Tea at Trianon: Dust to Dust

John Wilson Croker on Marie-Antoinette

"We have followed the history of Marie Antoinette with the greatest diligence and scrupulosity. We have lived in those times. We have talked with some of her friends and some of her enemies; we have read, certainly not all, but hundreds of the libels written against her; and we have, in short, examined her life with– if we may be allowed to say so of ourselves– something of the accuracy of contemporaries, the diligence of inquirers, and the impartiality of historians, all combined; and we feel it our duty to declare, in as a solemn a manner as literature admits of, our well-matured opinion that every reproach against the morals of the queen was a gross calumny– that she was, as we have said, one of the purest of human beings."

~from History of the Guillotine by John Wilson Croker, 1844

Edmund Burke on Marie-Antoinette

"It is now sixteen or seventeen years since I saw the queen of France, then dauphiness, at Versailles; and surely there never lighted on this orb, which she hardly seemed to touch, a more delightful vision. I saw her just above the horizon, decorating and cheering the elevated sphere she had just begun to move in, glittering like a morning star full of life and splendor and joy. Oh, what a revolution....Little did I dream that I should have lived to see such disasters fall upon her, in a nation of gallant men, in a nation of men of honor and of cavaliers! I thought ten thousand swords must have leaped from their scabbards, to avenge even a look which threatened her with insult. But the age of chivalry is gone; that of sophisters, economists, and calculators has succeeded...."

~Edmund Burke, October 1790

Sunday, October 4, 2020

Dust to Dust

From Phys.org:

Dr. Rivka Amit, at the Geological Survey of Israel, and her team initially set out with a simple question: why are some soils around the Mediterranean thin and why are some thick? Their investigation led them to discover not only that dust deposition played a critical role in forming thick soils in the Levant, but also that had the source of dust not changed 200,000 years ago, early humans might have had a much tougher time leaving Africa, and parts of the Fertile Crescent wouldn't have been so hospitable for civilization to take root.

Thick soils tend to form in areas with wet, humid climates, and thin soils form in arid environments with lower weathering rates. But in the Mediterranean, where much of the bedrock is dissolvable carbonate, the opposite is true: Wetter northern regions have thin, unproductive soils, and more arid southeastern regions have thick, productive soils. Some scientists have attributed these patterns to differences in the rates of erosion, driven by human activity. But for Amit, who has been studying the area for years, a high erosion rate alone didn't make sense. She challenged the existing hypotheses, reasoning that another factor—dust input—likely plays a critical role when weathering rates are too slow to form soils from bedrock.

To assess the influence of dust on Mediterranean soils, Amit and her team needed to trace the dust back to its original source. They collected dust samples from soils in the region, as well as nearby and far-flung dust sources, and compared the samples' grain size distribution. The team identified a key difference between areas with thin and thick soils: thin soils comprised only the finest grain sizes sourced from distant deserts like the Sahara, whereas the thicker, more productive soils had coarser dust called loess, sourced from the nearby Negev desert and its massive dune fields. The thick soils in the eastern Mediterranean formed 200,000 years ago when glaciers covered large swaths of land, grinding up bedrock and creating an abundance of fine-grained sediments. "The whole planet was a lot dustier," Amit said, which allowed extensive dune fields like those in the Negev to build up, creating new sources of dust and ultimately, thicker soils in places like the Levant. (Read more.)