The Idea Factory

by Pepper White

  He asked abruptly, "Why'd they pick you?"

  "Gee, Chet, I don't know; maybe they wanted somebody on the team to make the other two guys look smart."

  "Yeah, well, I guess you can have the time off. I should go along on that, though. If they really wanted to have a team that would solve it, they'd have someone like me along," Chet said.

  I wondered whether he'd posed as a graduate student and put his name in the hat for the team selection. I answered, "They only want students on this thing. Okay, I know you look young enough to be a student, but you'd have an unfair advantage. You're gifted."

  "Yeah, well, just try not to embarrass the institute by what you say on TV," Chet said. "Let the other guys do most of the talking."

  Thank you, Chet, for that vote of confidence.

  "Oh yeah, but before you go I want you to do some runs of a computer model I've put together to make sure the RCM simulates the stroke of a real diesel engine. I think the guys who worked on the machine before us may have messed up the assembly of the snubbing chamber," Chet said.

  I left his office and went to talk to Professor Gyftopoulos, to ask him for reference materials on perpetual motion machines.

  "That's very interesting. I wonder why they picked you," he said.

  "They liked my application."

  "Well, look for places where irreversibility may occur in the machine. There will certainly be friction, and there will certainly be an energy supply within the machine. Do what you can to locate these."

  Greene was a little more positive. "Congratulations," he said. "That's quite an honor, being picked as a representative from MIT. "

  I'm glad somebody thinks so.

  "You'll have some tough competition from Berkeley, though. But it's a lovely area. I hope you're giving yourself time to take in a few of the sights."

  "Yes, I'll cycle there for about a week. Do you have any suggestions as to how to think about the problem?"

  "Yes, well, look for where there is degradation in the quality of the energy. Most of the attempts at perpetual motion machines over the ages have included sections where energy is removed from the process and other sections where it's put back into the process. The problem is that wherever you have energy flow, in real life you have entropy increase. You remember that with your cycling example."

  "Thanks for your help, sir," I said. "I'll let you know when the show is on."

  January 6

  More salt mines. Chet showed me his model for the motion of the piston of the RCM and made a copy of the program on the lab's Digital (Ken Olsen, '50) VAX computer. Chet redrew the machine for me on a piece of green and white computer paper.

  "So you see, the idea in modeling the motion of the shaft is to write Newton's second law for the moving shaft; at every point in its motion, the sum of the forces on the shaft will equal the mass of the shaft assembly times its acceleration at that moment," he said. "We got the driving air pressure from the tank, and then we got the pressure of the gas in the cylinder pushing back on the combustion chamber's piston, and then we got the back piston dragging along and slowing the whole thing down, depending on how much space there is."

  I remembered Greene's balloon problem, how I'd made the balloon expand in just one direction.

  Then I looked at the RCM diagram again and translated it into the language of the model.

  Chet continued, "So what I want you to do is take the machine apart in the back and determine the ring geometries available and the snubbing piston diameter. Then I want you to change the order of the rings in the computer until the forward motion of the shaft matches the motion of the shaft in a real engine."

  I wondered why or whether it made much difference how the compression profile took place or whether Chet's point was, This is something we can control to make the experiment match real life better and therefore more useful, less questionable when we present a paper in Detroit, so we have to do it. It can be done; therefore, we do it. But there was another lesson to be learned here.

  My task was to take the machine apart, take the dimensions of the centerless disks, input the dimensions in the computer, and play with the order of the centerless disks until the piston moved through them as required, all on the computer. The alternative was trial and error-i.e., take the machine apart and put it together again and test it until we achieved the same result.

  Chet had set up the program so I only had to input a list of the ring diameters and see what happened. I took the RCM apart and put it back together ten times in an hour, just by changing the order of the ring diameters in the computer's input statement. In the real world, engineers do this kind of thing all the time because it is much cheaper to pay an engineer to set up a computer model and hack away at it than to pay a machinist to hack away at blocks of metal.

  I hacked for a few more hours that Friday but I made no progress. On Monday morning Chet said, "Don't worry about that problem; I finished it over the weekend."

  "Why, Chet?" I asked. "I thought that was my job. You let me start it; why didn't you let me finish it?"

  "I didn't want you to waste any more time on it. We gotta put the machine back together and do some firings before the consortium meeting in March. What with your week off and the next semester coming up we gotta make a lotta progress in January," he answered.

  This was Chet's style. The micromanager. Chet was stuck between a rock and a hard place in having me as a student. On the one hand, the point of my working on the experiment was for me to be trained as an engineer. On the other, perhaps more significant, hand, the point of my working on the experiment was to obtain results, publish papers, promote Chet to full professorship, and retain the sponsors' income stream.

  So when in my lumbering way I took too long to do things because I hadn't done them before and my thought processing wasn't as lean and mean as Chet's, he'd step in and help me. Or sometimes, like over the weekend, he'd jump in and do the task himself.

  That afternoon, Nick and I reassembled the ring assembly according to Chet's specifications. I felt the way Nick must have always felt, carrying out someone else's design, not knowing why it was that way, not being mentioned in the paper but knowing it was still better than working on an assembly line.

  Nick lowered the chain fall into place and I put the twenty bolts through the holes and into the threaded holes in the machine. I said to him, "I wonder whether anyone likes this kind of work."

  "Whadaya mean by that, Cap'n?"

  "Well, do you like this kind of work?"

  "Of course not. I gotta do it. It's a living," Nick answered.

  "That's what I mean. I wonder whether communists like this kind of work."

  "Don't talk that way, Cap'n. Communists are bad; they don't believe in God."

  January 14

  The guy in the seat next to me on the night flight to San Francisco International was an astrophysicist. He had a storybook life: he spent half his time doing research and teaching at Harvard; the other half he spent working on laser-induced fusion at Lawrence Livermore Laboratory.

  "Look at those stars," he said. "Just look at them. You could almost touch them from up here, they look so close."

  I switched places with him and couldn't see much of anything, what with the glare from the cabin lights.

  "You know," he said, "it's really a strange thing we're doing right now. We're inside an aluminum tube, traveling in the air, six miles above the ground. It's such an odd thing. I wonder what future generations will think about it."

  January 18

  I bicycled from Berkeley to Livermore to meet my friend from Belgium who'd been working for U.S. Windpower for the year and a half that I'd been at MIT.

  "What makes them work well," he said, "is that the wind blows steadily through the pass here for about eight months of the year. Unfortunately, January isn't one of the months, so none of them is turning for you."

  "Why does the wind blow one way only?" I asked him.

  "The Sacramento Valley is like a
giant solar panel. During the day, it heats up, and the air rises. As the hot air rises, it has to be replaced by air from somewhere. The air from somewhere is cool air from the ocean. It funnels its way through the pass here."

  I remembered Greene's balloon problem. The ocean was like the higher-pressure tank. The valley was the balloon; the Alta Mira Pass was the pipe between the tank and the balloon.

  January 20

  Contest day. Dan and Tim and I received our syllabus for the day. Dan wore his tuxedo and red carnation, Tim wore his normal plaid shirt and slightly short (i.e., high-water) corduroys. I wore the MITAA (MIT Athletic Association) sweatshirt that Cindy lent me, blue jeans, and Don's lab jacket. The red of the sweatshirt would show up well on the video camera, according to an article in The Globe.

  Berkeley's team had one MIT physics undergrad, who was doing his Ph.D. in astrophysics, plus two Berkeley undergrad computer jocks. From the moment he opened his mouth, it was evident that it was Berkeley's MIT guy who would pose the biggest problem for us.

  The contest would consist of first an introduction and toss of a coin by Dr. Glenn Seaborg, Nobel chemistry laureate, who is best known for his work on isolating and identifying elements that are heavier than uranium (plutonium, for example). Then Dr. David Jones, the machine's British inventor and acclaimed selfpromoter, would present the machine briefly. We would have a chance to ask him questions, and then we would break into our respective hotel rooms for discussions. At that point, we could request any test equipment and would have private access to the machine twice. At the end of the day we would present our results, and Dr. Jones would decide the winner.

  Before the camera started rolling, we sat in the room with the motionless machine. Dr. Jones gave it a good hard push, at what looked like its full speed. It stopped in about half a minute. "Umm. Excuse me, ladies and gentlemen, but I think I'll need a few minutes alone with the machine."

  Everyone left the room except Dr. Jones. Twenty minutes later we went back in. The machine was a spinning bicycle wheel mounted in a rectangular steel frame. At the top of the frame were two cigarette-box-size boxes with what looked like potential solar cells, and at the bottom of the frame was a larger box with two 3-inch metal disks on top. On either side of the wheel's hub, a rod extended down to a separate disk that moved up and down opposite the disk on the lower box. Copper tubes also aimed at the rim, set at such an angle that perhaps they could be blowing the wheel around.

  Before the toss, the sound guy said, "I'm getting some static on the mike near the machine." This was a hint.

  Team MIT won the toss, so we asked the first question. Tim asked, or rather told, Dr. Jones, "If I go into outer space, and I throw a rock from a space capsule, it will keep going at its initial speed more or less forever. But that's not a perpetual motion machine, because the rock doesn't deliver power outside itself. Your machine doesn't deliver power outside its own motion, so in the thermodynamic definition of perpetual motion machines of the first and second kind, your device fails."

  Dr. Jones was taken aback. Dr. Seaborg nodded his head up and down slightly. The camera caught it all.

  Dr. Jones answered, "The fact remains that this machine moves continually. I challenge you to define why."

  "How much did it cost?" I asked. If we had an upper bound on the materials cost, we could eliminate propulsive methods such as a micronuclear reactor in the lower box or a microwave receiver from a transmitter elsewhere in the room.

  "A few hundred dollars in equipment and hundreds of hours of labor and aggravation on my part," Dr. Jones answered to laughter from the studio audience.

  The MIT physics guy from Berkeley's team asked, "How long have you run it continually?"

  "It's been on display in a number of museums over the past several months, for periods as long as three weeks," he answered.

  My bicycling eye came in handy. "Is the wheel out of true for a reason?" I asked.

  "No. It's just the stress of shipping," Dr. Jones said.

  One of the non-MIT Berkeley guys asked, "How much does the whole thing weigh?" What a stupid question, I thought.

  "About 100 pounds."

  We broke for our respective hotel rooms.

  Tim started our discussion. "I think he was kind of ticked off at my first question to him. We're going to have to come up with an explanation that's really right if we're going to win this thing. That microphone interference from the sound guy was a golden hint, though. There must be some electromagnetic field interaction in some of those boxes. Let's ask for a transistor radio. When I was a kid I used to take my transistor radio, tune it between channels, turn up the volume, and put it next to things like my father's stereo, the back of the refrigerator, my mother's hair dryer. It drove my mother crazy, but I could sort of track what was happening in the air by the noise the radio made."

  "OK," Dan said. "I'll write that as one of the items of test equipment we want. What about the tubes?"

  "They could be blowing on the rim and providing enough force to overcome the friction in the wheel's bearings," I said. "A friend of mine in Belgium smoked a lot and we used his cigarettes to see what air flow was doing, so maybe we should put cigarettes and matches down on the list, too."

  "Check," Dan said. "Let's first do a power analysis on the wheel. We know that before Jones made the machine work continuously, it took about half a minute for it to come to a stop. That means that when the power isn't being tranferred from wherever to the wheel, the energy of the wheel will be dissipated in about 30 seconds. We can calculate the energy stored in the flywheel effect of the movement of the wheel, and divide by 30 seconds, to find the order of magnitude of the power required to overcome the air resistance and the friction of the bearings."

  Good idea, I thought. Dan had gone to MIT as an undergrad, too. He ran the calculation quickly, and the power requirement was about 0.05 of a watt. A fairly small battery or set of batteries would keep that wheel going for a few weeks.

  "OK; 0.05 watt is the power required to overcome the friction. Let's figure out whether air jets coming out of the copper tubes could provide that much power. Pepper, you're the fluids whiz. Got any ideas how to calculate that?" Dan asked me.

  "Well, I know how to calculate how much power is coming out of the tubes, how that relates to the speed of the air coming out of the tubes. And I'll throw in a 10 percent efficiency factor; i.e., one-tenth of the energy of the air jet coming out of the tube might actually go into turning the wheel. That's as reasonable an assumption as any we can make in the next hour."

  I wrote down the equations with lots of wavy equals signs, meaning "approximately equal"; I'd learned something in Shapiro's class. "So that means that for the air jet to keep the wheel going, the air speed would have to be about 3 feet per second. If we put a cigarette next to the tube, the other 90 percent of the air should blow the smoke pretty visibly."

  "That's good," Dan said. He was sort of taking on the role of our team leader, with Tim the really smart guy, and me sort of smart and sort of creative.

  "Now let's consider other ways this thing can turn," Dan said.

  "We need to determine whether the plates are driving the wheel or the wheel is driving the plates via the connecting rods," I suggested. "How about asking for a magnifying glass, and I'll get a good close look at the connecting rod at the wheel. If the wheel is driving the rod, the connecting pin will be on the bottom of its sleeve at the top of its stroke, and at the top of its sleeve at the bottom of the stroke. The opposite will be true if the rod is driving the wheel." I'd learned that trick from Professor Heywood's discussion of bearings in engines. "We'll need a magnifying glass, plus a spotlight for me to be able to see anything."

  "Sounds good," Tim said. "We should also check out whether the thing gets any power from the lights in the room. Those little disks on the boxes on the frame could be solar cells."

  I added, "Yeah, if that's how it works, then we can count revolutions of the wheel in a given time, then shut the
lights out in the room for a minute or so, and then count revolutions of the wheel in the same time. If it slows down, we'll know that it's getting its power from the lights in the room."

  Dan answered, "Right, let's do that test. It's a little on the obvious side, though; I mean, I bet he put those solar-panellooking things on there just to fool us. But we should check it for completeness."

  Tim said, "What about air currents? Maybe it's placed in the room so that the air from the air-conditioning is going up on one side of it and down on the other side of it. Or maybe the air currents from the heat of the bright lights hit the boxes on the rim so that the thing keeps turning. It's sort of a long shot, but hey, we're brainstorming here, aren't we? One wild and crazy idea could lead to a good one."

  "We could put a big plastic bag over the thing," I said. "If they let us do that, and the air currents were driving it, it'd stop then. I mean that's within the rules, right? We wouldn't touch it. Barring that, how about we get some ice, a hair dryer, and an iron. We can move the ice and the hair dryer and the iron around so that we can try to break up the steady air flow that might be pushing the boxes around in such an orderly direction. We can introduce some entropy into the system that way."

  "Okay," Dan said. "I'll put 'large plastic bag' on the list. We'll need some string to hold it up, and some scotch tape to seal it, and maybe some rubber bands just for good measure. Are there any other things we should ask for?"

  "A large hammer," Tim said, "and a pepperoni pizza."

  "No seriously, though. Are there any other mechanisms we need to test?" Dan asked.

  "If the disks below are driving the thing, and they're running on some kind of capacitive repulsion principle-you know, like when you rub two balloons on your sweater and they repel each other-then we need to test that somehow. I'm not a physicist, though, and electromagnetic theory is why, so I don't know how to check that," I said.

  Tim replied, "I remember something in freshman Physics, eight oh two, about an induced current in a piece of metal between two capacitive plates. If the plates are working as a capacitor- i.e., they store electric charges-and we put a sheet of copper in between the two plates, as the amount of charge varies in the plates of the capacitor, the amount of charge of the copper should vary, and we should be able to measure a current."