Sep 292018
 

Enrico Fermi, the nuclear physicist was born in Rome on this date in 1901. The scientific school where I taught for 2 years in Mantua was named Enrico Fermi technical school and liceo (in Italian), so I feel the need to give him an extra nod even though I covered his supervision of the first sustained nuclear chain reaction here: http://www.bookofdaystales.com/cp-1/  Now I can be a tad more general.

Fermi was the third child of Alberto Fermi, a division head (Capo Divisione) in the Ministry of Railways, and Ida de Gattis, a primary school teacher. One of Fermi’s first sources for his study of physics was a book he found at the local market at Campo de’ Fiori in Rome, the 900-page Elementorum physicae mathematicae(1840), which was written in Latin by Jesuit Father Andrea Caraffa, a professor at the Collegio Romano. It covered mathematics, classical mechanics, astronomy, optics, and acoustics, insofar as these disciplines were understood when the book was written. Fermi befriended another scientifically inclined student, Enrico Persico, and together the two worked on scientific projects such as building gyroscopes and trying to measure the acceleration of Earth’s gravity accurately (a young Galileo). Fermi’s interest in physics was further encouraged by his father’s colleague Adolfo Amidei, who gave him several books on physics and mathematics, which he read and assimilated quickly.

Fermi finished secondary school in July 1918 and, at Amidei’s urging, applied to the Scuola Normale Superiore in Pisa. The school provided free lodging for students, but candidates had to take a difficult entrance exam that included an essay. The given theme was “Specific characteristics of Sounds”. The 17-year-old Fermi chose to derive and solve the partial differential equation for a vibrating rod, applying Fourier analysis in the solution. The examiner, Professor Giulio Pittarelli from the Sapienza University of Rome, interviewed Fermi and praised him, saying that he would become an outstanding physicist in the future.

During his years at the Scuola Normale Superiore, Fermi teamed up with a fellow student, Franco Rasetti, with whom he would indulge in light-hearted pranks and who would later become Fermi’s close friend and collaborator. In Pisa, Fermi was supervised by the director of the physics laboratory, Luigi Puccianti, who acknowledged that there was little that he could teach Fermi, and frequently asked Fermi to teach him something instead. Fermi’s knowledge of quantum physics reached such a high level that Puccianti asked him to organize seminars on the topic. During this time Fermi learned tensor calculus, a mathematical technique invented by Gregorio Ricci and Tullio Levi-Civita that was needed to demonstrate the principles of general relativity. Fermi initially chose mathematics as his major field, but soon switched to physics. He remained largely self-taught, studying general relativity, quantum mechanics, and atomic physics.

In September 1920, Fermi was admitted formally as a teacher in the physics department even though he was still an undergraduate. Since there were only three students in the department—Fermi, Rasetti, and Nello Carrara—Puccianti let them freely use the laboratory for whatever purposes they chose. Fermi decided that they should research X-ray crystallography, and the three worked to produce a Laue photograph—an X-ray photograph of a crystal. During 1921, his third year at the university, Fermi published his first scientific works in the Italian journal Nuovo Cimento, “On the dynamics of a rigid system of electrical charges in translational motion” (Sulla dinamica di un sistema rigido di cariche elettriche in moto traslatorio). A sign of things to come was that the mass was expressed as a tensor—a mathematical construct commonly used to describe something moving and changing in three-dimensional space. In classical mechanics, mass is a scalar quantity, but within relativity mass changes with velocity. The second paper was “On the electrostatics of a uniform gravitational field of electromagnetic charges and on the weight of electromagnetic charges” (Sull’elettrostatica di un campo gravitazionale uniforme e sul peso delle masse elettromagnetiche). Using general relativity, Fermi showed that a charge has a weight equal to U/c2, where U was the electrostatic energy of the system, and c is the speed of light.

A Fermiac

The first paper seemed to point out a contradiction between the electrodynamic theory and the relativistic one concerning the calculation of the electromagnetic masses, as the former predicted a value of 4/3 U/c2. Fermi addressed this the next year in a paper “Concerning a contradiction between electrodynamic and the relativistic theory of electromagnetic mass” in which he showed that the apparent contradiction was a consequence of relativity. This paper was sufficiently well-regarded that it was translated into German and published in the German scientific journal Physikalische Zeitschrift in 1922. That year, Fermi submitted his article “On the phenomena occurring near a world line” (Sopra i fenomeni che avvengono in vicinanza di una linea oraria) to the Italian journal I Rendiconti dell’Accademia dei Lincei. In this article he examined the Principle of Equivalence, and introduced the so-called “Fermi coordinates”. He proved that on a world line close to the time line, space behaves as if it were a Euclidean space.

Fermi submitted his thesis, “A theorem on probability and some of its applications” (Un teorema di calcolo delle probabilità ed alcune sue applicazioni), to the Scuola Normale Superiore in July 1922, and received his laurea at the unusually young age of 20. The thesis was on X-ray diffraction images. Theoretical physics was not yet considered a discipline in Italy, and the only thesis that would have been accepted was one on experimental physics. For this reason, Italian physicists were slow in embracing the new ideas like relativity coming from Germany. Since Fermi was quite at home in the lab doing experimental work, this did not pose insurmountable problems for him, and ended up making him something of a rara avis, a nuclear physicist equally at home with both theoretical and experimental physics.

While writing the appendix for the Italian edition of the book Fundamentals of Einstein Relativity by August Kopff in 1923, Fermi was the first to point out that hidden inside the famous Einstein equation (E = mc2) was an enormous amount of nuclear potential energy to be exploited. “It does not seem possible, at least in the near future”, he wrote, “to find a way to release these dreadful amounts of energy—which is all to the good because the first effect of an explosion of such a dreadful amount of energy would be to smash into smithereens the physicist who had the misfortune to find a way to do it.” Well, he did go on to find a way to do it, and was not smashed to smithereens. Unfortunately, many people were in Hiroshima and Nagasaki, and Fermi, after helping a team in Los Alamos develop the first atomic bombs in the US, became a staunch advocate for the limitation of nuclear weapons, especially after Russians invented a fusion bomb.

I could go on, but, combined with my post on Fermi’s CP-1 pile, you have a very good outline of his life’s work. I do wonder, more often than I would like, what goes into the making of geniuses such as Fermi. How can a teenager, barely starting as an undergraduate be more capable in his field than the head of the department?  A friend of mine who is a noted mathematician pointed out that mathematics and theoretical physics are often revolutionized by very young scholars, partly because their minds are agile and flexible, and partly because their lives are not cluttered with distractions. When they marry and have children their creativity begins to fade, although their work may still be very good.

One of the measures of Fermi’s greatness is the number of diverse things that are named after him: schools, roads, concepts in physics, devices, buildings, departments, and a trans-uranic element – fermium. This gives me an idea for creating a dessert in his honor: the Fermi Pile Tiramisu. Look at this photo for the general idea:

You need a package of ladyfinger biscuits, tiramisu custard, and high quality cocoa. Here is my recipe for the custard again:

Put 4 egg yolks and half a cup of sugar in the top of a double boiler. Bring the water in the bottom to a steady simmer, and make sure that the water does not touch the top part of the boiler. Whisk the sugar and egg yolk mixture vigorously for around 8 minutes. It will expand to a froth and cook. (Hint: you are not making scrambled eggs). Remove from the heat and fold in 1 pound (½ kg) of mascarpone. In a separate bowl whisk 1 cup of heavy cream to stiff peaks. Fold the mascarpone-egg mix into the cream. Chill in the refrigerator overnight.

Next day, make a base of custard and embed a layer of ladyfingers in it. Sprinkle some cocoa over the ladyfingers and then start layering custard and biscuits, finishing with custard and a generous shower of cocoa. Play with this concept to suit yourself.

Aug 152016
 

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Today is the Feast of the Assumption of Mary into Heaven in the Catholic Church, often shortened to the Assumption, or the Assumption of Mary. In the Orthodox Church it is called the Falling Asleep of the Blessed Virgin Mary. Both Western and Eastern rites assert that the Virgin Mary did not die (as such),  but was taken directly into Heaven at the end of her earthly life. For the most part, Protestant traditions do not accept this theology because it has no Biblical basis. In Italy, where I am now, this date is also Ferragosto, a major public holiday supposedly rooted in Roman Imperial times, although the historical links are a bit dodgy. August is a good time for an annual day off, so beaches and tourist spots are always mobbed. Because I live in a major tourist spot, I can expect the worst.

The Catholic Church now teaches as dogma that the Virgin Mary “having completed the course of her earthly life, was assumed body and soul into heavenly glory.” This doctrine was dogmatically defined by Pope Pius XII on 1st November 1 (All Souls), 1950 in the apostolic constitution Munificentissimus Deus by exercising papal infallibility. The Eastern Orthodox Church doctrine of the Dormition of the Theotokos (the falling asleep of Mary) is more or less the same as the Assumption, avoiding the idea of the physical death of Mary, but has not been dogmatically defined. In Munificentissimus Deus (item 39) Pope Pius XII pointed to the Book of Genesis (3:15) as scriptural support for the dogma of the Assumption in terms of Mary’s victory over sin and death as also reflected in 1 Corinthians 15:54: “then shall come to pass the saying that is written, Death is swallowed up in victory.”

Although the Assumption (Latin: assumptio, “a taking”) was only relatively recently defined as infallible dogma by the Catholic Church, and in spite of a statement by Saint Epiphanius of Salamis in 377 that no one knew whether Mary had died or not, apocryphal accounts of the assumption of Mary into heaven have circulated since at least the 4th century. The Catholic Church itself interprets chapter 12 of the Book of Revelation as referring to it. The earliest known narrative is the so-called Liber Requiei Mariae (The Book of Mary’s Repose), which survives intact only in an Ethiopic translation. Probably composed by the 4th century, this narrative may be as early as the 3rd century. Also quite early are the very different traditions of the “Six Books” or Dormition narratives.

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Teaching of the Assumption of Mary became widespread across the Christian world, having been celebrated as early as the 5th century and having been established in the East by Emperor Maurice around 600. It was celebrated in the West under Pope Sergius I in the 8th century and Pope Leo IV then confirmed the feast as official. Theological debate about the Assumption continued, following the Reformation, peaking in 1950 when Pope Pius XII defined it as dogma for the Catholic Church.

If you’ve paid any attention to my previous posts on feast days and the like, you’ll know what I think about all of this already. The Church has an endless need to tie up loose ends logically. Jesus died and was resurrected. Then what? What became of the risen Lord? Obviously he did not just hang around. Luke clears this mystery up in Acts 1:9-11. Jesus ascended into heaven. As I have said many times before, Luke likes to clean up things – Why was Jesus from Nazareth when the Hebrew prophets indicated the Messiah would be born in Bethlehem of the House of David?  Are followers of John the Baptist Christians? Etc. etc. Luke provides the “answers” by making stuff up – maybe out of whole cloth or from previous sources. Unfortunately for the early church, Luke is silent on Mary’s fate.

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Let me be crystal clear. As an ordained Christian pastor and (erstwhile) theologian, I take a certain amount of Christian dogma on faith, but I don’t accept Biblical narratives as history without serious reservations. If you want my thoughts on belief and Christianity this is a good place to start: https://www.amazon.com/Thinking-Christian-Essays-Prod-Believer-ebook/dp/B01DGJ2OIM/ref=sr_1_5?s=digital-text&ie=UTF8&qid=1471240630&sr=1-5  Luke, to my mind, is a horrible distraction. He was trained in the Greek philosophical tradition, and doesn’t like loose ends. For me, faith and logic do not have to be consistent. Logic and science are not always right. A certain amount of logical or scientific inconsistency is fine as far as I am concerned. Luke was more rigid. Unfortunately he had nothing to say about the end of Mary’s life, so the Church applied logic. Bad idea.

The veneration of Mary goes back a long way, and has led to some awfully dubious doctrines. The gospels tell us that Jesus had brothers. Did Mary have sex after Jesus was born? Horror !!! She must have been a perpetual virgin in order to be sinless. And . . . to be sinless, and give birth as a virgin to a sinless baby, she must have been born of a virgin (Immaculate Conception). Furthermore, she must have stayed a virgin to maintain her sinlessness, so these brothers must have been cousins (so twist the Greek a little to imply that when the gospels said “brother” this included biological cousins). That’s where logic gets you. Rather ironically, the Greek Orthodox church doesn’t like Aristotle much and the battles between East and West in the Middle Ages often pitted Catholics asserting theological points by using Aristotelian logic, and the Greeks laughing in their faces. The Greek answer to any question beginning, “How do you account for . . . ?” is “It’s a mystery.” End of story. I like it.

So . . . I think that the Assumption is one more case of the church tying up loose ends. But I’m all for holidays. Ferragosto in Italy falls on 15 August and is only by coincidence the same day as the Assumption of Mary. The Feriae Augusti (“Festivals of the Emperor Augustus”) were introduced by the emperor Augustus in 18 BCE. This was an addition to earlier ancient Roman festivals which fell in the same month, such as the Vinalia rustica or the Consualia, which celebrated the harvest and the end of a long period of intense agricultural labor. The Feriae Augusti, in addition to its propaganda function, linked the various August festivals to provide a longer period of rest, called Augustali, which was felt necessary after the hard labor of the previous weeks.

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During these celebrations, horse races were organized across the Empire, and beasts of burden (including oxen, donkeys and mules), were released from their work duties and decorated with flowers. Settling on 15th August as the main day is a modern tradition. During the Roman festival, workers formally greeted their masters who in return would give them a present. The custom became so strongly rooted that in the Renaissance it was made compulsory in the Papal States.

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The popular modern tradition of taking a trip during Ferragosto arose under the Fascist regime. In the second half of the 1920s, during the mid-August period, the regime mounted hundreds of popular trips through the Fascist leisure and recreational organizations of various corporations, including the establishment of the “People’s Trains of Ferragosto”, which were available at heavily discounted prices. The initiative gave the opportunity for people with little money to visit Italian cities or to reach seaside and mountain resorts. The offer was limited to 13, 14 and 15 August, and had two options: the “One-Day Trip”, within a radius of 50-100 km, and the “Three-Day Trip” within a radius of about 100–200 km.

Obviously Italian festival food has to be the fare of the day. I haven’t been out yet, but when I do I expect to see people scarfing down local specialties such as tortelli di zucca, torta Sbrisolona, and the like along with gallons of gelato and granita. Last night I made a festive dinner that was sort of Italian – all cold dishes because of the heat.

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The dessert was my own creation taking off from tiramisu. I began by baking a stracciatella cake – a moist vanilla sponge cake with chocolate chips. Whilst it was cooling I made a tiramisu custard. Some people use raw eggs, but I prefer to cook mine.

Put 4 egg yolks and half a cup of sugar in the top of a double boiler. Bring the water in the bottom to a steady simmer, and make sure that the water does not touch the top part of the boiler. Whisk the sugar and egg yolk mixture vigorously for around 8 minutes. It will expand to a froth and cook. (Hint: you are not making scrambled eggs). Remove from the heat and fold in 1 pound (½ kg) of mascarpone. In a separate bowl whisk 1 cup of heavy cream to stiff peaks. Fold the mascarpone-egg mix into the cream. Then fold in about a ½ pound (¼ kg) of mixed frozen berries (you can use raspberries, strawberries, blackberries, blueberries, or what ever you want).  Set aside.

Slice the stracciatella reasonably thin – less than ½ inch (1.25 cm). Line the base of a loaf pan with the cake slices. Spread in half of the custard. Add another layer of stracciatella slices. Top with the remaining custard, and chill in the refrigerator overnight.

Before serving top with a layer of berries, then whipped cream, then shaved dark chocolate.