Schrodinger’s Hametz

Image from Janet Rosenbaum.
Print Friendly, PDF & Email


Rabbi Katz had never approved of quantum hametz zappers, and it was not because he considered it part of his job to disapprove of newfangled things. On the contrary: he had a ke-zayit-measuring app on his phone, he believed the hyperspace drive was a possible sign of the Messianic Era, and he contributed heavily to the researchers who traveled back in time to retrieve lost manuscripts by Rav Yehuda He-Hasid. 

It also wasn’t because he disapproved of shortcuts. It was true that he had once viewed anything faster, easier, and more popular with deep suspicion. In his old age, though, he’d come to appreciate the opportunities for new humrot that changing technology provided.

Still, he wasn’t fond of gadgets that made everyone else’s life easier, but made his life harder.

And the hametz zapper was definitely one of those.

In the past, people had started preparing for Pesach months in advance. His own mother, he often told his children, had made him eat outdoors in the snow for two weeks both before and after Pesach! He remembered it fondly: the scrubbing, the sweeping, the steaming, the endless reading of articles telling them that (a) they were doing too much, it didn’t have to be so hard, and (b) there were a dozen more things to do that they had never even considered.

Those had been simpler times.

But the hametz zapper, according to its inventor (and also the OU, the Star-K, and the CRC), could take care of all that in minutes. Thirty seconds to set the quantum field, two minutes to remove all matzah from the home (the hametz zapper couldn’t distinguish it from leavened bread, a fact that had caused great crises of emunah for some), and—zap! (the literal sound the device made)—the zapper broke the hametz down into its subatomic particles. Which, according to many poskim, was sufficient, bedieved, to destroy them.

No more cramming into tiny pizza shops! No more subsisting on grilled chicken and potato starch! You could do all your Pesach cleaning the day before Pesach! (Or the day before you started cooking, if you didn’t live close to Pomegranate.)

And that was exactly what people did.

Until they discovered, twenty-four hours before Pesach, that their hametz zapper was supposed to be pre-tested, because, due to unavoidable quantum fluctuations, a quarter of them didn’t work.

And then—then —they called the rabbi.

In the four years since the hametz zapper had gone on the market, Rabbi Katz had given up all of his usual erev Pesach activities. He no longer prepared afikomen hiding places. He no longer made his famous quadruple-egg kugel. He no longer added to his long-running lecture series of divrei Torah on the first two pages of Maggid.

Instead, he answered panicked questions about hametz zappers.

He had grown resigned to that. Previous rabbis, he figured, had felt the same way about dishwashers, microwaves, and teleportation. None of those things had gone away.

But this question—on Hol ha-Moed!—was enough to make him consider whether some of the signatures on that hametz zapper ban had actually been real.

“We should have read the instructions more carefully!” the man on the phone admitted, after introducing himself as Mr. Schwartz. “But you know how erev Pesach is! After my wife pressed the button, we assumed it was done. We didn’t realize we had merely translocated the hametz into its quantum bag!”

“I see,” Rabbi Katz said, adopting what he thought of as his soothing tone. He had great confidence in the effectiveness of this tone, despite a complete lack of evidence that it had ever worked. “So the hametz is still in the bag?”

“Yes! And no!”

“You don’t know?”

“No, I mean it both exists and doesn’t exist!”

“Ah,” Rabbi Katz said. “I see. I’ll have to consult a physicist, and then I’ll call you back.” He could tell his caller was modern Orthodox, because the man addressed him in second person singular; and his modern Orthodox congregants were always impressed when he said he would consult a scientist.

They seemed to think he had a control board with the numbers of experts in every field, all of whom were happy to spend hours explaining how their specialties meshed with halakhah.

What he in fact did, after hanging up, was pull up Wikipedia.

He was halfway through an article about Einstein’s early interest in Talmud (having gotten a little sidetracked) when the phone rang again. Perhaps Mr. Schwartz had texted some other rabbi while waiting, and Rabbi Katz was off the hook? Rabbi Katz picked up the phone, cleared his throat, and said, “I was investigating —”

“My wife just got home,” Mr. Schwartz said. “She’s a physicist. Would that help?”


In the end, it was deemed best for Rabbi Katz to visit the Schwartzes at their home. They met on the front porch, where Mrs. Schwartz explained, over a plate of various potato starch confections, that reality doesn’t exist. (“Ah, yes,” said Rabbi Katz. “As the Mikhtav me-Eliyahu already knew.”) At the subatomic level, everything exists only as a range of probabilities, until observation forces the probabilities to choose one reality.

“The zapper is based on those quantum probability waves,” Mrs. Schwartz finished up, around a mouthful of macaroons, “so until we open it and look inside to see whether the hametz has been broken down, the probability waves haven’t collapsed into an actual, observable reality. So right now, the hametz both exists and doesn’t exist.”

“Hmm,” Rabbi Katz said warily. Clearly, they had left the realm of R’ Dessler behind. This sounded either like kefirah, or like something the Rambam might have said.

“So you see the problem,” Mr. Schwartz said. “If we open the zapper, and the hametz is there, we’ll have owned it on Pesach. In which case, it needs to be burnt. But we’ll only have a split second before the hametz dissolves into subatomic particles. At which point, it can’t be burnt.”

“Ah,” Rabbi Katz said.

“On the other hand, if the hametz isn’t there, it was never there!”

That sounded like it would be best.

“But if we look, we force one reality to happen,” Mrs. Schwartz said. “In which case, we’re actually making the hametz exist on Pesach!”

Which was probably an issur de-oraita. At least.

“Are we sure this whole quantum probability thing is true?” Rabbi Katz said suspiciously.

The Schwartzes exchanged glances. Mrs. Schwartz said, “Yes. I’m sure.”

“More or less sure than you are about evolution?”

Mrs. Schwartz cleared her throat. “There are numerous experimental and mathematical proofs.”

“Besides,” Mr. Schwartz said, “quantum theory refutes the previous scientific claim that the world is completely deterministic. It’s evidence for the existence of free will.”

“Oh.” Rabbi Katz made a mental note to use that concept in a shiur sometime. “Okay. Give me a moment.”

He buried his face in his hands. For several minutes, all was silent. Mrs. Schwartz wondered if it was possible that Rabbi Katz was both napping and not napping.

Then Rabbi Katz looked up, his face alight.

“Quantum, shmantum. This is simply a question of whether uncertainty cancels certainty, and the Talmud has already dealt with the issue.” He thrust his thumb into the air. “The quantum trigger is exactly the same as a weasel!”

Mr. Schwartz frowned. “But the whole point there is that a weasel might eat some hametz and leave the rest over.”

Rabbi Katz brightened. “Aha! You know the gemara.”

The gemara, indeed, discussed the question of what happened if a weasel ran into a house with hametz, then ran out without the hametz. It addressed issues of certainty, uncertainty, weasels’ eating habits, and also ancient burial customs, tithes, and the laws of ritual purity (similar, in many ways, to Rabbi Katz’s earlier internet-browsing research). It would certainly simplify things, Rabbi Katz thought, if he didn’t have to explain all that.

“But based on that mishnah,” Mr. Schwartz said thoughtfully, “don’t you think quantum probability waves are more equivalent to the dwelling place of a star-worshipper?”

On the other hand, maybe it wouldn’t simplify things at all.

“Although, the hametz zapper is intended to get rid of the hametz,” Mr. Schwartz went on.

“Perhaps that means we should rather analogize it to the storehouse of a dead sage?”

That particular mishnah, Rabbi Katz knew, ended with the phrase Ein Sof Li-Davar (there will be no end to the matter). Clearly, that was not just a reference to the multiverse theory.

“There’s only one choice,” Rabbi Katz said firmly. “You have to open the hametz zapper and force one version of reality to take place. If there’s no hametz, we can all breathe a sigh of relief. And if the hametz is there, at least you will have destroyed it in the process of opening the zapper.”

Mrs. Schwartz squared her shoulders. “All right.”

She disappeared into the house and emerged with the hametz zapper, which looked sort of like you would expect a hametz zapper to look, except a lot more colorful—the children had covered it with Trader Joe’s stickers. She took a deep breath and pressed a small blue triangle on the side.

Both men leaned forward. Three sets of breath were held.

Nothing happened.

“Maybe you have to press harder,” Mr. Schwartz said.

“No, that’s not it,” Rabbi Katz said. “Those buttons are so sensitive that a stiff enough sheitel can accidentally turn them on.” Mr. Schwartz raised his eyebrows, and Rabbi Katz shook his head. “A story for another time. You just have to plug it in.”

“Plug it in?” Mrs. Schwartz repeated.

Rabbi Katz stared at her. “You didn’t realize that you have to plug it in?”

“I’m a physicist,” she said defensively, “not an engineer.”

“If you never plugged it in,” Rabbi Katz said, “it never worked. There’s no hametz in there at all, because the hametz zapper did nothing.”

Mrs. Schwartz looked embarrassed. “I’m sorry to have bothered you.”

“Don’t be sorry!” Rabbi Katz assured her. “I’m happy to have clarified the subject of quantum mechanics as it applies to the laws of Pesach.” In fact, his next lecture for was practically written, which would leave him time to make another kugel.

“Wait,” Mrs. Schwartz said. “If the hametz zapper never worked at all—and I was relying on it to clean for Pesach—don’t I now have a much bigger problem?”

“Bigger,” Rabbi Katz said, “but simpler.”

He gave the Schwartzes the number of a rabbi in Israel who specialized in Pesach leniencies, then walked out the door, already mentally composing his second (and probably far more popular) shiur on The Dangers of Technology. 


Leah Cypess is the author of numerous fantasy stories and novels. Her most recent book, Thornwood (Random House/April 2021), is a middle grade retelling of Sleeping Beauty told from the point of view of Sleeping Beauty’s little sister. You can find out more about her at