0000,0000,0000,,and you start to get an inkling\Nof a sense of motion
Dialogue: 0,0:03:49.52,0:03:50.92,Default,,0000,0000,0000,,between the disparate frames.
Dialogue: 0,0:03:51.48,0:03:52.72,Default,,0000,0000,0000,,One frame per second.
Dialogue: 0,0:03:55.52,0:03:56.80,Default,,0000,0000,0000,,Two frames per second.
Dialogue: 0,0:03:59.48,0:04:00.92,Default,,0000,0000,0000,,Four frames per second.
Dialogue: 0,0:04:02.44,0:04:04.62,Default,,0000,0000,0000,,Now we're starting\Nto get a feeling of motion,
Dialogue: 0,0:04:04.64,0:04:06.58,Default,,0000,0000,0000,,but it's really not very smooth.
Dialogue: 0,0:04:06.60,0:04:09.82,Default,,0000,0000,0000,,We're still aware of the fact\Nthat we're looking at separate images.
Dialogue: 0,0:04:09.84,0:04:11.76,Default,,0000,0000,0000,,Let's speed up. Eight frames per second.
Dialogue: 0,0:04:14.20,0:04:15.68,Default,,0000,0000,0000,,12 frames per second.
Dialogue: 0,0:04:16.56,0:04:18.24,Default,,0000,0000,0000,,It looks like we're about there.
Dialogue: 0,0:04:21.44,0:04:24.94,Default,,0000,0000,0000,,At 24 frames per second,\Nthe motion looks even smoother.
Dialogue: 0,0:04:24.96,0:04:26.76,Default,,0000,0000,0000,,This is standard full speed.
Dialogue: 0,0:04:28.12,0:04:30.82,Default,,0000,0000,0000,,So, the point at which we lose\Nawareness of the intervals
Dialogue: 0,0:04:30.84,0:04:32.42,Default,,0000,0000,0000,,and begin to see apparent motion
Dialogue: 0,0:04:32.44,0:04:35.12,Default,,0000,0000,0000,,seems to kick in at around\Neight to 12 frames per second.
Dialogue: 0,0:04:36.04,0:04:38.78,Default,,0000,0000,0000,,This is in the neighborhood\Nof what science has determined
Dialogue: 0,0:04:38.80,0:04:40.90,Default,,0000,0000,0000,,to be the general threshold\Nof our awareness
Dialogue: 0,0:04:40.92,0:04:42.22,Default,,0000,0000,0000,,of seeing separate images.
Dialogue: 0,0:04:42.24,0:04:44.66,Default,,0000,0000,0000,,Generally speaking,\Nwe being to lose that awareness
Dialogue: 0,0:04:44.68,0:04:47.06,Default,,0000,0000,0000,,at intervals of around\N100 milliseconds per image,
Dialogue: 0,0:04:47.08,0:04:50.22,Default,,0000,0000,0000,,which is equal to a frame rate\Nof around ten frames per second.
Dialogue: 0,0:04:50.24,0:04:51.62,Default,,0000,0000,0000,,As the frame rate increases,
Dialogue: 0,0:04:51.64,0:04:53.78,Default,,0000,0000,0000,,we lose awareness\Nof the intervals completely
Dialogue: 0,0:04:53.80,0:04:56.72,Default,,0000,0000,0000,,and are all the more convinced\Nof the reality of the illusion.