(Roughly) Daily

Posts Tagged ‘Cosmology

“A hole can itself have as much shape-meaning as a solid mass”*…

Holes. Caity Weaver wonders about them:

What is a hole?

A hole is a portion of something where something is not. Beyond that, holes are slippery. (As a concept — only some in reality.) Is a hole necessarily empty on both sides, like the gaps in a slice of Swiss cheese? Or need it only be empty on one side, like a pit dug into the earth? Is a hole with a bottom less of a hole than one without one? Can a slit be a hole, or must a hole be vaguely round? Does a straw have two holes, as one Reddit user pondered, or just one — a single thick hole, if you will?…

[She then proceeds to explore the concept etymologically…]

Wait — What Is a Hole?

The Stanford Encyclopedia of Philosophy goes right for the, well… philosophical:

Holes are an interesting case study for ontologists and epistemologists. Naive, untutored descriptions of the world treat holes as objects of reference, on a par with ordinary material objects. (‘There are as many holes in the cheese as there are cookies in the tin.’) And we often appeal to holes to account for causal interactions, or to explain the occurrence of certain events. (‘The water ran out because the bucket has a hole.’) Hence there is prima facie evidence for the existence of such entities. Yet it might be argued that reference to holes is just a façon de parler, that holes are mere entia representationis, as-if entities, fictions.

[There follows a fascinating account of the theories of holes…]


A whole lot about nothing…

*Henry Moore


As we hit ’em where they ain’t, we might spare a thought for mathematician Henri Cartan; he died on this date in 2008. A founding member (n 1934) of and active participant in the Bourbaki group, Cartan made contributions to math across  algebra, geometry, and analysis, with a special focus on topology (that branch of math that plays with holes in toruses, Klein bottles, and other other-worldly shapes).


Written by (Roughly) Daily

August 13, 2023 at 1:00 am

“When demons are required someone will always be found to supply the part”*…

Hell (detail, c1515) by Hieronymus Bosch and studio

… Interestingly, that role, Professor Martha Rampton explains, has evolved…

Christianity developed in a world with a well-articulated understanding of a multilayered and hierarchical universe that was, above all, animated. Most inhabitants of the ancient world envisioned cosmic energy as alive, meaning that the essence of physicality, spirituality and ethics rested in a host of supernatural sentient beings. Among those beings were demons who dwelt in the space between the earth and the Moon.

In the mid-2nd century, CE Justin Martyr explained the role of demons in Christian thought. The sons of God succumbed to intercourse with human women, and they begot children called the Nephilim (meaning giants). The progenies of the Nephilim were demons. These demons enslaved the human race, sowing wars, adulteries, licentiousness and every kind of evil. All the pagan gods, Justin warned, were, in fact, demons who haunt the earth. The North African bishop Augustine offered a different genealogy. He identified demons as the rebel angels who fought alongside and suffered the same fate as Lucifer (also known as Belial, Beelzebub, the Devil, Satan, and the ‘Day Star’) whom God cast out of heaven after he mounted a failed rebellion.

Both pagan and Christian ideologies envisioned demons in prominent roles but, for pagans, demons could be both good and bad. They resembled deities in that they shared in their immortality, but they were also subject to obnoxious, irrational cravings. Demons were positioned between humans and gods, and could act as guardian angels. Demons were corporeal, though of a material much lighter than, and superior to, the human form; they could move faster than mortals, read thoughts, and slip in and out of spaces impossible for the human body to occupy.

For the Church, all demons were malevolent. Christians saw demons as shape-shifters who copulated promiscuously with human beings, controlled the weather, sickened their victims, flew through the atmosphere, impersonated the dead, predicted the future, and were always to be feared…

Rampton then leads us through the shaping thoughts of Lactantius, Augustine, and others…

… The foundational metaphors of Christianity and paganism differed and conflicted with one another. The importance of place emerged for Christians as they crafted a new identity and a way to express it through ritual. Pagans looked to the natural world for meaning. Christian identity, on the other hand, was manifest in human-made consecrated structures such as churches and shrines. The new place of worship had to be one where demons did not feel welcome. When Christians established consecrated sites (the settings of ritual), they were often competing with pagan holy places that abounded in the world of nature – spots near lakes, beneath trees, at hallowed rocks, and in forests. Although Near Eastern and Mediterranean religions were temple-oriented with a sophisticated concept of enclosed ceremonial, the common person did not, as a rule, enter the hallowed domain, and most popular ritualistic, religious activity took place in the fields or outside the temple precinct – in short, out of doors.

Christians created a new kind of space where demons dared not tread and in which continuity with old rites and the worldview they stored were thwarted. These churches provided a clean slate on which Christians could write in the language of ritual. The building became a symbol for the new religion. It was more than just a different location from those frequented by pagan celebrants and inhabited by their demonic deities. It was a new concept of place particular to Christianity – cleansed of demons, consecrated to that special creator god who does not inhere in his creation (trees, rocks, springs) and should not be worshipped through it. Nothing filled demons with dread and kept them at bay like a sanctified church. The motif of demons fleeing in terror from a consecrating bishop was familiar in late antiquity when the fight against idolatry was a matter of openly confronting pagan cults. In the 3rd century, Gregory the Miracle-Worker prayed at the local temple, and the next morning the temple warden could not induce a lingering demon to enter. Christian structures were fortifications against demons.

The distinctive Christian approach to death emerged as a central feature in the competition with pagans for cultural dominance. Despite the radical differences in pagan and Christian notions of mortality, there were also similarities, and these frustrated the new religion in its effort to establish itself as unique.

Necromancy in the ancient world pertained to the practice of calling the dead back to life for the purpose of learning the future. Pagan works portray contact with the dead as ghoulish and repugnant, but, if approached gingerly and undertaken for desirable ends, it was justified. Revivification of the dead was a major feat that required concentrated syncopation with cosmic powers, and such collaboration was realised and made safe through carefully executed rituals. For example, in his novel The Golden Ass, the 2nd-century pagan philosopher Apuleius relates a story of the corpse of Thelyphron, whom the Egyptian prophet Zatchlas temporarily revivifies so that the deceased can solve a mystery regarding his sudden demise…

Many people in late antiquity saw Jesus and his followers as necromancers. This perception brought forth persistent denials from some of the best minds of the Patristic era. In one respect, pagans were right, Jesus had redefined death, and Christians did approach the deceased differently than their polytheistic neighbours. Whereas most pagan cults dreaded, shunned and burned the dead, Christians formed tender and mutually beneficial relationships with the spirits (and, in some cases, the material remains) of those who ceased to exist on a mortal plane. Rather than ostracising the dead beyond the city limits, by the 2nd century, Christians sought out the remains of their loved ones.

The idea that the dead could live again was a central tenet of Christian belief. Following his resurrection, Jesus assured humanity that they could have eternal life. In the Gospel of Matthew, Jesus invests the disciples with the power to emulate his miracles, including resuscitating the dead. In the Gospel of John, Jesus revivifies Lazarus who had been gone for four days.

Early Christians bristled when others censured them for necromancy, certainly because the efficacy of the necromantic art rested on demons of the lower air, but also because they sought to distinguish themselves from the many other religions and belief systems in the ancient world. Christian authors worked tirelessly to defend Jesus specifically and Christians generally against accusations of maleficium (malignant magic). Throughout the Early Middle Ages (c500-1000), Christian writers insisted that the power of their holy men and women rested not on demons that lurked between the Moon and the earth, and not on elaborate rites, but on faith, simple Christian rituals, and ultimately on God alone. Elaborate rituals equated to demonism…

Christians walked a tightrope on the issue of revivification. The earliest Christian theologians were univocally in harmony with their pagan neighbours on the evils of using (or trying to use) the deceased either for fortune-telling or to exploit the power of death’s liminal state for nefarious purposes. Dealings with reanimated corpses involved the worst sort of traffic with demons. Yet Jesus and his closest male followers resuscitated the deceased, and all Christians honoured the spirits and bodily remains of departed saints and fostered friendly relationships with these special dead. In the end, through sermons from the pulpit and private correction in the confessional, Christian intellectuals were able to convince converts that Christian resurrection was different from necromancy.

Christianity was ultimately successful at establishing itself as the only legitimate religion in the Roman world. However, the struggle for supremacy was protracted and hard fought. The Church was met with the challenge of facing down an ancient, finely-chiseled and much beloved cultural system of which demons and magic were a part. Christianity’s success was due, in part, to the development of a new and thoroughgoing system of rituals responsive to its own worldview…

The history of Christian belief- it took a tremendous effort to distinguish early Christianity from the finely tuned world of pagan beliefs and rituals: “Miracles not magic,” in @aeonmag.

* Margaret Atwood


As we go deep on demons, we might recall that it was on this date in 306 that Constantine I (AKA Constantine the Great) was proclaimed Roman emperor by his troops. Nine years later, on this date in 315, the Arch of Constantine was completed near the Colosseum in Rome to commemorate Constantine’s victory over rival emperor Maxentius at the Milvian Bridge.

In the meantime, Constantine had warmed and then converted to Christianity. He played an influential role in the proclamation of the Edict of Milan in 313, which declared tolerance for Christianity in the Roman Empire. And he convened the First Council of Nicaea in 325, which produced the statement of Christian belief known as the Nicene Creed.

“It is well to remember that the entire universe, with one trifling exception, is composed of others”*…

This artist’s impression shows the temperate planet Ross 128 b, with its red dwarf parent star in the background. Credit: ESO/M. Kornmesser

For centuries, scientific discoveries have suggested humanity occupies no privileged place in the universe. But as Mario Livio argues, studies of worlds beyond our solar system could place meaningful new limits on our existential mediocrity…

When the Polish polymath Nicolaus Copernicus proposed in 1543 that the sun, rather than the Earth, was the center of our solar system, he did more than resurrect the “heliocentric” model that had been devised (and largely forgotten) some 18 centuries earlier by the Greek astronomer Aristarchus of Samos. Copernicus—or, rather, the “Copernican principle” that bears his name—tells us that we humans are nothing special. Or, at least, that the planet on which we live is not central to anything outside of us; instead, it’s just another ordinary world revolving around a star.

Our apparent mediocrity has only ascended in the centuries that have passed since Copernicus’s suggestion. In the middle of the 19th century Charles Darwin realized that rather than being the “crown of creation,” humans are simply a natural product of evolution by means of natural selection. Early in the 20th century, astronomer Harlow Shapley deepened our Copernican cosmic demotion, showing that not only the Earth but the whole solar system lacks centrality, residing in the Milky Way’s sleepy outer suburbs rather than the comparatively bustling galactic center. A few years later, astronomer Edwin Hubble showed that galaxies other than the Milky Way exist, and current estimates put the total number of galaxies in the observable universe at a staggering trillion or more.

Since 1995 we have discovered that even within our own Milky Way roughly one of every five sunlike or smaller stars harbors an Earth-size world orbiting in a “Goldilocks” region (neither too hot nor too cold) where liquid water may persist on a rocky planetary surface. This suggests there are at least a few hundred million planets in the Milky Way alone that may in principle be habitable. In roughly the same span of time, observations of the big bang’s afterglow—the cosmic microwave background—have shown that even the ordinary atomic matter that forms planets and people alike constitutes no more than 5 percent of the cosmic mass and energy budget. With each advance in our knowledge, our entire existence retreats from any possible pinnacle, seemingly reduced to flotsam adrift at the universe’s margins.

Believe it or not, the Copernican principle doesn’t even end there. In recent years increasing numbers of physicists and cosmologists have begun to suspect—often against their most fervent hopes—that our entire universe may be but one member of a mind-numbingly huge ensemble of universes: a multiverse.

Interestingly though, if a multiverse truly exists, it also suggests that Copernican cosmic humility can only be taken so far.

The implications of the Copernican principle may sound depressing to anyone who prefers a view of the world regarding humankind as the central or most important element of existence, but notice that every step along the way in extending the Copernican principle represented a major human discovery. That is, each decrease in the sense of our own physical significance was the result of a huge expansion in our knowledge. The Copernican principle teaches us humility, yes, but it also reminds us to keep our curiosity and passion for exploration alive and vibrant…

Fascinating: “How Far Should We Take Our Cosmic Humility?“, from @Mario_Livio in @sciam.

* John Holmes (the poet)


As we ponder our place, we might send carefully-observed birthday greetings to Arno Penzias; he was born on this date in 1933. A physicist and radio astronomer, he and Robert Wilson, a collegue at Bell Labs, discovered the cosmic microwave background radiation, which helped establish the Big Bang theory of cosmology– work for which they shared the 1978 Nobel Prize in Physics.

MB radiation is something that anyone old enough to have watched broadcast (that’s to say, pre-cable/streaming) television) has seen:

The way a television works is relatively simple. A powerful electromagnetic wave is transmitted by a tower, where it can be received by a properly sized antenna oriented in the correct direction. That wave has additional signals superimposed atop it, corresponding to audio and visual information that had been encoded. By receiving that information and translating it into the proper format (speakers for producing sound and cathode rays for producing light), we were able to receive and enjoy broadcast programming right in the comfort of our own homes for the first time. Different channels broadcasted at different wavelengths, giving viewers multiple options simply by turning a dial.

Unless, that is, you turned the dial to channel 03.

Channel 03 was — and if you can dig up an old television set, still is — simply a signal that appears to us as “static” or “snow.” That “snow” you see on your television comes from a combination of all sorts of sources:

– human-made radio transmissions,

– the Sun,

– black holes,

– and all sorts of other directional astrophysical phenomena like pulsars, cosmic rays and more.

But if you were able to either block all of those other signals out, or simply took them into account and subtracted them out, a signal would still remain. It would only by about 1% of the total “snow” signal that you see, but there would be no way of removing it. When you watch channel 03, 1% of what you’re watching comes from the Big Bang’s leftover glow. You are literally watching the cosmic microwave background…

This Is How Your Old Television Set Can Prove The Big Bang

“The sciences of cryptography and mathematics are very elegant, pure sciences. I found that the ends for which these pure sciences are used are less elegant.”*…

Mary, Queen of Scots wrote 57 encrypted messages during her captivity in England; until recently, all but 7 of them were believed lost. Meilan Solly tells the tale of their discovery and decryption…

Over the course of her 19 years in captivity, Mary, Queen of Scots, wrote thousands of letters to ambassadors, government officials, fellow monarchs and conspirators alike. Most of these missives had the same underlying goal: securing the deposed Scottish queen’s freedom. After losing her throne in 1567, Mary had fled to England, hoping to find refuge at her cousin Elizabeth I’s court. (Mary’s paternal grandmother, Margaret Tudor, was the sister of Elizabeth’s father, Henry VIII.) Instead, the English queen imprisoned Mary, keeping her under house arrest for nearly two decades before ordering her execution in 1587.

Mary’s letters have long fascinated scholars and the public, providing a glimpse into her relentless efforts to secure her release. But the former queen’s correspondence often raises more questions than it answers, in part because Mary took extensive steps to hide her messages from the prying eyes of Elizabeth’s spies. In addition to folding the pages with a technique known as letterlocking, she employed ciphers and codes of varying complexity.

More than 400 years after Mary’s death, a chance discovery by a trio of code breakers is offering new insights into the queen’s final years. As the researchers write in the journal Cryptologia, they originally decided to examine a cache of coded notes housed at the National Library of France as part of a broader push to “locate, digitize, transcribe, decipher and analyze” historic ciphers. Those pages turned out to be 57 of Mary’s encrypted letters, the majority of which were sent to Michel de Castelnau, the French ambassador to England, between 1578 and 1584. All but seven were previously thought to be lost…

What they found and how they made sense of it: “Code Breakers Discover—and Decipher—Long-Lost Letters by Mary, Queen of Scots,” from @meilansolly in @SmithsonianMag.

Jim Sanborn, the sculptor who created the encrypted Kryptos sculpture at CIA headquarters


As we crack codes, we might spare a thought for a rough contemporary of Mary’s, a man who refused to communicate in code: Giordano Bruno. A Dominican friar, philosopher, mathematician, and astronomer whose concept of the infinite universe expanded on Copernicus’s model, he was the first European to understand the universe as a continuum where the stars we see at night are identical in nature to the Sun.  Bruno’s views were considered dangerously heretical by the (Roman) Inquisition, which imprisoned him in 1592; after eight years of refusals to recant, on this date in 1600, he was burned at the stake.


Written by (Roughly) Daily

February 17, 2023 at 1:00 am

“To see a world in a grain of sand and a heaven in a wildflower”*…

Where, exactly is Heaven? Stephen Reid Case explains how a very concrete, physical answer to that question became much less concrete…

The Christian concept of heaven, so familiar today from popular depictions of clouds and haloed angels, was an invention – one that came about as early Christians interpreted their religious writings in the context of the Greek culture in which their movement grew up. Christian writers combined Plato’s ideas about the soul’s ascent to the sky at death with Aristotle’s understanding of the structure of the universe, a combination that allowed them to apply a cosmological framework to terms like ‘heaven of heavens’, as well as the ascents, described in the New Testament, of both Jesus and Paul. By the Middle Ages, anyone who uttered the words ‘Our Father, who art in heaven …’ had a clear spatial understanding of where heaven was: God dwelt in the third heaven, above the heaven of the air and the heaven of the stars. This third heaven, the empyrean, became an article of Christian faith – until the new cosmology of Copernicus and Galileo placed the Sun rather than Earth in the centre of the universe. This transformation from an Earth-centred to a Sun-centred universe did not simply displace Earth; it destroyed heaven as a place within the cosmos.

If I asked my astronomy students where heaven was located, I would no doubt receive a classroom full of bewildered stares, despite the fact that I teach at a Christian university – where the majority of students believe in both heaven and the afterlife. When pressed, they might offer thoughts about heaven being a different plane of reality or perhaps another dimension. They believe, but they don’t conceptualise heaven as a location; it is not a part of their spatial understanding of the universe. For most of the history of Christianity, though, the opposite was true…

For hundreds of years, Christians knew exactly where heaven was: above us and above the stars. Then came the new cosmologists: “Where God dwelt.”

* William Blake, “Auguries of Innocence” l. 1 (ca. 1803)


As we muse on metaphor and morphology, we might recall that it was on this date in 1972 that the Apollo 17 mission launched; on their way to the moon, about 18,000 miles from the Earth, astronauts Harrison Schmitt and Ron Evans took the photo now known as “The Blue Marble”– one of the most reproduced images in history.


Written by (Roughly) Daily

December 7, 2022 at 1:00 am

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