WEBVTT 1 00:00:00.200 --> 00:00:07.126 In this series, Being means the system's state: how it is now. That state is what we are 2 00:00:07.126 --> 00:00:08.360 trying to measure. 3 00:00:08.360 --> 00:00:13.610 A measurement gives us a reading about the state. Different states can produce the same 4 00:00:13.610 --> 00:00:19.293 reading. That matters for Becoming: uncertainty about the state can leave us unsure how 5 00:00:19.293 --> 00:00:21.240 it could change after an action. 6 00:00:21.240 --> 00:00:26.980 Watch what one reading establishes, what stays unresolved, and how the actual state 7 00:00:26.980 --> 00:00:28.360 differs from our estimate. 8 00:00:29.680 --> 00:00:31.760 A small device has a lamp. 9 00:00:31.760 --> 00:00:34.848 A reader reports zero, meaning off. 10 00:00:34.848 --> 00:00:38.187 Does that reading tell us the whole state of the device? 11 00:00:38.187 --> 00:00:45.333 By the end, you should be able to separate what the device is doing from what its observer is justified in writing down. 12 00:00:45.333 --> 00:00:55.200 We will build the explanation in three steps: specify the possibilities, compare them with the reading, and check what a notebook edit actually changes. 13 00:00:55.990 --> 00:00:59.030 For this example, the device is our system. 14 00:00:59.030 --> 00:01:03.090 The reader and its notebook sit outside that chosen boundary. 15 00:01:03.090 --> 00:01:06.010 The boundary marks what our model describes. 16 00:01:06.010 --> 00:01:12.363 Drawing a larger boundary could include the reader too, but it would not physically change the device. 17 00:01:12.363 --> 00:01:14.614 We return to the device alone. 18 00:01:14.614 --> 00:01:17.537 Here the reader simply receives a lamp reading; 19 00:01:17.537 --> 00:01:20.710 we are not assuming awareness or an inner experience. 20 00:01:21.340 --> 00:01:27.280 Our teaching model allows four configurations, named u, v, w and z. 21 00:01:27.280 --> 00:01:29.760 The letters are names, not measurements. 22 00:01:29.760 --> 00:01:33.160 The device occupies one configuration at a time. 23 00:01:33.160 --> 00:01:38.140 The four rows list possibilities for one device, not four devices. 24 00:01:38.140 --> 00:01:41.420 The lamp output is zero in u and v. 25 00:01:41.420 --> 00:01:43.160 Zero means off. 26 00:01:43.160 --> 00:01:46.420 The lamp output is one in w and z. 27 00:01:46.420 --> 00:01:48.028 One means on. 28 00:01:48.028 --> 00:01:54.300 This table is the model: a roster of states and a rule linking each state to its lamp output. 29 00:01:54.300 --> 00:01:56.460 No probabilities have been assigned. 30 00:01:57.250 --> 00:02:01.050 For this illustration, we reveal an audience-only cutaway. 31 00:02:01.050 --> 00:02:04.490 The actual configuration is v. 32 00:02:04.490 --> 00:02:07.670 Now look at observer access. 33 00:02:07.670 --> 00:02:10.550 The observer does not receive our cutaway. 34 00:02:10.550 --> 00:02:13.490 Its only reading is still zero. 35 00:02:13.490 --> 00:02:17.830 We know the actual state because the illustration tells us. 36 00:02:17.830 --> 00:02:21.230 The observer must work from its reading and the known model. 37 00:02:22.100 --> 00:02:23.650 Start with the full model. 38 00:02:23.650 --> 00:02:27.600 Compare each predicted lamp output with the received zero. 39 00:02:27.600 --> 00:02:31.080 The row for u predicts zero, so it fits. 40 00:02:31.080 --> 00:02:35.060 The row for v also predicts zero, so it fits too. 41 00:02:35.060 --> 00:02:38.132 The rows for w and z predict one. 42 00:02:38.132 --> 00:02:42.880 They conflict with this exact reading and are ruled out for the current state. 43 00:02:42.880 --> 00:02:46.452 The current estimate is therefore u or v. 44 00:02:46.452 --> 00:02:55.000 Here, estimate means the possibilities still compatible with the evidence, not a best guess or a probability distribution. 45 00:02:55.000 --> 00:02:58.780 The model still contains all four rows. 46 00:02:58.780 --> 00:03:02.447 We have narrowed the estimate, not rewritten the output rule. 47 00:03:02.447 --> 00:03:08.320 Given only the zero reading, can the observer conclude that the state is u? 48 00:03:08.320 --> 00:03:16.780 Use the table, without borrowing the audience cutaway. 49 00:03:16.780 --> 00:03:19.780 No. Both u and v fit. 50 00:03:19.780 --> 00:03:24.980 Knowing what each row predicts does not tell the observer which of those rows is actual. 51 00:03:25.850 --> 00:03:34.090 Suppose someone replaces u or v with the guess u, without a new reading or any operation on the device. 52 00:03:34.090 --> 00:03:36.530 Only the notebook entry changed. 53 00:03:36.530 --> 00:03:39.290 The received reading is still zero. 54 00:03:39.290 --> 00:03:45.010 In our audience-only cutaway, the actual configuration is still v. 55 00:03:45.010 --> 00:03:47.070 We can see that the guess is wrong. 56 00:03:47.070 --> 00:03:49.770 The output rule also stayed fixed. 57 00:03:49.770 --> 00:03:55.320 Editing an estimate is different from changing the model that relates states to readings. 58 00:03:55.320 --> 00:03:59.346 Restore the warranted estimate, u or v. 59 00:03:59.346 --> 00:04:03.250 More definite wording cannot create the missing evidence. 60 00:04:03.960 --> 00:04:11.860 Match these four pictured items to their roles: system, model, observation record and current estimate. 61 00:04:11.860 --> 00:04:19.120 Use what each item does. 62 00:04:19.120 --> 00:04:21.200 The device is the system. 63 00:04:21.200 --> 00:04:24.280 The full roster and output rule are the model. 64 00:04:24.280 --> 00:04:27.480 The received zero is the observation record. 65 00:04:27.480 --> 00:04:32.120 The remaining possibilities, u or v, are the current estimate. 66 00:04:32.120 --> 00:04:36.960 The actual state is the one configuration occupied by the device. 67 00:04:36.960 --> 00:04:40.000 In our illustration it stayed v throughout. 68 00:04:40.790 --> 00:04:44.650 Being asks what state the specified system is in now. 69 00:04:44.650 --> 00:04:47.457 Becoming asks how it changes. 70 00:04:47.457 --> 00:04:55.910 To describe either, keep the system and its actual state separate from the model, the observation record and the current estimate. 71 00:04:55.910 --> 00:05:00.190 This lesson held the device fixed while we changed what was written about it. 72 00:05:00.190 --> 00:05:04.662 A change in a description is not, by itself, a change in the device. 73 00:05:04.662 --> 00:05:11.542 Next, we ask how available observations group the possibilities, and which differences remain hidden. 74 00:05:11.542 --> 00:05:15.670 Keep u or v as the unresolved pair for the observer.