There is a dispute in the Talmud as to when was the world created. According to Rabbi Eliezer, the world was created in the month of Tishrei. According to Rabbi Yehoshua, the world was created in 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 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 post 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 quantum wavefunction. The universal wavefunction continued to evolve for billions of years until first human observers, Adam and Eve, collapsed the wavefunction and brought the world into a tangible physical existence as we know it today.
However, the property of the quantum-mechanical wavefunction is such that when collapsed, it brings with it all of its 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 collapsed its wavefunction, it brings along its history of either being alive and hungry for some time or being dead 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 wavefunction. 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 wavefunction, there is no physical world yet, only the wavefunction evolving in time. Let us recall that the wavefunction is a mathematical concept—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 wavefunction, they 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 we assume the motion of planets to commence in Nisan, before they were actually created. When Adam and Eve collapsed the universal wavefunction 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.