Author Archives: gmcdavid

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About gmcdavid

Retired IT professional with a wide range of interests. Married. Three sons, two with autistic-spectrum disorders and the third being transgender with Ehlers-Danlos syndrome. From Chicago but now living in the Twin Cities metro, Minnesota. Episcopalian. Carleton College (BA 1972, physics) and Stanford University (MS 1974, Applied Physics; MS 1976 Statistics).

Columbus and the Flat Earth

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Inventing the Flat Earth: Columbus and Modern Historians, by Jeffrey Burton Russell, is the book for the day. Columbus did not show the world that the Earth was round. No educated European in 1492 believed that the Earth was flat. They all knew it was round. As all math geeks know, Eratosthenes of Cyrene had made a good calculation of the circumference of the Earth about 200 BCE.

Catholic church authorities did not say that the plan of Columbus to reach the orient by sailing westward was impossible because the Earth was flat. Their scholastic theology was based on the philosophy of Aristotle, who understood perfectly well that the Earth was round.

There are passages in the Bible that suggest a flat Earth, but almost all theologians of ancient and medieval times knew the evidence for a round Earth was overwhelming, and understood the Bible was not to be taken literally in this and similar cases.

The objection to the plans of Columbus was that, thanks to Eratosthenes, people had a good idea of the distance from the west coast of Europe to the east coast of China, and could easily calculate that no ship of the day could possibly carry enough supplies for the voyage.

Columbus, acting like a 21st century Republican, rejected the best science of the day and chose a smaller alternative value for the circumference that suited his purposes. He was just lucky that the Americas happened to be there. As a result their inhabitants were then horribly unlucky.

The story about Columbus and the flat Earth is a 19th century invention, not history.

Also posted on Facebook.

The Fall of the Western Roman Empire

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Some quotes from The Fall of the Roman Empire: A New History of Rome and the Barbarians, by Peter Heather.

“…this book will argue that the view that Rome’s own internal transformations had so weakened it by the fourth century that it was ready to collapse under its own weight in the fifth, has become unsustainable. The roots of fifth-century collapse must be sought elsewhere.” [pp. 14-15]
“‘What we call the fall of the Roman Empire was an imaginative experiment that got a little out of hand.’ You can only argue this, it seems to me, if you don’t let narrative history dirty your hands. Any attempt to reconstruct fifth-century events brings home just how violent the process was. In my view, it is impossible to escape the fact that the western Empire broke up because too many outside groups established themselves on its territories and expanded their holdings by warfare.” [p. 436]
“All the evils identified in the western system applied equally, if not more, to the eastern. If anything, the Roman east was more Christian, and more given to doctrinal argument. Also, it operated the same kind of governmental system over the same kind of economy. Yet the east survived, when the west fell. This alone makes it difficult to argue that there was something so inherently wrong with the late imperial system that it was bound to collapse under its own weight.” [pp. 443-444]

This reminded that I had seen a similar argument in Arther Ferrill’s The Fall of the Roman Empire: The Military Explanation. As I noted in my Amazon review of that book:

“There is a lot of nonsense in circulation about the Fall of the Western Empire. Ferrill gets past all of it by starting from one obvious but often neglected criterion: Any explanation of the Fall of the Western Roman Empire must also account for the survival of the Byzantine East.”

American Poison Gas in World War II

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During World War II the United States was prepared to use poison gas against the German army. 100 tons of mustard gas were shipped to the port of Bari in southern Italy, held by the Allies and far behind the front lines, on the ammunition ship John Harvey. Being an ammunition ship, the John Harvey also carried a full load of conventional explosive munitions. Disaster At Bari tells the story of how, on the night of December 2, 1943, the port of Bari was attacked by 105 Ju 88 Luftwaffe bombers. The attackers achieved complete surprise: the Allied high command did not think the Luftwaffe was still capable of a raid this far behind the front lines. The lights were on in the harbor so that unloading the docked ships could continue during the night. The Luftwaffe pilots and bombardiers made good use of this, and sank 17 cargo and transport ships, with 8 others damaged. One of the targets was the John Harvey. As an ammunition ship it blew up in a huge explosion, spreading mustard gas all around.

Hundreds of victims were taken to hospitals with strange symptoms. Many died and the medical staff had no idea why. The presence of mustard gas on the John Harvey was a closely guarded secret. Eventually a senior medical officer was flown in from Allied headquarters in Algiers. He quickly realized that the men had been exposed to mustard gas. With some difficulty, he was able find out that the John Harvey had mustard gas in its cargo. There 617 military and merchant marine mustard-gas casualities that night. 84 men died. No one knows about the casualties among the Italian civilians. Many lives could have been saved if the presence of mustard gas had been known immediately and proper treatment administered to the victims.

Evidence for Literacy in Ancient Judah

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The Babylonians sacked Jerusalem and conquered the biblical kingdom of Judah in 587 BCE. Just before then, c. 600 BCE, Judah maintained a small military outpost at Tel Arad, about 20 miles south of Jerusalem. Written inscriptions have been found there on ostraca (pottery fragments), a common writing medium in the ancient world. The fort at Tel Arad was a small place, with a garrison of 20-30 soldiers. Yet a handwriting analysis of 18 incriptions shows that there were least 6 and perhaps as many as 12 authors of these texts. This indicates that literacy was not uncommon in Judah at the time, at least among the army. It was not the exclusive domain a few scribes serving the king.

Given a substantial degree of literacy, it is plausible that some of the books of the Hebrew Bible, e.g. Deuteronomy, Joshua, Judges, Samuel, and Kings, were in fact written down before the fall of Jerusalem and the Babylonian exile.


References

More about phosphine on Venus

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Following up on Possible Sign of Life on Venus. After that announcement some scientists took another look at 1978 data from the Pioneer Venus Multiprobe. At the time nobody was specifically looking for phosphine, but a new analysis of the raw data supports the possibility that there is phospine in the atmosphere of Venus. Details at Is Phosphine in the Mass Spectra from Venus’ Clouds?.

This has happened before in astronomy. After both Neptune and Pluto were discovered, astronomers looked at old records and found that their predecessors had seen both bodies, but had not realized they were significant. In the case of Neptune one of those predecessors was Galileo.

Dating a passage in Acts

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Acts 18:12-17 reads (NRSV):

12 But when Gallio was proconsul of Achaia, the Jews made a united attack on Paul and brought him before the tribunal. 13 They said, “This man is persuading people to worship God in ways that are contrary to the law.” 14 Just as Paul was about to speak, Gallio said to the Jews, “If it were a matter of crime or serious villainy, I would be justified in accepting the complaint of you Jews; 15 but since it is a matter of questions about words and names and your own law, see to it yourselves; I do not wish to be a judge of these matters.” 16 And he dismissed them from the tribunal. 17 Then all of them seized Sosthenes, the official of the synagogue, and beat him in front of the tribunal. But Gallio paid no attention to any of these things.
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Rang Gaeilge, 22ú lá Mí na Mheán Fómhair 2020

Eachtraí Eilíse i dTír na nIontas

Caibidil XII: Fianaise Eilíse
Alice’s Testimony

  • “Anseo!” a ghlaoigh Eilís, agus í ag dearmad toisc a chorraithe is a bhí sí, cé chomh mór a d’fhás sí sna nóiméid deireanacha. Léim sí ina seasamh chomh tobann sin gur leag sí bosca an ghiúire le binn a gúna, rud a chaith na giúróirí anuas ar an slua thíos. D’fhan siad ina luí ansin ar a bhfad is ar a leithead, rud a chuir i gcuimhne di go baileach an babhla d’éisc órga a leag sí go tuaipliseach an tseachtain roimhe sin.

    “Here!” called Alice, and she had forgotten because she was excited how big she had grown in the last few minutes. She jumped to her feet so fast that she knocked over the jury box with the hem of her dress, which threw the jurors down onto the crowd below. They remained lying there far and wide, which reminded her of exactly the goldfish bowl that she had accidentally knocked over the week before.

    corraighmove, stir, agitate
    leagknock down; lay, set
    binnpeak, edge
    baileachexact
    babhlabowlm
    iascfishm gs npl éisc
    órgagolden
    tuaiplisblunderf

    • Léigh tuilleadh

Possible Sign of Life on Venus

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Yesterday I got an email from Cosmoquest about a science press conference (“presser”) where a new discovery would be announced. With all the new distance-based communication technology anybody could watch, rather than just those in a select room, however large. The event was put on by the Royal Astronomical Society today. I watched it on the Cosmoquest Twitch TV channel. I had never heard of Twitch TV before.

The occasion was that

An international team of astronomers, led by Professor Jane Greaves of Cardiff University, today announced the discovery of a rare molecule – phosphine – in the clouds of Venus. On Earth, this gas is only made industrially, or by microbes that thrive in oxygen-free environments.

The discovery was made by spectroscopy using two different radio telescopes. The significance of this is that the production of phospine by purely chemical processes is very unlikely in the atmosphere of Venus. The team looked at every possible chemical reaction they could think up, and failed to find any that could come close to producing the observed amount of phospine.

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More reading notes

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  • Christopher Matthew, A Storm of Spears: Understanding the Greek Hoplite at War. The most important conclusion from this is how the Greeks wielded their spears. Despite all the pictures, they did not hold them over their heads with a back-handed grip. Instead, they held them with the butt of the spear tucked under their armpits. This allowed for much greater reach and strength. Lots of good experiments with re-enactors.

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Some of my summer reading

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