Shape-from-shading

Brown University have published a topograph method. This is being touted for topologies on our MunMoon.

Recall that Apollo 11 nearly failed on account the Kerbals hadn't swept the boulders off the lander's way in time. The experience made an impression on the computer-scientists of the day. 1970s-era programmers made a whole educational(?) game-genre of landing craft on various planets. Although, yes, by the time we TRS-80 kidz got to the arcades, such games were on their way out (because we already had them at home, we supposed).

In our day we've seen a number of unmanned missions land upside down or sideways. Our maps still don't always suffice, especially in the high latitudes. Even with higher bandwidth and pinpointing than available in 1969, the Moon's sheer distance plus lightspeed imposes a latency which men in a lander don't suffer.

The technique should also help in mapping Deimos obviously, and asteroids.

Inhabiting the large rock

To make a home in space you need shielding and gravity. Rubble-piles are pretty-well handled; they might even be better than classic spin-habs built from imported material. How about solid rocks?

What a hollowed stone mass buys us, is a shielded hangar as can hold incoming and outgoing craft. Also its outer shield is solid rock, not a net with some cables (so the gravel on the outside surface stays on there). It doesn't spin (as much) so panels and sensors can be better-attached to the outside. Some solid rocks are differentiates, like 16 Psyche, which means GOLD.

Why even have people in there? the shipyard will want workers with decent bone-structure that don't need called-in from some other rock. It will above-all need a medical station, which is only had with gravity. I'm designing for safety, redundancy, and repairability.

Our constraint is the tensile strength of solid (so irregular) S-type silicates, or the larger Vestoids. That matters less the further down the surface you dig. So: let's dig Deimos.

Deimos proper is 6.27 km radius. Surface gravity is 3 mm/s² "milligravity" - hold onto that. Herein we can hollow a torus 1 km-radius, 6.283 km circumference; with plenty solid rock above us to spare. For a tenth that: take any irregular rock up to 627m, so let's say 200m radius = 1257m circumference. I'll work on those maths some other time.

What we do with 1.257km of track is run a maglev in it. The track runs cars at a speed to ensure like 9.8 m/s². For our Venereal visitors, 8.7 and so on. It will need extra speed to counteract the milligravity of the hard centripetal "ceiling" (= gravitational actual core) where we keep one, but our first track especially can likely neglect this.

Best is that the track be superconductive, for the bonus of hoisting a magnet to keep incoming ions off the rock's surface. The interior of the torus is near-airless anyway. We'll have regular vents to ensure that.

INTERJECT 6/2: For comparative-engineering against Earth, our fastest train is the Shanghai. We'll get to the speed maths on Sunday. As far as human capacity goes, Google AI says: The Shanghai Maglev train is 153 meters (502 ft 0 in) long, 3.7 meters (12 ft 2 in) wide, and 4.2 meters (13 ft 9 in) high. It can accommodate 574 passengers in three classes. Oh goody: this will physically fit in my 200m radius, 1257m circumference tube. We can cut the "passengers" to, oh, a hundred per tube/train. Some get personal cabins, others get bunks; but most cabins are med-stations, offices, laboratories.

For balance and redundancy each torus should be in pairs: for each car-set going one way in one torus, an equal car-set goes the other on the other.

Each car is designed to travel in either direction. At regular intervals - I suggest a multiple of the Earth or Martian day of 24-25 hours - the first car of each car-set offloads and slows between the... toro [dual]. This allows regular communication and trade between the twain.

It also allows work on the body of the rock itself, and shuttles to the rest of the solar-system. Agriculture and industry can be done on the outer crust of the rock in its milligravity, remotely where possible.

Even those [6/2: hundreds] in an Eros-sized rock be mostly transient. But it may well be able to call in spare headcount from close by. Deimos has 1.51e+15 kg mass; Jensen figured Atíra for 4.11e+13. Atíra has a companion. In the scales we're talking, we can park a rubble-pile in orbit around the main rock. Or just a Janhunen dumbbell.

Better combustion

ICE here stands for "internal combustion engine", the engine that dare not speak its name.

Casey Handmer thinks that electrical production is going to improve. I am skeptical that we will enjoy it. Governments are antipopulist by nature, so have the motive to Just Stop it. Or at least to hoard it.

Even given a citizen-responsive élite: I don't see energy getting so cheap that the inherent problems of vehicle-portable massive battery or capacitor will be overruled. Bump the chassis and - who's paying the ten-grand for the new battery? Who's putting out the battery-fire?

So I expect petrol to be with us for some time. Japan are finding room for improvement on what performance we can wring from its combustion. Including improved capacitor performance, as work is shunted over there.

What to make of 1 Thess 2:14-16?

I keep having to return to the Crucifixion, because we Christians insist on it. Too many of us insist on Jews being culpable; OnePeterFive took the questionable-timing of Torba's comments to attack Ben Shapiro, which is now explicit. I'd tried saying that Christianity doesn't need to accuse Jews of this particular crime, to exist; I also left on the table, updating the text. If we with Mark accuse the Sanhedrin instead of blasphemy, that might count as attempted deicide.

But now we cross into the territory of tafsir, not of matn.

I don't have all the links on me right now; but from what I recall of Saint Paul, his creed on Jesus' Last Supper evokes paradosis - a term from the second Isaiah. For Paul, Christ was "handed over", implicitly in the process of crucifixion. The "Egerton" scraps use this term too; we don't have their thus-foreshadowed Passion but we can suspect crucifixion. The "Barnabas" tract meanwhile was arguing that Israel - all twelve tribes, not just Jews - bound Jesus, had him suffer, and cast lots for his clothes. When Christ returns, his crucifiers shall see him. But - who are they? The Crucifixion is passive-voice. On the assumption of no rapture, Barnabas implicates Christians too in the crime. (You do recall that Christians consider ourselves the true Israel... right?)

Saint Mark offers the first full narrative. He presents something like the Spanish Inquisition: the religious authorities find blasphemy, then pass the blasphemer to the saecular authorities. The former authorities do not do the deed themselves. For Mark, the high priest... couldn't; the priests weren't running the joint. So Mark has Pilate do it - which meant Pilate needed to charge him under Roman law, here of brigandage.

We on the Catholic and Orthodox side hold that the Eucharist is central. We don't deviate from Paul; and although admittedly we don't have Egerton anymore and consider "Barnabas" postapostolic, we did (barely) keep Mark. More to the point we accept Mark's Passion - as did Matthew, with a couple insertions about the Jewish mob.

Given this textual backdrop, we may reread 1 Thessalonians 2:14-16. Here is said that the Jews (not Israel) killed Christ themselves. That couplet skips the paradosis and the crucifixion. For such reasons and many more, I dispute this as Paul...

... but the sentiment is early. "Barnabas" is already halfway there. And then we have the Parable of the Wicked Tenants. Mark has Jesus teach this as one of his last discourses, whilst he is in Jerusalem. A version is also in Hermas' Shepherd.

Although Paul did not say 1 Thessalonians 2:14-16, we must consider it an early footnote to 1 Thessalonians. And not Marcion either (he cared little for Jewish prophets). Looks more like Mark's party.

Should we consider this God's footnote?

The brain biome

We've been hearing murmurs about the gut biome being different for autists - and schizophrenics. Last year, mental faculties were looked-at, generally; last month we heard similar for Oldtimer's Disease.

Male homosexuals sometimes do things with their digestive systems that a normal man wouldn't. I dislike to be one of those "Just Asking Questions" but - might the brain biome contribute to frociaggine...?

The echthroi strike

Last January we got a tablet of Sagittarius-Orion. In it was a star as isn't there today. The tablet could show special interest in the field exactly because of this star in question, as a "nova". But maybe it was just a map of the winter night sky for use in planning the Adriatic year. I couldn't find where this star was noted as nova over in pre-Qin China or in the Achaemenid 'Iraq or by the Greeks.

The next question some might ask is - why not noted. One answer: it French-exited - just blinked out. Madeleine L'Engle had theories about that; which I assume she'd borrowed from Clarke.

A week or so ago, researchers pondered the natal kick of VFTS 243 A. They could do this because the smaller body is in this one case VFTS 243 A, a black hole (formerly larger) orbiting with a B around a barycentre. This orbit is circular. So the natal-kick was low, 4 km/s. This is lower than such visible "supernovae" as, say, the Crab Nebula (which was seen in China). The conclusion is that VFTS 243's implosion was not a super one; it just imploded and didn't eject much mass.

TOI-1136 revisited

The antiHawaiians using HIRES and the spacers on the TESS 'scope, in concert, have delivered a catalogue. A skim through this humble blog has picked up TOI-1136 at Praesepe. The researchers, Michelle Hill and others, figured this one worth the extra 157 total observations. Hill contributed to the dedicate paper to that one, before; now, to this sequel (pdf).

As noted earlier the TOI-1136 star is only 700My on main-sequence. So it is... volatile. Back in 2022 a skeptic (I wasn't a skeptic) might ponder starspots or mere fluctuation. And indeed the survey must scratch out a few Transits Of [then-]Interest - tho' not many, tho' not TOI-1136.

TESS was supposed to be observing this one again from 30 January; but the 'scope has experienced some off-time this spring, so I dunno.

What they got as of end-of-2023 was confirmation of six hot planets "b"-"g". Also a seventh dimming may recur at a Mercurial 80 days - although as-ever, more observations are needed for less-frequent patterns. 80 days is, they admit, abutting 2:1 with the 39.5 day "g"; it may be an alias.

In what the dedicate paper has constrained, the six confirmed masses are all subNeptunian and superEarth. Only "b" is rock-ably dense; the others are slightly thicker (given error-bars) than water. They're as "puffy" as we thought eighteen months ago. I assume heavy gas-envelopes and obscurant clouds - the researchers say again, hydrogen/helium. Sudarsky might say "IV" excepting that I don't think he was ever considering worlds as transitional as 700My-old worlds must be.

And yeah, I do see Sudarsky's influence here; they're using "equilibrium temperature" which depends on [zero] albedo. (They should be leaning more to insolation: 365, 213, 84, 49, 31, and 18.) Assuming total darkness: 737 K for "e", 658 K for "f", 574 K for "g". 350-800 K, recall, was Sudarsky's III range of cloudless planets, hot blue Rayleigh, low-albedo but not zero. That's where those hydrogen/helium envelopes might actually be deep enough for nontransparence. Anyway I assume that like Venus they're all much hotter than that at their surface. I have high hopes "g" at least will settle into III, later.

The comparisons (for c-g) are with Kepler-11 (older) and V1298 Tau (almost T Tauri); at 700My this system fits in between.

Nanotime

The new chapter of Galison's Einstein's Clocks, Poincare's Maps - or maybe Aczel's God's Equation - on microtime, went online last month.

Physicists tell time by measuring oscillations of atoms: classically caesium, now universe-level-accurate strontium. Maxwell's old daemon, by which detection heats up what you're measuring, nudges the atoms - which presents a noticeable error for strontium. Yay entropy! Anyway it seems Eliot Bohr (yes, one of those Bohrs) has worked around this by detecting (=nudging) one set of atoms, then the next set, then others before returning to the first lot which is now cooler again.

Eliot should get a Nobel... in engineering.

I'm getting into this now as we're seeing/hearing pushback on photon-transfer in space. Beaming power, or data, is not as accurate as it should be; requiring a wider band, wasting the edges. Better clocks would improve accuracy - so, power and bandwidth respectively. The space-to-Earth pipeline has other problems, which Portal didn't know in 1986; but I reckon point-to-point in space means (1) negligible interference and (2) accuracy matters even more at the deciAU level, like from planetary L1/2 to L4/5.

Psyche's thruster

Zimmerman is checking in on the Psyche mission. Last time this blog checked, it was for communications; now let's return to thrust. Now being thrusted.

It's ... not a lot of thrust. But what this li'l wonder does have, is specific-impulse. The ejected mass is going out hot enough that the mass-ratio isn't bad; so, delta-V (over time) is high-enough to get to Mars. Actually to a perihelion maybe 1 AU beyond Mars, after which it "falls" to Mars. Not Hohmann in the slightest.

Once at Mars, the craft will do a flyby to take additional thrust from the planet; a classic Space Age manoevre. Then the engine starts up again, to intercept this asteroid 16 Psyche at 3.1 AU; so, that's also not a Hohmann.

The electric-energy to burn the propellant is solar. Which isn't much at Mars and beyond.

Timor came late

Humans crossed the Wallace Line not-long after leaving east Africa / Yemen, and then got to Australia. But how? One island on the way is Timor. Timor had nobody 59-54 BP (57-52kBC). Then 42kBC it got some people.

I am not as surprised this month as I might have been before December, looking into the latitude. Timor (-Leste) is a seasonally-wet island today like Barbados, and in those Pleistocene millennia I expect it was mostly-desert. Humans fresh off Sunda will not be trained to handle the Dry Season.

Humans living around the monsoons for another dozen millennia might make a better go of it - which it seems they did; the settlement was done by a large group, as islanders go. Meanwhile islands further north got more-regular rain so the earlier less-focused Sundalanders could hit up what's our New Guinea, northern Sahul then.

Portal 1986

Now that Neuralink is coming online: let's look at the skiffy story in which I first read it. That'd be Portal. That's Rob Swigart's 1986 game for the Commodore 64; our family got this one in 1987 for the PCjrTandy 1200. I hear the Amiga had the better graphics, despite Tandy being good for it. In 1986 nobody was designing for the Tandy's graphics-card; so games like this and King's Quest and Starflight went out on PCjr settings, looking worse than they should have, and also not having mouse support. Below the Root would be another one looking better on the Commodore 64 than it ever did on PC.

Portal is an interactive-fiction. Interface is, like Starflight, windowed; but I had to use the keyboard. It is at heart a dialogue-tree... not unlike that Kharak manual. Your job is to expose exposition and story, between-which this "game" makes little distinction. Swigart also wrote a novel for those who didn't want the interface. The novel can be LibreOffice'd from the LRF file here, legally apparently.

Here's the plot: player is back from some trip to space, as in Planet of the Apes per Serling. Uh oh; nobody's home but us robots. The player learns, from the robots, about the genius teenaged protagonist Peter Devore, stand-in for the physics-GCSE part of the target audience. Devore believed he was in psychic FtL contact with a hibernate on her way to Alpha Lyrae Vega. (Less because of any decent planets there; more because it's poetic.) The transport-vessel then confirmed that the contact is reeeaal. Here is the irruption of magic (basically) into a supposedly-hard SF future. HP Lovecraft meets Robert Heinlein; both are namechecked.

As a fourteen-year-old, preGCSE (I didn't know about Lagrange et al.), I enjoyed King's Quest, and then Starflight and Below the Root. I did not enjoy Portal. The interface got in my way. If you play the DOS version, which is the PCjr version, you have to dial the clockcycle waaay back; after which, stuff loads too slow. Swigart tried a Kickstarter to republish this with a better UI but couldn't interest enough nerds; couldn't convince them "why not just a book".

- so now it's 2024. Let's check out the backstory. How [bad] was Swigart's crystal ball?

First up: space is hard. In our real timeline we did get a space-station on schedule - the ISS - but we didn't get any trips to the Moon or the "Elpies" (lagranges), much less Mars. (Although oddly Cassini went out before Swigart has his Saturn probe go out. And extrasolar planets are spotted just a few years later than spotted in our timeline.) Back in 1986 only governments could afford to get cargo into LEO, and badly at that. Kilos-per-dollar were ridiculous. Swigart I think assumed either that private costs would go down, or that governments would want to keep paying to it.

Swigart assumed that the USSR would hang around a few more decades; this USSR would form a check against NASA. That's even assuming Chernobyl, which is in the PCjr version of the story - I am guessing, rushed in, at the last moment. By May-June 1986, most of us in our juniorhigh figured that the Soviet system was a joke and wouldn't last in that form. I think no USSR meant no SDI and no pressing need for spaceflight at that price. Which all means I agree with Swigart we could have been running faster than we did; I blame politicians, not Sci-Fi. (Would've been nice if someone wrote Kerbal earlier. Not Swigart in 1986 obviously; but someone on a solid 486 in the mid1990s should have handled something.)

Medical-science is also lagging. We have many more vaccines. Most have come to us very recently; some question if we have good vaccines. And curing diseases once-caught is lagging behind Swigart's predictions. If space is hard, immunology and virus-fighting is/are for geniuses.

On the other hand Portal's gene-modding is good enough for furries (Swigart had a thing for... otters) and a "unisex" gender, although apparently not trans (ywnbaw).

Not lagging for Portal is computer-systems for personal use, but it's not much a plot-point. And there's cheap energy, beamed in from space and taken from fusion, on account fission is banned. In real-life of course there's no fusion and probably no space-energy either. Energy production itself is disliked in Davos because screw you, proles. We should have more energy than we have; again, Swigart had a rosier view of politicians than he should.

In Portal maglev is available in Japan by the early 2000s just like in real life. Liquid-nitrogen cars are supposed to take over from them but, LOL, no.

The best stuff Swigart was promising to us is now being delivered by Elon Musk . . . and only by Elon Musk. I already noted Neuralink, which, best I can tell, is on track for the story: 2020s. Tunnels under major cities weren't had in the 1990s but may be had now with the Boring Company. And then... there's space.

Planning before obsolescence

The grinding Ukraine war, and meanwhile Iran's swarm against Israel, has led to questions about how good the Patriot system be. That's the missile-defense missile-battery, which in Israel led to "Iron Dome", which can stop incoming enemy aircraft, manned or not. Or at least make it more expensive to attack than to defend; because even SCUDs don't grow on trees.

The Patriot was conceived during the later, Ford-Carter / Brezhnev days of Cold War. You know... when NATO was losing, rather thought we were. Warsaw Pact had its own issues, meanwhile. Sir John Hackett suspected that these issues were more-serious than the member states were letting on. Hackett predicted that the 'Pact might, by the early 1980s, see their window for a conventional strike. So: how to defend against a conventional attack?

Ignoring Hoyt's actual poast (which isn't good): "Fuzzy Lemon" reminisces over the Patriot development circa 1980. "Lemon" recalls the primary vector was manned aeroplanes, like the MiG.

One question which interns like "Fuzzy Lemon" raised (or, now claim they raised), is... what if the attacker can afford to swamp the Patriot. It's actually... worse, than "Lemon" imagines. The USSR didn't even need MiGs; they already had the SCUD, for decades. The 'Pact can just let the DDR and Bulgarians massproduce outdated SCUDlikes, ship them over to the Fulda Gap, and drain NATO's batteries. Then, launch the real stuff. What isn't modern braggadocio, is that such questions were probably raised elsewhere. But I think they had answers: namely, as soon as a sudden move of SCUD would be seen - yo, DEFCON. Or maybe the SCUDs get fired off: DEFCON 1, and now the commies got to worry about incoming ICBM.

NATO's refusal to abandon first-strike (Hackett aside) meant that the Patriot wasn't that much deterrent, compared to the whole DEFCON thing. I recall it wasn't as accurate as the West liked to pretend it was; "Lemon" blames the software (pdf). The Patriot did show that the US was serious about homeland defense; a doctrine perhaps-better envisioned in "Star Wars" SDI. The Patriot also had some direct use - selling to US allies concerned with those Third-Worldies... allies like Israel. In 1991, Israel was able to stop most of Saddam's SCUD (I keep wanting to spell out "SCUM", kek). It proved accurate enough that, well, Israel lived and Saddam's force-projection was crippled throughout the 1990s.

Anyway Iron-Dome may or may not work all that well anymore. And NATO may have figured out that a cheaper swarm might come eventually. But in 1980, or even 2010, the cheaper swarm wasn't there. Patriot, in short, had a run; a good run. Like /√ had a good run.

It occurs to me that in the early 1910s, the Germans like Moltke likewise thought - in an age of automobiles and aeroplanes - that wars would be fast. Blitzkrieg was, indeed, coming. And that is why they tinkered with the Schlieffen Plan of hitting France.

Some advisor should have told the Germans' Staff that they needs prepare for a preBlitzkrieg state of affairs on the part of France. As of 1910, France was in no position to roll into densely-populated German-speaking Elsass (France might still have sympathisers in Metz and northwest "Lorraine"). Germany could just set up a slew of pillboxes from Metz to Switzerland. Maybe even sweetening the deal by withdrawing from Metz: perhaps as another Luxembourg, perhaps just giving it to Belgium.

When the Black Hand is shown in the Balkans, Germany is then able to sweettalk France into not bothering with all that Slavonia in the East. If France attacks, it is France invading Belgium, such that Britain (and the Netherlands!) might even attack France. Either way it is still a nasty hairball, but not WW1.

To sum up, NATO 1980 was smarter in the short term than was Zweibund 1910. Germany made several other blunders in the leadup, as made the Habsburgs, and - less studied - the Hungarians made. But not digging Elsass for defence was, I think, the dumbest of these. A military must plan for the most-likely war coming up to the next year; leaving any wars for the next generation, to the likes of Jerry Pournelle.

Beware deepfakes

YouTube do a miserable job keeping scams off their site, I must report.

Flight Tests are national-broadcast events where Elon blows up a rogget, beyond doing "wet dress rehearsals". Due to lawfare, especially parachuting activists including a fake "indigenous" tribe, SpaceX doesn't telegraph when it will do one. Flight Test Four is... coming. Teslarati predict anytime 3-5 weeks. But it could happen Any Day Now.

... beware that it might not be any minute now.

So: Scammers can make an account that claims "SPACEX [LIVE]" with a stream of maybe a seven minute countdown, from file footage of previous flight-tests maybe lightly adjusted. At 30 seconds they'll "stop" the (spurious) countdown. Then "Elon" will get on stage... to promote some QR code for bitcoin or Doge. That bit is deepfaked, but you can sort-of tell that it's fake given it sounds soulless, like the souls of the scammers. [This is the point where I realised... I'm being had; luckily I personally was not had.]

Why doesn't Youtube do anything about this? - like, at least not raising this to #1 on my suggestions?

- because Youtube don't care. They're too busy protecting grifters from "The Alt Right", and hounding the latter. Since Youtube already has its thumb on the scale for one set of grifters, why not the other. Especially if they're grifting SpaceX watchers; X, owned by the same South African, is a Youtube semi-competitor.

TLL2 packs a kick

Yesterday morning this blog sketched delta-V from stored angular momentum. The source was a statite relative to Earth at 1 AU; the target was STL4 or STL5. The statite was chosen to mimick from Moon's Hill (against Earth) to Earth/Moon Hill (against the Sun): 93 m/s. More maths are needed, if from actual TLL2 - or any T/L halo. Because although all five of these Lagranges are statite relative to the Moon, they are no statite relative to the Sun... which is what anchors S/T Lagrange.

The Moon's angular velocity is obviously 2π/29 days so 2.38-2.96e-6 rad/sec so, whatever; 8/3 microrads prograde to the ecliptic. This is measured sidereally, not against Earth's own rotation; but those who might care about Earth are at TLL1, not '2 on the Pink Floyd side. To get the speed from the barycentre just multiply by the distance. Sanitychecking the Moon's axis of rotation, which in practical terms means any of the TLL3-5 haloes, coughs up 8/3000000 × 384400 km = 1.025 km/s, which is in-parameters from NASA.

We want, rather, the T/L Hill, as visualised: 8/3000000 × (384400 + 60000) = 1185 m/s.

I have to say - that is a lot. Even granted that I'm still in Earth's Hill, even granted I don't feel like relearning vinf; the craft will overshoot STL4 or '5 - or STL2. It isn't a Hohmann for Mars or Venus, either - so, all the Near-Earths are out. Moon-based trajectories may work as faster-than-Hohmann flyby past Earth and Mars both on aphelion; so some of those cyclers are possible (their vinf calcs didn't ponder stations on Luna or Deimos). And fries-by of Venus do allow for some aerobraking.

Launching from TLL1 means 865 m/s which is also a lot.

When/if STL4's rocks be settled, that'll need to be done from STL2 where Webb and Gaia be twirlin'-'bout. But the Moon's Hill supports no station for supply to any of the Earth's Lagranges, at least not direct and in bulk. Also: angular momentum won't do the job. The shuttles from Earth (or Luna) to STL2 will need to be boring massive roggets like... what delivered Webb up there, at massive cost. Mass drivers on the Moon might supply STL2 directly, but will require much energy to go retrograde against said Moon's own orbit; the cargo won't be fragile.

Moving Janhunen

On looking into Janhunen's dumbbell I pondered if its 89000 tonnes allowed too little for permanent residence. The red flag was the proposal to shield with hydrogen and boron-10; that is, by the least-possible, which must run out. So the dumbbell might work better as a shuttle. Just move a 89000 tonne spinning 230m-radius hourglass bro.

Let's ponder how we do that. It happens that spin - where a cable can be released - is a momentum capacitor.

As ever it starts with prior-planning, at construction. We're installing equipment on these dumbbells, and testing that such would work at our 9.8 m/s². These stations-in-making are not uninhabited. Human mechanics will want on-site, wasting minimal time on commutes. Their base will be in-site, with imported shield; we'll get further into that later. Point: it's already spinning from the moments of construction.

From 9.8 m/s², the outer edge runs 47.48 m/s. That's a vector we add to the vector at any given point in the orbit. That is: bomb the nexus of the spin. One side adds the vector to the orbit; the other adds the opposite to the orbit.

In technical terms 47.48 m/s is the delta-V. So: the usual maps apply, depending where we start. For reference Earth-Venus demands 280 m/s; assuming no actual Earth or Venus gravity is interfering. The delta-V gets more helpful for a station assembled at the edge of the Moon's Hill distance as wants off the Earth's Hill, here to Venus. To do that, on the (incorrect!) assumption that the Moon's motion doesn't matter, is only 92 m/s. I will set 90 m/s as (arbitrary) budget to hop from Cruithne, to STL4 or '5. The finetuning will involve various manifold maths, which we'll skip for this poast.

Any adjustment in a cabled dumbbell's tangential velocity can be had by adjusting the cable radius, as delta-velocity is applied to the outside. From to 47.48 to 90 m/s means, from 230m to 900m. This rocketry can be gradual; think, VASIMR by way of Ebrahimi-Alfvén. If the station has inhabitants, they won't even feel it, except for experiencing less Coriolis. A 1.8 km wide disc does risk intersecting any other stations there, but our whole point is to get rid of the thing, so - we don't care, at this point. Incidentally I accept Janhunen we commence the radius at 230m.

This method wastes least for pushing one end of the dumbbell to L4 as the other goes L5. At least, if we're starting from L1-3. Note: not TLLx to STLy; this is TL-to-TL or ST-to-ST. With Cruithne, much will depend on the day the year. From a planetary orbit: ~50-m/s-increments present a (drastic) means to clamber up the gravity-well until reaching the desired orbit, like GSO. I doubt we're doing any of that over Earth; rather, Phobos can use this scheme to export mass to Deimos' dangley tether.

To return to our mechanics, under what shield they got: as they build all this, they will want as little annoying spacesuiting as possible. If a dumbbell did have permanent air, that might be a problem as the ends go zero-gee in a sudden. Last year I did some maths on balancing the ceiling against light air-pressure. Without gravity the ceiling might, er, explode. Before the dumbbells go freefall, that air needs to be sequestered or, if impossible, vented. Could be that the mechanics are camping in inflatables.

Next problem: how the future permanent-populace put gravity back to the dumbbell-ends, now sailing off to their opposite Lagranges. Answer: at our start, we build two dumbbells, spinning in opposite directions. (Which also aids in their stability; they don't crash into each other, and don't wobble unpredictably off the planned axis.) If these are cut at the same time, more or less, we'll have two 45kT masses going in the same direction, and two in the other (but a different two!). It remains to reattach the (new) pair going to L4, as the counterparty going to L5 will do.

Thus far: the above might seem to shuttle from one empty part of space to another empty part of space. To that, as Cruithne already owns plenty of rock, and as TLL2 has access to imported regolith; STL4 and STL5 have access to Trojan Asteroids. At least L4 has some nice ones, 2010 TK₇ and (614689) 2020 XL₅. As long as L5's rocks be uncharted, recommend that the shuttle to L5 be half-manned at most, with one half of the dumbbell being simple rock and junk that the Earth system doesn't want in orbit.

UPDATE 11:30 AM - I'm reassembling this stuff at Cruithne, sharing the Earth orbit. The Earth/Moon Lagranges present their own problems as must be handled later. Like: tomorrow. Not now.

ABEP

One specie of perma-ramjet as we might actually get to use in an atmosphere is the Air Breathing Electric Propulsion (ABEP). It isn't used now because it hasn't been worth it... yet.

The issue here is that where we're trying it out, Earth, there's oxygen. Oxygen corrodes the electrodes. Although I do wonder about Venus or Mars; there's oxygen in both exospheres and in ionic form, but not much of it.

Mars has the advantage that the exosphere is pretty-much ... the sphere. This device could almost work from a human jumping distance.

I've fallen and I can't get up

ScienceDaily links to robo-limbs. When bouncing about in 1.622 m/s², the momentum is the same as on Earth. Lunar visitors fall down a lot; and with all that spacesuit gear (which additionally has to be dustprotected) that's not as funny the seventh time it happens.

MIT is testing at JPL, Supernumerary Robotic Limbs, expecting a trademark "SuperLimbs". Which astronauts have to carry around too.

It's designed for our Moon. It will work even better for exploring the outside of a Phobos-tier major asteroid. It may help for a spin-gravity asteroid's upper layer, given Coriolis; although here I wonder if the buddy-system would just work better. Above a certain gravity, meanwhile; do Martians still want this extra gear?

Eustathius

Yesterday was slow-enough I just let that gamer-thing get poasted; today there might be something. Well, from last year: Warren Treadgold on Eustathius of Epiphania.

We deal here with Byzantine historical-memory, again. Various mediaeval Greek-speaking world-historians reached back to AD sixth-century John Malalas of Antioch and another John of that city. That second John Antiochene's text is less datable because... we don't own it; its content is had from a third John, the mediaeval Zonaras. Treadgold would ponder whom Malalas and deutero-Antiochene used. Treadgold has identified their fundamental basis: Ammianus Marcellinus. This article handles the inevitable side-question: how?

Ammianus' earlier books are famously lost. Their reconstruction is highly desired, even for their own sake, because Ammianus is regarded in the top rank of Roman historians, as Malalas is not. This involves a synoptic-problem between the two Johns: their shared lore includes lore Ammianus did not use, not least the Greek language (so later Latins like Nicomachus Flavianus are ruled out). It happens Constantinople hosted fewer Latins in the sixth- and earliest seventh-century than she had in Ammianus' time. The "easiest" solution is parallel to Goodacre's solution: one used the other. But no-one has figured out how to order the twain.

One reason to hope for a Quelle before Malalas is that then we get to ignore Malalas, whose history is bad by constrast with his namesake compatriot and perhaps-contemporary. Also maybe we can get a proper edition of that other John; the last decade's two (rival) editions are an embarrassment to the field.

Treadgold for that (Greek) Quelle names its author, that Eustathius. Eustathius read Ammianus' Latin, sketched out a cursory summary in his own language, and compiled his own (shorter) world-history around that frame. That history stretches to the AD 503 Sasanian conquest of Amida before breaking off untimely; for that end, Treadgold argues that its author died in the AD 526 west-Syrian earthquake. One of the two Antiochene Joannae may have been aware of the other, or even consulted each other; but Eustathius, preserved in Antioch, made their basis. Meanwhile Ammianus never did get the full Greek treatment.

If Treadgold is right: the other John can be firmly placed in the seventh-century, and his refusal of Malalas' gharîb is easily explicable as distrust of Malalas.

Gavin Kelly is editing a new Ammianus. It may be better for scholarship if he avoid the earlier books, and instead reconstruct *Eustathius.

How Blackbird joined The Beast

Now that it's all over, I have to ask - was Homeworld ever all that good?

For 1999, we'll need to know the competition in space RTS. Starcraft would probably count. Maybe Master of Orion II. Um. Dune 2000?

The 1999 game hit a lot of 1999 bien-pensant tropes. We're fighting Imperial Japan, basically; except with more of a European Fascist aesthetic. Also "Turanic" raiders, but they've been bought by the Evil Empire - see the hypocrisy. That backstory, which became Deserts' backstory, had hit against Religion. "Hiigara" nodded to (nonShi'a) Islam, favourably. The final cutscene, before Yes take the mike, headtilts about how war is hell. So far, so Enemy Mine (Pitch Black will come out in 2000).

The first game was good enough, for 1999. Also we got a few diversions into a universe much grander and older than this one admittedly-vast conflict, cf. the junkyard and its robo-dog. So "The Message" wasn't obtrusive.

Barking Dog's Cataclysm ran with the expanded-universe of 20-AU-wide junkyards and unkillable abominations. I started to ask myself, how come Relic-cum-Blackbird didn't get in on it; then when Relic reacted so poorly, pointedly not calling their sequel "#3" I asked - why the posture.

I have to assume: ego. Not necessarily that Barking Dog did it better; Cataclysm's gameplay is about the same, with a few improvements. Rather: Barking Dog subverted the lore. Relic didn't ask, what's worse than fascism; they didn't want to ask. Warhammer was asking: answering, that a threat to human life itself is worse. Here, The Beast is worse. The old imperial-remnant works with The Beast; but these traitors could have been the Kharakis, if caught in a bad week.

Eventually the midwit with impostor-syndrome will reveal the nothing at his core. Thus why Homeworld 3 (and honestly 2) is bad. Thus why Exodus will disappoint.

PURPLE HAIR 5/17: ArchCast blames GearBox and one Lin Joyce. Linked here as an alternate-take; I'm not sure I'd blame them for filling-in what the devs couldn't. WAGONS 5/19: They're scrubbing the history. Reddit says "to protect from Harassment"; a lawyer might say "mens rea".

The Homeworld Trilogy

Relic's 1999 Homeworld is a classic, and Barking Dog's Cataclysm should be one. Relic's sequel was a miscue; last game I ever preordered. I've lately been hitting up prequel Kharak. One bitten, I wasn't going for it when it came out; instead I nabbed it in a 2020 sale-bundle; but then only got to Cape Wrath - I know, I know - "git gud n00b". [And there's a HW 3, currently being pilloried on Steam.]

The lore is... interesting. The first (now second) game came with a manual. It delved heavily into Kharak history and social-structure: a mix of clan (kiith) and faith, basically high-tech Dune. None of that matters to the first game we got. Except that if we read it, it makes for that much of a shock, when . . . If I may hazard a spoiler, the narrative choice reminds of Tolkien's first-edition of "Fall of Gondolin". (Much as Tolkien rejected Herbert's take on religion.)

Lately we're hearing from Relic's successor Blackbird (Rob Cunningham and Jon Aaron Kambeitz) that Homeworld was supposed to be about the actual world. Your kiith was in these wastes, or in orbit (the devs weren't sure, either) to cut apart ruins in SF-Late-Antiquity (by resource-scrounging first; then more-formally, from the second Sarathi mission on). In Kharak these devs have given to us that dying world, and meanwhile the same devs came up with Shipbreakers to go more into chopshops-in-space. Probably why they'd called their crew "Relic".

Problem: Blackbird have decided to go the way of the Creative Class. Apparently what players enjoyed during Shipbreakers' early-access is not what the game has become, which forces lazy agitprop into unskippable content.

I have to say that Kharak has some girlboss moments. Start with Rachel S'jet. Already she was/"will be" reified as the home base Mothership in the original game. Here she's got her own vessel, alongside the (usually) moveable carrier. You're not allowed to allow her to die; contrast, the uncounted drivers of assault-vehicles and, later, railguns. This means every sortie you take her on is an escort-mission. The plot often forces the player to drag bratty li'l sis along; sometimes she even interrupts the narrative. This game, structurally, is Rachel's story. The player must orbit Mary Sue; his (or her!) avatars are Rachel's betamales. I concede some sugar in this medicine, in that Rachel had/has a brother; so she at least doesn't hate men. Cunningham and Kambeitz make a point of hating men; the Gaalsien have a... oof . . . "Fathership".

Moving to Mandalore's review, I don't recall having to pay extra for this game's lore manual - although, sale. So I went onto Steam where, I regret to inform, I have verified: in normal process you gotta pay extra. As Mandalore notes, the planet's lore is not adequately fleshed in the game, so this manual needs inclusion at least as "fluff". That's some Kotick-tier corpocrat shadiness. I'll add: most content is copied over from the 1999 original Homeworld manual; and where not, we get ads for DLC like Khanseph. To the latter, as Mandalore also notes: such needed into the mission, which in mainline is all-Gaalsien-all-the-time.

Mandalore's right that the game still has bugs. For all that the developers have tweaked this game into a version "1.4.4" (as of end of 2023) they haven't fixed the display popin/popout I'm seeing in Cape Wrath and beyond (the sensor blackout doesn't hold for the whole episode). He's also likely right that additional missions were on the drawboard and that we're looking at too much tech being allowed to the player in too-large chunks (he's looking later in the game; I'm looking at Sarathi Basin, as far as I'd got last weekend).

You can't mod this game because of course you can't, chud. As Mandalore complains you can't even map the keys; which Americans may well consider a ADA vio. I'd not trust Blackbird toward a "1.5" on account they'd just make Rachel's brother a transgender.

Even the manual has bugs. That original 1999 continuity error with Gaalsi(en) being exiled in 717 when the authority to do that, Tiir, was founded in the 810 - that's still in there. Tiir needed to be founded in the 700s as Saju-ka's rival. The war can draggle on for another century, maybe Tiir rooting out Siidim diehards.

On the plus side: I like that I get to see Kharak in its final days, and at least a taste of the old kiith system (Gaalsien being the final holdout). That adagio hits that much harder.

On HW2's general badness I'd considered the canon to devolve back to Barking Dog. Given Blackbird's record of moneygrubbing, hypocrisy, and bait-and-switch... Doctor Disaster argues gamers would be fools to trust them with a preorder of the next sequel.

Where did Mercury come from?

Last weekend Anton Petrov linked the wonders of Mercury's history. Mercury looks like... Chile. Namely, it has salt deserts, caused by saltwater eruptions, to the point of blowing a sodium coma like a comet.

Which suggests that, also like a comet, Mercury didn't form where it exists now. It formed with a large iron core but lost its original crust and mantle to an impact. Also pointed out is boninite, found in Cyprus and (especially) Mars. So Mercury seems like Mars' twin with a larger core.

Several commenters are asking if Mercury's old crust might be sailing the present asteroid belt. I am unaware of this. We know what a piece of broken crust from a differentiated body should look like; there's a lot of upper Vesta floating around, even landing on Earth. But I've not heard of any differentiated crustal rocks as would match Mercury. Aubrite meteors look like the rocks which helped form Mercury, but not kicked off of Mercury-having-formed.

To make all this work, do we have: Venus, Mars, Mercury, Theia, Earth; with something whacking Mercury around the same time Theia hit Earth? That's ... a Velikovsky level of reshuffling. Theia's mantle was lately boosted to 13% iron so I don't even know.

Atheists do history bad

Timothy O'Neill made a name for himself over on Vox Popoli for saying stuff as Vox Day likes to hear. "Thanks" to Mark Tapscott, we're being reintroduced to "Jesus: The Evidence", likely Ian Wilson in... 1984. Some of that evidence comes from Whiston's edition of Josephus.

O'Neill in 2020 didn't like that Richard Carrier (among others) refused the Whiston testimony. O'Neill's conclusion: So the case is not closed. The question is moot. And it is likely to remain so, unless new evidence appears.

Unlike O'Neill and Carrier both, I am not an atheist. I will say this on Carrier's behalf: where a case is not closed, that case is worthless as evidence for another case. This pericope is no Josephan witness to Jesus as "Christ" (per Whiston). It is at best a text-transmission witness to (Lukan proto-orthodox) creeds. To the extent it is "moot", the historian's duty is to drop it. Move on to Tacitus and the younger Pliny. (Or for that matter to 1 Clement, as Carrier has done already.)

As to why O'Neill has so failed his duty as historian: I detect that he doesn't like Carrier personally. This is O'Neill's right as a human being. Carrier has chosen a lifestyle which, for my part, I judge objectively deviant from basic human morals (however natural be these impulses for a male animal).

- but we're not discussing Carrier. We are discussing Josephus: whether it be in character to write what Eusebius, then Jerome, says he wrote. It be not. The pericope drifted in from elsewhere. And unlike the extension to Mark which we Catholics heard yesterday morning; this was done deliberately to ape Josephan style.

That in style it was also Lukan is suggestive, to me. This forger was not a Marcionite; I don't think Marcion was much up for copying Jewish material of any sort. I figure: someone in Rome. Rome could appreciate Josephus and Luke both: because although both texts came from disbelievers in Rome's religion, they each supported Roman supremacy. Whoever fathered (or mothered) this cuckoo upon Josephus might, indeed, not have been a Christian. But why we should accept Roman propaganda any more than Eusebian propaganda, is not a question I care to entertain. It's bogus and O'Neill shouldn't entertain it either.

Dépêche

Irradiance is the function of stellar luminosity at a given distance. I must ask if 80% is the barrier at which chlorophyll becomes competitive with Purple. The very graph of outgoing radiation, in the 70s%, should be redshifted, nu? like with K? We know the Archaean had no ozone.

I might allow indigenous chlorophyll wherever a stromatolitic planet hits the 80%-irradiance mark. That can be at 1.1-Gy rather than, as here, 2.1. K and G planets once habitable stay habitable, for billions. Albeit fewer billions for us G inhabitants; for our part we've wasted at least one Gy, and since then arguably had an extinction-event too many. εEridani is still too young by the way.

This further opens up F stars in distant orbits which, note, aren't T Tauri for long; so allow even more volatiles than we do. "But Chicxulubs!" - the impact velocity of that semimajor of (here) mushy asteroid will be less, 2 AU out (although we'll need to constrain the number of longer-period rocks).

Our Archaean timeline

As I was peeking into habitability prospects for star-systems, I had occasion to appeal to the age of the star. I'd based a lot of that on events here on Earth. Let's list up some milestones as this blog has been alerted.

Where stellar-age is marked for a given K or G type, this is calculated from the Main Sequence of hydrogen fusion. That's also whence luminosity; from the baseline of 67.7%, to the 100% of today.

That 2001 paper further implies that we entered the Sequence like 30 million years prior to those first rocks. However: this looks like rounding-error. Our "T Tauri era" when Sol roasted out all its interior soot is, therefore, a "B.C." to this exercise.

... which exercise must be general. We are excluding the "Boring Billion", the abrupt core transitions, the 19-hour Moon lock, Ediacara, Cambrian or Chicxulub. I figure them for ludus naturae specific to this system, or Acts Of God. For all I know, the Lord G-d unpurpled our planet too; so, that's where we'll leave this count to the 'alamûn.

Also excluded: "Late Heavy Bombardment". It's untestable for Luna and didn't hit Vesta. I did however divert to Mars as a proxy for the water-ocean here on Earth too; it's a prerequisite for stromatolites. UPDATE 6/6: The water seems sudden upon the Earth, amidst nonmagnetism. This seems bombardic.

So, we're focused on the unbreathable Archaean. In millions of years:

• 0 - Cooling of first asteroids [4.567 Gya]
• 107 - Theia crash [4.46 Gya]
• 550 - Nonoceanic hydro cycle [4 Gya]
• 867 - Magnetic field starts [3.7 Gya; 75% L] - end of Mars' Noachian
• 867-1600 - Mars' Hesperian ocean [3.7-3 Gya]
  • 1090 - Oceanic stromatolites [3.48 Gya]
• 1600-2100 - Cratons [3-2.5 Gya; 80% L]
• 1900 - CO₂ measurement [2.7 Gya]
• 2107-2141 - Oxidation [2.460–2.426 Gya]
• 2300 - Free atmo oxygen [2.2 Gya]

For other systems: M dwarfs take longer to enter the main sequence. Its oldest (roasted) rocks will precede the start of the star's clock. I don't know about K except that its "goldilocks" status has been overstated.

In our future: 4800 My will occasion that last desert continent when the Sun be 102%. 5 My, we're steamworld although the core will probably keep us a nice cloudy Sudarsky II from a distance. 6 My, tectonics stall and we're fully Venereal.

Why our nearest systems don't have aliens

For chuckles over the last week, I did a pulsecheck on every exo-system known within three-digit milliarcseconds, aka ten parsecs / 30ish lightyears. Oft-nicknamed "Sirius Sector" in SF.

This close to us: I assume if any sizable star in this sphere had large close-in planets, we'd know by now (cf. that hotneptune desert). For those we know, which skew toward Mercury-orbit superearths, I looked to the possibility of also something human-habitable up to one Sol AU. In light of TOI-4633 I'm not excluding binaries. I am excluding white dwarfs and any binary with those - so long, 40 Eridani and Sirius. I also figure that Proxima fills all our needs for irradiated eyeballs orbiting a red, directly; we're going green, not purple. The remainder, I sorted by stellar mass.

You could say I was fact-checking the Halo backstory, before the Covenant. This assumes a local answer to Drake Equation: that the Sirius Sector holds nothing worth the attention of what sentient aliens there be.

I started with εIndi, well-constrained by now. This remains a candidate, far as I know; I am unaware of it flaring up like, oh, Gliese 75. Over time, the "B" browndwarf pair has pulled A's 3jovian to a peri' now 4.576 UPDATE 7/25 17.2 AU (e=0.4 a=28.4). This system is young by the way: preVendian. I wouldn't rule out a planet in the habitable-zone (HZ), which is 0.4-0.8 AU; even with oxygen. My problem is that such a planet may well be orbiting from 0.4 to 0.8 AU, or outside those parameters. It's either a mercurylike or very cold; surface uninhabitable. I hereby declare this star's mass the absolute floor for HZ consideration.

5-Gould Capricorni = Gliese 785 now shining at 38+% hosts two Neptunelikes at 0.32 and 1.21 bracketing that HZ. Outer circular c carves a Hill of 0.033+ AU; inner b's effect is more on aphelion which rises to 0.355 AU. Between runs plenty of room for an Earthlike. Problem: factoring the system's age, we're looking at a Marslike without a spinning core.

GJ 892 = HD 219134 has many superearths of which g, in the Venus zone, is almost Uranian; it is 11Gy old so running low on essentials like phosphorus. Count this one out too. τCeti rotates edge-on. The planets claimed 2017 could be false-positives. Of these "f" was a superearth - but, who knows.

Over the edge of half Sol luminosity: εEridani is too young for free oxygen. 66-Gould Centauri = HD 102365 A, the furthest in our sample, has a Neptunelike in an eccentric orbit clearing out the HZ.

Closest to Sol mass at 82% luminosity is 61 Virginis, a bit on the far side, which we've looked at here. First up is that it's too old for any tectonics in Earthsized planets of its HZ. For those still reading I further note: outer d has a Marslike eccentricity which normally points to something large out there for *e. That debris disk from 30+ AU constrains mass and location for outer planets. Also by 2012 we'd ruled out anything large up to 6 AU, which range we can assuredly expand by now - although a long-period signal exists in the 55-year range (browndwarf at Saturn?). 1+ AU has mass for an Earthlike ... but will have to be superEarth to hold tectonics. Whatever's here has e=0.2 too, and I suspect further than that 1 AU. Futureproofing will prefer another cold dead Marslike.

We might post a watch on those "planet candidates". Alsafi / σDraconis, for one, may or (more likely) may not host a superEarth in its own HZ 0.7 AU. Weighing in heavier than Sol comes δPavonis (which that February 2023 poast looked at). This could own a Saturnlike at 11 AU; buuut... this star is old, so if it ever had an Earthlike at like 1.1 AU that planet is roasted. No tectonics after 6Gy either. Ditto β Hydri, μHerculis, 107 Piscium. I don't know about the core beneath, however. Check for ruins.

82-Gould Eridani is 3/4 L so habitable from 0.86+ AU; its inner planets b and c/d (tags vary in the literature) run well within that, if eccentric. I saved this system for "candidate" on account of the outer planets. Of these the most-likely option skates 0.816 AU perihelion. That ousts anything nice. CONFIRMED 1/30/25: Stay out.

What did we learn? Basically, most stars are M dwarfs. Of those as are in our K/G range, one hot superEarth means probably more, and eccentric - sweeping planets like this one, out of the way. I get the feeling the astronomers already knew that and tried to warn us.

Any other nearby star could well have smaller close-in planets than we see, with larger planets out in their Saturn belt. Pretty much... like us! As to binaries like HU 918: ηCassiopeiae, 70 Ophiuchi, ξBoötis, χDraconis could have smaller planets in their HZ, but haven't turned up anything yet.

HD 45364's Milankovich

Last couple years I missed this one: the HD 45364 system. 34.35 ±0.04 parsecs from here, in the southern "Bigger Dog" constellation, its star shines 0.637 L_⊙. In 2009 its two known planets were seen to orbit at 3:2 resonance like Neptune and its plutini. (It was actually the first resonance raised to publication.) Zhexing Li, Stephen Kane and three others were curious what another decade of study might offer.

They went with a dynamical model, which is of course better than Kepler (meant for a two-body system only) and feasible for these narrow bounds. Their equations echo more Laplace:

φb = 3λc - 2λb + ϖb
φc = 3λc - 2λb + ϖc

... but integrated numerically. They say the resonance is impermanent; the planets librate. It looks like 3:2 now but will shift, then shift back. That is the stability here. Eccentricity changes too, b 0-0.07 and c 0-0.03. Ah! Milankovitch. Which is about the limit of interplanetary interreactions, compare lately Gliese 1153 = HD 104067.

All this constrains the planets' mutual ratio of mass. It actually cuts the mass of c, which is unusual given that radial mass when not transiting is always given in M sini. They are considered 0.19 and 0.55 M_j. The angles i are such that sini approaches 1. That is: each planet orbit wobbles into edge-on to us some of the time.

As to how these giants got to the inner system: they were thought to be migrates from further-out. Two models allow for arrival into the quasiresonance here. Keeping in mind we still own no constraints on radius therefore density / composition.

The authors see space for exomoons; as migrates, these planets had space to accrete Jupiter-like menageries of rock and ice, before rolling inbound. At 0.9 AU, c's maximum eccentricity is 0.03; this half-Jovian cuts into the inner sector of the HZ where our Earth would be. Such moons as exist might include Iolikes, a rocky Ganymede around b, and an ice Ganymede around c which becomes a watermoon.

Li et al. suggest we keep watching this space for when b and maybe also c transit/s, as at least b should soon. With any moons.

If c does own a moon free of its planet's tides, that brings up habitability; although, I don't hold hopes for its internal magnet, being certainly tidally-locked and small. But: more HZ stretches beyond 0.9 AU. The authors think planets could survive here too. Nothing here has budged the Milankovitch dance; so if anything is out to 5 AU / 10 year period, it's not Jovian. But most likely is that even small planets will be migrates - therefore, I think, little Neptunes. Hycean.

Interplanetary fission pulse engine

h/t Stephen "Vodka" Green and Gizmodo, Howe Industries promises fission-driven pulsed plasma. Harry Wolper in Green's comments informs us that this is no Orion rocket; this one is smaller-scale, "only" delivering 100kN thrust with its 5000 N/N s specific-impulse. So if nothing else NASA might actually get permission to torch it up, as with FireStar, like from TLL2.

RocketStar did their boast when at SBIR phase 2. Howe has completed the NIAC phase 1. Why the different acronyms? - because RocketStar are working with the military. Although they did get to test it on a NASA Artemis mission.

Howe's promise meanwhile is to get a manned mission to Deimos ("Mars") in two months, rather than the Hohmann six - or the Aldrin five. Unlike with Hohmann or Aldrin: here the transport must take the engine, and use it, to accelerate and to decelerate.

Even with those longer-duration missions, someone's got to bring some kind of engine to dock with Deimos which presently lacks a spaceport. Howe's engine looks ... let's say, competitive with RocketStar's. It helps that Howe supplied some numbers which RocketStar didn't.

Forgeworld

55 Cancri e is a hot planet with a molten rock and metal surface, with compressed solid rock beneath that. We were just wanting confirmation on the conductivity (convectivity rather) and composition of its atmosphere.

NASA delivers, from two of the Webb's instruments. Dayside is 1810 K, which must be convecting from some (violent) wind; carrying said wind, is carbon monoxide and dioxide.

CO is a reducing-agent. If there was any iron-oxide to smelt, on this surface, it would be quite smelted. I suspect it just sinks. Rising up rather, they say: are these carbon gasses themselves; there's no way a planet this hot keeps its gas unless it is being replenished. It's not a stiff dead Black Planet, however much it acts like one on the surface.

Inflatable modules are closets

Sierra Space and Max Space are competing in the inflatable-module, er, space. The pioneering work was done by Bigelow, with the Expandable Activity Module (BEAM) on the ISS. … but Bigelow haven’t updated their “news” since 2019.

It all seems a bit dangerous for LEO with all those Kessler shards flying about, even with better space-tugs. Luckily, buried in this EVA story, is coming an experiment to molniya out to 1400 km before pulling back to LEO.

For LEO I rate inflatable mods as best for nonhuman activity. The air should be low-pressure and no-oxygen. I can think of electronics and perishable storage. If the seal breaks, no-one gets hurt and the air we actually breathe isn't lost; if there's an electric short, no fires start. It's a bit of a pest to get over there and tweak something, but it won't need full EVA and, again, if there's a breach the mechanic can get reeled in quickly and won't, like, lose an eye.

Remote aeroponics are coming, also. Since this process gives off oxygen, I don't want it for electronics or storage. Here too, I don't rate as human-breathable; this is whither we dump as much CO₂ as we can. We'll need, instead, circulation between this and the main station.

Persians on the moon

Reynolds links the wall of death. The "millennial" generation might rather consider Prince of Persia - in its 2000s form (not to be confused with our 2D version, fellow X'ers).

Imagine if the Islamic Republic could lob rockets to the Moon instead of at Jews all the time, sigh. But anyway.

I expect this is transportable to Mars' and Mercury's gravity. Maybe not for spinwheel space habitats, because of Coriolis; luckily those are already arbitrarily-imbued with gravity.

Running around slightly-angled walls for that extra bit of G does sound fun. But it may be hard on the ankles. Special gear for those?

The Guardian, bless it, took the time to look up alternatives - up in Northumbria University, where they found Nick Caplan. He points out that once we're talking special gear, we may as well go all the way with inflatable cuffs.

Hussey 918

The most wonderful person on Youtube reports on the currently-offline TOI/TESS project: it has pinned down a G system at 95 parsecs.

This tiny spot on the late-nineteenth-century photo-plates avoided the consideration of Flamsteed and Draper. William Joseph Hussey at the Lick Observatory notched "1905.17" as a "double star", publishing it March 1905 in his ninth catalogue: HU 918. It was subsequently ignored, basically; until it became TESS's "Transit Of Interest 4633". Those... ugh... "citizen scientists" precovered the data to dig into the binary's deep(er) history.

With the additional attention the binary's orbit is resolved: period 231 +32/-24 years. This is not as constrained as it could be, but in all fairness our observations pre-TESS aren't great for some tiny 95pc dotpair in a disused catalogue.

These astronomers for their part avoid the name "Hussey 918". This blog's juvenilia aside: they're unsure which star in it is the transit-of-interest. They do know which is A: it's a ~1.1 sol mass; B is 0.05 masses less. Unfortunately they are eccentric (0.91!) so they are interfering with each other's light, currently. So I will call whichever star owns the planets, "TOI 4633".

There's a Saturn(?)like b but it does not transit, so of poorly constrained mass and even volume; it remains a "candidate" pending more observation. Anton Petrov is excited about TOI 4633 c - the actual transit. This planet is 47.8 Earth mass +23.8/-27.6, which again will get better constrained dependent on stellar and "b" finetuning. Radius is better-constrained: ~2.4 Earth; contrast Neptune 3.85. Whether you call it subNeptune or superNeptune depends on whether you're talking volume or mass. Eccentricity is 0.12 a bit more than Mars'.

At this mass in its location, which rounds to 1.6 Earth flux even without that other Hussey companion: expect a large gas envelope. This will settle into a wholly obscurant clouddeck like Venus': Sudarsky II. These clouds likewise will be low on pH; although a magnetic field will keep in the water, at least. Petrov already knows no-one's living on this planet. I add: the planet's own tides will disrupt any "Doppler" world at 0.85 AU's L4/L5.

Petrov waxes more hyper about the possibility of Galilean moons. The Hill Radius would fit one; "b" is far inbound of the place. Um. Well. There's no impactor on this thing as can offer a moon like ours, of a decent proportion of this planet's mass. Titan's mass is 0.0225 Earth and that's including its shell of ice, ice which these moons won't have.

Whether these warm moons have water... there we really must speculate. How far out is the planet's magnetic shield? Are any moons Ganymedean, themselves? One can imagine a small interior moon by itself without Io-like tectonics. Or a larger moon anywhere also not being squashed, with its own dynamo. Otherwise (and most-likely) they're tiny irradiated rocks: think, Titania and Oberon.

For those who consider HU 918 important, and however good it be to constrain parameters: it might not be a candidate for Webb time - yet. Petrov considers prime time for a few more decades hence, when A and B separate sufficiently we can at least see which star is the T.-o'-I.

What this system buys us, rather: is a model of a binary system which can support a Neptunelike at Earthlike irradiance, allowing for those short hot summers of perihelion. It even offers a "hot Jupiter" inbound. Skiffy worldbuilders rejoice.

TESS 5/8: Back in business, as of yesterday.

Intelligent design, by genehacking

I don't trust "Vox Day" so a fair start-assumption wherever monsignor Beale hits a hot-button issue in drive-by snark, is: he's not on the level. On whatever has caused species evolution on this planet Earth, he hasn't restrained himself. Lately though, he has been... arguing the point: mostly from a 1966 conference. Now he's got Frank Tipler on board. Tipler endorses the alien gene-meddling theory.

The alien cannot have launched from this planet. It must have come from some other ... region. We are running short of regions as can host a sufficiently-advanced technology - and we'd need to ask, why, did that technology deem this place worth the visit. If it breached Einstein's speedlimit then - perhaps - we should fall at Its feet, in homage. Note: the Baghestan has already restricted "god" to any entity with transcosmic access.

Beale still engages in more snark than he needs to, in mocking the modern biologic synthesis as "epicycles". Well... yeah. But what's wrong with epicycles? Any study of a dynamic process must pile on additional factors. The "epicycle" which corrected Uranus' orbit was Neptune, in its own orbit. Likewise in medicine: organs must play in concert, or we call the failure "nonfunctional" even "cancerous". Medicine flows down the stream from biology.

For those who care to explore the genehacking FTL-alien hypothesis: here's "Mittens", 1966, 1966, more 1966 and some maths. That's not an endorsement... unless you're already worldbuilding a "Jackaroo" universe where those benevolent aliens have started doling out marginal planets, in which case - have at it. You can even put those humanoid Klingons and/or catgirls in there. Who's to judge.

SOLAR SYSTEMS 5/10: Suppose TRAPPIST-1 was constructed?

When the seas boiled

The Earth's magnetic history last month was pulled back to 3.7Gya - like, 760My after 4.46 Gy; before even the cratons. This field removed xenon from our atmosphere. Now Prof. Tarduno at Rochester have the Vendian magnetism, which coincides with the Ediacara menagerie.

The Vendian started 635Mya. For 26My in this span the field was weaker than it has ever been.

This would have held whatever xenon was left (most was already gone by 2.5Gy) but stripped away hydrogen - just like over Venus. There would have been an oxygen pulse, so strong this injected into the (evaporating) oceans.

It follows that landmass was less before the Vendian, than after. Which I think might actually check out. Although "land" in those days probably also meant "snow".

Luckily the field spun up again, saving us from Venus' fate. Tarduno elsewhere says this started 565Mya. Cambrian won't start until 541Mya.

Anyone seeking to check further on Tarduno's thesis should ponder... deuterium. Did we have a lower deuterium-ratio, before the Vendian than afterward? Compare hydrates laid down during "Cryogenian", versus now...?

I still don't know why the dynamo abruptly cranked into a standstill and why it started again; nor, why then. I'm not seeing any abrupt Velikovskyian tacks in other planets. Unless... it's Theia. Chunks interfering?

The logothete, reworked

Two years ago Juan Signes Codoñer and Michael Featherstone published ten episodes in "Pseudo-Symeon", now on academia.edu. This concerns manuscript Paris BnF greek 1712. The essay argues that this reworks the end of a "Logothete Chronicle"; with aims to create a "new" chronicle, from the beginning of the Cosmos, and Adam.

So far, so much like the AD-846's rework of Syriac chronicle AD-819. Except that AD-846 was, I think, finished; #1712 looks like "Pseudo-Symeon" wasn't. There it's more like the Zuqnîn.

Also, #1712 is synoptic with Theophilus Continuatus, but here - the authors argue - neither used the other. They both took, independently, anecdotes from a (thriving) Palace.

So: what did #1712 use, before the Macedonian period - which it summarises, to add more lore? I, uh... don't know directly. Few of us know. Not only wasn't #1712 finished at the time, but it's not edited now. Far as I know, it's only used as a witness to the state of the texts before it. I'm reliant on Wiki.

As to these precurrent texts, besides the Logothete: Theophanes, George Hamartolos ["sinner"; i.e. the monk], John Malalas and John of Antioch. Students of Late Antiquity will observe we already own all the above excepting maybe John Antiochene. So if anyone ever does bother publishing this (I suspect AI will be doing this job) it won't help Dark-Age bros like myself.

It may however tell us something about the Macedonians' presentation of antiquity. The paper argues for Nicephorus II Phocas, who could pretend to be the new Justinian.

Jewish blasphemy-code as Federal law

Legislation is making its way through Capitol Hill, to bestow that Ring of Power we call "the 1964 Civil Rights Act" unto the rabbis.

Andrew Torba holds that this would render illegal much Christian scripture; Eugene Volokh agrees. David Bernstein would suggest the controversy is overblown. He's not here to take your Bibles away ("we're not going to take your guns away, we're just...").

The Baghistan's stance toward Islam, meanwhile, is that the Quran is malformed and that Muslims need to reconsider certain suwar, particularly the ninth. So it is with the Jewish position toward Christianity: Christians have had almost two thousand years to reconsider verses like 1 Thessalonians 2:15, and perhaps entire Gospels like Luke's. The hour, one might say, is close to hand.

Richard Hanania would prefer we just throw the whole Civil Rights Act into a volcano. That might be easier. Or it might not.

The leper's wall

The wall in the (real) Old City of Jerusalem, which is south of the mediaeval square, is radiocarbon-dated "First-Temple". It has been assumed from Hezeqiah. Hezeqiah was Jerusalem's most celebrated builder of the post-Rehoboam Kingdom; Hezeqiah was he who drilled the cistern and repelled Sennacherib (with Nubian help). Problem: radiocarbon is a highly blunt instrument.

The dendrochronology is in - it was rebuilt after Amos' quake. So Hezeqiah's predecessor(s) had built it already. The Daily Mail names the rebuilder: Uzziah. Let's look into Uzziah's reign and legacy.

The paraleipomenic Chronicles paint Uzziah as a near-ideal... until he crossed the Sanctum in the Temple. The Chronicler makes much of Uzziah's (supposed) military might. Gluska and Lipshits read the Chronicler as painting Uzziah in Nehemiah's image. (The Book of Nehemiah is not directly in what we found at Qumran, but the Temple Scroll cites it and its version of Ezra is ours.)

"Azariah", as Uzziah is also called, was anointed king as a sixteen-year-old subservient to mighty Jeroboam II to the north. On Jeroboam's death, Uzziah was able to branch out more on his own, building - per Reigns, not just Chronicles - the Red Sea port Eilat. He did at least maintain good economic ties with the north. Around 750 BC Uzziah had to rule through his son Jotham; 4 Reigns 15:35 names Jotham as building the "higher gate" of the Temple (bet-YHWH).

Notable is that Reigns also notes "Azariah" (Uzziah) as entering the Temple, contracting leprosy in the process. Graham Hancock famously saw this event as a witness to the Ark.

I suspect that Uzziah didn't build much monumental nor protective in Jerusalem as long as Jeroboam II was issuing policy. Uzziah could, however, rebuild; and Uzziah and Jotham together could have collaborated on projects. One project was to unite the Temple with the Throne; I suspect Uzziah's queen Jerusha bint Zadok was in fact a Zadokite. Clearly that didn't work, but the Temple did get some improvements as byproduct.

VEL13:10:8 isn't a bus station

For giggles I ran the maths on station VEL13:10:8, on cyclers it might run from Venus, to Earth, and to Mars.

Laplacians didn't bother with cyclers in the Jovian planets, and the same seems to hold here. Venus to this station (approximating nine Venus years to two synods, but I suppose I could try 13-to-1) incurred a nasty offset of 13.49° on return; and there just weren't cyclers from the station to Earth (five orbits to one synod). Permacyclers tend to assume higher-order resonances between planets, like Earth:Mars; even Venus:Earth was a bit of a stretch.

The station kind of is a cycler, being the Venus-Earth Hohmann without the "transfer" part. Everything here is one-way; if someone is stuck here, s/he's there until the next Hohmann window out.

So: how's the cycling from the station to Mars?

I got 7 interior orbits to 4 synods. 2.04° internal offset is twice Earth-Mars-Earth's but arguably not so bad with a shorter orbital circle. Problem here was the angle: the Aldrin alone has insane angles to both planets and is a fryby in order to get to Mars in the first place. Four synods does offer wiggle-room for permacycles but it turned out, not enough.

Neptune's tongue

An old theory from 1972 is that those -ssa suffixes in Greek are non-IndoEuropean; but "preGreek" like Basque is preCastilian. Alternatively they could be from the Luwian adjectival suffix. In the late 2000s, one Robert Beekes revived 1972 in attempts to debooonk the Luwianism. In 2010 Robert Beekes with Lucien van Beek got published an Etymological Dictionary of Greek through Brill, no less. This hypothesis has, via a map, trickled over to the Turtle: in keeping with perturbant planet Neptune, famous thalassa came from *talakya. So: let's read modern reactions to the Beekses.

Stella Merlin has done a dive into the Dictionary and finds several examples of words as can be explained by means other than loans from a single preGreek substrate. Some might be IndoEuropean, like Greek, but variously distorted by other IndoEuropean languages (like Phrygian) or close-enough (Lydian or Luwian).

I don't know that Brill made the right call in publishing so strident an argument as the Beekses'. Merlin seems right.

The poisonous Hettangian

As we work our way back through extinction-cycles, before Chicxulub wasn't P/T - but T/J. P/T gets the press; to solve that mystery, we should get better data on later events (so better-preserved). Tonight let's look at the Triassic's closing bracket.

Triassic's last good epoch is called "Rhaetian". The post T/J epoch is called "Hettangian"; the Jurassic-proper gets going in the next epoch the "Sinemurian".

Bas van de Schootbrugge at Utrecht University is pointing to mercury (Hg) in Hettangian plants (Copenhagen, Aarhus, and Tianjin are also represented; but ScienceDaily pointed me to Utrecht). Northern Germany was then a coastal lagoon. It was full of... ferns, sucking up the carbon-dioxide of which the Hettangian had much. We read that ferns are a colonising plant, like conifers; they take root first in disturbed and mildly toxic soil. I suppose they always were; when vascular plants first took to the land, the soil there wasn't much better than it was under the Proterozoic (yaaayyy lichens).

First up, the T/J Hettangian rocked this planet back to the Proterozoic - again. Even the conifers weren't doing well. Of especial interest to the researchers is that the ferns were mutated. Something was trying to kill them too and it certainly wasn't CO₂. That something was the Mad Hatter.

The paper pins the toxic Hettangian to a ~1.2My span, in which they fit four pulses of quicksilver enrichment with a fifth after that (+1.62My?). The pulses match the 405ky eccentricity-cycle (thereby itself verified for the late Triassic). The paper notes that the isotopes of new mercury taper out such that they waver over counting the expected fifth pulse in the Hettangian (they'd extend the bad times to 2My!). It concludes that these pulses, therefore, are simply pulses of atmospheric intake, not additional spewings of poison.

The initial dose must have injected a megayear's supply of horror into Triassic air. It is certainly volcanic.

So yeah: let's not use mercury in low-orbit plz.