The multi-aperture telescope

Spyware is constantly trying to improve upon resolution constraints; Raytheon have been funding quite a bit of it. But as our Nancy Grace Roman telescope shows, what is designed for spying on people can be repurposed to spy upon other stars and dwarf-planets. Today we're discussing the Rayleigh criterion. The minimum resolvable angle is proportional [1.22] to the wavelength (λ) over the diameter (D) of the aperture of a monolithic telescope. Or: tyranny of the aperture limit.

They want their multitude of 'scopes to be pushed into orbit or the Lunar farside or, most-likely, some SpL2. In space it's presently constrained by the Starship (D = 9 m), which compares with the Chilean 8.5 m mirror-'scopes.

In 2023, Stephen Fleming with Amit Kumar Jha and some others presented a telescope which might obviate the "monolithic" side of that, kind of like putting rockets in series to boost thrust. Last year they got their idea published.

They want to image other worlds without having to go there. We want to go to the Uranian moons and Triton again, so the project isn't for them. It might however be of use to get some better imaging of the KBOs, and Sedna.

They are teasing this for other systems. In that case they think they can remove the starlight from the array of images, without blocking the star in the 'scope itself (like with the Coronagraph). I expect the prime targets will be the Proxima and Trappist worlds.

The (smaller, cheaper) mirrors in space will have to stay at 20 meters, or whatever, from each other. So - pack poles? A better idea is to give Beyond Reach something to do.

Precedence

Over my time studying early Islam through Islamic sources, I stumbled upon Gerald Hawting's The first dynasty of Islam. This was published 1986; I had some 2000 paperback, but it really hadn't absorbed much 1990s scholarship. It was anyway hard to read - for me - because it concentrated on internal debates about who got dibs on all that pelf. In particular I had trouble with "Muhajirun" versus "Anṣar".

Adrien de Jarmy (with whom readers will be familiar) offers some help, which we may read in preprint.

For sura 9, Mahajirun and Anṣar are peers. What matters is precedence - tasbîq - within each group. This may even react to chauvinists in one camp or the other. These sentiments become rife among the poets, but such may be earlier: I suspect Ḥassan bin Thabit as an Anṣarist representative. I find in Ḥassan little contact with suras 9 (or 48).

De Jarmy finds the crux at the turn of the 2nd/8th century. That implies AH 80-100 / AD 700-720: the reign of al-Hajjaj in the east, after the fitna of Ibn al-Ashʿath. In the Madina, the family of ʿUmar was paramount: these included ʿAbd Allah bin ʿUmar's (d. 73/693) mawla Nafiʿ, and the governor ʿUmar future caliph. Anyway before the Ashaʿitha, the muhajir was the man who went out for the sake of God in the conquests. This agrees well with suwar such as 3-6 and 8 (not 9 - nor 48), and with the consistent Syriac term mhaggrayë (which will naturally lag Arabic semantics). De Jarmy sees an attempt to define the sabiq first in al-Kufa: he is one who pledged the oath to the Prophet himself AH 6 in al-Ḥudaybiyya under a, uh, tree. These are the ahl al-shajara. The anṣar don't figure in this side of the paper's conclusion and seem an afterthought in the tradition; some anṣar may well themselves have been muhajirs.

This paper sees the Madinese offering their alternate definitions. Such may have been floated in the Madina first, only getting out to the rest of Islam after ʿUmar the governor became ʿUmar II the caliph. This city restricted the muhajir such that one only existed in the time of the Prophet; if you emigrated to Iraq after that, that wasn't a real hijra/hegira. All those muhajirs are sabiq by definition; the Anṣar may or may not also count, depending on when their ancestors joined the crew. De Jarmy promises a new paper to explore another clear implication, that the Madinese had also raised the Madinese Hegira to preëminence.

Amateur thermodynamics

American Thinker is posting Douglas J Cotton's theory on Planetary Core and Surface Temperatures. This addresses the "carbon" theory of global warming on Venus and, on Earth, "climate change".

Until the late 1970s, we had no real consensus on whether Earth was heating or cooling. We had Venus' surface temperature from flybys, a knowledge of main-sequence evolution (effective over hundreds of millions of years), and the historical record. This wasn't enough.

Soviet landers, including near-landers, got us the temperature gradient of Venus' (long) atmosphere. In the 1980s, the Scientific Community settled upon the bathtub-drain theory of global warming for Earth. 1361 W/m² are coming dayside; less than that are radiating nightside. So the joules are accumulating. To blame: the manmade (anthropogenic) change in atmospheric chemistry. We got more CO₂ now, also CH₄ and H₂O.

Cotton is a degreed physicist, but not of a high degree. His findings here could work toward a Masters if any university saw fit to reach out to him.

He argues that gas doesn't work like a greenhouse. A greenhouse glass is transparent for entry, but translucent for exit. This allows internal higher equilibrium temperature before its sheer heat must radiate into the chill of the Boston Zoo. A non-ionic gas lacks a specific direction. All it can do is slow heat transfer, going in as well as going out. So there is no "greenhouse gas".

To explain Venus and Earth, Cotton proposes instead "heat creep". This is the effect of gravity on a temperature-gradient, which Cotton takes from Josef Loschmidt (1876). Maxwell had rejected Loschmidt as a vio of Clausius (1850) no process is possible whose sole result is the transfer of heat from a body of lower temperature to a body of higher temperature. Cotton points out that Clausius was ignoring the relation between temperature and pressure: Gay-Lussac, or Amontons. So where Maxwell rejected, Maxwell should have sidestepped: "assume uniform pressure, such that we neglect gravity". If we are talking planetary scale, Cotton refuses to neglect gravity.

That's about where I'll leave the dispute, which is presently one-sided, Cotton having failed to attract serious attention, only the attention of unserious bloggers. I will however suggest that it seems falsifiable. It might be testable at - say - Uranus, whose own composition is presently unconstrained.

Berber revolt!

Among the early converts to Islam were Imazighen from Morocco. The way conversion worked in those days was to get adopted as mawla by a Muslim. The Africans' sponsor was one Musa bin Numayr, and one of his proteges - Tariq - proceeded into Spain.

The jealous caliphate then recalled Musa and executed him. In AH 122, his mawali back home - still being called "Berbers" - revolted. 740 for Christians today; 778 for the Mozarabic Chronicler.

Antonia Bosanquet in 2023 published a survey of Islamic historians' view.

Robert Hoyland had flagged the Mozarabic Chronicler for using a rah-rah Umayyad source (in Latin) probably extending past the revolt to Walid II, since it is synoptic with another chronicle that stops at 724 but assuredly written after that. The pro-Muslim stuff ends after this caliphate, at which point the Mozarabs - living in an Islamic state (and probably an Awza'ite jihad state, at that) quit offering religious opinions on the Islamic side. It doesn't much touch even Christianity besides supporting Catholic bishops against Sabellians and other in-house heretics. So the reports on Arab and Berber affairs in Spain (and eighth-century Africa) are purely secular, to be judged on how well the people are being ruled. Unfortunately - for our purpose - that's where Hoyland loses interest, because now we are outside of the "origins" period he'd inherited from Crone.

MC 84 is what handles the revolt against Kulthûm of Damascus. This became a real black eye for the waning years of Hishâm (and Walid II) back in Rusafa. I don't think the Umayyads ever really did retrieve that part of Andalus.

It turns out that the Muslims also viewed this 122 revolt in secular terms. The Mozarab blames "Arures"; the Muslims historically blamed the Sufriya. (Later ones added the Ibadis, but that sect likely came to the west later, apparently subsuming the Sufris.) I sense parallels with the Khurasani movement of Abu Muslim. The former were, they say, at first led by a self-styled prophet, but this prophet was soon overthrown for blasphemy, justly in my opinion. As a more-orthodox movement the Berbers could appeal to the caliph as loyal Muslims, or at least could make a show of it, and rally a pan-Muslim coalition against the Umayyads. We'll note that Abu Muslim's entourage of absolute weirdos will switch to support the 'Abbasid family.

Tabari even offers some of the rebels' propaganda, although here we must be cautious, because we could be reading Tabari's brief against caliphal ('Abbasid) tyranny put in the mouths of faraway people in little position to rebut him. Ancient historians were prone to making up speeches. I do think Muslims were more scrupulous, given that Tabari's peers expected valid chains of transmission and didn't tolerate forgers. So: let's be cautious.

For Tabari, the rebels actually were Muslims, in comparison with the Umayyad court anyway, and deserved a hearing. Khalifa bin Khayyat agreed that as "Haruris" went, the Sufris were more like Ibadis in today's Oman: moderates. (Contrast, the Jarudiya among the Zaidi-Hanafis.) Khalifa by the way disagreed with the revolt in a way Tabari didn't. Khalifa just figured the rebels were angry at the disrespect shown their patron Musa.

Rapa Nui and Hawaii

Undeterred by anklebiters, Alexander Ioannides and others are rolling on with Hawaiki Ultima. This posts the origin of Rapa Nui (which Christians found on Easter Sunday AD 1722 Gregorian) and of our "Hawaiï" chain - here-on, Sandwich - as from Mangareva.

I had to look up Mangareva. I only just heard about this one, like in 2020ish I'd first heard of Marquesas.

Okay: mostly undeterred. There's a DEI statement at the end. They stick "ethics" in there to make it DEEI. #woke isn't dead; it's prepping the battlespace for after-November. At least the buncombe is sequestered.

I had thought that Rapa Nui, at least, was peopled by the Marquesas. I take it that the evidence was too broad at the time to say more than "eastern Polynesia". Mangareva is further south than the Marquesas, so in better-position for South American exploration (Rapa Nui is so near that continent, that Chile now governs it). It is, however, very far from our Sandwich Isles.

Present Sandwich genes come with some admixture, not to say pollution, from the waves of immigration from elsewhere in the Pacific, Europe, and Africa in modern times. That makes difficult to tease possible South American admixture of old, from what happened over the Age of Exploration. Some Sandwich genes in the recent study have "AMR" influx; but some have zero. This is telling me that Easter Island got to South America separately, carrying on their new crops around Polynesia secondarily.

Also possible: in between the dual radiations to Rapa Nui and to Sandwich, Marquesas took on a new wave of visitors from their western Hawaikan cousins. This may have blended their genomes more with Tahiti, leaving Sandwich and Rapa Nui as outliers.

R-M12205

The Balt / Iran split in language also has a genetic component, which is being hashed out among the mostly-Semitic Tribe. Specifically there is an old R1a signature in Levites, who then assuredly are not Levides save by adoption.

Jewish Genomics has the scoop. Which it is, because @FamilyTreeDNA is supposed to get more-formal publication later.

A "Tajik" from Pamir shares R-Y2619 ancestry but was clearly no Jew. The relevant Levites are now reclassified: R-M12205, counting down from AD 750.

So far the Levites in question are Ashkenaz, which is why - beforehand - it was a tossup if R-Y2619 were just East European. Pamir is now Badakhshan so decidedly Iranic. Something like Avestan, Parthian, Bactrian et al.. 'Twould be later that the region became Persianate (or, before that... Buddhist).

"Dienekes" Lazaridis thinks some north-Iran tribe off to itself from 700 BC to injection into Judaea, whenever that was. They'd have drifted west. Lazaridis could call them Medes.

If Lazaridis be right that the injection was so early: I find personally difficult to understand how this bloodline got restricted to the Ashkenaz, "the Scythia" to Greeks and "Saka" to Seistanis (and it's probably not them anyway).

Other commenters are reviving the Khazar hypothesis - was Elhaik right for the wrong reasons? Or maybe this is old Radhan, spreading out to the Caspian shores to the Tatarstan around Kazan. I mean, I know only my femme ancestry and that is decidedly Oriental.

I suspect that we have an incomplete record of male Y-DNA from Sephardic and Mizrahi populations. To be kept in mind: occasional "Ashkenaz" signatures can be imported, like in AD ~1666.

How the Persians failed to make their case

I skipped chapter 2 because it's covering similar ground as Mark Durie. Between chapters 1 and 3, one might explain why it was that Europeans thought that the Persians had degenerated under their Achaemenid shahs. To use the Middle Persian for xšāyaθiya.

Germans and, maybe, Russians and certainly Greeks and Latins could see that the Persian language changed 500-350 BC. I pick on those four because they retained, stubbornly, the inflexions of their own languages; against such pressures as applied to English and French. But the English and French orientalists were saying the same. Since Beowulf and Tolkien I suppose some of the English have inflexion-envy. Frenchmen might, also.

Value-judgements might also be brought at the empire filling its palaces with eunuchs and harems. Van Bladel, head-scratchingly, makes a point of refusing to judge. Okay. The Greeks sure diagnosed the Persians as an unsteady empire, and literally wrote the book on politics. Eventually the Greeks proved that thesis by destroying their empire. Difficult to dispute results.

Even before the disaster of Alexander III's takeover, Persians already could see that the spoken common language was not that of Behistun anymore. This embarrassed some, who then tried to spell their monuments in the good old way. It appears they had no textbook for that; so such inscriptions ended up being... wrong. Like the Book of Mormon (in its first editions) did Tudor/KJV English wrong. If what you put out there isn't evolved but is just wrong, someone is going to point and laugh at you.