Pioneers of the Ice Age Models: A Brief History from Agassiz to Milankovitch

It is currently known that astronomical factors trigger the emergence of glacial and interglacial periods. However, nearly two centuries ago, the overall situation was not as apparent as it was with today’s scientists. In this article, I briefly discuss the astronomical model of ice ages put forward between the 19th and 20th centuries. This century was indeed annus mirabilis for scientists to understand the ice age phenomenon. Agassiz, Adhémar and Croll laid the foundation stones for understanding the dynamics of ice ages. But it was Milankovitch who combined empirical geology with mathematical astronomy. To put specifically, he identified the shortcomings of the preceding ice age models and modified his model accordingly. In what follows, I review former approaches to the ice age problem and show how they failed to meet their objectives. Next, I show how Milankovitch’s model managed to capture all sufficient astronomical elements. Last sections focus on Milutin Milankovitch’s genuine approach, including his accomplishment of tackling the problem mathematically.

The origin of rest-mass energy

Today we have a solid, if incomplete, physical picture of how inertia is created in the standard model. We know that most of the visible baryonic ‘mass’ in the Universe is due to gluonic back-reaction on accelerated quarks, the latter of which attribute their own inertia to a coupling with the Higgs field – a process that elegantly and self-consistently also assigns inertia to several other particles. But we have never had a physically viable explanation for the origin of rest-mass energy, in spite of many attempts at understanding it towards the end of the nineteenth century, culminating with Einstein’s own landmark contribution in his Annus Mirabilis. Here, we introduce to this discussion some of the insights we have garnered from the latest cosmological observations and theoretical modeling to calculate our gravitational binding energy with that portion of the Universe to which we are causally connected, and demonstrate that this energy is indeed equal to $$mc^2$$ m c 2 when the inertia m is viewed as a surrogate for gravitational mass.

DANIEL FELSENFELD (b. 1970)Annus Mirabilis (2007)

This chapter looks at American composer Daniel Felsenfeld’s Annus Mirabilis (2007). From a wide choice of Felsenfeld’s varied works, this short, witty, and oddly poignant setting of the well-known Philip Larkin poem is a real find and an especially welcome addition to the limited repertoire for bass voice. It is ideal for histrionically gifted performers wishing to enliven a recital programme of more serious fare. Felsenfeld neatly captures the painfully ironic, rueful essence of the text, and, in incongruous parody, draws on quotations from Purcell as well as two of the Beatles’ hits. Also an experienced writer, he obviously relishes supplying pithy notes for the performers, such as ‘with overdone pathos’, ‘melodramatically grand’, and ‘eerily strict’. The piano takes a major role, veering from baroque gestures and direct quotes to bravura gestures, amid constantly changing tempos and frequent rubato.

Plotting the Modern City: John Dryden's Sir Martin Mar-All on the Dorset Garden Stage

Over the course of four days in September, 1666, a fire sparked in a bakery turned four-fifths of central London to dust. Wandering the streets around his home three days after the Great Fire subsided, the diarist John Evelyn describes a city in ruins—its buildings and landmarks “mealted, & reduc'd to cinders by the vehement heats,” its “bielanes & narrower streetes … quite fill'd up with rubbish, nor could one have possibly known where he was, but by the ruines of some church, or hall, that had some remarkable towre or pinacle remaining.” John Dryden echoes Evelyn's sense of disorientation in Annus Mirabilis, his poem dedicated to the people of London and published in 1667; he describes “the Cracks of Falling houses,” the “Shrieks of Subjects” as the Fire “wades the Streets,” threatens the palace, and lays the city's famed financial centers “to waste.” And he describes, too, the desperate attempts by those left homeless by the Fire to make spaces for themselves in the ruins: Those who have [no home] sit round where once it was, And with full Eyes each wonted Room require: Haunting the yet warm ashes of the place, As murder'd Men walk where they did expire.