When You Forget, I'll Remember, Chapter 2

Early morning just after sunrise. The old grey-brick market street is empty, every stall shut, the cloth awnings rolled up, the paving still wet and blue in shadow; at the far end of the street a low gold sun breaks between the tiled roofs and throws one long band of light down the middle of the paving. Xiaoyu, eleven, runs towards us down that band of light, alone, the clearest and warmest thing in the picture: ponytail flying, mouth open with breath, eyes fixed ahead past us, determined and afraid. Her faded sky-blue thistle t-shirt, khaki shorts, white trainers, the black digital watch on her LEFT wrist. Two street lamps are still lit, small and soft. No other people, NOT a crowd, no stall-keepers. The pale sky above the roofs fills the top third, calm, for the title. Signs and shutters carry no writing.

Chapter 2第二章Before the Machines机器之前

Night, before five in the morning, the room dark except for the faint grey of the window onto the balcony. Xiaoyu has just woken and sits up in the narrow bed, the blue-and-white checked quilt at her waist, listening hard towards the door on the RIGHT of the picture: eyes wide, head turned, very still. She sleeps in her faded sky-blue thistle t-shirt. The small screen of the black watch on her LEFT wrist glows faintly, no numbers painted. The fan is off. Her face sits in the middle of the panel, NOT in the top quarter. The dark wall above her is the quiet area. Only Xiaoyu.

Three days after Grandpa's seventieth birthday. Five in the morning.外公过完七十大寿第三天，凌晨五点。

creak…吱呀……

Night (the same time as the panel before), dark, only grey light from the window and the light from the hallway behind the camera falling across the floor. Grandpa's narrow wooden bed is EMPTY: the thin summer quilt thrown back, the bamboo mat bare, the pillow dented. His old slippers stand neatly side by side by the bed; his cloth shoes are gone. His reading lamp is off, no glow. Xiaoyu's small hand on the door frame at the panel's left edge, nothing else of her. No people in the room.

Grandpa's bed was empty.外公的床空着。

Night (the same time as the panel before). The living room is dark, one small lamp by the sofa now on, its warm light only near it. Grandpa's FRONT DOOR stands WIDE OPEN, and the metal security gate in front of it hangs open too, still moving a little; beyond it the stairwell is black, the landing lamp off. Xiaoyu stands in the middle of the floor, seen from behind, barefoot on the pale terrazzo, in her faded sky-blue t-shirt and khaki shorts, shoulders up, frozen, looking at the open door. Grandpa's olive-green armchair by the radio is empty. The open door and the black stairwell are the focal point. The dark wall and ceiling above are the quiet area. Only Xiaoyu.

‹Grandpa?›外公？

Night (the same time as page 1), one small lamp on beside the sofa. Mama, who flew in for the birthday, has been sleeping on the beige sofa with the white lace covers under a thin cotton blanket, still in her pale blue-grey blouse. Xiaoyu, standing on the left, shakes Mama's shoulder with one hand, leaning over her, urgent and frightened, looking down and to the RIGHT at her. Mama is just opening her eyes. The dark wall above them is the quiet area. Only these two.

Mum. Mum! Grandpa's gone. The door's open.妈，妈！外公不见了！门开着！

Night (the same time as the panel before), lamplight. Mama sits bolt upright on the sofa, the blanket fallen, her own phone (a plain black phone) held to her ear in her right hand, her other hand pressed flat to her chest; her face is white and frightened, eyes wide, looking at nothing, listening to it ring. Her face sits in the middle of the panel, NOT in the top quarter. Dark wall behind her, plain.

‹Pick up, Dad. Pick up.›爸，快接电话，接啊。

Night (the same time as the panel before). The tiny kitchen is dark; Xiaoyu has pulled the cord of the bare bulb and it glows over the counter. On the counter the tea tray: a row of Grandpa's tall clear tea glasses, four standing, and in the row TWO EMPTY GAPS where two glasses are missing; beside the tray a pale round ring on the counter where the red-and-gold flowered thermos always stands, and NO thermos. The tray and the two gaps are the clearest thing. Only Xiaoyu's hand on the door frame at the panel's left edge, nothing else of her. The plain white tiles above are the quiet area.

His thermos is gone. And two of his tea glasses.热水瓶不见了，茶杯也少了两个。

Night (the same time as the panel before), lamplight from the side. Behind the glass of the cabinet, among the small chess trophies, one small framed photo is the clearest thing: a faded old colour photo, drawn in the same simple manga style as everything else, of a young man of about twenty with thick black hair and a young woman with two long braids and a white towel round her neck, sitting at a square pale grey stone table with a chessboard, both laughing, in early morning light. Reeds and a river behind them, NO lake. The photo is small and soft; no writing anywhere. The glass reflects the lamp faintly. The dark shelf above is the quiet area.

Grandma Meilan. She died before I was born.外婆美兰。我出生前，她就走了。

Night, about five in the morning, the landing lamp now on, a single warm bulb; the high window is black. Grandpa's door on the LEFT stands open; Haoran's family's door on the RIGHT has just opened. Mama stands at the left by Grandpa's door, phone to her ear, frightened; Xiaoyu beside her, now in white trainers. Haoran, twelve, in his doorway on the right, hair flattened on one side, glasses crooked, pulling his too-big red basketball vest down over his white t-shirt, sleepy and alarmed; his one wired earbud in his LEFT ear (on the viewer's right). He is half a head taller than Xiaoyu; Xiaoyu reaches Mama's shoulder. The plain wall above the doors is the quiet area. No other people.

‹Auntie Huihui? What's happened?›慧慧阿姨？出什么事了？

‹Grandpa Chen's gone out. In the dark.›陈爷爷自己出去了。天还黑着呢。

Night (the same time as the panel before), the landing bulb lighting him. Haoran holds his own phone (a black case) in one hand the ordinary way, the screen facing him, his thumb on the screen, its glow on his glasses; he grins with sudden confidence and looks to the LEFT of the picture, towards Xiaoyu and Mama off panel. His face sits in the middle of the panel, NOT in the top quarter. Plain wall behind him.

Try one. Haoran's map.第一次，浩然的地图。

Easy. At the birthday I put a family map on his phone. One minute.小意思。生日那天我给他手机装了家人定位，一分钟搞定。

Night (the same time as the panel before). Over Haoran's shoulder (his red vest at the edge), close on his black phone in his hand, his thumb on the screen. The screen shows a plain map app: pale grey streets, a blue river, and ONE round dot with a soft pulse ring, sitting on a block of flats by the river. No letters, no numbers, no names painted on the screen. The dark landing around the phone is quiet.

Grandpa Chen is at home. Updated just now.陈爷爷在家刚刚更新

Night (the same time as the panel before), one lamp on. In the foreground on the right stands Grandpa's empty olive-green armchair by the radio; from under its seat cushion pokes the corner of an old black phone in a worn brown flip case, buzzing (small shake lines round it), its screen lit. In the open front doorway on the left the three of them stare at it: Haoran in front, his own phone lowered, his grin gone, mouth open; Xiaoyu beside him; Mama behind them, her phone at her ear, closing her eyes. The buzzing phone is the focal point. The dark wall above is the quiet area.

…It finds phones. Not people.……它找的是手机，不是人。

bzzz bzzz嗡嗡嗡嗡

Night, a little after five, two lamps on, the balcony doors black. Mama stands on the left, phone to her ear, one hand gripping the back of a stool, speaking fast and clearly, frightened but holding it together. Xiaoyu and Haoran sit at the round folding table on the right, watching her, still. Xiaoyu reaches Mama's shoulder when standing; here she sits. The plain wall above is the quiet area. Only these three.

‹My father. He's seventy. His memory comes and goes. A grey cardigan.›我爸，七十了，记性时好时坏，穿件灰开衫。

The police said they would send someone. They said to try the places he knew first.警察说会派人来，让我们先去他熟悉的地方找找。

Night (the same time as the panel before), lamplight. Mama has lowered her phone; her jaw is tight, her eyes hard with fear, and she looks to the RIGHT of the picture, at Xiaoyu off panel. Her face sits in the middle of the panel, NOT in the top quarter. Plain wall behind.

When we find him, he's getting a tracker. On his wrist.等找到他，就给他买块定位手表，戴手上。

Night (the same time as the panel before), lamplight. Xiaoyu, sitting at the round table, looks up and to the LEFT of the picture at Mama off panel; her chin is set but her voice is small, her hands flat on the table: stubborn, quiet. Her face sits in the middle of the panel, NOT in the top quarter. Plain wall behind.

He's not lost, Mum. He took his tea. He's going somewhere.妈，他没走丢。他带着茶呢，他是有地方要去。

Night (the same time as the panel before), lamplight. Mama looks to the RIGHT at Xiaoyu off panel, softer now but tired and certain, one hand pushing her hair back from her forehead. Her face sits in the middle of the panel, NOT in the top quarter. Plain wall behind.

When memory slips, people get lost, Xiaoyu. It happens.小雨，记性不好的人，是会走丢的。这种事常有。

Night (the same time as the panel before), lamplight on the tabletop. Mama's hand writes a short list in pen on the back of a plain white envelope lying on the round folding table: six short lines, the first one crossed through, drawn as pen scribble only, NOT readable. Her own black phone lies beside the envelope, screen down. Only her hand and the envelope; the bare tabletop around them is the quiet area.

Try two. Mum's list of the places in his life. The park, where Uncle Wu was looking. The hospital, the library, the radio factory, the Bridge Street shop, Haoran's school. All in the old town, all close.第二次，妈妈的单子，外公这辈子待过的地方。公园有吴伯伯在找。还有医院、图书馆、无线电厂、桥街的店、浩然的学校，都在老城，不远。

SEARCH. From the 1950s, early AI treated a problem like a map, with each road a possible move. The map is far too big to try every road, so programs used rules of thumb to try the likeliest roads first. Mum's list was a rule of thumb.搜索。五十年代起，早期的人工智能把问题看成一张地图。每条路是一步走法，解题就是找一条通到终点的路。地图太大，没法条条都走，程序就凭经验，先走最有希望的路。妈妈的单子，就是这样一条经验。

Still dark, about twenty past five, a deep blue sky with no stars, the street lamps on. The old city hospital, five storeys of pale yellow plaster with grey trim, most windows dark, only the glass night entrance at the top of the wide stone steps lit warm and bright. Mama hurries up the steps first, Xiaoyu close behind her, Haoran a step behind, all three small against the building, the lit doorway the focal point. Xiaoyu reaches Mama's shoulder; Haoran is half a head taller than Xiaoyu. No other people, NOT an ambulance. The dark blue sky above the roof is the quiet area. No writing on the building or the sign.

The old city hospital. If anyone had found him, they would bring him here.老城医院。谁要是碰见他，多半会送到这儿来。

Still dark outside (the glass doors behind are black), the hall inside lit by cool even night lights. Mama leans over the reception counter on the left, both hands on its edge, asking, desperate; behind the counter on the right a young night nurse in a white uniform and a small white cap, tired and kind, shakes her head gently, looking left at Mama. Xiaoyu and Haoran are out of frame. The plain pale wall above them is the quiet area. No other people.

‹An old man, seventy, a grey cardigan. Has anyone brought him in?›有没有人送来一个老人？七十岁，穿灰开衫。

‹No one tonight. I'm sorry.›今晚没有。对不住啊。

Still dark, the deep blue sky, the lit night entrance glowing behind and above them. Mama has sat down heavily on a stone step on the left, elbows on her knees, her phone in one hand hanging down; she looks up and to the RIGHT at Xiaoyu, exhausted, and a small sad smile comes. Xiaoyu stands one step below her on the right, looking left at her. The dark sky at the top is the quiet area. Haoran is out of frame.

He was born in this hospital. The summer of 1956.他就是在这家医院出生的。一九五六年夏天。

Still dark (the same time as the panel before). Haoran stands on the steps, his black phone in his hand with its screen facing him, its glow on his glasses; he can't help himself, he says it half to himself, eager and nervous at once, looking to the LEFT of the picture towards the others. His one earbud in his LEFT ear (on the viewer's right as he faces us). His face sits in the middle of the panel, NOT in the top quarter. The dark sky behind him is the quiet area.

That's the summer AI started! At a college in America.人工智能也是那年夏天生的！在美国一所大学。

Still dark, the lit doorway's glow on one side of her face. Mama turns sharply to the RIGHT of the picture, towards Haoran off panel, her brows down, snapping: too tired and frightened for facts. Her face in the middle of the panel, NOT in the top quarter. Dark plain background.

‹Haoran. Not now.›浩然，现在别说这个。

Still dark (the same time as the panel before). Haoran lowers his phone, its screen dark now; he looks down and away, ashamed and honest, glasses slipping a little, and speaks low to Xiaoyu, off panel to the LEFT. His face in the middle of the panel, NOT in the top quarter. Dark plain background.

Sorry. Knowing things helps. When I'm scared.对不起。知道点什么，我就没那么怕。

Flashback to the summer of 1956, soft edges, the colours faded warm like an old postcard so it reads as the past. A green college lawn in summer sunshine in front of an old red-brick building with white window frames and a small white bell tower. A few men in white shirts with rolled sleeves and loose ties stand and sit round a portable chalkboard on the grass, talking with their hands; they are small in the picture and drawn simply, NOT recognisable faces. The chalkboard shows only chalk scribble, NOT readable. The pale summer sky above the roof is the quiet area. No writing anywhere.

Tell me. Quietly.你小声讲给我听。

In 1955 four scientists first wrote the words "artificial intelligence". They met the next summer.1955年，四个科学家头一回写下“人工智能”这几个字。第二年夏天，他们聚到了一起。

Still dark (the same time as the panel before). Mama, still sitting on the hospital step, holds her black phone to her ear the ordinary way, hope jumping in her face, eyes wide, mouth open, looking down and to the left. Her face in the middle of the panel, NOT in the top quarter. The dark sky behind is quiet.

‹Huihui! I've been all round the lake. He's not at the tables!›慧慧！湖边我转了一大圈，棋桌那儿没有他！

Still dark (the same time as the panel before), the deep blue sky, a street lamp's glow on her cheek. Xiaoyu looks out to the RIGHT of the picture, past the edge of the panel, into the dark streets; her face is worried and thinking hard, her lips pressed. Her face in the middle of the panel, NOT in the top quarter. The dark sky behind her is quiet.

He's going somewhere. Where?他是有地方要去。会去哪儿呢？

First grey light, about twenty to six: the sky over the roofs has turned from deep blue to pale grey-blue, and the street lamps are still on. The old city library, a two-storey stone building with four columns and wide steps, its tall windows dark and dusty, weeds in the cracks of the steps, a big plane tree beside it. A tall iron gate in front is shut, a heavy chain and padlock round its bars. Mama stands at the gate on the left, one hand on the chain; Xiaoyu and Haoran a few steps behind her on the pavement in the middle and right, small. The empty grey sky above is the quiet area. No other people. No writing anywhere, NOT a sign.

The old city library. Shut for years. The sky was turning grey.老图书馆，关了好多年了。天蒙蒙亮了。

First grey light (the same time as the panel before), a street lamp still on behind her. Mama's hand rests on the chained gate; she looks through the bars at the dark library, remembering, a small sad smile, and speaks to Xiaoyu off panel to the RIGHT. Her face in the middle of the panel, NOT in the top quarter. The grey sky behind is the quiet area.

He read here all through his teens. In his coat. The reading room was freezing in winter.他十几岁的时候，天天来这儿看书。冬天阅览室冷得要命，他就穿着棉袄看。

Flashback to a winter morning in the early 1970s, soft edges, the colours faded and cool blue-grey so it reads as the past. Inside the old reading room: long wooden tables, tall windows with frost in the corners, pale winter light. Young Grandpa, about seventeen, thick black hair, sits alone at the end of a long table in a dark blue padded cotton coat and a grey knitted scarf, a thick open book about radios in front of him (diagrams drawn as scribble lines only, NOT readable), his breath a small white cloud, his face lit up with interest. All the other chairs are empty. The high cold ceiling is the quiet area.

First grey light (the same time as 7.1), the street lamp still on. Haoran sits on the bottom step of the library on the left, his black phone dark in his lap, his shoulders slumped, glum, looking at the phone. Xiaoyu sits down beside him on the right, one body's width of step between them, and looks left at him. He is half a head taller than her, seated too. The grey sky above them is the quiet area. Mama is out of frame.

I said my map would find him in one minute. I promised too much.还说我的地图一分钟就能找到他。牛吹大了。

First grey light (the same time as the panel before). Haoran looks up from his lap to the RIGHT of the picture, towards Xiaoyu off panel, with a crooked, rueful half smile. His one earbud is in his LEFT ear, on the far side of his head here, so the ear we see is bare. His face in the middle of the panel, NOT in the top quarter. Plain grey stone behind.

AI people did that too. They promised thinking machines in twenty years.搞人工智能的人也吹过。说二十年内就能造出会思考的机器。

First grey light (the same time as the panel before). Xiaoyu looks back to the LEFT at Haoran off panel, a little curious despite everything, her arms round her knees. Her face in the middle of the panel, NOT in the top quarter. Plain grey stone behind.

And?然后呢？

A concept panel, the 1970s: an empty university computer room in winter, faded cool colours: a row of big old cabinet computers with reels of tape, a desk with a typewriter-like terminal, all switched off and dusty, frost on the window, a sheet over one machine. In the far corner one desk lamp is still on, warm, the only light, and at that desk one person seen from behind keeps working, small, NOT a recognisable face. The dark ceiling is the quiet area. No writing anywhere.

Nobody got there. So the money stopped.没人做到，钱就断了。

AI'S FIRST WINTER. Programs that solved small puzzles got stuck on big problems, because the choices multiply too fast. In 1973 a report in Britain by James Lighthill said so, and Britain cut most of its money for AI. The promises had run far ahead of the results. Still, some people kept working through the cold.人工智能的第一个冬天。解得了小谜题的程序，一碰上大问题就卡住，因为岔路翻得太快。1973年，英国数学家莱特希尔在一份报告里把这话挑明了，英国随即砍掉了人工智能的大部分经费。话说在了前头，成果远远跟不上。可再冷，也还有人在干。

First grey light, a little brighter now; the street lamps still on. Mama, on the left, still at the chained gate, turns her head to the RIGHT, to Xiaoyu, who has come up beside her and looks up at her. Xiaoyu reaches Mama's shoulder. Mama's face is softer, remembering. The pale grey sky above is the quiet area.

He came all winter anyway. Even when nobody else did.可他一冬天都没断过。别人都不来了，他还来。

Where did he go after the library?出了图书馆，他去哪儿了？

Dawn, about five to six: the sky in the east, over the factory roofs, is pink and pale grey, and the street lamps are just going off. The old radio factory: two square red-brick gateposts, a wide iron sliding gate shut between them, an empty iron frame over the gate where a name once was (NO letters), a tall brick chimney and saw-tooth roofs behind. On the RIGHT a small guard booth with a lit window; the old night guard leans out of its window, looking LEFT towards the road. Mama and Xiaoyu hurry up from the left (Haoran a step behind, out of frame). The pink dawn sky above the chimney is the quiet area. No writing anywhere.

The radio factory. Closed since the nineties. Dawn was coming.无线电厂。九十年代就关了。天快亮了。

Dawn (the same time as the panel before), the pink sky behind the booth, the booth's own lamp warm on him. The old night guard leans out of the booth window, one forearm on the sill, his enamel tea jar beside it, and lights up with surprise as he looks to the LEFT at Mama off panel. His face in the middle of the panel, NOT in the top quarter. The booth's plain wall above is the quiet area.

‹Old Chen? He was here! Half an hour ago.›老陈？来过！半个钟头前。

Dawn (the same time as the panel before). Mama grips the booth's window ledge with both hands and leans in, eager and frightened, looking RIGHT at the guard off panel. Her face in the middle of the panel, NOT in the top quarter. The pink sky behind her is the quiet area.

‹Where did he go?›他往哪儿去了？

Dawn (the same time as the panel before). The guard scratches under his cap, puzzled, remembering, looking LEFT at Mama off panel. His face in the middle of the panel, NOT in the top quarter. Plain booth wall behind.

‹He said he was late for the morning shift. Someone was waiting for him.›他说早班要迟到了，有人在等他。

Dawn (the same time as the panel before). Mama turns from the booth to Xiaoyu, on the left, her face crumpling with fear, one hand at her mouth; Xiaoyu on the right looks up at her, her face lit with certainty, eyes bright. Xiaoyu reaches Mama's shoulder. The shut iron gate behind them; the pink sky above is the quiet area.

He thinks it's fifty years ago.他以为还是五十年前。

Then he's going somewhere. On purpose.那他是有地方要去。他是特意去的。

Dawn (the same time as page 9), the sky a little lighter. The guard taps his own ear with one finger, proud of his old workmate, a crooked smile, looking LEFT at the others off panel. His face in the middle of the panel, NOT in the top quarter. Plain booth wall behind.

‹Old Chen could tell what was wrong with a radio just by listening.›老陈修收音机，耳朵一听，就知道哪儿坏了。

Dawn (the same time as the panel before). The guard shakes his head and laughs a short dry laugh, both hands spread a little on the window ledge. His face in the middle of the panel, NOT in the top quarter. Plain booth wall behind.

‹The bosses made him write it all down. Three hundred rules. Nobody else could make them work.›厂里让他把本事全写下来，写了三百条规矩。别人照着做，就是不灵。

Dawn (the same time as the panel before). Haoran, on the left, has caught up; he turns to Xiaoyu on the right, amazed, his eyes wide behind his glasses, one hand out flat as if laying down a card. Xiaoyu looks left at him. He is half a head taller. The red-brick gatepost behind them; the pink and grey sky above is the quiet area.

That's exactly what AI did in the eighties!八十年代的人工智能，就是这么干的！

EXPERT SYSTEMS. In the 1980s AI boomed again. People wrote down an expert's know-how as hundreds of "if this, then that" rules. One, called MYCIN, chose medicine for blood infections about as well as specialists did in tests. But the rules broke at the edges, and they cost a fortune to write, because experts know more than they can tell.专家系统。八十年代，人工智能又热了起来。人们把专家的本事写成几百条"如果这样，就那样"的规则。有个叫 MYCIN 的系统，给血液感染挑药，测试时跟专科医生差不多。可规则一碰上例外就不灵，写起来还贵得吓人，因为专家心里有数的，比嘴上说得出的多。

Dawn, the pink fading to pale gold in the east. The whole shut factory from the road: the iron gate shut, the saw-tooth roofs, grass growing along the walls, the tall brick chimney cold, no smoke; one bird on the chimney top. The guard booth's lamp has gone off, no glow. No people. The wide pale sky is the quiet area. No writing anywhere.

The factory closed in the early nineties. Around then AI's boom went bust too. Its second winter.九十年代初，厂子关了。差不多同时，人工智能的热潮也退了，迎来第二个冬天。

Sunrise, about ten past six: the first gold sun lights only the top floors and the roof tiles of the two-storey shop houses; down on the street everything is still in cool blue shadow. Every shop's roll-up metal shutter is down, except that one shop in the middle keeps its glass display window behind a metal grille: inside it, a few phones on stands and one old boxy television, dark. Mama stands at that window on the left, Xiaoyu in the middle, Haoran on the right, all three small. The gold-lit roofs and the sky above are the quiet area. No other people. No writing on shutters, signs or the window.

Bridge Street. The sun came up.桥街。太阳出来了。

Sunrise (the same time as the panel before), the street in blue shadow. Mama stands close to the shop window, one hand flat on the metal grille, looking in at the old dark television; her faint reflection shows in the glass. Her face is tender, remembering. She speaks to Xiaoyu off panel to the RIGHT. Her face in the middle of the panel, NOT in the top quarter. The dark shop interior behind the glass is plain.

After the factory closed, he mended radios and TVs in this shop.厂子关了以后，他就在这家店里修收音机、修电视。

Flashback to 1997, evening, soft edges, warm faded colours like an old photo. Inside the small shop, seen from behind: a man of about forty with thick BLACK hair in a white short-sleeved shirt, and a girl of twelve with two pigtails beside him, both standing at the counter looking up at a shelf of six old boxy televisions. Every screen shows the same soft picture of a chessboard, NO letters or numbers. We see only their backs and the backs of their heads, NOT their faces. Radio parts and tools on the counter. The dark wall above the televisions is the quiet area.

I was twelve. A computer beat the world chess champion. It was on every TV in here.那年我十二岁。电脑下棋赢了世界冠军，这店里每台电视都在放。

Sunrise (the same time as 11.2), the street in blue shadow, a stripe of gold light on the roof tiles above. Haoran, on the left, looks at the old television in the window and speaks to Xiaoyu, serious now, explaining with one hand. Xiaoyu, on the right, looks left at him, listening. He is half a head taller. The window glass shows only soft dark shapes. The blue shadowed wall above them is the quiet area.

Deep Blue didn't learn anything. It checked moves really fast and judged them with rules people wrote.深蓝其实什么也没学。它就是算棋算得飞快，哪步好哪步坏，规矩全是人一条一条写的。

Sunrise (the same time as page 11), the street still in blue shadow; the first sunlight has just reached the top of the window frame. Xiaoyu stands close to the shop window, looking in at the old radios and the dark television, her faint reflection over them; her face is thoughtful, putting something together. Her face sits in the middle of the panel, NOT in the top quarter. The dark glass is plain.

Grandpa didn't learn radios from rules. He learned from thousands of radios.外公修收音机，不是照规矩学的。是修了几千台，修出来的。

Sunrise (the same time as the panel before). Mama lowers her black phone from her ear after a call, her face grey and empty, looking down. Her face in the middle of the panel, NOT in the top quarter. The blue-shadowed shutter behind her is plain.

That was the police. Nothing. Nobody's seen him.警察打来的。没消息，谁都没见过他。

Sunrise (the same time as the panel before). Mama turns to the RIGHT, to Xiaoyu off panel, and her voice cracks: angry, guilty, eyes filling. Her face in the middle of the panel, NOT in the top quarter. Plain shutter behind.

I live in Scotland, Xiaoyu. I can't watch him from there. A tracker can.小雨，我在苏格兰，隔那么远看不住他。定位手表看得住。

Sunrise (the same time as the panel before). Xiaoyu looks up and to the LEFT at Mama off panel; hurt, but she holds her ground, her chin up, her eyes wet. Her face in the middle of the panel, NOT in the top quarter. Plain shutter behind.

A tracker tells you where he is. Not where he's going.定位手表只能告诉你他在哪儿。告诉不了你他要去哪儿。

Sunrise (the same time as the panel before). Haoran, uncomfortable between the two of them, holds Mama's white envelope in both hands at his chest, the way you read a page, its written side towards HIM so we see only its plain back; he looks up from it to the LEFT, towards Mama off panel, quietly. His face in the middle of the panel, NOT in the top quarter. Plain shutter behind.

‹Last one, Auntie. My school.›最后一个了，阿姨。我们学校。

Early morning, about twenty-five past six: a low gold sun from the left throws long shadows across the road. The school gate: a wide low metal sliding gate, shut, a small guard hut beside it with its door closed, and on a short pole above the gate one small round security camera. Behind the gate an empty yard, a flagpole with NO flag yet, and a five-storey teaching building with rows of windows. Haoran and Xiaoyu stand at the gate, small, looking through the bars, their long shadows behind them; he is half a head taller. Mama is out of frame. The pale morning sky above the building is the quiet area. No other people. No writing anywhere.

Haoran's school. Early sun, long shadows.浩然的学校。太阳刚出来，影子拉得老长。

Early morning (the same time as the panel before), low gold sun on the side of his face. Haoran holds one bar of the gate and looks through it into the empty yard, remembering, a small fond smile; then he glances to the RIGHT at Xiaoyu off panel. His face in the middle of the panel, NOT in the top quarter. The empty yard behind the bars is plain.

Grandpa Chen ran the chess club here. Saturdays. Until two years ago.陈爷爷以前每个星期六在这儿教国际象棋。一直教到两年前。

Early morning (the same time as the panel before). Haoran points up at the small round camera on its pole above the gate, his finger ending on it, his face wry; the camera, small, plain grey with a dark lens and NO face, sits in the upper right, catching a glint of gold sun. His face in the middle of the panel, NOT in the top quarter.

That camera knows every kid's face. If he came, it wouldn't know him. It only knows faces it was shown.那摄像头认得每个学生的脸。陈爷爷就算来过，它也认不出，它只认见过的脸。

Early morning (the same time as the panel before). Close, from below: the small round grey security camera on its short pole above the school gate, its dark lens catching the low gold sun, NO face, NO eyes; behind it the pale morning sky and the top edge of the gate. The camera is the focal point. The sky is the quiet area. No writing anywhere.

DEEP LEARNING, 2012. Machines that learn to see took off in 2012. A program called AlexNet learned from a huge collection of labelled photos, on chips made for video games. Given five guesses for each photo, it was wrong only 15 times in 100. The next best program was wrong 26 times. Soon nearly every program that looks at pictures learned this way, like this camera.深度学习，2012年。机器学会"看"，是从2012年开始的。一个叫 AlexNet 的程序，用打游戏的显卡，从一大堆标好名字的照片里学。每张照片猜五次，一百张里只错了15张，第二名错了26张。没过几年，看图的程序差不多都这么学了，这个摄像头也是。

Early morning (the same time as page 13), low gold sun. Xiaoyu looks up and to the LEFT at Haoran off panel, surprised, almost a smile. Her face in the middle of the panel, NOT in the top quarter. The bars of the gate behind her are soft.

He taught you chess too?他也教过你下棋？

Early morning (the same time as the panel before). Haoran rubs the back of his neck and shrugs, looking to the RIGHT at Xiaoyu off panel, a little embarrassed. His face in the middle of the panel, NOT in the top quarter. The bars behind him are soft.

He taught everybody. Half the park learned chess from him.他谁都教。半个公园的人，都是跟他学的棋。

A memory of three days before, soft edges, the colours warm and a little faded: Grandpa's 70th birthday, late afternoon, warm low sun through the balcony door. Xiaoyu stands at the round table holding her sheet of squared practice paper (white with a pale green grid) in both hands, the written side towards her so we see only its plain back, and speaks, nervous but brave, looking to the RIGHT. Only her, the edge of the table with the peach-shaped longevity buns, and the glass cabinet behind; no other faces. The wall above her is the quiet area.

Try three. A line from my toast.第三次，我祝寿词里的一句话。

‹You taught the whole park chess.›您教会了全公园下棋。

Early morning, low gold sun, back at the school gate (the same time as 14.2). Xiaoyu spins round to the LEFT of the picture, towards Mama off panel, her face lit with sudden certainty, eyes wide, mouth open to shout. Her face in the middle of the panel, NOT in the top quarter. Plain soft background.

I'd seen it at five. I just hadn't said it loud enough.五点钟我就看见了，只是没大声说。

Mum! Two glasses! Someone's waiting for him at the chess tables!妈！两个杯子！有人在棋桌那儿等他！

Early morning (the same time as the panel before), low gold sun. Mama, by the gate, turns to the RIGHT towards Xiaoyu off panel, tired, shaking her head, her phone in her hand. Her face in the middle of the panel, NOT in the top quarter. Plain wall behind.

Uncle Wu looked, love. He's not there.吴伯伯去找过了，宝贝。他不在那儿。

Early morning (the same time as page 14), low gold sun. Xiaoyu, looking LEFT at Mama off panel, counts on her fingers as she talks, fast and sure, the fingers clearly apart. Her face in the middle of the panel, NOT in the top quarter. Plain soft background.

Uncle Wu looked too early! Grandpa was still at the factory then.吴伯伯去得太早了！那时候外公还在厂门口呢。

Early morning (the same time as the panel before), gold sunlight on the edge of the phone. Over Haoran's shoulder (his red vest at the edge), close on his black phone in his hand, his thumb on the screen. The plain map app now shows a blue walking line from a square block (the factory) along the river to a green patch with a lake (the park). No letters, no numbers painted on the screen.

Forty minutes' walk. He'd be there by now.走过去四十分钟。他早该到了。

Radio factory to Riverside Park. 40 minutes on foot.无线电厂到河边公园步行40分钟

Early morning, low gold sun at the far end of the old grey-brick street, all the market stalls still shut, the wet paving shining. Xiaoyu runs towards us down the middle of the street, the clearest and largest figure, ponytail flying, fists pumping, face set and desperate. Far behind her, small, Mama starts to run, one arm out as if to call her back, and Haoran runs beside Mama. Long shadows. No other people. The pale sky above the roofs is the quiet area. No writing anywhere.

I ran.我拔腿就跑。

‹Xiaoyu! Wait!›小雨！等等！

Early morning, about a quarter to seven: the sun is just over the willows, low and gold, and a thin white mist lies on the lake. The row of square stone chess tables under the trees is empty except the end table, where Grandpa sits alone, small but clear in a shaft of gold light, back straight, very still, on the RIGHT side of the table facing LEFT along the lake path. On the table the Western chessboard is set up in the starting position, two tall clear glasses of pale green tea stand steaming, one at his side and one at the EMPTY seat opposite him, and his red-and-gold flowered thermos stands by the board. In the near ground on the left Xiaoyu has stopped running, seen from behind, out of breath, one hand on a willow trunk. Glasses on the cord at his chest. The misty lake and pale sky are the quiet area. No other people.

Riverside Park. A quarter to seven.河边公园。六点三刻。

Early morning (the same time as the panel before), low gold sun on his face. Grandpa sits on the RIGHT side of the stone table, facing LEFT, his hands resting on his knees, calm and content, a little expectant, looking along the lake path to the left, waiting. In front of him the set-up board and two steaming tall glasses of green tea, one by his hand and one by the empty stone stool opposite. His cardigan's right pocket is on his far side, NO notebook showing. Glasses on the cord at his chest, NOT on his face. The willow shade above is the quiet area.

Early morning (the same time as the panel before), low gold sun. Xiaoyu walks up slowly from the LEFT, her breath still fast, her face full of relief and care, looking RIGHT towards Grandpa off panel; she speaks gently. The misty lake behind her is the quiet area.

‹Grandpa.›外公。

Early morning (the same time as the panel before), low gold sun, mist on the lake. Grandpa, seated on the right, looks up at Xiaoyu on the left with a happy secret on his face and lifts one finger to his lips, shh. Xiaoyu stands by the empty seat on the left, her head a little above his while he sits, puzzled. The set-up board and the two glasses of tea between them. The willow shade above is the quiet area. No one else.

‹Shh. Meilan comes at sunrise. She does her exercises by the river, then she plays me.›嘘。美兰太阳一出来就到。她先在河边打一套拳，打完了跟我杀一盘。

Early morning (the same time as page 16), low gold sun through the willows. Close on the stone tabletop by the empty seat: one tall clear glass of pale green tea, steaming, the leaves turning slowly in it, set neatly at the edge of the chessboard where a second player would sit. The glass is the focal point, gold light through it. The pale stone around it is quiet.

Two glasses. One was for her.两个杯子，有一个是给她的。

Early morning (the same time as the panel before). Xiaoyu sits down carefully on the empty stone stool on the left, opposite Grandpa, and looks at him across the board, gentle and shy, asking. Grandpa on the right looks back at her, kind, a little hurried, glancing down the path. Seated, her head reaches his shoulder. The set-up board between them, each one's pieces nearest them: Grandpa's cream pieces on his side, Xiaoyu's dark brown pieces on hers. The willows above are the quiet area.

‹Can I play… while you wait?›我陪你下一盘，等她来？

‹Quick, then. She's never late.›那得快点。她从来不迟到。

Early morning, the sun a little higher, gold on the board, the mist thinning on the lake. Xiaoyu and Grandpa PLAY CHESS, sitting FACING EACH OTHER across the stone table, the Western 8 by 8 board set square between them, each one's own pieces nearest them, a few moved forward, every piece standing ON a square. Grandpa moves a cream knight, holding it by its top between thumb and finger, calm and absorbed; Xiaoyu watches the board, concentrating, her chin on one fist. The two glasses of tea at the board's edges, the thermos by Grandpa. The willows and sky above are the quiet area. No one else.

He didn't ask who I was. He just played.他没问我是谁，只管下棋。

Early morning (the same time as the panel before), low gold sun behind them. Mama has stopped dead on the lake path, out of breath, one hand pressed to her chest, staring RIGHT at the stone table off panel; her face is stunned, then breaking. Haoran, half a step behind her, bends with his hands on his knees, panting, looking up. The willows above them are the quiet area.

Early morning (the same time as the panel before). Grandpa looks up from the board to the LEFT of the picture, towards Mama off panel, and his face lights with simple delight. His cardigan's right pocket on his far side, NO notebook showing. Glasses on the cord at his chest. The willow shade behind him is quiet.

‹Huihui! Your mother's late today.›慧慧！你妈今天来晚了。

Early morning (the same time as page 17), low gold sun. Mama's eyes fill, and then she chooses: she does not correct him. She steadies, a small brave smile through the tears, looking RIGHT at Grandpa off panel. Her face in the middle of the panel, NOT in the top quarter. The misty lake behind her is plain.

‹Dad… tell me how you met her.›爸……给我讲讲，你们是怎么认识的。

Early morning (the same time as the panel before). Mama sits down on the stone stool at the left end of the table, close to Grandpa; Grandpa, on the right, turns to her, pleased to be asked, his hands opening as he begins the story. Xiaoyu is out of frame. The board and the two glasses of tea between them. The willows above are the quiet area.

‹Nineteen seventy-five. I was nineteen.›一九七五年。我十九。

Flashback to a summer sunrise in 1975, soft edges, warm faded colours like an old photo. The SAME square pale grey stone table and stools as today, but NO lake yet: beyond the table a reed bank and the wide river, small trees newly planted. Young Grandpa, nineteen, thick black hair, white short-sleeved shirt, sits on the RIGHT side of the table over a chessboard, looking up, startled and charmed. Young Meilan, nineteen, two long braids, a white towel round her neck after her morning exercises, stands on the LEFT by the table, leaning in and pointing at one of his pieces with one finger, laughing. The sunrise sky over the river is the quiet area. Only these two.

‹She stopped on her way back from her exercises and said my bishop was in danger.›她打完拳往回走，停下来说，我的象要被吃了。

Early morning (the same time as 18.2), low gold sun. Grandpa laughs, head tipped back a little, eyes creased with joy, one big hand on the stone table. Glasses on the cord at his chest. The willows behind are quiet.

‹She beat me in eleven moves. I came back every morning for a year.›她十一步就赢了我。我天天早上来，来了整整一年。

Early morning (the same time as the panel before). The laugh fades. Grandpa has taken the small worn dark red notebook from his RIGHT cardigan pocket and holds it closed in his hand without opening it; he looks from it to the second glass of tea, and his face goes quiet and very sad, understanding, eyes wet. Glasses on the cord at his chest. Plain willow shade behind.

‹…She's not coming, is she.›……她不会来了，是吧。

Early morning, the sun higher now, the mist almost gone, clear gold light. Mama, on the left, holds Grandpa's big hand in both of hers on the stone table, crying quietly. Grandpa, on the right, has put the notebook down closed on the table; with his other hand he pushes the second glass of tea across the board's edge towards Xiaoyu, a small wry smile coming back. Xiaoyu, in the middle, sits looking at him, eyes wet. Three clear separate outlines. The willows above are the quiet area. Haoran is out of frame.

‹Xiaoyu. You came all this way. Drink it. Don't waste good tea.›小雨，大老远跑来的。喝了，好茶别糟蹋。

Early morning (the same time as the panel before), gold light. Xiaoyu holds the tall glass of green tea in both hands and drinks, her eyes over the rim looking RIGHT at Grandpa off panel, tears on her cheeks and a smile coming. Her face in the middle of the panel, NOT in the top quarter. Plain willow shade behind.

He forgot Grandma was gone. He never forgot where to find her.他忘了外婆已经不在了。可去哪儿等她，他一直记得。

Early morning (the same time as the panel before). A few steps from the table, Haoran stands on the left with his black phone in his hand, screen dark, and speaks to Xiaoyu, honest, a little humbled. Xiaoyu on the right looks left at him, calm, wiping her cheek with the back of one hand. He is half a head taller. His one earbud in his LEFT ear, on the far side of his head here, so the ear we see is bare. The lake behind them is the quiet area.

My map knew where his phone was. You knew where he was going.我的地图知道他手机在哪儿。你知道他要去哪儿。

I've listened to him all summer.他的话，我听了一整个夏天。

Morning, about half past seven, the sun up over the trees, the lake clear and bright, the mist gone. Seen from behind, small, Grandpa walks home along the lake path between Mama, who holds his arm with one hand and her phone to her ear with the other (telling the police he is found), and Xiaoyu, who carries his red-and-gold thermos by its handle. Xiaoyu reaches Grandpa's chest and Mama's shoulder. Far off on the right, very small, Haoran runs away up another path with his arms pumping. Behind them the stone table is empty, the board still set. The wide morning sky is the quiet area. No other people.

That summer Grandpa was seventy, and so was AI, more or less. Both had had their winters. Both were still here.那年夏天，外公七十岁，人工智能也差不多七十岁。两个都熬过了冬天，也都还在。

I'm SO late for school!我上学要迟到啦！

That night. The tiny kitchen under the bare bulb, its warm light on the small square table; the window over the sink black. Mama sits at the table on the left with her black phone in her hand, its screen facing her, its glow on her face; she looks tired and thoughtful. Xiaoyu stands in the doorway on the right, in her faded sky-blue t-shirt, looking left at her. The plain wall above is the quiet area. Only these two.

That night.那天夜里。

Night (the same time as the panel before), the bare bulb above. Mama lays her phone face down on the table with a small decided tap and looks to the RIGHT at Xiaoyu off panel. Her face in the middle of the panel, NOT in the top quarter. Plain tiled wall behind.

I was going to order him a tracker tonight.我今晚本来要给他买个定位手表。

And?然后呢？

Night (the same time as the panel before). Mama gives a small, wry, tired smile, looking RIGHT at Xiaoyu off panel, her eyes still a little red. Her face in the middle of the panel, NOT in the top quarter. Plain tiled wall behind.

It would tell me where he is. Not where he's going.它能告诉我他在哪儿。告诉不了我他要去哪儿。

Night (the same time as the panel before). Mama sits up straight, both hands flat on the table, and says it plainly, looking RIGHT at Xiaoyu off panel: her face calm, decided, a little frightened of her own decision. Her face in the middle of the panel, NOT in the top quarter. Plain tiled wall behind.

We're staying. One year.我们留下来，住一年。

Night (the same time as the panel before). Mama's phone stands propped against the thermos on the table, its screen facing her and its back to us, its glow on her face, so we do NOT see the screen (Papa is heard, not seen). Mama has said it; she waits, holding her own elbows, her face anxious. The dark window above is the quiet area.

Callum? We're staying a year.Callum？我们要在这边待一年。

Dad went very quiet.电话那头，爸爸半天没出声。

Next: Chapter 3. Rules and Habits.下一章：第三章规则和习惯

The ideas, a little slower

Some ideas in this chapter were left to the people and the pictures, so the frightened and the quiet moments could stay that way. Here they are in words.

On page 6 Haoran whispers about the summer of 1956. On 31 August 1955 four American scientists, John McCarthy, Marvin Minsky, Nathaniel Rochester and Claude Shannon, wrote a plan for a summer study at Dartmouth College. It was the first time anyone wrote the words "artificial intelligence". Their bet was bold. Every part of learning, they said, could be described so exactly that a machine could copy it. They met the next summer, the summer Grandpa was born. They made no big breakthrough that summer, but the people who met there led the field for decades.

On page 12 Xiaoyu sees that Grandpa did not learn radios from rules. He learned from thousands of radios. In those same years, some machines began to learn that way too. In 1986 three scientists showed a good way to train a "neural network", a program made of many small connected parts, from examples instead of rules. By 1989 one could read handwritten postcodes on letters in America, and by the late 1990s networks like it were reading many of the cheques there. Slowly the question in AI changed, from "what rules does the expert follow?" to "what patterns are in the examples?"

On page 14 Haoran says Grandpa taught half the park. In 1950, before AI even had a name, the English mathematician Alan Turing asked "Can machines think?" His guess was that instead of writing a grown-up mind into a machine, we could build something like a child's mind and teach it. Machines learn very differently from children. But teaching a machine, not just telling it, is the road AI took.

On page 19, walking home, Grandpa and AI are both about seventy, and both have had their winters. Here is the whole story in one line. At first people tried to make clever machines by writing rules by hand. That did not work for everything, so most AI today learns from many, many examples. Rules and search are still very good at many jobs, and many modern systems use both.

What is true here

Can machines think?

In 1950 Alan Turing opened a paper with that question, then set it aside as too vague. In its place he proposed a game. A judge exchanges typed messages with a hidden person and a hidden machine, and tries to tell which is which.

In the last part of the same paper Turing wondered whether it would be easier to build something like a child's mind and educate it. Real machine learning turned out very unlike a child's. But the idea of teaching a machine, instead of telling it everything, is the road AI later took.

Searching a huge map

Early AI treated many problems as search. Every possible move is a road on a map, and solving the problem means finding a road to the goal. The map is far too big to walk every road, so programs used rules of thumb, called heuristics, to try the most promising roads first. Mama's list of Grandpa's old places is a rule of thumb of exactly this kind.

The first winter

In the late 1950s and 1960s some researchers predicted that machines would match people within a decade or two. They did not. In 1973 the mathematician James Lighthill wrote a report for Britain's Science Research Council. He argued that methods which worked on small puzzles fell apart on big problems, because the choices multiply too fast. AI research in Britain was cut back. People call this the first AI winter.

The neat story is a simplification. Research never stopped, and John McCarthy argued with the report as soon as it came out.

Three hundred rules

In the 1980s AI boomed again with expert systems. People wrote down an expert's know-how as hundreds or thousands of "if this, then that" rules. MYCIN, built at Stanford, recommended antibiotics for blood infections. In tests it did about as well as specialists, though it was never used routinely in hospitals. Another system, R1, later called XCON, was used in business to put together orders for computers, part by part.

The rules broke at the edges, where real cases did not quite fit. They were also slow and costly to gather, because experts often cannot say what they know. The philosopher Michael Polanyi put it in a few words. "We can know more than we can tell." Grandpa wrote three hundred rules for the factory, and nobody else could make them work. That is Polanyi's point.

The second winter

The market for expert systems collapsed in the late 1980s. Money and interest drained away again, and a second AI winter lasted into the early 1990s.

Deep Blue searched, it did not learn

When Deep Blue beat Garry Kasparov in 1997, the year Mama was twelve, it did not win by learning. It won mainly by searching through moves very fast on special chips, and by scoring each position with a recipe that people had tuned by hand. It was a triumph of the old search tradition.

The year machines learned to see

In 2012 a deep network called AlexNet entered a contest built on ImageNet, a huge collection of photos labelled by people. It was trained on graphics chips made for video games. Given five guesses for each photo, it missed the right answer 15.3 times in a hundred. The next best entry missed 26.2 times.

Within a few years almost every program that looks at pictures learned this way. The camera at the school gate is one of them.

SourcesTuring (1950), Computing machinery and intelligence.Newell and Simon (1976), Computer science as empirical inquiry, symbols and search.Hart, Nilsson and Raphael (1968), A formal basis for the heuristic determination of minimum cost paths.Lighthill (1973), Artificial intelligence, a general survey.Nilsson (2010), The Quest for Artificial Intelligence.McCarthy (1974), Review of "Artificial Intelligence, a General Survey" by Professor Sir James Lighthill.Buchanan and Shortliffe (1984), Rule-Based Expert Systems, the MYCIN Experiments of the Stanford Heuristic Programming Project.McDermott (1982), R1, a rule-based configurer of computer systems.Polanyi (1966), The Tacit Dimension.Crevier (1993), AI, the Tumultuous History of the Search for Artificial Intelligence.Campbell, Hoane and Hsu (2002), Deep Blue.Krizhevsky, Sutskever and Hinton (2012), ImageNet classification with deep convolutional neural networks.Deng and colleagues (2009), ImageNet, a large-scale hierarchical image database.LeCun, Bengio and Hinton (2015), Deep learning.

What is pretend

Bridge City and everyone in it, Grandpa's life (the hospital where he was born, the library, the radio factory, the shop, the school chess club), Grandma Meilan, the night guard and his three hundred rules, the family map app and the gate camera. Grandpa's memory is drawn from no one in particular, and the story makes no medical claim. People whose memory slips do sometimes get lost, and sometimes live for a while in an earlier year.

The best book-length histories are Nilsson (2010), which is free to read, McCorduck (2004) and Crevier (1993).

Who made this

Yingying Fu created this manga. She chose the story and its people, directed every page, and edited every word and picture. The words were drafted with Claude, an AI by Anthropic. The pictures are made with AI image generation, painted panel by panel from her direction and checked and corrected by hand.

慢慢再讲一遍

这一章有些道理交给了人物和画面，好让害怕的地方就害怕，安静的地方就安静。这里再用文字讲一遍。

第6页，浩然小声讲起1956年的夏天。1955年8月31日，四位美国科学家，麦卡锡、明斯基、罗切斯特和香农，写了一份计划，打算第二年夏天在达特茅斯学院一起做研究。"人工智能"这几个字，是头一回有人写下来。他们的想法很大胆，认为学习的方方面面都能讲得清清楚楚，清楚到机器可以照着做。第二年夏天他们聚到了一起，那正是外公出生的夏天。那个夏天没出什么大突破，可在那儿碰头的人，后来领着这一行走了几十年。

第12页，小雨想明白了，外公修收音机不是靠规矩学会的，是修了几千台修会的。差不多那些年，有些机器也开始这样学。1986年，三位科学家找到了一个好办法，让"神经网络"不靠规则、靠例子学东西。神经网络是由很多相连的小部件组成的程序。到1989年，它已经能认出美国信封上手写的邮政编码；到九十年代末，美国很多支票都是这类网络读的。人工智能慢慢不再问"专家用什么规则"，改问"例子里藏着什么规律"。

第14页，浩然说半个公园的人都是外公教会下棋的。1950年，人工智能还没有名字，英国数学家图灵就问："机器能思考吗？"他猜，与其把一个大人的头脑直接写进机器，不如造一个像孩子那样的头脑，再慢慢教它。机器跟孩子学东西很不一样。可是"教它，不只是告诉它"，正是后来人工智能走的路。

第19页，走在回家的路上，外公七十岁，人工智能也差不多七十岁，两个都熬过了冬天。整个故事，一句话就能说完。一开始，人们想靠手写规则造出聪明的机器。规则管不了所有的事，所以今天大多数人工智能，是从很多很多例子里学出来的。规则和搜索在很多事上依然好用，很多现代系统两样都用。

哪些是真的

机器能思考吗？

1950年，艾伦·图灵在一篇论文的开头问了这个问题，接着又说它太含糊，先放一放。换成了一个游戏。一位裁判打字传话，同时跟一个藏起来的人和一台藏起来的机器聊，猜哪边是人，哪边是机器。

在同一篇论文的最后，图灵想过，与其直接造一个大人的头脑，会不会不如造一个像孩子那样的头脑，再慢慢教它。后来的机器学习，跟孩子学东西很不一样。可是"教它，而不是什么都告诉它"，正是人工智能后来走的路。

在一张大地图上找路

早期的人工智能，把很多问题都看成"搜索"。每一步走法是地图上的一条路，解题就是找一条通到目标的路。地图大得没法每条路都走一遍，程序就靠经验法则，先走最有希望的路。妈妈列出外公以前常去的地方，正是这样一条经验法则。

第一个冬天

五六十年代，有研究者预言，一二十年内机器就能赶上人。结果没做到。1973年，数学家莱特希尔给英国科学研究委员会写了一份报告。他说，在小谜题上管用的办法，一碰上大问题就垮了，因为岔路翻得太快。英国的人工智能研究随后被大幅削减，这就是人们说的第一个冬天。

这样讲是简化了的。研究其实一直没停，报告一出来，约翰·麦卡锡就写文章反驳了。

三百条规矩

八十年代，人工智能靠"专家系统"又热了起来。人们把专家的本事写成几百上千条"如果这样，就那样"的规则。斯坦福做的 MYCIN 给血液感染推荐抗生素，测试时跟专科医生差不多，不过从没在医院里常规用过。另一个系统叫 R1，后来改名 XCON，被公司用来给电脑订单一件件配零件。

真实情况只要对不太上，规则就不灵了。从专家那儿一条条问出来，又慢又贵，因为专家往往说不出自己知道的东西。哲学家波兰尼说过一句话，"我们知道的，比我们说得出的多"。外公给厂里写了三百条规矩，别人照着做就是不灵，说的就是这个。

第二个冬天

八十年代末，专家系统的市场垮了。钱和热情又一次退了下去，第二个冬天一直延续到九十年代初。

深蓝靠的是搜索，不是学习

1997年，"深蓝"赢了卡斯帕罗夫，那年妈妈十二岁。它赢棋不是靠学，主要靠专用芯片飞快地往下算，再用一套人手调好的办法给每个局面打分。这是老派"搜索"路线的一场大胜。

机器学会"看"的那一年

2012年，一个叫 AlexNet 的深度网络参加了 ImageNet 比赛。ImageNet 是一大批由人标好名字的照片。AlexNet 用打游戏的显卡训练，每张照片让它猜五次，一百张里有15.3张五次都没猜中。第二名是26.2张。

没过几年，几乎所有看图的程序都改用这种办法学了。校门口的那个摄像头，也是其中之一。

出处Turing (1950), Computing machinery and intelligence.Newell and Simon (1976), Computer science as empirical inquiry, symbols and search.Hart, Nilsson and Raphael (1968), A formal basis for the heuristic determination of minimum cost paths.Lighthill (1973), Artificial intelligence, a general survey.Nilsson (2010), The Quest for Artificial Intelligence.McCarthy (1974), Review of "Artificial Intelligence, a General Survey" by Professor Sir James Lighthill.Buchanan and Shortliffe (1984), Rule-Based Expert Systems, the MYCIN Experiments of the Stanford Heuristic Programming Project.McDermott (1982), R1, a rule-based configurer of computer systems.Polanyi (1966), The Tacit Dimension.Crevier (1993), AI, the Tumultuous History of the Search for Artificial Intelligence.Campbell, Hoane and Hsu (2002), Deep Blue.Krizhevsky, Sutskever and Hinton (2012), ImageNet classification with deep convolutional neural networks.Deng and colleagues (2009), ImageNet, a large-scale hierarchical image database.LeCun, Bengio and Hinton (2015), Deep learning.

哪些是虚构的

桥城和城里的每个人，外公的经历（他出生的医院、图书馆、无线电厂、那家店、学校的国际象棋社），外婆美兰，厂门口的门卫和那三百条规矩，家人定位软件和校门口的摄像头。外公的记性不取材于任何具体的人，故事不做任何医学上的说法。记性不好的人，有时确实会走丢，有时也会在一段时间里以为自己还活在从前。

延伸阅读

写得最好的几本人工智能史，是尼尔森（Nilsson, 2010，可以免费读到）、麦考黛克（McCorduck, 2004）和克雷维尔（Crevier, 1993）。

谁做了这本漫画

这本漫画由 Yingying Fu 创作。故事和人物由她决定，每一页由她导演，每一句话、每一幅画由她修改。文字是和 Anthropic 的人工智能 Claude 一起起草的。画面由人工智能生成，按她的要求一格一格地画，再逐张检查、修正。

When You Forget, I'll Remember你忘了，我记得