The mirror neutron, we barely knew thee

Leah Broussard has looked in on one of the more-testable Dark Matter theories and nixes it. Here, the question is the 877.8 second lifespan of a free neutron. Give or take nine seconds. They last longer in a beam - as Turtle Island pointed out at the time last year. (Personally I'd wondered about Relativity, if the beam is some fraction of C.)

Anyway a serious theory (not by me) was that the neutron was doing what neutrinos do, flip from one sort to the other. In the (posited) "mirror" state they do not interact with such neutron-soaking material as our good buddy boron.

Broussard's team has rated this Ethereal-Plane thesis as "wrong". Boron will trap ALL the neutrons.

Suppose we didn't need light to grow food

On topic of acetate, UCR speak of using it to grow food. I figured I'd dig out what I supposedly learned in GCSE Chemistry. This was one of my "A" exams. I need to prove that time and expense wasn't wasted, at least to me mum.

Acetate is a family of organic molecules; "acetate" on its own is the ion. Plain hydrogen acetate is the acetic acid - that is, vinegar.

I don't think acid is good for plants. Here, other acetates will be used. When I looked it up on Bing I got a bunch of stuff attached to a radical "R". That R is an organyl group; those diagrams will be esters.

Without light the plants won't be giving off oxygen - but they don't die. They don't need light to live, they need fuel. As for the dirt they grow on, this is also a process we don't need lights-on for.

What has happened here is that the process of creating fuel, for the plant, has given off the oxygen already. Photosynthesis turns carbondioxide and water into glucose. The plants eat that; day or night.

Elizabeth C. Hann, Robert Jinkerson and their crew are making several claims. First, that plants can eat the nonacidic acetates, instead of the sugars. Second, that this team can create acetate(s) (much) cheaper than sugars, and in fact cheaper than any plants create sugars. Just add energy which energy can come from anywhere. The two processes together - creation of alternate plantfood, and the plants' consumption of the plantfood - add up to the savings. Which - they also claim - beats out The Natural Way.

They are teasing Mars, as usual; but we should also consider the Moon or just plain space. For my part, I like that this method should work underground. Under Venus, the energy-supply is a katabasis-driven dynamo which output is effectively infinite.

Yeast can be fed 18x as efficiently through this process; even algae at 4x. UCR are also looking at cowpea, tomato, tobacco, rice, canola, and green pea. Wut? Toe-bah-koe...? I am a Coloradan, tell me more of this strange herb of which you speak.

BOY THIS POST WAS BAD 8/22/23: So I rewrote it.

Space reactor benchmarks

If you want power in deep space or deep underneath a vacuum lowgrav planetoid, you need a nuclear reactor. ToughSF has been posting on some of the more-theoretical ideas.

Pluta and Morata has this in 2012. With the original 4.2% efficient thermionic converters, this would mean 161 W/kg, but with a 20% efficient 'dynamic' converter and fuel load reduced to 3 years, 866 W/kg is possible. (That's alpha=1.155, considered excellent, honestly better than a nuclear submarine.) 25-200 MW.

Nathaniel Read submitted a PhD Thesis in 2020 (pdf): 89 W/kg for 1 MWe, for 7 years. Although at 1300K we suppose it should be easier to insulate - and to insure. ToughSF commiserated that the cold was making this as inefficient as it is.

I suspect solar-energy is a competitor for all of these up to Mars' orbit. Also, to boost a spacecraft to (say) Uranus. But outside 3 AU or so, maybe it's good for de-celeration on the VASIMR plan.

The permaflying hotel

I considered something like a permaflying aeroplane for Venus [h/t Drudge]. I eventually came around to a long-flying ramjet, on the Pluto model. Or a helicopter-assisted floating bubble.

However it is done, it seems more practical over Venus than over any place on Earth. Who's going to allow this thing? Arctic, Antarctic, Pacific, Indian? Sahara?

I am also curious as to how they're radiating excess heat. Submarines already have this problem - and caused me not to think much of it for Venus. But maybe they've fixed it for Earth such that, a little more height can hoist it over our sister's acid clouds.

Assuming anywhere will allow it, a flying community isn't the worst idea I've heard; although I'd not suggest it for the average tourist.

Falcon 9 to be deprecated

The Falcon 9 uses kerosene. Kerosene is a high-carbon fuel. When this burns, not all of its carbon becomes carbon-dioxide (or monoxide). Some of it becomes carbon non-oxide: soot, in short. That's a problem. h/t ScienceDaily

SpaceX already know soot is a problem - for their rockets. So Starship uses liquified high-pressure methane. Replacing the Falcon 9 with the Starship should be our goal anyway.

I dislike this last paragraph: There is still a lot we need to find out about the influence of rocket launch and re-entry emissions on the atmosphere - in particular, the future size of the industry and the types and by-products of new fuels like liquid methane and bio-derived fuels. My concern is that they have given to regulators, already hostile, another excuse to do what they do best, which is to stop a product and knock off work early for donuts.

SECOND OPINION 6/28: Zimmerman doesn't like it. I don't go as far as he does but I agree NOAA's overall argument was structured for FUD.

For the blue states

As we carry on, bien-pensant has words. It's a New England take, stretched to this entire band of Parias. Abortion of "monstrous births" has been a Yankee sacrament for some time now, we learn.

Albion's Seed and about the third part of the Moldbug oeuvre would agree.

This says nothing about the Constitution. Au contraire! the Constitution exists precisely that the Yankees may live by their sacrament, and the rest of us may live by ours.

For the red states

We (well, I) have had a weekend to calm down (I hope) and to see where we are at, in this restoration of 1972 in America.

The restoration is first-and-foremost a restoration of the Rule Of Law - which may be the rule of an ass, but still is a process. (Pace the boomers this is not Nehemiah Scudder; and If This Goes On getting retroHugo represents exactly why we needed Sad Puppies.) If states want The Procedure such states have The Procedure. Colorado has The Procedure. By this unruling, she has been installed as the Great Plains' Provider Of Choice. Like the state to the east of us used to be, with George Tiller, to whom I'll get.

It has been mooted on the Left that the Right cannot simply force children to birth, and do nothing for them afterward. Thus Quillette. Thoughtful thinkers in the Right actually... agree! The USG has a Foster System, and this System doesn't do much for those Fostered. Hence various charities springing up, like Child-Protective-Services. Cerno and Jake Shields are raising this flag.

And, I must disclose, mine own Church is involved (never mind this idiot). The Church, as the Communion Of [its] Saints, is (perhaps to a fault) a Right of early-modern Europe thus not on the lines of the American Right. The Church does attempt crisis-pregnancy and adoption, not just dumping kids upon The Foster System.

It should also be noted that even late-term abortion as a medical procedure deserves consideration. Blanket bans harm Suzanne. I am well aware that Suzanne has her own demons. I dislike that she went to Tiller, who did not restrain himself to cases like hers; but, she might not have had other options. I dislike more that S. starts her story with a sneer (Pro-lifers don't like complexity). Suzanne still does not deserve a horrible death, from an accident of biology. And her choice does not deserve condemnation nor - I posit - even forgiveness. (Her recent Twitter thread is another matter...)

Overall from the Right, if you do not wish your state to be like Colorado, I suggest considering those options. Tiller was a murderer but his service was provided even where it wasn't murder. Ranting on Twitter, on Disqus, on blogs saves no lives. Even Tiller saved (some) lives. What saves most lives - pace Quillette - are pro-life pregnancy centres. They just don't exist enough.

As to the Left: I suggest not supporting "Jane's Revenge".

ASSUMPTION 7/12: Molokites lie. I assumed for this post that Suzanne was telling the truth but, in real life, I admit to doubting this. In real life Suzanne has given me no reason to assume her veracity. Also: Tiller betrayed his oath.

Deimos' halfway house

I posed the Deimos mission last weekend, so let's fill it in. And yes I'm blowing off Phobos.

Solar-system traders want the entire moon as a momentum-bank with a tether, with an aim to make it areosynchronous (where it can be). In the meanwhilst, a Martian mission might not have the infrastructure to build all that, when Elon first goes there.

A few tasks can be done near Deimos without being on actual Deimos. For instance: parking the [star]ship[s] which take[s] Matt Damon back to Earth. That job would be a job for MDL4 and MDL5 halo; such can host an entire colony. These libration-orbits can also host the Laser.

The orbiting Deimos-adjacent stations host a temporary population, on account I do not expect any station to last past a decade with its original parts. Mining and manufacturing on Deimos is their goal.

Toward that goal, MDL4 and L5 should assemble stations affording the same centrifugal gravity as supported the Earthlings during their long trip by Hohmann. These are designed to be docked on Deimos.

The goal for stations of Deimos, to maximise the population up there, is to hollow out Deimos' interior for a big stone O'Neill. This does mean any tether drilled into Deimos must be detached. Although if the other shell has a magnet, that magnet might support a tether, as Paul Birch has proposed for orbital-rings.

End of the Eemian

After the Eemian, the Ice Age. Apparently the question here is how America's Ice Age extended itself into northern Europe and the Alps.

Continent Parias is horrible for climate, as every Coloradan can tell you. As Art Bell taught me in The End of Tomorrow, Europe gets a Gulf Stream / North Atlantic Current. A coldsnap like the Maunder Minimum might freeze the odd river. But - Marcus Lofverstrom says - even a long coldsnap is difficult to account for the north joining Baffin and Alaska as Ice Supercontinent Arctica.

Lofverstrom points to ocean gateways in the Canadian Arctic Archipelago. Bell said Panama's gateway was healthy for Europe; Lofverstrom adds the Northwest Passage. As long as it's open, American ice stays here. When it blocks out, Markland's white walkers come to Scandinavia.

The Christians made them do it

Michael Rozek has posted his MA thesis. Christian social-religious liberties did not immediately begin in conflict or legal restraint, but rather gradually developed and became restricted over time because Christians pressed in, crossed over, and challenged the religious beliefs of Islamic confessional communities, potentially prompting Arab-Muslims to convert to Christianity.

It's... a take. 120-something pages. I haven't read them.

We all agree with the first half, before the because. I remain uncertain of the second half. Although the timing is right - I am long on record that I don't hold sura 9 as a seventh-century sura. I can well imagine conflict between the qurrâ and Arabic-speaking missionaries along that crescent Jericho, Damascus, Tikrit, al-Hira, the Furat of Mayshan and Qatar. Our documentation down here is nowhere near as good as it is for the Syriac gzirta from Edessa to Nineveh to Kirkuk.

Stability of three new systems

Back to COPAINS. Let's return to HIP 29724 by way of HD 60584.

HD 60584 has proven an (?)accidental binary, F5V+F6V. CC1 is the closer to us at parallax 32.792 ± 0.035. This star weighs in at 1.352 ± 0.014 M_⊙. The two stars are not gravitationally locked as far as the study can tell us but then, CC2 was only identified within this study so could be observed for a mere few years.

HD 60584 CC1 might have an orbiter 16.58 ± 0.15 AU. 0.028 M_⊙ (29.316 M_j)... or maybe 0.008 ± 0.003 M_⊙. Stellar age is 300-1700 My so tagged an even billion. Note that F stars of this mass simply can't live much longer than 1700 My, before redgianting. The imaging data wasn't the best. I shall assume the worst, that is 30 M_j.

By my maths 1415/r² Jovian units of Pull go to the star; 30/(16.58-r)² to the browndwarf. Let's put r at a habitable 2 AU. 707.5 Junits to the star; out to the dwarf 0.141 Junits at conjunction and 0.087 at opposition. 3.2e-4 total which is slightly more than the 2.1e-4 ratio Jupiter exerts on Mars, with the proviso that this putative planet hasn't had as much time.

Overall I think HD 60584 CC1 can maintain a habitable planet if there be Venuslikes beneath that orbit, keeping it in circularity. HIP 29724's 66 M_j "dwarf" at 6.3 AU seems a tougher sell, frankly. On the other side, HIP 21152's 1.442 M_⊙ has its browndwarf at 18.28 AU, admittedly a slightly heavier 33.5 M_j.

DR4

'pon looking at ESA's Gaia DR3 (pdf), I am now anticipating DR4.

DR3 covered observations 25 July 2014 to 28 May 2017. The Early Data Release in 2020 had actually released most of the raw material, with the full DR3 being a cleanup. (Hence how that Brown Dwarf paper was able to use DR3 parallax.) With over a billion point-sources to study, said KP does take some time.

The Lazorenko-Sahlmann 2018 study of the Luhman 16 pair - also running up to 2017 - had used DR2. It used this as background only. For the pair itself, the study blew DR2 off. So now we have DR3, but I don't know to what extent Lazorenko and/or Sahlmann will care.

Even looking at the data is difficult on account it's all a lot of gigabytes, 9 TiB in fact. ("Ti" is the classic Microsoft terabyte, 1024 GiB on down.) Although if you are a nerd who hasn't filled up your hard drive with... whatever; it may be worth your while.

However the Gaia mission is not over. Upcoming is DR4. That release is on schedule for early 2026 (pdf); the raw data are already here.

Taking out the trash

Our Sun causes atmospheres to breathe in and out. The present Solar Maximum stands to deörbit satellites. These are satellites both intentional and unintentional, the latter being space-junk.

This absolutely will not be a problem for Mars / Phobos ... yet. It might become a problem with the plans for artificial magnetic-shielding with Phobos debris, but that's for later. The Venus coma, I expect, will be more affected as it has more insolation for baseline.

Over Earth I suggest we put our main human-occupied satellites between Van Allens. LEO should be for propellant-stations, and for temporary dirt-cheap microsats.

Ghost pepper

Another turtle-takeaway is the Ghost Population of Sonora. This broke from other New World genomes 22700 BC (where C-14 takes the pre-Los-Alamos baseline, I assume Y2k for genetics). That is of course long before muh Clovis and, more to the point, before that split in North America we were calling "ANC-A" and "ANC-B" back in 2018. This pre-A/B split looks VERY basal. But on the other side it came after Melanesia. This particular split, then, happened in northeast Siberia or Beringia.

The ghost makes up 28% of a genome from Sierra Tarahumara. That's where Gary Jennings put the Rarámuri, basically the Masai of northern Mexico - speaking an Aztecan language (but not Nahua) as of AD 1500. They are famed runners. Today it has spread as far as Brasil, presumed-unmediated by Spaniards. Dunno about the Caribs.

Meanwhile I do not find Melanesia anywhere in these early Norteño samples.

One possibility is a pre-ANC-A/B set of settlers. Another possibility - on the If It Happens Now It Happened Then principle - is that they are like the Navajo-Apache, rolling in from the northwest after the fact, subsequently blending in with the locals over millennia. This is a common pattern as witness the Mexica themselves who remember (accurately) coming in from the northwestern deserts. Yes, the [Pipil] Nahua got only as far as post-Ilopango El Salvador. Before 3000 BC even the Chibcha were not farmers so in less position to block migrants.

If we're looking north, as we should, I don't know how prevalent this ghost, in the great Bonneville basin pre-AD-100. There must have been a stronger (actual) Native presence in what is now a vast desert, ideal for preserving remains.

The long decline of Mesoamerica

Occasionally mooted, as a club to beat the moderns, is the ninth-century drought in North America. The Turkestan suffered one of their own around that time. An earlier - worse! - one might have struck AD 100ish (ht Turtle). Thus, the trees.

Now, the human genetics. Four days back bioarXiv got a major preprint spanning all this time, from the 200s BC to the Columbian Exchange. It talks Ancient North Mesoamerica, which is Mexico to us. Yesterday le turtle set to interpret the study more fully.

Since the genomes are ancient they don't have all that Old World schmutz - and Spanish-driven internal admixture - of contemporary now-Hispanics from the region. Thus they present a capsule not only of their selves but of their ancestors.

First up is that the Spaniard came at the end of a long decline in population. The Chol-Milpa system - and the Olmec, one imagines - exploded the local population until about AD 100, when came the decline. This decline actually surprises me a bit on account the Maya and the Teohuacanos had founded some serious polities Ai.D. 200-600, far superior technologically than the Olmec. But then, Kyle Harper tells us that Rome declined too during those centuries.

The decline might have started with that Norteño drought; but between the Ai.D. 100-800 there shouldn't have been drought. There WERE some local eruptions like Ilopango and, then, the hemisphere-wide late Ai.D. 530s disaster; maybe Chichon. It could also be that civilisation worked as roach-motels, dragging people from the farm and removing them from the gene-pool. When the civilisations died, such survivors (like the Lacandon Maya) as returned to subsistence or even huntergather lifestyles could hardly maintain their prior numbers.

'Neath Tarhuna's baleful gaze

Before opining further on HIP 29724 I should pause to consider the forces involved upon the Kirkwood Gaps. Prompted by news like this.

Say you are sailing a Solar orbit this side of Jupiter. Let's use Jovian units for mass; the Earth "AU" semimajor for distance. As Lagrange intuited, Jupiter's strength is most salient when you are between the Sun and this planet... and then, when you are ON THE OTHER SIDE of the Sun. Vector calculus, baybee!

1047/r² Jovian units of Pull go to the Sun. When between the Sun and ol' Jove, that's against 1/(R_j-r)²; R_j here being 5.2038 AU.

The Hungaria between 4:1 and 5:1 has proven not great for worldbuilding. Mars exists beneath that, so let's r = 1.524 AU. 450.7926 Junits pull to the sun. On the other side 0.07276 Junits pull to Jupiter. Now: compare the other side. 1/(R_j+r)² = 0.0221 units toward Jupiter ADDED to the Sun's pull. So for the delta, per half-revolution of 343.49 Earth days is about 0.09485 Junits, all pulling you toward Storm God Baal. I'm sure someone could come up with some better equations, involving radians and Newtonian Integration; but this is just a blog, I'm thumbing it.

I admit: against Solar 450.7926 Junits, 0.095 is negligible year by year - yes, we work by full sidereal revolutions here. As to that, Mars has had 1/1.88 the number of years as we've had on Earth. But it's still - what - 2439 million revolutions, which do add up. Hence why Mars has eccentricity, which I am sure would be a lot worse if Earth/Venus weren't here to force some mild synodality upon it.

Wolf 437's hellhound cub

A couple days ago the "Gl 486" paper dropped; h/t GalaxyMaps and of course Nyrath. We've met this before. As GalaxyMaps points out, this star was a 1919 Max Wolf discovery so really should be named Wolf 437.

The paper comes off a hunt for transiting exoplanets within triple-digit parallax == ten parsecs of us. Ignored are such exoplanets as don't transit, like Proxima's. The hope is to measure more of their atmospheres and radii so that Webb can look in on 'em - like 55 Cancri Ae and LHS 3844 b. The authors are aware of ten transits in total.

In the meantime these researchers figured they could constrain this particular system better. Wolf 437 at 8.1 pc is the third closest of all transits. The 55 Cancri system is two-digit parallax (barely) so - beyond that.

What we have here is a "warm" planet at 700 K if we assume zero albedo. That temperature is thereby a maximum - if there's no greenhouse. Per Mansfield, M., Kite, E. S., Hu, R., et al. ApJ 886 (2019) 141; 880 K means lavaworld, like Io I guess. Mind you, I did say it was a transit - unless we are very lucky, those are so close to their star they are tidally locked. As is the case here.

It is three times Earth's mass but 1.343 times the radius - so 4/5 the density. The paper did calculate the metallicity of the star, so they figure on a low-mass core. All surrounded by silicates, maybe hydrated. It could be that the circle of opacity means this (large) radius is only apparent, showing only an opaque atmosphere like Venus'.

The haze would be water or maybe sulfuric-acid droplets like Venus'. Much would depend on any magnetic field, which is not constrained in the study.

MANSFIELD 7/16: She's got dibs. The argument goes, I think, that Wolf 437 being closer and not saddled with a binary star suggests it'll be easier to study, such as nail down constraints (the Rosetta is noted). I'm sure 55 Cancri A will be forthcoming, but what is learnt at Wolf 437 will be applied to further systems later.

Lori Garver

Lori Garver speaks for all of us. NASA is a pork distributor first, an enforcer of Current Year orthodoxy second, and a space-agency somewhere down the list. We must endorse the message despite its messenger, herself a Current Year scold.

One takeaway is that Garver is hardly in position to talk sexism, and less of ageism, when she is so very careful to reveal Bill Nelson's 79 years.

A happier takeaway, if you like Bezos/Musk/Branson, is that Garver does not see them as sexist. Although this is only going to elicit more sneers like "Onion-Syndicate" Kelly's.

Anyway there are good reasons Garver wasn't promoted further and not just because She Won't Play Ball. Musk might have cause to worry if NASA could pry Shotwell off SpaceX however.

Recovering my fastball

Over the summer I've had some trouble keeping my reading going. Eyesight is getting strained: due partly to the way of all mortals, and also to the windows in my study not having, er, curtains. I'd taken those down years ago on account of Venetian blinds being unfit for purpose.

So I got reading-glasses a couple weekends ago and, this afternoon, the study now has proper accordion-type shades. Cracks in the shade are now vertical rather than horizontal, and fewer.

We'll see what else needs improving what can be improved.

Shut up and take my tribute

The Turtle led me to Kung et al., explaining the slow growth of what's now China and, also, of whatever states China has absorbed. I've some interest in the latter inasmuch as my maternal ancestry derives from these borderlands, in my case the southwest. On point, a footnote mentions the "Dali" state.

That's "Dali" in modern Mandarin. Locally, the people were and are Bai, who spoke some other dialect. It is hard to say a dialect of what exactly, as Bai has done the Armenian thing of perhaps being a related language during the Bronze Age but taking on more and more Imperial terms as the same sort of empire kept ruling over China. As of the "Dali" stage, the local Duan rulers - like the Arsacids - actually claimed to be Chinese, if Gansu west-Chinese.

"Dali", or "Dablit" as it went in Bai (=tenth-century Middle Chinese), means... "Marmara". It means "the Marble-stan". That and horseflesh is what Dali exported. Dali wanted to export tribute as well but the Chinese powers at the time, the Song, wouldn't accept it. What's up with THAT?!

The previous dynasty in China were the Tang and they were NOT shy about wanting to rule the trade-routes. Hence how the Tang got Gansu and beyond to the east Turkestan then Khotanese and Sogdian. (Especially after the Tang wiped out the local Turks.) There was, at the time, a second silkroad; this went through the Bai-speaking territories, southwest. Tang wanted it too. The local authorities, Nanzhao, resisted 738-900ish AD. Then came some upheaval for a generation or so, and the Duan took command. Over in China, the southwest was disunited; but Taizu of the Song took the southwest over the AD 960s.

The Tang, it seems, had tried and failed to take the Nanzhao. The Song figured that, once it had taken a decent heartland, it could let the outlying regions be. The Tanggut "western Xia" were a problem but, for whatever reason, Dali chose to be the opposite of a problem. It would be as if Australia was taken over by anime fan "weeabooes" and kept pestering Tokyo.

As to why the Song didn't take the [literal] cash, I wonder about the strings attached. Dali and the Duan seem to have faced trouble with the Viets and with internal discontents, respectively. If the Song had taken the money, they might be obliged to send an army over there to quell nobles and/or Viets. The Iranians had the Romans to worry about. The Chinese had... what exactly, beyond Yunnan? Angkor? those darn Viets?

If the Duans could just keep the traderoutes open (with a reasonable markup), the Song didn't see a problem with keeping them there and themselves OUT of there.

Mars Indirect

I'll take this space to follow up Gurrea-Zubrin. Here is a case for Deimos Direct. Mars can wait. So can Phobos.

Deimos, so Winchell Chung tells us, is a (far) better launchpad for asteroidal missions and even for supplying fuel to depots in high Earth orbit. Some Deimian missions can be on the Aldrin Cycler plan, dumping the main cargo onto Deimos and returning the (enlightened) Starship shell to aforementioned HEO for pickup and investigation. Deimos then does stuff like unrolling a tether and manufacturing the Mars-to-Earth propellant. Or supply lasers.

INTERJECT 6/22: A decent Deimos presence will take work, I concede.

Specifically Deimos clocks in with Gurrea's "Contingency Gamma". The crewed ship doesn't even try Mars, so doesn't care if there's a sandstorm. Mars gets its visitors - whenever. Deimos has its own "Omicron" and "Omega" issues, with Raptor failures or other potential blocks from returning to Earth; broken tech, at least, should be mitigated by multiple supply-runs from Earth.

A Deimos base with dangling tether leaves less propellant for the eventual Martians to make. Also, dropping cargo to Mars is a sight easier from Deimos than from Earth. A pit-stop between Mars and our own HEO does add a point-of-failure, but I think it overall makes life easier for Matt Damon.

Gurrea went Spanish for his expedition right to this new world so, I'd go Português for the Deimos mark: call this mission, the Gonçalo Velho Cabral. (The first cycler will be the Aldrin obviously.) I don't know offhand what Cabral named his caravel.

As to that point-of-failure, Mars-Indirect gets its own Continency Pi: Deimos offline. Say some asteroid damages Deimos or the Deimians go on strike/mutiny. Say China (or actual Portugal, lol) got to Deimos first where they charge toll. In this case, MD3 has already set up enough propellant and has its own Starship, that they can just run right to an Earth transfer, giving to Deimos the proverbial finger.

Mars Direct, III

Lately the Baghestan like the Ramans do things in threes; so, here's the third iteration of Zubrin's Mars Direct scheme (pdf). Yes I said "the". Miguel Gurrea did this document; but it has teh Zoob's blessing as the successor to the first two attempts. So if Zubrin ever does another MD, that'll be #4. h/t ToughSF.

Gurrea's aim is safety. The safety-features are made possible on the assumption of Starship allowing so much more cargo for both the dollar and for the chassis. Also, some flights deliver mechanical cargo only.

My notion of sending nutria there and back seems not to have impressed anybody . . .

Underwater turbine

Japan is testing a turbine to derive energy from the oceanic current. h/t ToughSF.

This should, I'd hope, serve energy to desert coasts near a bluewater undertow: California, southwestern Australia, Antarctica, Indo-Irania. Or for undersea bases. Assumed is that the current delivers worthwhile energy; so I'd not recommend this for mostly-landlocked seas like the Med, Red Sea, North Sea &c. Although I've experienced the current in south Texas (not far from Boca Chica!) and can attest the current might be workable there.

NIMBYs are a problem both from locals with the "eff off we're full" mentality and/or from politicians with a vendetta against the businessmen actually getting stuff done. These often masquerade as environmentalists. So far Japan has proven more based against these - especially since they (now) know what happens when one puts a nuclear power plant near these coasts.

I actually wonder if Portugal might find use for this, since they're becoming Oceania again.

Gaia, III

Remember Gaia, aka IntCal-in-Space? Over the past week, Nyrath's twitter has filled up with science-fiction nerds frantically updating their galactic maps with the new (third) data-release. Today we have a write-up, for the rest of us.

Gaia like Webb is a L2 halo-orbiter. Gettin' crowded up there. The write-up says we've decempled (10x, if it be a word) our spottage of nearby asteroids so, maybe next time it can see one before it whacks the 'scopes up there.

And the prior dataset of 300k+ binary systems is now 800k. Also promised - promised - is that Gaia will find pretty much every Jupiter-plus planet in our solar neighbourhood. I am unsure how this radius be defined and, further, how they can tell for a wide-orbit planet, since such would require lengthy observation. Precision is necessary but insufficient, as the saying goes.

Behind-the-scenes, the dataset has got parallax accurate to the 10-microarcsecond +/- 50 μas. I mean, if the parallax is above HD 57852's 0.030as +/- 230 μas. Inverse of that is 34.65-35.21 parsecs which is, indeed, skating the classical 100 lightyear range. Seems to me that this is plenty accurate for our Local Bubble.

Gaia did, it seems, verify ε Indi A's (cold!) 3.25-Jupiter planet; which we add to its brown-dwarfs which are Ba and Bb. I am told Webb may be on the track to observe this Jovian directly. At 11.55 AU from a K5V, its Kirkwoods are well outside ε Indi's habitable-zone.

And then there was this 9J around a whitedwarf.

HD 53143

HD 53143 is 59.8 light years away and a billion years old, so an analogue to our solar-system at, what, 3567 Mya. Its terrestrial planets, if any, should be Archaean not Hadean.

The accretion discs should have hollowed out, in short. What we're seeing is that HD 53143 still has discs. And they insist on the plural; one disc is eccentric.

They suspect something twisting the planetesimals. If there was a brown-dwarf or even a Jovian, I'm surprised it hasn't been seen already - it may simply have been overlooked as candidate. The perturber perhaps passed close some many million years prior.

G238-44

As white dwarfs chew up their planets, sometimes we catch a WD1145 + 017 at supper. Now G238-44, 86 lightyears out.

This one is consuming not just rock but also ice.

The rock, they say, looks more like iron. The planet was once like Mercury - alternatively, the mantle has been blasted or consumed already, and the star is now getting to the core. I don't know if there has been a proper analysis of the dwarf's composition.

The ice is nitrogen so seems Kuiperish. I don't think nitrogen is much created in the death of A-class stars.

Time crystal update

Let's cheat basic physics again. That's right, it's a time crystal poast.

No, they still haven't left the laboratory.

This time it's MIT. They've entangled two of them. This creates perpetual-motion. Near absolute-zero Kelvin. If nobody looks at the system.

They're using the ghost-particles called quasiparticles, gaps in a lattice which gaps behave like true particles. This one is the "magnon", which I read about last year in a bad German article which didn't explain it.

BACKDATE 6/18 and HAT/TIP PIXY. I mean, obviously. I've found difficult to blog lately. Pretty much every non-weekend post this month should be assumed a backdate.

Moral hazard

MIT suggest mitigating solar radiation via L1. They're talking Earth; it's a more-specific L1 shield notion. But I already poasted the basics around the physics. Their poast handled the ethics; so, so must my poast.

The naysayers are calling out the Moral Hazard. A cooler Earth will prefer more carbon. Same goes - in automobiles - for the plasma spark-plug, and the rotary engine. Or, if you're Michael Hudson, for debt-forgiveness.

Moral hazard is a thing. Someone who is insured might go for a long drive into the mountains for a hike, or for a ski. When I was uninsured I didn't do that so much. I mean, accidents happen even when stuck at home; but - as Machiavelli said - we are sometimes less concerned with our lives than with our finances.

Michael Hudson has called out that the "moral hazard" argument is often a mere excuse. I too part ways with the Right, on whether to forgive (here) student loans. Yes it is a giveaway to the upper middle class, who hate us. But they hate us in large part because we're threatening to make them peons.

Hudson's argument is applicable to the Right against the uppermiddleclass Left, in the case of energy policy.

Bill Gates and Klaus Schwab would rather we starve. No seriously, their aim is to drive around in a $263k solar-powered car whilst the rest of us make do with mass-transit, or no-transit.

Plus, it would seem to be a no-brainer, if we're fine with watching the uppermiddleclass lose wealth, at least with making their new lives more comfortable on the cheap. It would seem to be a win-win for those of us not in the uppermiddleclass also.

Dopple World doesn't exist

Let's revisit Comins' "Dopple World". Last May, astronomers lost patience trying to find any.

Many factors keep Dopple from forming in practice. Moving Jovians early in the system's formation might perturb one but not the other. For Earth, resonance with Venus would have done for a Dopple before it started. (Theia was never a Dopple; our own Moving Jovian brought it in from on up.)

Although Lagrange doesn't care if Dopple World exists, the worlds care. When a large mass comes in and out of focus, it raises tides. The planets we've found tend Neptunian so are presumed squishy. Laplace found that tides can stabilise orbits, as around Jupiter - and beyond. But that's when there are three or more orbiters around... Jupiter, or a sun. Absent a family of stabilisers, one or the other Dopple World will do a not!Theia or just get yeeted.

Lagrange's minimum is 24.96 times the subplanet; I don't know that our observations suffice to find, say, 0.0123 times the main planet (like our own Moon) in a Libration halo. Especially if the larger planet is not tidal, or perhaps negligibly tidal.

Sean Raymond envisioned creating a full Dopple system. I allow these could counteract one anothers' tides. This can only work with a LOT of space in between the mutual Lagrange points, such that the tides are Lunar-level. And Raymond's system is a megastructure - if we find one, we must assume Larry Niven has been there.

JANUS 5/16/23: Raymond has abandoned his Dopple notion but now asks after horseshoe orbits, like Cruithne I guess. They might be stable if of similar mass. I still don't know about tides however.

HIP 29724 might have an Earth someday

Telescope-designers talk Hill-Radius. Worldbuilders, faced with a Jovian or brown-dwarf, should look instead to the Kirkwood Gaps. Between 3:1 and SJL1, only asteroids form. Note that Ceres is a capture, therefore unnaturally large for the Belt.

We'll start with the Hadean systems recently identified. Of these, HD 43976 = HIP 29724's B has the tightest orbit at 6.3 AU. This star is a now-G2V 1.04 M_⊙; its presumed-main companion is, at 0.063 M_⊙, a brown-dwarf.

The paper didn't tell us a year so we'll ask Kepler: (a*a*a) /(y*y) = 1.04+0.063 for this system's barycentre. 15.056 Earth years; compare ol' Jove, 11.862. The main (canonical) Kirkwood will be a third that, 5.019 years; Kepler says this is 3.029 AU (compare our gap 2.5 AU / 3.95 years). Note: well inside the 4.59 AU orbit of this sucker's 1.71 AU L1.

I find in 4:1 and 5:1 no safe-space, either; betwixt 4:1 and 5:1 lies the Hungaria. That's <2.06 AU here; HIP 29724's corresponding Hungaria runs 2.15-2.5 AU. Mars makes difficult to figure what might exist in the Hungaria; if Mars weren't actually, like, here. Maybe instead a Magyar planet could exist at a high inclination. It's metastable so best if resonant, also, with an Earthlike say at 3:2.

HIP 29724's habitable-zone is trickier inasmuch as my immediate source the Universe Guide is wrong about the star's age. This error, I suspect, comes from that the star is hot like an old star even though it is very young. I just have to trust 1.08 luminosity and the 5000s K. These will grow over time in any case. According to the calculator, expect (at 6000 K, which seems reasonable once it all gets Archaean and beyond) a habitable-zone from maybe 0.95 AU out to 1.7 AU.

All assumes a general lack of eccentricity which seems unconstrained so far. I will say that as the ratio gets longer (closer to the main star), the distances between the gaps shorten - therefore, the available mass to form a planet shortens. On the other hand also lengthening is the epoch against n-body chaos; such that Mars does exist in our System, and so much more the Earth-Venus resonance.

As necessarily-small Mars hasn't hurt us down in the 0.7-1.0 AU range, neither would (I think) a super-Earth "Planet Budapest". So I'm not (yet) seeing a problem with HIP 29724 spawning planets in habitability.

SEEING IT NOW 6/25: I did some dynamic sketches. HIP 29724 is a long shot. These guys thought HIP 21152 was more interesting anyway.

When you know where to look

Bern University in Switzerland links to Bonavita et al., on the COPAINS survey. They looked at 25 candidates for companion bodies, southern-hemisphere. They have found ten bodies. Although some are already-reported. (It would be fourteen but four were ruled out as background.)

Five are low-mass (red) dwarfs; one is this white dwarf in GJ/Gliese 3346. The exciting stars here be HIP 21152, HIP 29724, HD 60584, and HIP 63734 since - we are now told - they have brown dwarfs. For all the press they get, we were still only up to forty as have been directly imaged around stars (as opposed to free floaters). Transits, I think, are not considered direct images, like last summer's five. Well now that's forty-four.

Slightly annoying in the team's papers is that distance from Earth is given by "pi", Gliese 3346 being "∼42 mas". That's π for πarallax; 1000/π for parsex. I also see proper-motion in these stats. I suppose this is best for astronomers, if they don't want tie their paper to some distance as might be revised later. Although Nyrath's merry band of cartographers should prefer the parsec.

The Earth-closest candidate is HIP 17439 at the highest parallax 61.84 = 16.17pa = 52.7ly. This paper didn't find anything for that one through all the dust. I suppose within 50ly if there were any brown dwarfs (or red or white!), we'd have seen 'em already.

As noted none of the new four are transits. GJ3346's companion was out at 87 AU, as befits direct-imaging. All of them are star-distant and presumed cold, except for the actual stars of course. Although - they're warm enough that we can see them. Accordingly with this star's exception, obviously old enough that its companion has died already, the other candidates are all under a billion years old. A cold brown dwarf gives no heat and, out here, they reflect no light.

ECON in space

Philippos Metzger has dropped some threads on The Big Bird about the economics of near-Earth settlement. Here is Mars (contra krugtron the short); here is the Moon.

I will state up-front I am no ecomalomyist, beyond the bare Hanania minimum of accepting that an ecomalomy exists. And that I haven't trusted krugtron since his Enron days.

Metzger is of interest since he is NOT a Marsbro. He makes clear in his comments that he's more interested in asteroid-settlement by way of mining colonies ("O'Neill"). Metzger is here playing the part of "HistoryForAtheists" in taking Mars' part because bad anti-Mars arguments will be used against Metzger's own er, hobby horse.

Winchell Chung would suggest the Musk-Metzger compromise of settling not Mars but Deimos.

BACKDATE 6/12

NASA didn't listen

James Webb's telescope is encountering space trash in... an orbit. Any L2 halo is, yes, an orbit (if not a stable orbit). About which NASA were warned.

h/t Will Gater who is delivering toljaso on Twitter; also Zim. The mirrors present the greatest surface-area to space pebble, and indeed a mirror is what has taken this particular (heh) shot.

This one was a "micro" meteor. I suppose the other three were nano'. Hate to see what milli' will look like.

I don't know how we shield this. NASA's calculations were "so much impact in as much time as we have so much propellant".

Only three more centuries of LEO silliness

One problem with the International Space Station is that it had to be International, and one such nation was Russia. For a long time Russia was the cheapest manufacturer of rockets to get up there. This meant that the ISS orbit had to be tilted. Worst of all there's a patch of nonmagnet in the south [UPDATE 7/15 which blows bubbles at us]. In orbital dynamics what starts north must come south.

"Today" (I know, it's 21 June as I poast) we got word that anomaly is going away. In AD 2320. But still!

This comes from an archaeology of pottery, Ceramic I assume. So from 7000 BC onward. Ceramics are available in Jomon pre-Japan before then but they weren't looked at. Our time is tagged most like to 600 BC.

Planet to planet

Gary "XRM" Johnson has words about planet-to-planet propulsion. With a focus on Mars/Earth but also applicable to Venus/Earth.

He boils it down to I_Sp. If I_Sp is chemical - under 500 [N/N] seconds - the fuel will likely all be used by the time you get there. Note that high-thrust solutions like entering/leaving Hohmann tend to the low I_Sp, although overall Hohmann will net you the least overall δV. This means you'll need to make the fuel at the destination. Energy too, I might add. Deimos is looking VERY good here!

Matters get better with 1974 NERVA, 800 s. I don't know that we got NERVA (legally) but we're getting close-enough to that with our HALEU options. 1300 s also exists but, as Johnson points out, these are low-thrust. Honestly I'd leave that to the outer system.

Also from the Earth side, he'll say (later) that propellant should be provided from our own Deimos, namely Luna.

What this means for Venus colonists is that, er, there's not a lot of propellant to be had there. But if you've been reading here early 2011 you knew that. I was hoping to net hydrogen from the planet's coma.

The melting ramjet

As the Nowicki ramjet runs Mach 3-10 through hydrogen, not only the oxidiser will be heating up. Ex Rocket Man explains. To the extent Sabine hadn't already.

The ramjet solution runs into problems (in low pressure, 200 K temperature) Mach 6. If the 200 K is at 2 bar and pure hydrogen... how well does 2 bar hydrogen gas conduct away the heat? My guess is "pretty well". But if we mix this with oxygen gas like Nowicki wanted...

The XRM recommends "one shot ablatives". I think this means flakes of skin that are allowed to fall off the rocket's hull. Maybe a skin of water ice? It wouldn't flake off - it would just steam off. That's more initial mass of course but Nowicki was already allowing for that when he suggested bringing an oxidiser.

No soup for neutron-stars

Two years ago I called shens about whether Quark Soup exists. Last year the Lead Radius Experiment (Pb-R-Ex, pronounced "prex" I guess) cast further doubt. Zaven Arzoumanian's team at NICER, and others, looked at pulsars J0030 then J0740; Arzoumanian promised some results on a third pulsar at that time. [h/t Nyrath's twitter.]

Neutron-star radii can actually be measured, even from this distance. Their magnetic poles - like ours - don't always align with their rotational poles. Such are "pulsars" which send X-Rays our way. Then we know their rotation-period... to the nanosecond. Apparently when the magnetic pole runs on the other side of the pulsar, the gravity of the ex-star bends the radiation just so. Now we got radius, and gravity. Even if the ex-star doesn't have planets or other companions (Kepler, yo!), which some do.

As for which pulsar they want next, formal publication is slow. I had to dig in the arxiv. Turns out: this one's famous. They're looking into J0437−4715, the closest (at about 391.79 light years away) and brightest. (Told you pulsars are measurable... and that publication is slow.) As to why NICER didn't measure it yet, maybe that's because it's in an orbit with a white dwarf perhaps muddying the readings.

LOW MASS 10/24 This might be a quark star.

Saint Thomas' children

I wish I'd had this article in 2009 - István Perczel, on the Malayalam liturgical tongue. It's Aramaic. I've actually attended a Malayalam Episcopal service; I was struck by the Aramaic elements in it.

Perczel explains what happened here. Basically the Portuguese made a mess, introducing Catholicism as the correct Christendom to all those brown bumpkins. Many, many MSS were burned or at least left to rot uncopied. At the same time, the trade routes were opened so all the Near Eastern Christians found out about their wayward brothers. Some of them still spoke Aramaic as a first language - Edessene Syriac. So the Jacobi chuch of Antioch sent men, the Nestorians sent men, and then Catholics sent men to the Nestorians who showed up in India as Syriac-speaking Catholics. Oh and some Anglicans (somehow) horned in on the Jacobi racket as "fellow" not-Catholics.

What a mess! I'll admit to not making much sense of what happened in south India over the centuries.

One weird factor is that the south Indians demanded copies of what the Portuguese had stolen from them. Some traders brought in Syriac, Arabic, and Latin apocrypha - still not entirely lost to the world as of 1600ish AD. (Yes, by now the Indians were using AD and not AG, and even their Jacobites weren't using AG.) So this stuff got copied / translated into Syriac and endured in India. So when you read a Syriac apocryphon in India, you are often not reading the original text but something longago copied into Arabic (sometimes Latin) and then back-translated. One wonders whatever was made of the Pseudo Methodius over there.

The external lung (half of it)

With h/t to Glenn Reynolds, Extracorporeal Membrane Oxygenation. Our lungs are internal membranes. If we don't even need to use lungs (temporarily), firstly those on a transplant-list can, er, wait that bit longer.

I'd also call this good for hibernators in space except that, I think, a more-pressing issue is the decaying muscles and brain.

More important: what about scrubbing chemicals OUT of the blood? This starts with carbon-dioxide and, honestly, carries on to urea.

Overall good news, just incomplete news.

Fusion, the energy of the future

Fusion is still the energy of the future and likely to remain so, says Daniel Jassby. Again.

Jassby has the attention of Dr Woit because he used to work at the Princeton physics lab, whence the Ebrahimi-Alfven drive and, someday, fusion propulsion. The lab is a good 'un and has done much excellent work. Just not in sustainable fusion power, down here on Earth.

Jassby argues that magnetic confinement fusion is a dead end, looking mainly at ITER in France; and that fusion research should pretty-much scrap the whole idea. C.F. research can move on to inertial confinement, with lasers. This is (mainly) what's been in the news the past year. Jassby doesn't wetblanket "ICF" as such... but. He does see ICF as such an infant technology that it will take another generation to mature.

Unsure where beams come in, here.

Meanwhile ToughSF was last week pointing out that fusion reactions are still, like, radioactive and stuff. Neutrons, mainly; also tritium. So there will still be nuclear waste, and hazard.

TOKAMAK 7/25: Better magnets... for a dead tech. Maybe they can use that for something useful, like a fusion NERVA.

COLD 8/19: Well that didn't happen last year.