Kabbalah, kabbala, kabala, qabalah, cabalah

Vectors, Spins, and Gender

Vectors, Spins, and Gender Speak to the children of Israel, and have them take for Me an offering; from every person whose heart inspires him to generosity, you shall take My offering. (Ex. 25:2) Every physics professor teaching physics 101 to freshmen spends the first lecture teaching vector algebra. Why vectors are so important? Because most quantities in mechanics (a branch of physics dealing with motion and forces) are vectors. A vector is a mathematical object that has a magnitude and a direction. For example, velocity is a vector – it shows not only how fast the object is moving, but also in what direction it is moving (it is different from “speed” which is an average velocity and is just a number). Similarly, acceleration is a vector, force is a vector, angular [...]

Fractal Tu B’Shevat

When thou shalt besiege a city a long time, in making war against it to take it, thou shalt not destroy the trees thereof by wielding an axe against them; for thou mayest eat of them, but thou shalt not cut them down; for is the tree of the field man, that it should be besieged of thee? (Deut. 20:19) On Tu B’Shevat we celebrate the New Year of the trees. There is much to be said about the legal, ecological, homiletical, and mystical meaning of this day. And, indeed, much has been written about this minor holiday from these perspectives. In this post, however, I’d like to focus on the mathematical and biological aspects of this holiday that, to my knowledge, had not been discussed until now. When the Torah rhetorically asks, [...]

Wellsprings from Above and Wellsprings from Below

In the six hundredth year of Noah's life, in the second month, on the seventeenth day of the month… all the fountains of the great deep were broken up, and the windows of heaven were opened. (Gen. 7:11)   In calculating the time of the dawn of Messianic revelation, the Zohar writes, And after six hundred years of the sixth thousand there will be opened the gates of wisdom above and the fountains of wisdom below, and the world will make preparations to enter on the seventh thousand as man makes preparation on the sixth day of the week, when the sun is about to set. (Zohar I, 117a) The Zohar calculates this based on the letters of the Tetragrammaton, but brings the verse from this parshah as the mnemonic: “In the six [...]

Tishrei—Past, Present, and Future

The months of Tishrei is full of holidays, and they all share a common theme—the unification of time—past, present, and future. Picart, Blowing of the Shofars on Rosh Hashanah It all starts with Rosh HaShanah. Traditionally translates as the New Year, it literally means the Head of the Year. The word shanah has the same letters as the word shinui — “change.” As Aristotle famously wrote, time is change. The sages of Kabbalah agree—time in its essence is change. Thus, Rosh HaShanah can be translated as the Head of Time, or Beginning of Time (since a related Hebrew word, reshit means “beginning”). Indeed, it is all about time. Rosh HaShanah has three main themes—Zichronot (remembrances), Shofrot (Sounds of the Shofar), and Kabalat Ol Malchut Shamayim (acceptance of the yoke of the [...]

The Beard of the Long Face is Found

The previous Lubavitcher Rebbe, the Rebbe Rayatz (a.k.a. the Fridriker Rebbe) told the story about his father, the Rebbe Rashab. Once the brother of Rebbe Rashab, Rabbi Menachem Mendel (a.k.a. the RM”M) told him that he read in a magazine an article that stated that scientists found a nerve in the brain regulating the cognitive function so that when a person needed to remember something he would tilt his head looking up, whereas when the person needed to concentrate, he’d tilt his head down. The Rebbe Rashab took his brother to his study, took from the shelf a book by the Second Lubavitcher Rebbe, the Mittler Rebbe, in which it stated the same thing. The Rebbe Rashab said to his brother, “You’d think he was a doctor, but he wasn’t. He saw Adam [...]

Tisha B’Av on Shabbat – A Relativistic Perspective

Yesterday was the 9th day of the month of Av or, in Hebrew, Tisha B’Av. Usually, Tisha B’Av is marked by mourning and fasting. Yesterday, however, we ate festive meals, drank wine and were prohibited from fasting or displaying any signs of mourning. Because yesterday was Shabbat. Shabbat pushes off the observances of Tisha B’Av by a day. Indeed, today, Sunday, we fast and mourn the destruction of the First and the Second Holy Temple  – Bet Hamikdash – in Jerusalem, we remember the Holocaust and many other tragedies that befell the Jewish people. Why couldn’t we observe Tisha B’Av on Shabbat? After all, that was the day when on the 9th of Av, both Temples were destroyed! The simple explanation, of course, is that on Shabbat there is no mourning. On Shabbat, [...]

Grand Unification

In physics, we seek Grand Unification, also known as the Theory of Everything. The Standard Model describes three out of the four fundamental forces: the strong (nuclear) force, the weak force (beta decay), and the electromagnetic force. The gravitational force, described by the General Theory of Relativity, does not fit into the Standard Model. Developing a quantum theory of gravity, and unifying gravity with the other three forces is the holy grail of theoretical physics. Jewish people are also in need of Grand Unification. There is a schism that runs through the history: it is the schism between Joseph (Yosef) and Judah (Yehuda). Judah represents a “shtetl yid,” a Jew who lives in a ghetto, who sits in a yeshivah, who learns Torah, and who sees the world outside as hostile, as a [...]

Abraham Meets Abraham from a Parallel Universe

And he [Abraham] lifted up his eyes and looked, and, lo, three men stood over against him…  (Gen. 18:2) On this blog, we often discuss the collapse of the wavefunction as the result of a measurement. This phenomenon is called by some physicists the “measurement problem.” There are several reasons, why the collapse of the wavefunction – part and parcel of the Copenhagen interpretation of quantum mechanics – is called a problem. Firstly, it does not follow from the Schrödinger equation and is added ad hoc. Secondly, nobody knows how it happens or how long it takes to collapse the wavefunction.  This is not to mention that any notion that the collapse of the wavefunction is caused by human consciousness, as proposed by Von Newman, leading to Cartesian dualism is anathema to physicists. [...]

Three-and-a-half Hakafot — Topology of Simchat Torah

Why is this night different from all other nights, asks a child on the Seder night. On this Simchat Torah I asked a different question—why is the day different from the night? Indeed, on the night of Simchat Torah, we dance seven hakafot-circuits. However, during the morning service of the next day, we only dance three-and-a-half hakafot. What is the meaning of this number—three and a half? There are a few instances the Torah, Talmud, and Rabbinic instances where this number is mentioned (e.g., during the Gaonic period, c. 590–1000 CE, in some communities in the Land of Israel, the Torah reading cycle was completed in three and a half years; Maimonides rules that only half of the tzitzit string should be dyed blue leaving three and a half strings white), but none of them [...]

Sex, Drugs and Rock n’ Roll

And the Lord spoke unto Moses, after the death of the two sons of Aaron, when they drew near before the Lord, and died. (Lev. 16:1)   The first verse of the Torah portion of Acharei Mot, which we read yesterday, seem perfectly innocuous and, on the surface, serves as a mere introduction to the laws of Yom Kippur service that follows. Much, however, lies beneath the surface. Some of the deepest secrets of Kabbala are hidden therein. Allow me to present them along the lines of Sex, Drugs and Rock n’ Roll. Nadab en Abihu verteerd door het vuur, gravure van Gerard Hoet, Den Haag 1728 Sex The story of two eldest sons of Aaron—Nadab (Nadav) and Abihu (Avihu)—dying is told in the Torah portion of Shemini: And Nadab and [...]



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