# collapse of the wavefunction

/Tag:collapse of the wavefunction

## 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 a 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 leading to Cartesian dualism is anathema to physicists. It is a problem, no matter how you [...]

## Pesach Sheini – in a State of Superposition

In physics, we speak of systems and states. A system is a collection of physical objects (particles, waves, etc.). A system can be in various states. For example, a coin could have two states – heads and tails. A top also has two possible states – it can be spinning clockwise or counterclockwise. Light can have two states as well – being in the vertical polarization or horizontal polarization. In classical mechanics a system can only be in a pure state, i.e., at any given point in time, a coin can be either in a state “Heads” or the alternative state “Tales”. A top can be spinning either clockwise or counterclockwise, each of which is a pure state. In quantum mechanics, a system can be in a pure state or in a state [...]

## Secrets of the Talking Ass

And God opened the mouth of the ass, and she said to Bilam: "What have I done to you, that you have struck me these three times?" And Bilam said to the ass: "Because you have mocked me; I would there were a sword in my hand, for now I would kill you." And the ass said to Bilam: "Am not I your ass, upon which you have ridden all your life to this day? Was I ever wont to do so to you?" And he said, "No." Num. 22:28-30 Despite the simple dialogue between Balaam (Bilam) and his ass in the Torah portion of Balak, this ass was no ordinary ass. This ass saw an angel where a prophet as great as her owner, Balaam, did not. It stands to reason that [...]

## Manna – Superposition of All Tastes

While traveling in the Sinai desert, Israelites were fed by the heavenly bread – the manna. The Torah portions – parshat Beshalach – states that raw manna tasted like wafers that had been made with honey: וַיִּקְרְאוּ בֵית-יִשְׂרָאֵל אֶת-שְׁמוֹ, מָן; וְהוּא, כְּזֶרַע גַּד לָבָן, וְטַעְמוֹ, כְּצַפִּיחִת בִּדְבָשׁ. And the house of Israel called the name thereof Manna; and it was like coriander seed, white; and the taste of it was like wafers made with honey. (Ex. 16:31): However, in Numbers, it says that it tasted like cakes baked with oil: כְּטַעַם לְשַׁד הַשָּׁמֶן The taste of it was as the taste of a cake baked with oil. (Num. 11:8)  The Talmud (Yoma 75b) reconciles this discrepancy by explaining that the tastes varied depending who ate the manna – to small children it tasted [...]

## Witnesses – See and be Seen

עַל פִּי שְׁנַיִם עֵדִים אוֹ שְׁלֹשָׁה עֵדִים יוּמַת הַמֵּת לֹא יוּמַת עַל פִּי עֵד אֶחָד: By the mouth of two witnesses, or three witnesses, shall the one liable to death be put to death; he shall not be put to death by the mouth of one witness. (Devarim-Deuteronomy 17:6) Earlier this summer, I wrote about witnesses in the post imaginatively called Witnesses. As Deuteronomy, restates many mitzvoth (commandments) introduced earlier, which is why it is also called Mishneh Torah – the repetition of Torah – the parshah Shoftim, which we read yesterday in Synagogues, restates the law of witnesses first introduced in in the book of Bamidbar-Numbers, parshat Massei. So we shall revisit this fascinating subject. The Judgment of the Sanhedrin: "He is Guilty!" (1892 painting by Nikolai Ge) I.     An accused criminal and a Schrödinger cat Most criminals are convicted [...]