[Editor’s Note: In this excerpt from Where Do You Stop?, Peter Leroy recalls Miss Rheingold, his seventh-grade general science teacher, and the unforgettable movie that she showed in class one day.  —MD]

HE MOVIE that Miss Rheingold showed us was called Quanto the Minimum. It was developed, or at least sponsored, by the telephone company, and it featured a tiny cartoon character, Quanto the Minimum himself, who explored the constitution of matter as it was then understood. Try as I might, I’ve been unable to scare up a copy of this film to review for this book, so I will have to rely on memory to summarize it for you.
   As I recall, Quanto was an impish sort, sarcastic and even a bit nasty. He seemed always to be telling us, the captive audience, how stupid or ignorant we were. This abuse started right off the bat, when Quanto stood with his little hands on his cartoon hips and said right at us, “Hey, kids, I'll bet you think you're really something, don't you? Ya-ha-ha! Well, get this--you're really mostly nothing! Just wait till I get through here. You'll find out that you're mostly empty space. Ya-ha-ha! Come on! Come on along with me! I'll take you on a remarkable voyage of discovery--from the farthest reaches of the universe to the tiniest heart of the tiniest atom--from the vastness of your ignorance to the tiniest little twinkling photon of enlightenment, which is really about all I can realistically expect to pass on to you with the budget they've given me to work with. So hang on! You're in for some surprises. You're about to find out that most of everything is nothing.”
   Quanto did take us on a remarkable voyage, as he promised, but he was a difficult guide to follow because his style, like Miss Rheingold's, was discontinuity. He jumped from one topic to another with no more transition than saying, “Wow! That was really something. Aren't you excited? I am. I'm really excited!” Then, foom, off he'd go. He seemed to whiz right off the screen and rocket through a radioactive blue miasma for a couple of seconds, eventually reappearing in another location, calmer, a little worn out, breathing heavily, his snazzy red outfit torn here and there, to tackle the next topic. “Whew!” he might say. “That was quite a ride. Where are we? Ah! Alamogordo. Wait till you see this.”
   We saw many things, a fascinating jumble: an atomic bomb blast flipping battleships like toys in a tub, solar flares lashing out like the whip my favorite movie cowboy carried, a Tinkertoy lattice that represented the molecular structure of some crystal or other and made chemistry look like lots of fun, and more. We learned a word that all of us went around using whenever we got half a chance since it was such a pleasure to say. It began with a funny buzzing, hissing, and shushing, generated a lot of saliva along the way, and its ultimate syllable made my mouth a cavernous space in which a howl resounded. This wonderful word was Zwischenraum, the word Quanto used for the empty space that is most of everything, the nothing that permeates and separates it all. . . .
   Among all the marvels in Quanto the Minimum, however, the universal favorite was a demonstration of the mousetrap model of a fission reaction. In this demonstration, a Ping-Pong table was covered with mousetraps, densely packed, but set at angles to one another, so that the model wouldn't seem to be regularizing matter too artificially. All of the mousetraps were cocked and ready to spring, and resting on the wire bail of each was a Ping-Pong ball. An announcer appeared at the side of the Ping-Pong table. Quanto leaped onto the screen, said, “Keep your eye on this guy,” and leaped off, laughing.
   The announcer waved his hand toward the Ping-Pong table, taking in its entire magnificent array of cocked traps and ready balls, and said in defiance of all logic, “This is Uranium 235.”
   Then he went on to explain some things he seemed no clearer about than we were. He seemed to keep losing the distinction between the Ping-Pong ball he was holding as the Ping-Pong ball it actually was and the neutron it was meant to represent. Whenever he said that a neutron was used to bombard the Uranium 235 he made a dart-throwing motion with his hand, suggesting that the bombarding process was a heck of a lot like dart throwing, or at least that was the impression it left on most of us. When he had finished his taxing explanation, he said, “And this is the result,” and with coy insouciance tossed the ball into the array of traps.
   Wow.
   What resulted may or may not have been a good demonstration of what occurs during nuclear fission, but I am certain that I will never see a more vivid demonstration of an idea that my parents had tried to hammer into me back when I was just a kid, before I took up junk browsing as a pastime, whenever I became bored on rainy vacation days and pleaded with them to mitigate my boredom with a new model airplane kit or a dozen comic books. What they said--and this Ping-Pong ball experiment so spectacularly proved--was, “You don't need model kits and comics to have fun. You can have a lot of fun with the things you find around the house if you just use a little imagination.” Definitely so, provided you could find a few dozen mousetraps and Ping-Pong balls.
   The film ended. The fluorescent lights stuttered and flickered into life.
   “We just have time for a few questions,” said Miss Rheingold.
   Hands shot up all over the room. Miss Rheingold beamed with pleasure and satisfaction.
   “Yes, Spike,” she said.
   “How do they get those Ping-Pong balls to stay on the mousetraps like that?” She was poised to take notes.
   “I--I don't really know,” said Miss Rheingold. “Um, Peter?”
   “Do you think a little piece of tape would do it?” I asked. “If you curled it around and stuck it back on itself, the way you do when you want to stick something up on the wall without using a tack?”
   “I guess it would,” said Miss Rheingold. “But that's not really what--”
   “Rubber cement,” called Dave Botsch, from the back of the room. These were the first words I'd ever heard the overgrown thug volunteer in a classroom in the seven years that he'd been attending school with me. Even his highly persuasive arguments about the wisdom of my giving him portions of my lunch were mostly nonverbal. “You can steal it from the supply closet in the art room,” he elaborated. “First cabinet on the left. One little drop on each ball. Let it dry a little, so it's just tacky. Then set it in place. Carefully.” With that he lapsed again into his accustomed silence and did not break it again from that day to the day he quit school nearly four years later, when he said something that I remember as “Yaaaaahhhh!”
   “Well--” said Miss Rheingold. “And you, Bill?”
   “Can you use just regular mousetraps, or do you have to get that model 235 they were using there in the movie?”
   It took Miss Rheingold a moment to recognize what a depth of misunderstanding underlay this question. When she did, her shoulders and the corners of her mouth dropped simultaneously. “Oh,” she said, or perhaps she just moaned. The bell rang.
   We hear from time to time about the power of an idea to influence people, as individuals and in the mass. Usually it's politicians, religious fanatics, or pop philosophers who expect to use ideas to whip people into line, but the most powerful idea I've ever encountered had nothing to do with phony promises, false gods, or bogus ontologies. It was that table covered with mousetraps and Ping-Pong balls. Now that was a powerful idea! I would guess that, at minimum, 95 percent of the students in Miss Rheingold's class walked out of the Purlieu Street School that afternoon with the firm determination to make whatever sacrifice might be necessary to acquire a Ping-Pong table and a couple of dozen mousetraps and balls, and recreate the experiment we'd seen in Quanto the Minimum. I know that most of us didn't actually do it, but that isn't surprising. In time the task must have come to seem too hard, or much less important than other tasks that came along, or even just plain silly. It takes a special mind to stick to a determination to do something just for the hell of it, the kind of mind my great-great-grandfather Black Jacques Leroy had and few others do.
   I wanted to ask one more question before I left, so I stopped at Miss Rheingold's desk, where she sat on the edge watching the class converge on the door, pass through it, and expand into the hall. “Venturi,” she muttered.
   “Miss Rheingold?” I said.
   She pressed a hand to her honeydew brow. “Peter,” she said. “I hope this isn't another question about mousetraps.”
   “No,” I said. “Oh, no.” Actually, I had wanted to ask if the traps had to be aligned precisely as those in the film had been and, if so, whether it might be possible for me to come back after school and see Quanto the Minimum again so I could memorize the arrangement, but I could tell from the way she ran her fingers through her shandy hair that for some reason Miss Rheingold didn't want to talk about mousetraps, and I certainly didn't want to annoy her, so I said, “No, no. It's about my question, 'Where do you stop?' I tried to find the answer in the library, but they don't have any books there that have anything about it. All their books are kind of simple.”
   She smiled. I was pleased to have caused it.
   “I think I can help you,” she said.
   The smile that came to her lips, the twinkle that came to her eye told me that my discovery that the library's books were too simple for the Big Questions had all been part of her plan for me. I was supposed to discover that the question took me beyond the obvious sources. I was supposed to come to her, or to go elsewhere, but in any event to expand my horizons. I must be getting somewhere, I reasoned. She went to the storeroom and returned with a book even thicker and heavier than our general science text.
   “Try this,” she said.
   It was called Elementary Introductory Physics Made Easy for Beginners (Book One). I tried to read it. I really did. My problem was that I understood only a portion of what I read, and the portion I understood was not the portion that conveyed most of the meaning. I moved my eyes along the sentences, did my best to pronounce the words, and used my dictionary quite a lot, but so much of what I read was incomprehensible to me that . . . it resembled coleslaw: discontinuous but recognizable shreds of cabbage in an indescribably complex entanglement, with an opaque sauce that almost fills the Zwischenraum. Remarkably, I managed to derive two ideas from the first chapter. They were these:

1. Things get very much more difficult to understand as you get very much closer to them. 
2. As Quanto said, “Most of everything is nothing.”

A Topical Guide to the Complete Peter Leroy (so far) is a work of fiction. The characters, incidents, dialogues, settings, and businesses portrayed in it are products of the author’s imagination and are not to be construed as real. Any resemblance to actual events or persons, living or dead, is entirely coincidental. 

All rights reserved. No part of this guide may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or by any information storage and retrieval system, without permission in writing from the author. 

Portions of A Topical Guide to the Complete Peter Leroy (so far) were first published by Voyager, Inc., as part of The Complete Peter Leroy (so far).

The illustration at the top of the page is an adaptation of an illustration by Stewart Rouse that first appeared on the cover of the August 1931 issue of Modern Mechanics and Inventions. The boy at the controls of the aerocycle doesn’t particularly resemble Peter Leroy—except, perhaps, for the smile.