Mercurial > thoughts
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add dylan's sloman transcript.
author | Robert McIntyre <rlm@mit.edu> |
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date | Tue, 13 Aug 2013 00:47:01 -0400 |
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1 #+TITLE:Transcript of Aaron Sloman - Artificial Intelligence - Psychology - Oxford Interview | |
2 #+AUTHOR:Dylan Holmes | |
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4 #+STYLE: <link rel="stylesheet" type="text/css" href="../css/sloman.css" /> | |
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23 *Editor's note:* This is a working draft transcript which I made of | |
24 [[http://www.youtube.com/watch?feature=player_detailpage&v=iuH8dC7Snno][this nice interview]] of Aaron Sloman. Having just finished one | |
25 iteration of transcription, I still need to go in and clean up the | |
26 formatting and fix the parts that I misheard, so you can expect the | |
27 text to improve significantly in the near future. | |
28 | |
29 To the extent that this is my work, you have my permission to make | |
30 copies of this transcript for your own purposes. Also, feel free to | |
31 e-mail me with comments or corrections. | |
32 | |
33 You can send mail to =transcript@aurellem.org=. | |
34 | |
35 Cheers, | |
36 | |
37 ---Dylan | |
38 #+END_QUOTE | |
39 | |
40 | |
41 | |
42 * Introduction | |
43 | |
44 ** Aaron Sloman evolves into a philosopher of AI | |
45 [0:09] My name is Aaron Sloman. My first degree many years ago in | |
46 Capetown University was in Physics and Mathematics, and I intended to | |
47 go and be a mathematician. I came to Oxford and encountered | |
48 philosophers --- I had started reading philosophy and discussing | |
49 philosophy before then, and then I found that there were philosophers | |
50 who said things about mathematics that I thought were wrong, so | |
51 gradually got more and more involved in [philosophy] discussions and | |
52 switched to doing philosophy DPhil. Then I became a philosophy | |
53 lecturer and about six years later, I was introduced to artificial | |
54 intelligence when I was a lecturer at Sussex University in philosophy | |
55 and I very soon became convinced that the best way to make progress in | |
56 both areas of philosophy (including philosophy of mathematics which I | |
57 felt i hadn't dealt with adequately in my DPhil) about the philosophy | |
58 of mathematics, philosophy of mind, philsophy of language and all | |
59 those things---the best way was to try to design and test working | |
60 fragments of mind and maybe eventually put them all together but | |
61 initially just working fragments that would do various things. | |
62 | |
63 [1:12] And I learned to program and ~ with various other people | |
64 including ~Margaret Boden whom you've interviewed, developed---helped | |
65 develop an undergraduate degree in AI and other things and also began | |
66 to do research in AI and so on which I thought of as doing philosophy, | |
67 primarily. | |
68 | |
69 [1:29] And then I later moved to the University of Birmingham and I | |
70 was there --- I came in 1991 --- and I've been retired for a while but | |
71 I'm not interested in golf or gardening so I just go on doing full | |
72 time research and my department is happy to keep me on without paying | |
73 me and provide space and resources and I come, meeting bright people | |
74 at conferences and try to learn and make progress if I can. | |
75 | |
76 ** AI is hard, in part because there are tempting non-problems. | |
77 | |
78 One of the things I learnt and understood more and more over the many | |
79 years --- forty years or so since I first encountered AI --- is how | |
80 hard the problems are, and in part that's because it's very often | |
81 tempting to /think/ the problem is something different from what it | |
82 actually is, and then people design solutions to the non-problems, and | |
83 I think of most of my work now as just helping to clarify what the | |
84 problems are: what is it that we're trying to explain --- and maybe | |
85 this is leading into what you wanted to talk about: | |
86 | |
87 I now think that one of the ways of getting a deep understanding of | |
88 that is to find out what were the problems that biological evolution | |
89 solved, because we are a product of /many/ solutions to /many/ | |
90 problems, and if we just try to go in and work out what the whole | |
91 system is doing, we may get it all wrong, or badly wrong. | |
92 | |
93 | |
94 * What problems of intelligence did evolution solve? | |
95 | |
96 ** Intelligence consists of solutions to many evolutionary problems; no single development (e.g. communication) was key to human-level intelligence. | |
97 | |
98 [2:57] Well, first I would challenge that we are the dominant | |
99 species. I know it looks like that but actually if you count biomass, | |
100 if you count number of species, if you count number of individuals, | |
101 the dominant species are microbes --- maybe not one of them but anyway | |
102 they're the ones who dominate in that sense, and furthermore we are | |
103 mostly --- we are largely composed of microbes, without which we | |
104 wouldn't survive. | |
105 | |
106 | |
107 # ** Many nonlinguistic competences require sophisticated internal representations | |
108 [3:27] But there are things that make humans (you could say) best at | |
109 those things, or worst at those things, but it's a combination. And I | |
110 think it was a collection of developments of which there isn't any | |
111 single one. [] there might be, some people say, human language which | |
112 changed everything. By our human language, they mean human | |
113 communication in words, but I think that was a later development from | |
114 what must have started as the use of /internal/ forms of | |
115 representation --- which are there in nest-building birds, in | |
116 pre-verbal children, in hunting mammals --- because you can't take in | |
117 information about a complex structured environment in which things can | |
118 change and you may have to be able to work out what's possible and | |
119 what isn't possible, without having some way of representing the | |
120 components of the environment, their relationships, the kinds of | |
121 things they can and can't do, the kinds of things you might or might | |
122 not be able to do --- and /that/ kind of capability needs internal | |
123 languages, and I and colleagues [at Birmingham] have been referring to | |
124 them as generalized languages because some people object to | |
125 referring...to using language to refer to something that isn't used | |
126 for communication. But from that viewpoint, not only humans but many | |
127 other animals developed abilities to do things to their environment to | |
128 make them more friendly to themselves, which depended on being able to | |
129 represent possible futures, possible actions, and work out what's the | |
130 best thing to do. | |
131 | |
132 [5:13] And nest-building in corvids for instance---crows, magpies, | |
133 [hawks], and so on --- are way beyond what current robots can do, and | |
134 in fact I think most humans would be challenged if they had to go and | |
135 find a collection of twigs, one at a time, maybe bring them with just | |
136 one hand --- or with your mouth --- and assemble them into a | |
137 structure that, you know, is shaped like a nest, and is fairly rigid, | |
138 and you could trust your eggs in them when wind blows. But they're | |
139 doing it, and so ... they're not our evolutionary ancestors, but | |
140 they're an indication --- and that example is an indication --- of | |
141 what must have evolved in order to provide control over the | |
142 environment in /that/ species. | |
143 | |
144 ** Speculation about how communication might have evolved from internal lanagues. | |
145 [5:56] And I think hunting mammals, fruit-picking mammals, mammals | |
146 that can rearrange parts of the environment, provide shelters, needed | |
147 to have .... also needed to have ways of representing possible | |
148 futures, not just what's there in the environment. I think at a later | |
149 stage, that developed into a form of communication, or rather the | |
150 /internal/ forms of representation became usable as a basis for | |
151 providing [context] to be communicated. And that happened, I think, | |
152 initially through performing actions that expressed intentions, and | |
153 probably led to situtations where an action (for instance, moving some | |
154 large object) was performed more easily, or more successfully, or more | |
155 accurately if it was done collaboratively. So someone who had worked | |
156 out what to do might start doing it, and then a conspecific might be | |
157 able to work out what the intention is, because that person has the | |
158 /same/ forms of representation and can build theories about what's | |
159 going on, and might then be able to help. | |
160 | |
161 [7:11] You can imagine that if that started happening more (a lot of | |
162 collaboration based on inferred intentions and plans) then sometimes | |
163 the inferences might be obscure and difficult, so the /actions/ might | |
164 be enhanced to provide signals as to what the intention is, and what | |
165 the best way is to help, and so on. | |
166 | |
167 [7:35] So, this is all handwaving and wild speculation, but I think | |
168 it's consistent with a large collection of facts which one can look at | |
169 --- and find if one looks for them, but one won't know if [some]one | |
170 doesn't look for them --- about the way children, for instance, who | |
171 can't yet talk, communicate, and the things they'll do, like going to | |
172 the mother and turning the face to point in the direction where the | |
173 child wants it to look and so on; that's an extreme version of action | |
174 indicating intention. | |
175 | |
176 [8:03] Anyway. That's a very long roundabout answer to one conjecture | |
177 that the use of communicative language is what gave humans their | |
178 unique power to create and destroy and whatever, and I'm saying that | |
179 if by that you mean /communicative/ language, then I'm saying there | |
180 was something before that which was /non/-communicative language, and I | |
181 suspect that noncommunicative language continues to play a deep role | |
182 in /all/ human perception ---in mathematical and scientific reasoning, in | |
183 problem solving --- and we don't understand very much about it. | |
184 | |
185 [8:48] | |
186 I'm sure there's a lot more to be said about the development of | |
187 different kinds of senses, the development of brain structures and | |
188 mechanisms is above all that, but perhaps I've droned on long enough | |
189 on that question. | |
190 | |
191 | |
192 * How do language and internal states relate to AI? | |
193 | |
194 [9:09] Well, I think most of the human and animal capabilities that | |
195 I've been referring to are not yet to be found in current robots or | |
196 [computing] systems, and I think there are two reasons for that: one | |
197 is that it's intrinsically very difficult; I think that in particular | |
198 it may turn out that the forms of information processing that one can | |
199 implement on digital computers as we currently know them may not be as | |
200 well suited to performing some of these tasks as other kinds of | |
201 computing about which we don't know so much --- for example, I think | |
202 there may be important special features about /chemical/ computers | |
203 which we might [talk about in a little bit? find out about]. | |
204 | |
205 ** In AI, false assumptions can lead investigators astray. | |
206 [9:57] So, one of the problems then is that the tasks are hard ... but | |
207 there's a deeper problem as to why AI hasn't made a great deal of | |
208 progress on these problems that I'm talking about, and that is that | |
209 most AI researchers assume things---and this is not just AI | |
210 researchers, but [also] philsophers, and psychologists, and people | |
211 studying animal behavior---make assumptions about what it is that | |
212 animals or humans do, for instance make assumptions about what vision | |
213 is for, or assumptions about what motivation is and how motivation | |
214 works, or assumptions about how learning works, and then they try --- | |
215 the AI people try --- to model [or] build systems that perform those | |
216 assumed functions. So if you get the /functions/ wrong, then even if | |
217 you implement some of the functions that you're trying to implement, | |
218 they won't necessarily perform the tasks that the initial objective | |
219 was to imitate, for instance the tasks that humans, and nest-building | |
220 birds, and monkeys and so on can perform. | |
221 | |
222 ** Example: Vision is not just about finding surfaces, but about finding affordances. | |
223 [11:09] I'll give you a simple example --- well, maybe not so simple, | |
224 but --- It's often assumed that the function of vision in humans (and | |
225 in other animals with good eyesight and so on) is to take in optical | |
226 information that hits the retina, and form into the (maybe changing | |
227 --- or, really, in our case definitely changing) patterns of | |
228 illumination where there are sensory receptors that detect those | |
229 patterns, and then somehow from that information (plus maybe other | |
230 information gained from head movement or from comparisons between two | |
231 eyes) to work out what there was in the environment that produced | |
232 those patterns, and that is often taken to mean \ldquo{}where were the | |
233 surfaces off which the light bounced before it came to me\rdquo{}. So | |
234 you essentially think of the task of the visual system as being to | |
235 reverse the image formation process: so the 3D structure's there, the | |
236 lens causes the image to form in the retina, and then the brain goes | |
237 back to a model of that 3D structure there. That's a very plausible | |
238 theory about vision, and it may be that that's a /subset/ of what | |
239 human vision does, but I think James Gibson pointed out that that kind | |
240 of thing is not necessarily going to be very useful for an organism, | |
241 and it's very unlikely that that's the main function of perception in | |
242 general, namely to produce some physical description of what's out | |
243 there. | |
244 | |
245 [12:37] What does an animal /need/? It needs to know what it can do, | |
246 what it can't do, what the consequences of its actions will be | |
247 .... so, he introduced the word /affordance/, so from his point of | |
248 view, the function of vision, perception, are to inform the organism | |
249 of what the /affordances/ are for action, where that would mean what | |
250 the animal, /given/ its morphology (what it can do with its mouth, its | |
251 limbs, and so on, and the ways it can move) what it can do, what its | |
252 needs are, what the obstacles are, and how the environment supports or | |
253 obstructs those possible actions. | |
254 | |
255 [13:15] And that's a very different collection of information | |
256 structures that you need from, say, \ldquo{}where are all the | |
257 surfaces?\rdquo{}: if you've got all the surfaces, /deriving/ the | |
258 affordances would still be a major task. So, if you think of the | |
259 perceptual system as primarily (for biological organisms) being | |
260 devices that provide information about affordances and so on, then the | |
261 tasks look very different. And most of the people working, doing | |
262 research on computer vision in robots, I think haven't taken all that | |
263 on board, so they're trying to get machines to do things which, even | |
264 if they were successful, would not make the robots very intelligent | |
265 (and in fact, even the ones they're trying to do are not really easy | |
266 to do, and they don't succeed very well--- although, there's progress; | |
267 I shouldn't disparage it too much.) | |
268 | |
269 ** Online and offline intelligence | |
270 | |
271 [14:10] It gets more complex as animals get more sophisticated. So, I | |
272 like to make a distinction between online intelligence and offline | |
273 intelligence. So, for example, if I want to pick something up --- like | |
274 this leaf <he plucks a leaf from the table> --- I was able to select | |
275 it from all the others in there, and while moving my hand towards it, | |
276 I was able to guide its trajectory, making sure it was going roughly | |
277 in the right direction --- as opposed to going out there, which | |
278 wouldn't have been able to pick it up --- and these two fingers ended | |
279 up with a portion of the leaf between them, so that I was able to tell | |
280 when I'm ready to do that <he clamps the leaf between two fingers> | |
281 and at that point, I clamped my fingers and then I could pick up the | |
282 leaf. | |
283 | |
284 [14:54] Whereas, --- and that's an example of online intelligence: | |
285 during the performance of an action (both from the stage where it's | |
286 initiated, and during the intermediate stages, and where it's | |
287 completed) I'm taking in information relevant to controlling all those | |
288 stages, and that relevant information keeps changing. That means I | |
289 need stores of transient information which gets discarded almost | |
290 immediately and replaced or something. That's online intelligence. And | |
291 there are many forms; that's just one example, and Gibson discussed | |
292 quite a lot of examples which I won't try to replicate now. | |
293 | |
294 [15:30] But in offline intelligence, you're not necessarily actually | |
295 /performing/ the actions when you're using your intelligence; you're | |
296 thinking about /possible/ actions. So, for instance, I could think | |
297 about how fast or by what route I would get back to the lecture room | |
298 if I wanted to [get to the next talk] or something. And I know where | |
299 the door is, roughly speaking, and I know roughly which route I would | |
300 take, when I go out, I should go to the left or to the right, because | |
301 I've stored information about where the spaces are, where the | |
302 buildings are, where the door was that we came out --- but in using | |
303 that information to think about that route, I'm not actually | |
304 performing the action. I'm not even /simulating/ it in detail: the | |
305 precise details of direction and speed and when to clamp my fingers, | |
306 or when to contract my leg muscles when walking, are all irrelevant to | |
307 thinking about a good route, or thinking about the potential things | |
308 that might happen on the way. Or what would be a good place to meet | |
309 someone who I think [for an acquaintance in particular] --- [barber] | |
310 or something --- I don't necessarily have to work out exactly /where/ | |
311 the person's going to stand, or from what angle I would recognize | |
312 them, and so on. | |
313 | |
314 [16:46] So, offline intelligence --- which I think became not just a | |
315 human competence; I think there are other animals that have aspects of | |
316 it: Squirrels are very impressive as you watch them. Gray squirrels at | |
317 any rate, as you watch them defeating squirrel-proof birdfeeders, seem | |
318 to have a lot of that [offline intelligence], as well as the online | |
319 intelligence when they eventually perform the action they've worked | |
320 out [] that will get them to the nuts. | |
321 | |
322 [17:16] And I think that what happened during our evolution is that | |
323 mechanisms for acquiring and processing and storing and manipulating | |
324 information that is more and more remote from the performance of | |
325 actions developed. An example is taking in information about where | |
326 locations are that you might need to go to infrequently: There's a | |
327 store of a particular type of material that's good for building on | |
328 roofs of houses or something out around there in some | |
329 direction. There's a good place to get water somewhere in another | |
330 direction. There are people that you'd like to go and visit in | |
331 another place, and so on. | |
332 | |
333 [17:59] So taking in information about an extended environment and | |
334 building it into a structure that you can make use of for different | |
335 purposes is another example of offline intelligence. And when we do | |
336 that, we sometimes use only our brains, but in modern times, we also | |
337 learned how to make maps on paper and walls and so on. And it's not | |
338 clear whether the stuff inside our heads has the same structures as | |
339 the maps we make on paper: the maps on paper have a different | |
340 function; they may be used to communicate with others, or meant for | |
341 /looking/ at, whereas the stuff in your head you don't /look/ at; you | |
342 use it in some other way. | |
343 | |
344 [18:46] So, what I'm getting at is that there's a great deal of human | |
345 intelligence (and animal intelligence) which is involved in what's | |
346 possible in the future, what exists in distant places, what might have | |
347 happened in the past (sometimes you need to know why something is as | |
348 it is, because that might be relevant to what you should or shouldn't | |
349 do in the future, and so on), and I think there was something about | |
350 human evolution that extended that offline intelligence way beyond | |
351 that of animals. And I don't think it was /just/ human language, (but | |
352 human language had something to do with it) but I think there was | |
353 something else that came earlier than language which involves the | |
354 ability to use your offline intelligence to discover something that | |
355 has a rich mathematical structure. | |
356 | |
357 ** Example: Even toddlers use sophisticated geometric knowledge | |
358 #+<<example-gap>> | |
359 [19:44] I'll give you a simple example: if you look through a gap, you | |
360 can see something that's on the other side of the gap. Now, you | |
361 /might/ see what you want to see, or you might see only part of it. If | |
362 you want to see more of it, which way would you move? Well, you could | |
363 either move /sideways/, and see through the gap---and see it roughly | |
364 the same amount but a different part of it [if it's a ????], or you | |
365 could move /towards/ the gap and then your view will widen as you | |
366 approach the gap. Now, there's a bit of mathematics in there, insofar | |
367 as you are implicitly assuming that information travels in straight | |
368 lines, and as you go closer to a gap, the straight lines that you can | |
369 draw from where you are through the gap, widen as you approach that | |
370 gap. Now, there's a kind of theorem of Euclidean geometry in there | |
371 which I'm not going to try to state very precisely (and as far as I | |
372 know, wasn't stated explicitly in Euclidean geometry) but it's | |
373 something every toddler--- human toddler---learns. (Maybe other | |
374 animals also know it, I don't know.) But there are many more things, | |
375 actions to perform, to get you more information about things, actions | |
376 to perform to conceal information from other people, actions that will | |
377 enable you to operate, to act on a rigid object in one place in order | |
378 to produce an effect on another place. So, there's a lot of stuff that | |
379 involves lines and rotations and angles and speeds and so on that I | |
380 think humans (maybe, to a lesser extent, other animals) develop the | |
381 ability to think about in a generic way. That means that you could | |
382 take out the generalizations from the particular contexts and then | |
383 re-use them in a new contexts in ways that I think are not yet | |
384 represented at all in AI and in theories of human learning in any [] | |
385 way --- although some people are trying to study learning of mathematics. | |
386 | |
387 * Animal intelligence | |
388 | |
389 ** The priority is /cataloguing/ what competences have evolved, not ranking them. | |
390 [22:03] I wasn't going to challenge the claim that humans can do more | |
391 sophisticated forms of [tracking], just to mention that there are some | |
392 things that other animals can do which are in some ways comparable, | |
393 and some ways superior to [things] that humans can do. In particular, | |
394 there are species of birds and also, I think, some rodents --- | |
395 squirrels, or something --- I don't know enough about the variety --- | |
396 that can hide nuts and remember where they've hidden them, and go back | |
397 to them. And there have been tests which show that some birds are able | |
398 to hide tens --- you know, [eighteen] or something nuts --- and to | |
399 remember which ones have been taken, which ones haven't, and so | |
400 on. And I suspect most humans can't do that. I wouldn't want to say | |
401 categorically that maybe we couldn't, because humans are very | |
402 [varied], and also [a few] people can develop particular competences | |
403 through training. But it's certainly not something I can do. | |
404 | |
405 | |
406 ** AI can be used to test philosophical theories | |
407 [23:01] But I also would like to say that I am not myself particularly | |
408 interested in trying to align animal intelligences according to any | |
409 kind of scale of superiority; I'm just trying to understand what it | |
410 was that biological evolution produced, and how it works, and I'm | |
411 interested in AI /mainly/ because I think that when one comes up with | |
412 theories about how these things work, one needs to have some way of | |
413 testing the theory. And AI provides ways of implementing and testing | |
414 theories that were not previously available: Immanuel Kant was trying | |
415 to come up with theories about how minds work, but he didn't have any | |
416 kind of a mechanism that he could build to test his theory about the | |
417 nature of mathematical knowledge, for instance, or how concepts were | |
418 developed from babyhood onward. Whereas now, if we do develop a | |
419 theory, we have a criterion of adequacy, namely it should be precise | |
420 enough and rich enough and detailed to enable a model to be | |
421 built. And then we can see if it works. | |
422 | |
423 [24:07] If it works, it doesn't mean we've proved that the theory is | |
424 correct; it just shows it's a candidate. And if it doesn't work, then | |
425 it's not a candidate as it stands; it would need to be modified in | |
426 some way. | |
427 | |
428 * Is abstract general intelligence feasible? | |
429 | |
430 ** It's misleading to compare the brain and its neurons to a computer made of transistors | |
431 [24:27] I think there's a lot of optimism based on false clues: | |
432 the...for example, one of the false clues is to count the number of | |
433 neurons in the brain, and then talk about the number of transistors | |
434 you can fit into a computer or something, and then compare them. It | |
435 might turn out that the study of the way synapses work (which leads | |
436 some people to say that a typical synapse [] in the human brain has | |
437 computational power comparable to the Internet a few years ago, | |
438 because of the number of different molecules that are doing things, | |
439 the variety of types of things that are being done in those molecular | |
440 interactions, and the speed at which they happen, if you somehow count | |
441 up the number of operations per second or something, then you get | |
442 these comparable figures). | |
443 | |
444 ** For example, brains may rely heavily on chemical information processing | |
445 Now even if the details aren't right, there may just be a lot of | |
446 information processing that...going on in brains at the /molecular/ | |
447 level, not the neural level. Then, if that's the case, the processing | |
448 units will be orders of magnitude larger in number than the number of | |
449 neurons. And it's certainly the case that all the original biological | |
450 forms of information processing were chemical; there weren't brains | |
451 around, and still aren't in most microbes. And even when humans grow | |
452 their brains, the process of starting from a fertilized egg and | |
453 producing this rich and complex structure is, for much of the time, | |
454 under the control of chemical computations, chemical information | |
455 processing---of course combined with physical sorts of materials and | |
456 energy and so on as well. | |
457 | |
458 [26:25] So it would seem very strange if all that capability was | |
459 something thrown away when you've got a brain and all the information | |
460 processing, the [challenges that were handled in making a brain], | |
461 ... This is handwaving on my part; I'm just saying that we /might/ | |
462 learn that what brains do is not what we think they do, and that | |
463 problems of replicating them are not what we think they are, solely in | |
464 terms of numerical estimate of time scales, the number of components, | |
465 and so on. | |
466 | |
467 ** Brain algorithms may simply be optimized for certain kinds of information processing other than bit manipulations | |
468 [26:56] But apart from that, the other basis of skepticism concerns | |
469 how well we understand what the problems are. I think there are many | |
470 people who try to formalize the problems of designing an intelligent | |
471 system in terms of streams of information thought of as bit streams or | |
472 collections of bit streams, and they think of as the problems of | |
473 intelligence as being the construction or detection of patterns in | |
474 those, and perhaps not just detection of patterns, but detection of | |
475 patterns that are useable for sending /out/ streams to control motors | |
476 and so on in order to []. And that way of conceptualizing the problem | |
477 may lead on the one hand to oversimplification, so that the things | |
478 that /would/ be achieved, if those goals were achieved, maybe much | |
479 simpler, in some ways inadequate. Or the replication of human | |
480 intelligence, or the matching of human intelligence---or for that | |
481 matter, squirrel intelligence---but in another way, it may also make | |
482 the problem harder: it may be that some of the kinds of things that | |
483 biological evolution has achieved can't be done that way. And one of | |
484 the ways that might turn out to be the case is not because it's not | |
485 impossible in principle to do some of the information processing on | |
486 artificial computers-based-on-transistors and other bit-manipulating | |
487 []---but it may just be that the computational complexity of solving | |
488 problems, processes, or finding solutions to complex problems, are | |
489 much greater and therefore you might need a much larger universe than | |
490 we have available in order to do things. | |
491 | |
492 ** Example: find the shortest path by dangling strings | |
493 [28:55] Then if the underlying mechanisms were different, the | |
494 information processing mechanisms, they might be better tailored to | |
495 particular sorts of computation. There's a [] example, which is | |
496 finding the shortest route if you've got a collection of roads, and | |
497 they may be curved roads, and lots of tangled routes from A to B to C, | |
498 and so on. And if you start at A and you want to get to Z --- a place | |
499 somewhere on that map --- the process of finding the shortest route | |
500 will involve searching through all these different possibilities and | |
501 rejecting some that are longer than others and so on. But if you make | |
502 a model of that map out of string, where these strings are all laid | |
503 out on the maps and so have the lengths of the routes. Then if you | |
504 hold the two knots in the string -- it's a network of string --- which | |
505 correspond to the start point and end point, then /pull/, then the | |
506 bits of string that you're left with in a straight line will give you | |
507 the shortest route, and that process of pulling just gets you the | |
508 solution very rapidly in a parallel computation, where all the others | |
509 just hang by the wayside, so to speak. | |
510 | |
511 ** In sum, we know surprisingly little about the kinds of problems that evolution solved, and the manner in which they were solved. | |
512 [30:15] Now, I'm not saying brains can build networks of string and | |
513 pull them or anything like that; that's just an illustration of how if | |
514 you have the right representation, correctly implemented---or suitably | |
515 implemented---for a problem, then you can avoid very combinatorially | |
516 complex searches, which will maybe grow exponentially with the number | |
517 of components in your map, whereas with this thing, the time it takes | |
518 won't depend on how many strings you've [got on the map]; you just | |
519 pull, and it will depend only on the shortest route that exists in | |
520 there. Even if that shortest route wasn't obvious on the original map. | |
521 | |
522 | |
523 [30:59] So that's a rather long-winded way of formulating the | |
524 conjecture which---of supporting, a roundabout way of supporting the | |
525 conjecture that there may be something about the way molecules perform | |
526 computations where they have the combination of continuous change as | |
527 things move through space and come together and move apart, and | |
528 whatever --- and also snap into states that then persist, so [as you | |
529 learn from] quantum mechanics, you can have stable molecular | |
530 structures which are quite hard to separate, and then in catalytic | |
531 processes you can separate them, or extreme temperatures, or strong | |
532 forces, but they may nevertheless be able to move very rapidly in some | |
533 conditions in order to perform computations. | |
534 | |
535 [31:49] Now there may be things about that kind of structure that | |
536 enable searching for solutions to /certain/ classes of problems to be | |
537 done much more efficiently (by brain) than anything we could do with | |
538 computers. It's just an open question. | |
539 | |
540 [32:04] So it /might/ turn out that we need new kinds of technology | |
541 that aren't on the horizon in order to replicate the functions that | |
542 animal brains perform ---or, it might not. I just don't know. I'm not | |
543 claiming that there's strong evidence for that; I'm just saying that | |
544 it might turn out that way, partly because I think we know less than | |
545 many people think we know about what biological evolution achieved. | |
546 | |
547 [32:28] There are some other possibilities: we may just find out that | |
548 there are shortcuts no one ever thought of, and it will all happen | |
549 much more quickly---I have an open mind; I'd be surprised, but it | |
550 could turn up. There /is/ something that worries me much more than the | |
551 singularity that most people talk about, which is machines achieving | |
552 human-level intelligence and perhaps taking over [the] planet or | |
553 something. There's what I call the /singularity of cognitive | |
554 catch-up/ ... | |
555 | |
556 * A singularity of cognitive catch-up | |
557 | |
558 ** What if it will take a lifetime to learn enough to make something new? | |
559 ... SCC, singularity of cognitive catch-up, which I think we're close | |
560 to, or maybe have already reached---I'll explain what I mean by | |
561 that. One of the products of biological evolution---and this is one of | |
562 the answers to your earlier questions which I didn't get on to---is | |
563 that humans have not only the ability to make discoveries that none of | |
564 their ancestors have ever made, but to shorten the time required for | |
565 similar achievements to be reached by their offspring and their | |
566 descendants. So once we, for instance, worked out ways of complex | |
567 computations, or ways of building houses, or ways of finding our way | |
568 around, we don't need...our children don't need to work it out for | |
569 themselves by the same lengthy trial and error procedure; we can help | |
570 them get there much faster. | |
571 | |
572 Okay, well, what I've been referring to as the singularity of | |
573 cognitive catch-up depends on the fact that---fairly obvious, and it's | |
574 often been commented on---that in case of humans, it's not necessary | |
575 for each generation to learn what previous generations learned /in the | |
576 same way/. And we can speed up learning once something has been | |
577 learned, [it is able to] be learned by new people. And that has meant | |
578 that the social processes that support that kind of education of the | |
579 young can enormously accelerate what would have taken...perhaps | |
580 thousands [or] millions of years for evolution to produce, can happen in | |
581 a much shorter time. | |
582 | |
583 | |
584 [34:54] But here's the catch: in order for a new advance to happen --- | |
585 so for something new to be discovered that wasn't there before, like | |
586 Newtonian mechanics, or the theory of relativity, or Beethoven's music | |
587 or [style] or whatever --- the individuals have to have traversed a | |
588 significant amount of what their ancestors have learned, even if they | |
589 do it much faster than their ancestors, to get to the point where they | |
590 can see the gaps, the possibilities for going further than their | |
591 ancestors, or their parents or whatever, have done. | |
592 | |
593 [35:27] Now in the case of knowledge of science, mathematics, | |
594 philosophy, engineering and so on, there's been a lot of accumulated | |
595 knowledge. And humans are living a /bit/ longer than they used to, but | |
596 they're still living for [whatever it is], a hundred years, or for | |
597 most people, less than that. So you can imagine that there might come | |
598 a time when in a normal human lifespan, it's not possible for anyone | |
599 to learn enough to understand the scope and limits of what's already | |
600 been achieved in order to see the potential for going beyond it and to | |
601 build on what's already been done to make that...those future steps. | |
602 | |
603 [36:10] So if we reach that stage, we will have reached the | |
604 singularity of cognitive catch-up because the process of education | |
605 that enables individuals to learn faster than their ancestors did is | |
606 the catching-up process, and it may just be that we at some point | |
607 reach a point where catching up can only happen within a lifetime of | |
608 an individual, and after that they're dead and they can't go | |
609 beyond. And I have some evidence that there's a lot of that around | |
610 because I see a lot of people coming up with what /they/ think of as | |
611 new ideas which they've struggled to come up with, but actually they | |
612 just haven't taken in some of what was...some of what was done [] by | |
613 other people, in other places before them. And I think that despite | |
614 the availability of search engines which make it /easier/ for people | |
615 to get the information---for instance, when I was a student, if I | |
616 wanted to find out what other people had done in the field, it was a | |
617 laborious process---going to the library, getting books, and | |
618 ---whereas now, I can often do things in seconds that would have taken | |
619 hours. So that means that if seconds [are needed] for that kind of | |
620 work, my lifespan has been extended by a factor of ten or | |
621 something. So maybe that /delays/ the singularity, but it may not | |
622 delay it enough. But that's an open question; I don't know. And it may | |
623 just be that in some areas, this is more of a problem than others. For | |
624 instance, it may be that in some kinds of engineering, we're handing | |
625 over more and more of the work to machines anyways and they can go on | |
626 doing it. So for instance, most of the production of computers now is | |
627 done by a computer-controlled machine---although some of the design | |
628 work is done by humans--- a lot of /detail/ of the design is done by | |
629 computers, and they produce the next generation, which then produces | |
630 the next generation, and so on. | |
631 | |
632 [37:57] I don't know if humans can go on having major advances, so | |
633 it'll be kind of sad if we can't. | |
634 | |
635 * Spatial reasoning: a difficult problem | |
636 | |
637 [38:15] Okay, well, there are different problems [ ] mathematics, and | |
638 they have to do with properties. So for instance a lot of mathematics | |
639 that can be expressed in terms of logical structures or algebraic | |
640 structures and those are pretty well suited for manipulation and...on | |
641 computers, and if a problem can be specified using the | |
642 logical/algebraic notation, and the solution method requires creating | |
643 something in that sort of notation, then computers are pretty good, | |
644 and there are lots of mathematical tools around---there are theorem | |
645 provers and theorem checkers, and all kinds of things, which couldn't | |
646 have existed fifty, sixty years ago, and they will continue getting | |
647 better. | |
648 | |
649 | |
650 But there was something that I was [[example-gap][alluding to earlier]] when I gave the | |
651 example of how you can reason about what you will see by changing your | |
652 position in relation to a door, where what you are doing is using your | |
653 grasp of spatial structures and how as one spatial relationship | |
654 changes namely you come closer to the door or move sideways and | |
655 parallel to the wall or whatever, other spatial relationships change | |
656 in parallel, so the lines from your eyes through to other parts of | |
657 the...parts of the room on the other side of the doorway change, | |
658 spread out more as you go towards the doorway, and as you move | |
659 sideways, they don't spread out differently, but focus on different | |
660 parts of the internal ... that they access different parts of the | |
661 ... of the room. | |
662 | |
663 Now, those are examples of ways of thinking about relationships and | |
664 changing relationships which are not the same as thinking about what | |
665 happens if I replace this symbol with that symbol, or if I substitute | |
666 this expression in that expression in a logical formula. And at the | |
667 moment, I do not believe that there is anything in AI amongst the | |
668 mathematical reasoning community, the theorem-proving community, that | |
669 can model the processes that go on when a young child starts learning | |
670 to do Euclidean geometry and is taught things about---for instance, I | |
671 can give you a proof that the angles of any triangle add up to a | |
672 straight line, 180 degrees. | |
673 | |
674 ** Example: Spatial proof that the angles of any triangle add up to a half-circle | |
675 There are standard proofs which involves starting with one triangle, | |
676 then adding a line parallel to the base one of my former students, | |
677 Mary Pardoe, came up with which I will demonstrate with this <he holds | |
678 up a pen> --- can you see it? If I have a triangle here that's got | |
679 three sides, if I put this thing on it, on one side --- let's say the | |
680 bottom---I can rotate it until it lies along the second...another | |
681 side, and then maybe move it up to the other end ~. Then I can rotate | |
682 it again, until it lies on the third side, and move it back to the | |
683 other end. And then I'll rotate it again and it'll eventually end up | |
684 on the original side, but it will have changed the direction it's | |
685 pointing in --- and it won't have crossed over itself so it will have | |
686 gone through a half-circle, and that says that the three angles of a | |
687 triangle add up to the rotations of half a circle, which is a | |
688 beautiful kind of proof and almost anyone can understand it. Some | |
689 mathematicians don't like it, because they say it hides some of the | |
690 assumptions, but nevertheless, as far as I'm concerned, it's an | |
691 example of a human ability to do reasoning which, once you've | |
692 understood it, you can see will apply to any triangle --- it's got to | |
693 be a planar triangle --- not a triangle on a globe, because then the | |
694 angles can add up to more than ... you can have three /right/ angles | |
695 if you have an equator...a line on the equator, and a line going up to | |
696 to the north pole of the earth, and then you have a right angle and | |
697 then another line going down to the equator, and you have a right | |
698 angle, right angle, right angle, and they add up to more than a | |
699 straight line. But that's because the triangle isn't in the plane, | |
700 it's on a curved surface. In fact, that's one of the | |
701 differences...definitional differences you can take between planar and | |
702 curved surfaces: how much the angles of a triangle add up to. But our | |
703 ability to /visualize/ and notice the generality in that process, and | |
704 see that you're going to be able to do the same thing using triangles | |
705 that stretch in all sorts of ways, or if it's a million times as | |
706 large, or if it's made...you know, written on, on...if it's drawn in | |
707 different colors or whatever --- none of that's going to make any | |
708 difference to the essence of that process. And that ability to see | |
709 the commonality in a spatial structure which enables you to draw some | |
710 conclusions with complete certainty---subject to the possibility that | |
711 sometimes you make mistakes, but when you make mistakes, you can | |
712 discover them, as has happened in the history of geometrical theorem | |
713 proving. Imre Lakatos had a wonderful book called [[http://en.wikipedia.org/wiki/Proofs_and_Refutations][/Proofs and | |
714 Refutations/]] --- which I won't try to summarize --- but he has | |
715 examples: mistakes were made; that was because people didn't always | |
716 realize there were subtle subcases which had slightly different | |
717 properties, and they didn't take account of that. But once they're | |
718 noticed, you rectify that. | |
719 | |
720 ** Geometric results are fundamentally different than experimental results in chemistry or physics. | |
721 [43:28] But it's not the same as doing experiments in chemistry and | |
722 physics, where you can't be sure it'll be the same on [] or at a high | |
723 temperature, or in a very strong magnetic field --- with geometric | |
724 reasoning, in some sense you've got the full information in front of | |
725 you; even if you don't always notice an important part of it. So, that | |
726 kind of reasoning (as far as I know) is not implemented anywhere in a | |
727 computer. And most people who do research on trying to model | |
728 mathematical reasoning, don't pay any attention to that, because of | |
729 ... they just don't think about it. They start from somewhere else, | |
730 maybe because of how they were educated. I was taught Euclidean | |
731 geometry at school. Were you? | |
732 | |
733 (Adam ford: Yeah) | |
734 | |
735 Many people are not now. Instead they're taught set theory, and | |
736 logic, and arithmetic, and [algebra], and so on. And so they don't use | |
737 that bit of their brains, without which we wouldn't have built any of | |
738 the cathedrals, and all sorts of things we now depend on. | |
739 | |
740 * Is near-term artificial general intelligence likely? | |
741 | |
742 ** Two interpretations: a single mechanism for all problems, or many mechanisms unified in one program. | |
743 | |
744 [44:35] Well, this relates to what's meant by general. And when I | |
745 first encountered the AGI community, I thought that what they all | |
746 meant by general intelligence was /uniform/ intelligence --- | |
747 intelligence based on some common simple (maybe not so simple, but) | |
748 single powerful mechanism or principle of inference. And there are | |
749 some people in the community who are trying to produce things like | |
750 that, often in connection with algorithmic information theory and | |
751 computability of information, and so on. But there's another sense of | |
752 general which means that the system of general intelligence can do | |
753 lots of different things, like perceive things, understand language, | |
754 move around, make things, and so on --- perhaps even enjoy a joke; | |
755 that's something that's not nearly on the horizon, as far as I | |
756 know. Enjoying a joke isn't the same as being able to make laughing | |
757 noises. | |
758 | |
759 Given, then, that there are these two notions of general | |
760 intelligence---there's one that looks for one uniform, possibly | |
761 simple, mechanism or collection of ideas and notations and algorithms, | |
762 that will deal with any problem that's solvable --- and the other | |
763 that's general in the sense that it can do lots of different things | |
764 that are combined into an integrated architecture (which raises lots | |
765 of questions about how you combine these things and make them work | |
766 together) and we humans, certainly, are of the second kind: we do all | |
767 sorts of different things, and other animals also seem to be of the | |
768 second kind, perhaps not as general as humans. Now, it may turn out | |
769 that in some near future time, who knows---decades, a few | |
770 decades---you'll be able to get machines that are capable of solving | |
771 in a time that will depend on the nature of the problem, but any | |
772 problem that is solvable, and they will be able to do it in some sort | |
773 of tractable time --- of course, there are some problems that are | |
774 solvable that would require a larger universe and a longer history | |
775 than the history of the universe, but apart from that constraint, | |
776 these machines will be able to do anything []. But to be able to do | |
777 some of the kinds of things that humans can do, like the kinds of | |
778 geometrical reasoning where you look at the shape and you abstract | |
779 away from the precise angles and sizes and shapes and so on, and | |
780 realize there's something general here, as must have happened when our | |
781 ancestors first made the discoveries that eventually put together in | |
782 Euclidean geometry. | |
783 | |
784 It may be that that requires mechanisms of a kind that we don't know | |
785 anything about at the moment. Maybe brains are using molecules and | |
786 rearranging molecules in some way that supports that kind of | |
787 reasoning. I'm not saying they are --- I don't know, I just don't see | |
788 any simple...any obvious way to map that kind of reasoning capability | |
789 onto what we currently do on computers. There is---and I just | |
790 mentioned this briefly beforehand---there is a kind of thing that's | |
791 sometimes thought of as a major step in that direction, namely you can | |
792 build a machine (or a software system) that can represent some | |
793 geometrical structure, and then be told about some change that's going | |
794 to happen to it, and it can predict in great detail what'll | |
795 happen. And this happens for instance in game engines, where you say | |
796 we have all these blocks on the table and I'll drop one other block, | |
797 and then [the thing] uses Newton's laws and properties of rigidity of | |
798 the parts and the elasticity and also stuff about geometries and space | |
799 and so on, to give you a very accurate representation of what'll | |
800 happen when this brick lands on this pile of things, [it'll bounce and | |
801 go off, and so on]. And you just, with more memory and more CPU power, | |
802 you can increase the accuracy--- but that's totally different than | |
803 looking at /one/ example, and working out what will happen in a whole | |
804 /range/ of cases at a higher level of abstraction, whereas the game | |
805 engine does it in great detail for /just/ this case, with /just/ those | |
806 precise things, and it won't even know what the generalizations are | |
807 that it's using that would apply to others []. So, in that sense, [we] | |
808 may get AGI --- artificial general intelligence --- pretty soon, but | |
809 it'll be limited in what it can do. And the other kind of general | |
810 intelligence which combines all sorts of different things, including | |
811 human spatial geometrical reasoning, and maybe other things, like the | |
812 ability to find things funny, and to appreciate artistic features and | |
813 other things may need forms of pattern-mechanism, and I have an open | |
814 mind about that. | |
815 | |
816 * Abstract General Intelligence impacts | |
817 | |
818 [49:53] Well, as far as the first type's concerned, it could be useful | |
819 for all kinds of applications --- there are people who worry about | |
820 where there's a system that has that type of intelligence, might in | |
821 some sense take over control of the planet. Well, humans often do | |
822 stupid things, and they might do something stupid that would lead to | |
823 disaster, but I think it's more likely that there would be other | |
824 things [] lead to disaster--- population problems, using up all the | |
825 resources, destroying ecosystems, and whatever. But certainly it would | |
826 go on being useful to have these calculating devices. Now, as for the | |
827 second kind of them, I don't know---if we succeeded at putting | |
828 together all the parts that we find in humans, we might just make an | |
829 artificial human, and then we might have some of them as your friends, | |
830 and some of them we might not like, and some of them might become | |
831 teachers or whatever, composers --- but that raises a question: could | |
832 they, in some sense, be superior to us, in their learning | |
833 capabilities, their understanding of human nature, or maybe their | |
834 wickedness or whatever --- these are all issues in which I expect the | |
835 best science fiction writers would give better answers than anything I | |
836 could do, but I did once fantasize when I [back] in 1978, that perhaps | |
837 if we achieved that kind of thing, that they would be wise, and gentle | |
838 and kind, and realize that humans are an inferior species that, you | |
839 know, have some good features, so they'd keep us in some kind of | |
840 secluded...restrictive kind of environment, keep us away from | |
841 dangerous weapons, and so on. And find ways of cohabitating with | |
842 us. But that's just fantasy. | |
843 | |
844 Adam Ford: Awesome. Yeah, there's an interesting story /With Folded | |
845 Hands/ where [the computers] want to take care of us and want to | |
846 reduce suffering and end up lobotomizing everybody [but] keeping them | |
847 alive so as to reduce the suffering. | |
848 | |
849 Aaron Sloman: Not all that different from /Brave New World/, where it | |
850 was done with drugs and so on, but different humans are given | |
851 different roles in that system, yeah. | |
852 | |
853 There's also /The Time Machine/, H.G. Wells, where the ... in the | |
854 distant future, humans have split in two: the Eloi, I think they were | |
855 called, they lived underground, they were the [] ones, and then---no, | |
856 the Morlocks lived underground; Eloi lived on the planet; they were | |
857 pleasant and pretty but not very bright, and so on, and they were fed | |
858 on by ... | |
859 | |
860 Adam Ford: [] in the future. | |
861 | |
862 Aaron Sloman: As I was saying, if you ask science fiction writers, | |
863 you'll probably come up with a wide variety of interesting answers. | |
864 | |
865 Adam Ford: I certainly have; I've spoken to [] of Birmingham, and | |
866 Sean Williams, ... who else? | |
867 | |
868 Aaron Sloman: Did you ever read a story by E.M. Forrester called /The | |
869 Machine Stops/ --- very short story, it's [[http://archive.ncsa.illinois.edu/prajlich/forster.html][on the Internet somewhere]] | |
870 --- it's about a time when people sitting ... and this was written in | |
871 about [1914 ] so it's about...over a hundred years ago ... people are | |
872 in their rooms, they sit in front of screens, and they type things, | |
873 and they communicate with one another that way, and they don't meet; | |
874 they have debates, and they give lectures to their audiences that way, | |
875 and then there's a woman whose son says \ldquo{}I'd like to see | |
876 you\rdquo{} and she says \ldquo{}What's the point? You've got me at | |
877 this point \rdquo{} but he wants to come and talk to her --- I won't | |
878 tell you how it ends, but. | |
879 | |
880 Adam Ford: Reminds me of the Internet. | |
881 | |
882 Aaron Sloman: Well, yes; he invented ... it was just extraordinary | |
883 that he was able to do that, before most of the components that we | |
884 need for it existed. | |
885 | |
886 Adam Ford: [Another person who did that] was Vernor Vinge [] /True | |
887 Names/. | |
888 | |
889 Aaron Sloman: When was that written? | |
890 | |
891 Adam Ford: The seventies. | |
892 | |
893 Aaron Sloman: Okay, well a lot of the technology was already around | |
894 then. The original bits of internet were working, in about 1973, I was | |
895 sitting ... 1974, I was sitting at Sussex University trying to | |
896 use...learn LOGO, the programming language, to decide whether it was | |
897 going to be useful for teaching AI, and I was sitting [] paper | |
898 teletype, there was paper coming out, transmitting ten characters a | |
899 second from Sussex to UCL computer lab by telegraph cable, from there | |
900 to somewhere in Norway via another cable, from there by satellite to | |
901 California to a computer Xerox [] research center where they had | |
902 implemented a computer with a LOGO system on it, with someone I had | |
903 met previously in Edinburgh, Danny Bobrow, and he allowed me to have | |
904 access to this sytem. So there I was typing. And furthermore, it was | |
905 duplex typing, so every character I typed didn't show up on my | |
906 terminal until it had gone all the way there and echoed back, so I | |
907 would type, and the characters would come back four seconds later. | |
908 | |
909 [55:26] But that was the Internet, and I think Vernor Vinge was | |
910 writing after that kind of thing had already started, but I don't | |
911 know. Anyway. | |
912 | |
913 [55:41] Another...I mentioned H.G. Wells, /The Time Machine/. I | |
914 recently discovered, because [[http://en.wikipedia.org/wiki/David_Lodge_(author)][David Lodge]] had written a sort of | |
915 semi-novel about him, that he had invented Wikipedia, in advance--- he | |
916 had this notion of an encyclopedia that was free to everybody, and | |
917 everybody could contribute and [collaborate on it]. So, go to the | |
918 science fiction writers to find out the future --- well, a range of | |
919 possible futures. | |
920 | |
921 Adam Ford: Well the thing is with science fiction writers, they have | |
922 to maintain some sort of interest for their readers, after all the | |
923 science fiction which reaches us is the stuff that publishers want to | |
924 sell, and so there's a little bit of a ... a bias towards making a | |
925 plot device there, and so the dramatic sort of appeals to our | |
926 amygdala, our lizard brain; we'll sort of stay there obviously to some | |
927 extent. But I think that they do come up with sort of amazing ideas; I | |
928 think it's worth trying to make these predictions; I think that we | |
929 should more time on strategic forecasting, I mean take that seriously. | |
930 | |
931 Aaron Sloman: Well, I'm happy to leave that to others; I just want to | |
932 try to understand these problems that bother me about how things | |
933 work. And it may be that some would say that's irresponsible if I | |
934 don't think about what the implications will be. Well, understanding | |
935 how humans work /might/ enable us to make [] humans --- I suspect it | |
936 wont happen in this century; I think it's going to be too difficult. |