entanglement

Home/Tag: entanglement

Suspected Adulteress as a Schrödinger Cat

In quantum mechanics, the state of a physical system is described by the so-called wave function (or the "wavefunction"). All attempts by Schrödinger, who first introduced the wave function, and others to interpret it as a scalar potential of some physical field, or as the de Broglie wave (as in particle-wave dualism) were not successful. In 1926, Max Born noticed that the squared amplitude of the wavefunction of a particle in a given region gives the probability of finding the particle in this region. He suggested that the wavefunction represented not a physical reality but rather our knowledge of the quantum state of an object. The wave function represents our knowledge of all possible quantum-mechanical states of an object and their probabilities. In other words, the quantum-mechanical state of a physical system is [...]

Ye Shall be Disentangled

Ye shall be holy, for I, the Lord, your G‑d, am holy. Leviticus 19:2 This Torah portion begins with an astonishing statement: Speak unto all the congregation of the children of Israel, and say unto them: Ye shall be holy; for I, the Lord, your G‑d, am holy. Leviticus 19:2 The gist of this commandment is “Be kadosh (or pl., kedoshim) because I, the Lord, your G‑d, am kadosh.” The question is, what does the word “kadosh” mean. It is usually translated as “holy.” The word “holy” means sacred, sanctified, blessed, divine. But this translation presents a problem. It would be a tautology to say that G‑d is divine. It is also self-understood that G‑d is holy. He is the definition and the source of all that is divine and holy, i.e., godly. [...]

Second Adar – The Month of Quantum Physics

Today is Rosh Chodesh Adar Bet – the New Moon and the beginning of the second month of Adar.  If we ever to have a month commemorating quantum physics, there would be no more appropriate month for that than the second month of Adar – Adar Bet.  A state of superposition is a physical state unique to quantum theory.  In classical physics (such as Newtonian mechanics or thermodynamics) a physical system is either in one state or the other, say in a state A or a state B. Only in quantum physics a system can be in a blended state C which is a linear superposition of states A and B. For example, the spin of an electron can be either Up or Down.  However, an electron can be in a blurred state of [...]

The Entangled Twins

Entanglement is often called the most baffling and the most quintessential aspect of quantum mechanics. What is entanglement, in a nutshell? Two particles born out of one reaction (or two particles that interacted through a collision) remain connected, no matter how distant from each other. A change in the status of one particle instantaneously causes a change in the status of the other particle. Einstein called it "spooky action at a distance." Entanglement is often associated with a certain symmetry and corresponding conservation laws. For example, the law of conservation of angular momentum requires that the spin (the quantum-mechanical analog of the angular momentum) of two entangled particles always point in the opposite directions. This means that, if two entangled particles have their spin in a state of superposition of Up (↑) and Down (↓), and we collapse [...]

Cosmological Rosh HaShanah

This Rosh HaShanah I had the strangest dream. I dreamed that I was giving a lecture in cosmology at a university when I suddenly realized that it was Rosh HaShanah. I panicked… What was I doing at the university on such a day instead of being in my synagogue, praying and listening to sounds of a shofar?! I decided to save the day by trying to weave the three main themes of Rosh HaShanah into my lecture on cosmology. And so I began… NASA/WMAP Science Team - Original version: NASA; modified by Cherkash In the Rosh HaShanah liturgy, we refer to this day as yom harat olam – the birthday of the world (Machzor Rosh HaShanah). According to modern cosmology, the world was born in an unfathomable explosion called the Big [...]

Tale of Entangled Goats

And he shall take the two he goats, and place them before the Lord at the entrance to the Tent of Meeting. And Aaron shall place lots upon the two he goats: one lot "For the Lord," and the other lot, "For Azazel." (Leviticus 16:7-8) In the last Torah portion, Metzorah, we learned about two entangled birds. This week, we learn about two entangled goats. I don’t know if these goats studied quantum mechanics, but they can sure teach us a thing or two about quantum entanglement. Entanglement is one of the mysteries of quantum mechanics. On a macro level, entanglement is easy to understand. Imagine a coin sawn into two halves along the plane parallel to the face of the coin. One half has only heads and the other half has only [...]

Archives

Categories

DON’T MISS A BEAT

Be the first to know when we publish a new post.

Go to Top