The Shulchan Aruch – the Code of Jewish Law – states that 30 days before Pesach (Passover) one needs to start learning the laws of Pesach. The simple meaning of this directive is clear – the laws are many and complicated and there is a lot to learn – so one needs to start early. There may be a deeper meaning in this, however.

Let us recall that Pesach and Purim are exactly 30 days apart. To start learning about Pesach 30 days before, means to start learning about Pesach on Purim. Or, perhaps, the message is that from Purim we can learn about Pesach.

The word Purim means “lot.” The story of Purim is about throwing lots. Evil Haman threw one lot to choose a month for the pogrom against Jews of Persia and another lot to choose a day of the month to carry it out. The Zohar says that Yom Kippur, also called Yom HaKippurim, could be read yom ha-k’Purim – a day like Purim. The connection is through a lot – on Yom Kippur the Cohen Gadol (High Priest) also threw lots – which goat is to G‑d and which is to Azazel (see Acharei-Kedoshim: Tale of Entangled Goats). What is the significance of throwing a lot? A lot is an instrument of random choice. Instead of relying on our own choice, we throw a lot as a gesture of surrendering our will and relying on a random choice as a manifestation of hashgachah protit – Divine Providence. To summarize, Purim teaches us about the importance of randomness as a portal into Divine Providence. (See Saved by Randomness.)

Randomness plays a critical role in Physics too. Randomness is at the core of the paradigm shift from deterministic classical physics to quantum physics, based on statistics. In quantum mechanics, we cannot say with any certainty where a particle is; we can only predict a probability of finding the particle in a particular region.

In this sense, Purim, which teaches us about importance of randomness, is an introduction to Pesach. Pesach literally means “to skip over” – that is why it is called in English, “Passover.” On a literal level, G‑d passed over – “skipped” – Jewish houses when He punished Egyptians. On a spiritual level, Pesach means skipping spiritual levels. Jews are pulled out in one instant from the nun sha’arei binah – 50 gates of impurity. In spiritual worlds above, Kabbalah speaks of an accelerated development of Divine conciseness, called “Partzuf Zeer Anpin” (the Small Visage). This is why we must count 49 days between Passover and Shavuot to “fill in the gaps” created by this “skipping” of the levels.

Such level skipping is characteristic of quantum mechanics. Electrons can skip energy levels in “quantum leaps.” It is precisely this property of electrons first described by Niels Bohr in his Atomic Theory that led to the development of quantum mechanics.

On Passover, we celebrate the Exodus from Egypt. Egypt – in Hebrew “Mitzrayim” – literary means “limitations.” On Pesach, we celebrate the historic event of leaving the prison of Egyptian slavery and everyday necessity of transcending our limitation. Quantum physics teaches us about transcending limitation because nothing is impossible in the world of quantum physics. If an electron, found on the once side of the wall, in an instant can be on the other side of the wall without actually going through the wall – an effect called “quantum tunneling” – we can surely transcend our limitation, break out of our personal prisons without actually “breaking walls.” This is the lesson of Pesach that we begin to learn on Purim. Maybe this is another reason why we need to learn about Pesach 30 days in advance. But then, again, it takes at least 30 days to brush up on quantum mechanics…

Happy tunneling!