Neolefty

We was just playing in the woods. Me and Sal had an old phone that didn’t have no minutes but still had good batteries and some stuff in it. We was just taking pictures of leaves and flowers and having it tell us about them. We had to use the light because it was so dark down under the trees, and it couldn’t tell us nothing if the pictures was too dim.

Well, the phone got warm, I guess, and we didn’t pay no mind, and then before we know it, it was hot and I dropped it, and then I saw smoke coming from it, and sparks, and them dry leaves caught, and then we was running from a fire. I practically carried Sal up the ravine to the house, and I saw Mom running at us the other way. We was keeping away from the fire, but the smoke got all around us, so our eyes was burning and we was coughing all dry.

“Fire, Ma, there’s a fire!” and I run straight into the house, pulling Sal.

“I know, god dammit Al! I ain’t blind!” She run straight past me to the machine shed, which we never opened because them machines is too expensive to run.

I got Sal down to the house basement. I heard thunder outside and wanted to go see what it was.

“Don’t go up there, Al!” Sal was crying and holding onto my hand like I was Mom or Dad. “We’s supposed to stay in the shelter.”

But I pulled my hand out of hers and run back outside.

The first thing I noticed, was the helicopters. There was two of them, yellow and as big as our house, and they was what sounded like thunder. They was spraying orange goo into the trees in the ravine.

Smoke was pouring up like a gray dirt cloud out of the tops of the trees, where the helicopters was spraying. I couldn’t see no flames.

Then I saw Mom, tearing down the drive on the tractor, with the big empty spray tank on the back. I couldn’t hear nothing from it, but smoke was coming out of it’s pipe, so I knew she was running the carbon motor and everything.

I started to run down after Mom and the tractor, but a huge voice from one of the helicopters practically knocked me on my butt. “Please stand back from the affected area and all emergency vehicles. Find a place of safety immediately. Please stand back from the affected area and emergency vehicles …” It was saying the same thing over and over. Me and Sal still like to say it. “Please stand back from the breakfast area and all eatin’ brothers.” Mom and Dad don’t particularly like it, but Me and Sal laugh at it every time.

I got back into the house and watched out the basement door. Sal was crying down below, but wouldn’t come over to the door to look out. For a minute I saw fire in the smoke, but then I guess the orange stuff started to work, and the fire didn’t keep going.

Mom come by later to check on us, just to see we was okay, but she didn’t come inside the house. It was night before she and Dad came back in.

So that’s how I was practically born in carbon debt. I had to bank it and bank it, my Dad made me bank it every day, which is why I didn’t play learning much, like Sal did. Sal never got blamed for that fire, even though we was both there, because she was only five, and I was seven.

My Dad gives me credit for stuff like branches I cut off his trees — if he seen me cut them — if I also haul them to the swamp to bank in anox.

“Albert!” My Dad is calling. “Albert, you seen my axe?”

“Dad, I’m playin’ Emerald Kids!” Which I was. While we still had power. Our house batteries are shot, and we don’t have the carbon to replace them. And besides it’s summer, so we don’t need them at night anyway. “Can’t it wait ’til after dark?”

“Albert, I need that axe now, ‘n’ there’s still daylight. I’ve got a poplar ‘sabout to fall, an’ I got to get it in the ravine. If it don’t fall uphill, I’ll bust my back gettin’ it down to the swamp.”

“Can’t it wait until tomorrow, an’ we can cut the limbs off?”

But that’s going too far. “Dammit boy, you can’t let wood sit!” I can hear his face get red, “It’s goin’ to the swamp tonight or you’re goin’ with it!”

I put that game down. “I’m comin’!” I yell. I always mean to leave that axe on its peg, but I must have forgot, or else my Dad wouldn’t be calling about it.

I shiver because I remember where it is. “I think I left it on the Harp Slope!” I call to him, and I run out the front door past him, trying not to look in his face. It’s going to be darker before I get back with the ax.

He don’t let wood sit even a day above water, and it had better lay in anox too. He says rot starts right away. Foolheaded stubbornness, I say. Even though I mostly play a geosat boy in Emerald Kids, I know it takes years for all the carbon to come out of a dead tree. It sure don’t give up nothing appreciable its first day down.

Anox, that’s water that don’t got no oxygen in it. It’s dead water, and fish can’t live in it, which is a waste. But it kind of balances because if you put wood into anox, the carbon banks. It doesn’t rot out into the air. And the sats, they can see that you’ve done a good job, and you get to keep the credit you got from growing them trees in the first place.

Our place — our hills — they’s full of buried anox, more full every year. We dig out a lagoon at the bottom of a slope and we seed it with weeds to soak up the oxygen. Then we pull trees down into it with the battery hauler. When it’s full, we cover it up again. If we can find clay, we put that over the trees first. And that’s about it. We get credit for our carbon, so long as the sats can see it.

Problem is, carbon ain’t worth what it used to be. Mom says time was a couple of good trees could get you a month’s groceries. I can’t remember nothing like that. All I know is if I can get a tree underwater in the morning and another in the afternoon, it can keep the line above red for another day, and we can get net service, and Mom can have her pills every month that the doctor says she needs to take. And we can eat some kind of meat besides deer.

Here’s a video I’ve wanted to post for a long time. It was a project for a college class in 1994, taught by one of MIT’s most understanding professors, Donald Troxel. Carlton Mills digitized the old VHS copy of our video report.

It was built by a team of three students: John Wallberg, Adam Holt, and me—we were the leftovers, actually, who hadn’t already found lab partners. Our two project ideas were this and robotic air hockey, and we were pretty sure a sheepdog would be both easier and safer. But we still finished it about 10 days late, working right up until we all had to leave for winter break. But it still won a prize (follow the link and search for “Newton”)!

The sheepdog itself is a LEGO robot covered by a cardboard box, and the sheep is a jittery baby toy. The sheepdog controls are three hand-built computers running 5-volt TTL logic, 8-bit 10MHz microcontrollers, miscellaneous op-amps and potentiometers, and at best 256 bytes of RAM and a few kilobytes of EEPROM. It turns out you can do some basic vision, navigation, and motor control with that!

Some details:

• The sheep had to be juiced down by power engineer Adam — I think he used 3 good batteries and a dud instead of 4 good batteries, because it was just too vigorous otherwise.
• The navigation system required the most complex computer of the three; Adam had 16 bits to work with on his main bus, which he had to divide into address and data lines; I think he settled on 10 bits for addressing and 6 bits of numerical precision in his trigonometric lookup tables. That way he could have 1024 instructions, of which he probably used 1023. While the vision system was being debugged, Adam and John had to find creative ways to test the navigation and driving blind. Because of their preparation, the whole thing basically worked the first night we plugged in the vision sensor. I think it was only possible because of Adam’s love of trigonometry and navigation. In his spare time he was downloading publicly available street grid data and displaying it interactively in ASCII on his home computer — a precursor to modern web-accessible maps.
• The vision system did simple light-dark thresholding and looked for blobs. We didn’t have a wide-angle lens, so we jammed our camera up as high in the ceiling as we could, to get about an 8-foot square field of view. My favorite feature was the debugging display, visible at 1:42, which was an RGB screen hooked straight to various internal signal lines of the vision system. It showed a raw greyscale camera channel in green, thresholded blobs in red, and the center of one of the blobs in blue (but aliased into a grid and with computation noise mixed in because I ran out of wiring space). You could see it compute the blobs at the top of each frame and then settle out into a clean debugging pattern that followed a blob around. It’s briefly visible in the background.
• The mechanical robot was amazingly reliable. John built it out of proven 6.270 parts, including what must have been at least 3 pounds of cross-linked LEGO Technic pieces, two small DC motors, rechargeable lead-acid motorcycle batteries (housed in the chassis itself) and a pulse-width modulation circuit. After we tweaked constants to match slight difference between the two drivetrains, the robot could go straight or curve along fairly accurate arcs. But even if it wasn’t exact, the feedback loop from sensor to navigation planning was tight enough (30 hertz?) that corrections were pretty immediate. At about 4:00, for example, it navigates tightly around the sheep and butts it from the other side. (Another, less fortunate team the same semester used a different brand of toys for their robot, along with stepper motors, which are theoretically simpler to control digitally but proved to be much less mechanically robust. Their robot hardware never did function properly, but the teachers were understanding and graded them well based on their circuits and software.)