There is a dispute in the Talmud as to when the world was created. According to Rabbi Eliezer, the world was created in the month of Tishrei, the seventh month of the Jewish calendar when we celebrate the Jewish New Year, Rosh HaShanah. According to Rabbi Yehoshua, the world was created in the first month of the year, the month of Nisan (Tr. Rosh HaShanah, 10b).
The Chasidic thought attempts to reconcile these opposite opinions suggesting that both opinions are correct—the world was created in Nisan in thought, whereas in deed, it was created in Tishrei. The problem with this approach is that for halakhic (Jewish ritual law) purposes of calculating the Jewish calendar, the planets are deemed to have commenced their heavenly orbits in Nisan, not in Tishrei! How could planets that haven’t yet been actually created, start their orbital movements in Nisan?!
This can be explained by using the approach I suggested in my essay “Two Beginnings” and, earlier, in my articles “Towards Reconciliation of Biblical and Cosmological Ages of the Universe” and “On the Age of the Universe in the Many-Worlds Interpretation of Quantum Mechanics”. The gist of this approach is that when the world was first created during the Big Bang some 13.78 billion years ago, the world existed in a proto-physical state as a distribution of probabilities expressed as the universal quantum wavefunction. The universal wavefunction continued to evolve for billions of years until the first human observers, Adam and Eve, collapsed the wavefunction and brought the world into tangible physical existence as we know it today.
However, the property of the quantum-mechanical wave function is such that when collapsed, it brings with it its entire past history. For example, if you put a Schrödinger cat in a box and leave it there for a few days, the cat will exist there in a state of suspended animation — half-dead and half-alive—a state of superposition of being dead and alive, to be precise. When you look inside the box, thereby collapsing the wavefunction of the cat into being either dead or alive (but not both), you will find a cat either very smelly or very hungry depending on its fate. Although the cat assumed a definite state and became either alive or dead the moment the observer collapsing its wavefunction, it brings along its history of either being alive and hungry for some time or being dead and decaying for some time. This is why cosmologists find the universe to be some 13.78 billion years old, notwithstanding the fact that the universal wavefunction was collapsed by the first human observers much more recently—less than six thousand years ago, according to the Jewish tradition.
This explains the dispute (machloket) between Rabbi Yehoshua and Rabbi Eliezer. Rabbi Yehoshua is talking about the first creation when the world was in a proto-physical state being described by a wave function. We call that moment of initial creation “Nisan”—the first month. In Hebrew, the word for month is “chodesh,” which means new. The first month, Nisan, is the very beginning of the new creation—the universe. However, at that point, prior to the collapse of the universal wave function, there is no physical world yet, only the wave function evolving in time. Let us recall that the wave function is a mathematical concept—a distribution of probabilities (the square amplitude of the wavefunction is the probability of finding the particle in a given area of space). Thus, it is a mental construct. This is why the Chasidic though tells us that in Nisan, the world was created in thought. In Tishrei, when Adam and Eve collapsed the wave function, they indeed brought the world into physical reality—this is why we say that in Tishrei the world was created in deed.
We can now also understand why the Talmudic Sages assumed the motion of planets to commence in Nisan, before they were actually created. When Adam and Eve collapsed the universal wave function in Tishrei, they brought the Universe’s past history into reality. This is why the planets, which became tangible only in Tishrei, are seen as to be moving since Nisan—for the same reason as we see this universe to be 13.78 billion years old.