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Moon-lit Earth:

A "Global Dimming" Macroproject Cure

Richard Brook Cathcart
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Artificial illumination of the inhabited Earth can be instituted using Moon-based mirrors reflecting sunlight and/or by a substituted "sunlight" source made to glow by fusion-powered electrical generators fueled with Moon-mined 3He or by enrobing the Moon's crust with photovoltaic panels. Curative macro-engineering may be needed if Earth undergoes a natural "global dimming", a regionalized or local catastrophic haze, and even a major macroproject's failure or infrastructure breakdown. Photonic-crystal filaments lighting may also be applicable, playing an important future role in ongoing "anti-global dimming" R&D – the "Moon-as-Disco Ball" solution. Additionally, we proposed NOOM, a "Natural Observatory-Orb Macroproject", meant to serves as a HQ for the human inhabitants of an anthropogenic Dyson sphere.

"Yours is the day, yours also the night; you established the luminaries and the Sun"
Psalm 74:16

1. Introduction

Human familiarity with the Moon's phases had considerable practical consequences in pre-Industrial Revolution societies reliant on the dimly reflective Moon for all nighttime outdoor illumination. "Between 1750 and 1900, Europeans and Americans discovered how to turn night into day. New methods of making light ... shifted the concept of night from its traditional associations with seclusion, rest, and fear.... [Night] ... gradually acquired its modern identity as a time of additional work, public entertainment, and education." The natural full Moon is ~0.0000067 as bright as the Sun. Increasingly, indoor and outdoor lighting plays a really significant role in the world-public's acceptance of 21st century architecture.

Despite its low Bond (0.11) and visual geometric (0.12) albedoes, the Moon is so near the Earth, and reflects so much sunlight, as "moonshine", that it qualifies as the second brightest light source in Earth's sky, after the Sun. Each spherical body receives a solar irradiance of ~1367.6 W/m2 and each has its unique absolute spectral reflectance. In post-Industrial Revolution societies, romance-inspiring moonlight is not yet a matter of everyday practical importance; that may quickly change as a globalized civilization becomes increasingly industrialized, ever more technically reliant upon controlled energy. Humanity's present-day needs now exceed ~13 TW. A society separately situated on the Moon, which has ~7% of Earth's total area, could measure and monitor Earth's current Bond (0.306) and visual geometric (0.367) albedoes; "earthshine" – the exact phenomenal counterpart of energetically non-equivalent "moonshine" and "moonlight" – may afford a future 21st century Moon base industry some significant fraction of its total energy supply. Manufactured full-spectrum light sources, perhaps of the photonic-crystal filament type, erected and operated on the Moon's surface and fully trained on the Earth, may permit control of Earth-received irradiance totals or, possibly, even substitute for entirely absent ground-level sunlight.

Currently, the best commercially available white light-emitting diodes produce ~25 lm/W, whilst the best incandescent white light sources emit ~17 lm/W. Approximately ~13,000 TW of solar energy strikes the Moon, and except for three hours during a full lunar eclipse, the Moon is exposed to steady sunlight all the time except during eclipse; during the period AD 2001-2200, the Moon colonists and Earthlings will experience 155 total eclipses. Settlement of the Moon is expected to occur during the 21st century. Human groups thereon are legally obligated to conform to the "Agreement Governing the Activities of States on the Moon and Other Celestial Bodies (Moon Agreement)", which entered force on 11 July 1984. By AD 2200, it is alleged, humans will have operational control of ~1,000 TW of dependable Moon-produced solar power. However, if indium gallium nitride (InGaN) semiconductors achieve 50% full-spectrum efficiency, then a potential of 6,500 TW may be harvestable. The Moon's rough surface reflects ~7-11% of the sunlight it intercepts, and about 40% of that amount is in the form of humanly visible light; each square meter of the Sun-lit Moon is equivalent to a 275 W light bulb. The Moon is ~31% brighter at perigee than at apogee: during the 21st century its closest perigee (of ~356,421 km) will happen on 6 December 2052 AD; during the 22nd century, its most distant apogee will be ~406,720 km on 3 February 2125. Envision a "disco ball" Moon emitting continuously 225,000 × 1012 lm, it grayish natural landscape totally obscured.

The physics, chemistry, and dynamics of Earth atmosphere's recognized geophysical event-processes are intensively studied so that humans may be enabled to understand, predict, and control abrupt and steady planetary event-processes affecting weather, climates, and pollution. During the 20th century, harnessed energy released from mined non-renewable energy resources was added to a recently assessed variable and interrupted geothermal heat flow as a known net heat source tending to warm Earth's atmosphere. (If J. M. Herndon's "georeactor" theory prediction becomes applicable, then Earth's fluctuating geothermal heat flow will diminish, in a punctuated manner, during geological time, and eventually terminate its energy output. Apparently, cessation of the Earth georeactor won't precipitate any of the society-stressing geophysical disasters so vividly dramatized portrayed in the 2003 Hollywood cinema The Core.) Earth's economically excavated nonrenewable energy resources are quantitatively finite since humans cannot remove the supportive ground beneath their species' life-maintenance activities! Abrupt geophysical catastrophes, both natural and artificial, do impend and the Earth-confined civilization, generally conversant with the likeliness of certain specified event-processes, may eventually decide to exploit another celestial body's crust – the Moon's – for its renewable energy sources derived from, and imparted by, the Sun (photovoltaic electricity based on current solar irradiance and 3He isotope fusion fuel energy founded upon past solar wind-deposited elements).

2. The Sun

Continuous close monitoring of the Sun commenced during February 1996 when the Solar and Heliospheric Observatory (SOHO) became operational. Isotropic radiation from the Sun produces an average flux of ~63.2 MW/m2 at the topmost boundary of its photosphere. The Sun's energy output is moderately variable, and Solar System event-processes such as, from any Earthling's viewpoint, a total solar eclipse can interrupt the solar wind and sunlight, measurably affecting wind movements within Earth's atmosphere by its temporary shade.

3. The Earth-Moon System

Earth's global mean total insolation – the solar radiation actually absorbed by the planet's surfaces, heating all impinged rocks, soils, freshwater and seawater, and living creatures – is ~168 W/m2. The atmosphere-less Moon, however, receives ~1367.6 W/m2, some of which is reflected, causing some of Earth's air situated in a region below a time of full Moon to be warmer by ~0.02°C compared to the time of the new Moon. Positioned 1 AU from the Sun, both spherical bodies endure a nearly constant light pressure of ~4.53 × 10-6 N m-2; light pressure was predicted by James Clerk Maxwell and thoroughly investigated by Pyotr N. Lebedev in 1902; moderns have calculated the magnitude of solar-light pressure exerted on a perfectly absorbing surface to be ~4.56 × 10-6 N m-2.

The nearby natural satellite's gray-colored solid surfaces are so visibly different that "moonscape" is a synonym for "eyesore", "blighted" and "scarred"! Selenography, the equivalent of geography, has few landmarks, such as the ocean-land separation on Earth, to serve as an easily recognizable region-organizing framework. Even as Neil A. Armstrong first stepped onto the pitted and cratered Moon on July 20, 1969, macro-engineers were still uncertain about that place's human-scale geomorphology. Whether laboriously walking in the encumbering spacesuits, or riding each of the three Moon buggies (Lunar Roving Vehicles) abandoned on the Moon in an operable condition by Apollo missions 15, 16, 17 since July 30, 1971, for past Moon explorers as well a future explorers, the lunar bulge (horizon) along a 6 km chord is about 1.5 m! During the Space Age's early years, both the USA and the USSR considered detonating rocket-delivered nuclear explosives on the Moon's surface, in part as a means to facilitate spectroscopic observations of surface materials thrown upwards by such a powerful mineralogical survey test procedure, replicating natural impact event-processes. In other words, Armstrong and his daring colleagues participating in the technologically bold Apollo mission might have been ordered to visit an anthropogenic crater to collect unnaturally radioactive rock and gas samples! Thankfully, current technologies permit assessment of the Moon's mineral wealth.

Human exploration of the Moon has caused a measurable degradation of the lunar vacuum because of the emplacement of a tenuous artificial atmosphere. Remarkably, accurate topographic mapping only became possible and available subsequent to the 1994 Clementine mission, which produced the first global altimetric data set for the Moon; the first map of Earth's surface at a known and uniform accuracy followed the successful production of a global altimetric data set by the Shuttle Radar Topography Mission (SRTM30). Earth has an estimated hypsographical relief range of ~20 km, the Moon ~16 km.

4. Geophysical Catastrophes

Earthly global warming is a commonplace, first widely touted during the late 20th century. Indeed, it is the keystone of accumulating geophysical evidence utilized by those who have theorized about, and declared a name for, a dawning Earth-only geological time period, the "Anthropocene". Because Earth reflects about 1 W/m2 owing to anthropic aerosols and radiates approximately -2 W/m2 owing to the presence of anthropogenically produced greenhouse gases, certain scientists say: "A miniature Christmas tree bulb dissipates about one watt, mostly in the form of heat. So it ... [is] as if humans had placed two of these bulbs over every square meter of the Earth's surface, burning night and day." Complex non-linear mechanical, chemical and biological interactions among the components of Earth and the Moon are nowadays the increasingly important focus of scientific research; these interactions are driven externally by the Sun and internally by geothermal heat flow.

Anthropic activity, which trends to enforce schedules on objects and flows included in all planetary event-processes, is an operating integral component of all Earth-Moon system changes, especially since the Space Age's 1957 inauguration. Nevertheless, the unexpected and the accurately forecasted future geophysical catastrophe can impact the Earth-Moon system, causing profound, and comprehensive, macro-planned post-event-process readjustments of human societal behaviors.

General nuclear war's infamous anthropogenic postwar "nuclear winter", surprise dust-raising large asteroid and/or comet impacts, and unpreventable regional volcanic super-eruptions are the three event-processes often alleged as the most likely to adversely affect the Earth-atmosphere's albedo and the planet's overall human habitability. Each of these threats to present-day and near-future human life and life-styles stems from the fact that humanity is dependent largely on annual crop yields; global agriculture is subject to sunlight's variations and interruptions since nature's basic life-supporting output is essentially photosynthetic. Furthermore, such "global cooling" event-processes could instigate a permanent snow and ice-covered Earth-surface. A significantly less likely global cooling event-process may be started by Earth's encounter with a dense interstellar cloud; in that instance, our Sun's heliosphere could contract, exposing the inhabited and cultivated Earth to new and unusual flows of energy and materials. Earth's atmosphere could endure a catastrophic global cooling due to gravitational scattering and ejection from the Solar System following the Solar System's close encounter with a foreign star, resulting in Earth becoming a rogue planet.

However, some obviously important real atmospheric mysteries, such as a "global dimming", have yet to capture very many scientists attention. Each year, evidently, less sunlight reaches the Earth's surface to heat rocks, plants, and animals. Global dimming, in brief, is an accurately, if preliminarily, measured ongoing geophysical event-process affecting humanity's only planetary residence. The most significant suspected causes of global dimming may be: (1) a less intense solar constant impacting Earth's uppermost atmospheric boundary; (2) anthropogenic dust injections cluttering the Earth-atmosphere; (3) unexamined aspects of atmospheric gas interactions; (4) a combination of causal factors, such as numbered items 1 through 3, as well as some still unanticipated causes. Our report looks at a possible "cure" for global dimming since a Snowball Earth outcome is quite undesirable from our civilization's viewpoint. Few humans can survive, let alone flourish, in climatically extreme Earth-biosphere regions. A 3% per decade reduction of the total sunlight reaching the Earth's surface would result, mathematically speaking, in a potential for total darkness after ~330 years! The ultimate doomsday for the Earth-biosphere would come as a result of the absence of sunlight impinging our homeland; it is rather macabre to contemplate the geologic and biotic even-processes occurring following such an (nearly impossible) interruption, nevertheless, a reasonable robust computer model of the termination of incoming solar radiation found that the simulated Earth's atmosphere could retain its essential characteristics even after ~50 days of complete darkness!

5. Curatorial Management

Since World War II, and as a direct consequence of certain scientific discoveries and vital inventions, humans are at risk of losing all of their infrastructure and even the Earth-surface itself. During 1998, one of us (RBC) coined a phrase, "greenglass effect" naming a prospective geophysical phenomenon – as, for example, nuclear winter – that could take place after a general nuclear war. The first test of a nuclear explosive during 1945 in New Mexico produced a glassy geomorphic surface formed of a new material, trinitite, which is melted sand that is resolidified and radioactive. "General nuclear war, a brief epigenic process instigated by a nationalized H. sapiens, would create on Earth's discrete landmasses thousands of darkly-tinged circular spots of glazed landscape... Such deathly 'shadows' of humanity's immediate past would probably disfigure postwar lands everywhere. However, global nuclear winter might be shortened in duration by an atmospheric circulation stimulated by these numerous darkened regions with artificial albedoes – all unnaturally made without a macroproject plan: a greenglass effect could replace a broken greenhouse effect. This useful neologism, "greenglass effect", serves to highlight another facet of the global nuclear winter geopolitical scenario and anthropogenic global warming debates. Homo sapiens' contamination of Earth by terminating our species, with postwar biosphere recovery speedier under a greenglass effect than under a mega-greenhouse effect." The complete disappearance of all humans, the terminus of a short-lived Earth-only Anthropocene time period, will leave other long-lasting traces of humanity's existence. Chances of a general nuclear war seem to be diminishing, so that presents humans with the worldwide macro-problem of global dimming and the necessity of finding renewable energy to power a populous and geographically spreading civilization.

6. Moon Macro-Engineering

Offsetting Earth's global dimming will be a broadly vital challenge to the abilities and capabilities of the most masterful extant proponents of Space Age macro-engineering. After all, the rapid onset of the Mount Pinatubo 1991 volcanic eruption resulted in a calculated reduction of ~5.64 × 1022 J of heating within Earth's biosphere! Mount Pinatubo's eruption dust loading of the atmosphere, interestingly, caused a measurable increase in global diffuse radiation that, subsequently, caused a measurable reduction of atmospheric carbon dioxide gas, thereby promoting "global cooling"! Until the early 21st century, only certain aspects of near-future ancillary Moon base development were fully assessed. During 2001, James T. Downey announced he was personally dedicated to undertaking an Earth-based artistic effort, "Paint the Moon: A Collaborative Work of Celestial Art", with red-beamed lasers. His effort's stated purpose is to help unite humanity since he planned to have a large number of unrelated participants, living on the appropriate Moon-facing Earth hemisphere at a certain specified time, shine their hand-held personal wand-like red-light laser pointers at the whitish orb dominating the sky. Downey's artwork is an unscientific and impossible-to-fulfill personal illuminative quest! Light pollution, the high light levels at night produced mainly by outdoor artificial illumination (street and building lighting, for example), has caused Earth-bound astronomers and the public to bemoan the recently noted invisibility of once visible stars. During 21st century nights, only the Moon remains, more or less, constant in its looming presence! The decline in monetary cost of artificial lighting, from prehistoric firelight, to ancient oil-lamps and candles, to roadside lampposts emitting gaslight and all kinds of modern-day electric lighting fixtures was rigorously compared with a consumer price index (CPI). William Nordhaus carefully computed and ultimately concluded that his assumed well-founded CPI did not represent a meaningful quality improvement: 21st century CPI-adjusted anthropogenic light price is >103 greater than the true price. Increasing "moonshine" by artificial means may be an inexpensive Moon macroproject, approximately the cost of observatories on the Moon.

Complete industrialization of the Moon's 37.96 × 106 km2 surface, which is largely composed of anorthosite and gabbro or norite, broken by meteor impacts into mixed and shattered rocks and fine fragments labeled regolith or breccia, is usually portrayed as humanity's goal-quest for additional energy, ores and other resources. All realistic macro-engineering projections foresee the high cost of ensconcing comfortable Earthlings on the Moon: ignoring all transportation costs, the expense if every human (~6 × 109 persons) were to migrate, or be evacuated as refugees, simultaneously to a cost-free, pre-prepared built Biosphere-3 Moon City, would tally 2004USA~$54 × 1015, at least, just for the single building to safely shelter them. After, somehow, getting to the Biosphere-3 Moon City, an isolated base/settlement in inhospitable conditions that must rely on outside help, supplies and energy to survive, such colonist/refugee persons will undoubtedly be very depressed! (And, it is unlikely that any Biosphere-3 Moon City would be an enclosure mirroring the "Blue Moon Project", a City of Groningen, The Netherlands, urban project based on a mirror-Moon architectural design theme in which five discrete landscapes are macro-planned for construction that are "... to appear as if in the shadow of a lunar crater"!) Relative to Earth's populace, a future small elite group of Moon-dwellers could be quartered in diatom-like enclosure, imitative shatterproof glass-roofed houses, factories and other vital working installations; but, more likely, such persons will be protected from the vacuum-at-the-surface dangers, as well as those threats to life caused by released volatiles produced during 3He mining activities, by extensive underground settlements.

Owing to the Moon's 1.62 m/s2 surface gravity, the maximum speed of movement for any wheeled vehicle traveling its rocky surface is ~40 km/h; an autonomous robotic rolling Sun-synchronous Moon exploring vehicle must move only at ~16 km/h along the Moon's 10,914 km equator to keep pace with the Sun's path over its rugged terrain. Greater surface wheeled vehicle speeds could be obtained using Sun-shaded Maglev railroads with wheeled trains locked to tied-down rails. In a sense, the entire Moon is a Sun-lit and Earth-lit potential parking lot for active and inactive spacecraft, motor-powered passenger and freight-carrying rovers. "From the viewpoint of scientific research, the Moon has a very important feature. Its far side, which never faces the Earth, is the only place in the Solar System which is completely immune from [electronic and light pollution] disturbances due to human activity."

Self-moving, autonomous robotic factories are presumed to be a near-future technology, and some R&D experts think many such solar-powered mobile multi-machine complexes can be used to build by means of adapted stereo-lithographic techniques – from in situ superficial resources like the Moon's breccia and regolith – a vast area of installed InGaN (indium gallium nitride) solar energy collection panels. In other words, 100% of the Moon's surface may become covered by a special kind of anthropic rock knitted into an enshrouding anthropogenic Moon surface that is interlaced with electricity-conveying superconductor cables! That's not far from being a so-called parking lot surface! In fact, should a purely anthropic Moon crust ever be formed in situ – never, of course, obliterating or obscuring the 20 July 1969 Apollo 11 landing site, "Tranquility Base" – it would surely constitute a special type of "super-structure" laid by a historically datable robotic wheeled installer-facility during the most recent period of the Moon's geological time – the Anthropocene (Moon). Contemporaneously, these motile strip-miners/solar panel factories could collect 3He – the Moon is estimated to have accessible deposits of ~106 tonnes compared to Earth's 0.5 tonnes – for use in nuclear fusion reactors safely situated beyond the Earth-biosphere. Because of Earth's proximity, the round trip communication period for a Moon-traversing tele-robotic machine is ~2.42 seconds (at perigee) to ~2.70 seconds (at apogee). It must be noted that such spatially widespread 3He-harvesters/pavement-making machinery fostered by industrialists may be the Moon's equivalent of Earth's "primitive polluters", an anthropological appellation for non-industrialized human groups (shifting cultivators) that are designated so because such migrating non-industrialized societies cause carbon dioxide gas deposition in Earth's atmosphere. There is a substantial macro-problem: What would the Moon's albedo (moonshine) be after installation of a super-structure composed of several kinds of processed materials? Related to this question, would interplanetary communications be successfully facilitated by mirroring the Moon's surface? [William Henry Pickering (1858-1938) calculated that a conspicuous ~1.3 km2 mirror on Earth could signal persons living on Mars. Might not the flashing Moon be used for communication over interstellar distances?] And, complementarily, what would be the maximum amount of solar power that could be generated supposing the Moon's entire surface were clothed with photovoltaic cells and photonic-crystal filaments embedded in the super-structure as panels?

7. Moon-Day Project

Because the Earth rotates (1 day) faster than the Moon revolves (27.3217 days), and dissipation leads to a time lag in the response of the Earth to the tide-raising potential, the Earth's tidal bulge leads the Moon; a net torque retards the Earth's axial spin and, at the same time, increases the Moon's orbital angular momentum, thereby increasing the Earth-Moon system separation distance by ~3.8 cm/yr. The slowing rotation of the Earth results in longer days as well as a longer month; once the length of day equals a month, the tidal friction connection will cease. Receding from the Earth, in a few hundred million years – when the Earth-Moon separation distance increases from today's ~383,000 km to ~434,000 km – a Moon-caused total solar eclipse phenomenon won't ever again occur naturally; presently, the largest possible path width of a total eclipse crossing Earth's face is < 300 km. "Earth is effectively held upright at low obliquity by the strong gravitational influence of the Moon." The Sun and the Moon appear about the same size when those two almost unique Solar System bodies are viewed from Earth: of all the moons in the Solar System, "…ours yields the best match to the Sun as viewed from a planet's surface, and this is only possible during a fairly narrow window of Earth's history, encompassing the present." (The Moon's far side went unobserved until the USSR's Luna 3 spacecraft made the first remote images of it during 1959.) A solar power plant located at the Moon's poles should be capable of nearly continuous operation, in contrast to a power plant sited at an equatorial location that would be in darkness for approximately half of a month (~14 days).

In a routine report, the USA's Department of Commerce tallies the weight of imports and exports moving across the nation's international borders. Analysis of its most recent FT-920 report shows that the tonnage of materials shifted is only slightly greater than it was in the last half of the 20th century. In other words, useful insights emerging from R&D on exactly how materials and energy ought to be used has kept the tonnages nearly stable despite an increase of population! Energy is an important driver of all civilization advancements considered as progress. Microwaves beamed to the Earth are reputed to be a clean extraterrestrial import solving the social macro-problem of regional energy shortages; however, the operation of electrical machinery emits waste heat, amplifying a commonly alleged Earth-atmosphere global warming event-process. Vast ground-based mirrored surfaces, perhaps best located in the Sahara, have been computed as a complete global warming "cure". Some experts, however, do currently extol the global economic benefits for Earth's peoples of "The Moon as a solar power satellite". At the same time, vast Moon-crust sited mirrors focusing reflected sunlight onto selected regions of the Earth have been claimed as an economical technical means to deliver additional renewable energy without increasing the requirement for importation or exportation of material energy resources (coal, petroleum, natural gas). Mirror reflections do have unusual properties. There is a substantial macro-problem: Can our Moon, remade to resemble a glittering 1970s era dancehall "disco ball", cause health problems for Earthlings? Even worse, what if laser beams were generated, collimated and projected from the Moon and deeply penetrated Earth's atmosphere, perhaps causing painful skin burns and blindness to animals and people? The USA's military has investigated a macroproject using a laser beam, of a specified wavelength, to "floodlight" a large Earth-biosphere region – typically, a battlefield – with additional photons of the wavelength that can be detected by ground-based enhanced visual observational systems. Future establishment of a very powerful laser facility on the Moon has been proposed in order to easily and economically facilitate direct exploration of the Sun's photosphere. What might the imposed albedo (of a Moon sheath composed of man-made Moon photovoltaic cells/photonic-crystal filaments and/or massive mirror fields) be versus the Moon's natural, pre-Space Age albedo? In other words, "green-glass effect".

8. Moon-Lit Earth?

A decade ago, in 1996, a professor of physics and astronomy at the University of British Columbia in Canada, Lorne A. Whitehead, penned and got published a clever tarradiddle proposing "Whitehead Earth Tugs and Artificial Suns". During the 19th century, a "tarradiddle" was a lie or hoax; "tarradiddle" is based on "diddle" which is derived from the Anglo-Saxon "(meaning "to deceive"). Besides changing Earth's Sun-centered orbit by using the Moon as an Earth-pulling "tugboat", Professor Whitehead sought to illuminate a darkened Earth being piloted away from the Sun by installing many replaceable full-spectrum light bulbs or, more likely, encased photonic-crystal filaments everywhere on the Moon's hard-vacuum environment surface that were made to glow with electricity furnished by nuclear fusion reactor(s) emplaced on the Moon's unseen-from-Earth far side. He banked on the astronomical fact that "…the Moon, in a stunning cosmic coincidence, is exactly the right size, relative to its distance from Earth, to appear to us the same size as the Sun." (Earth's sky encompasses 41253 square degrees while the Moon and Sun, each, incorporate ~0.2 square degrees.) The Moon's axis of rotation is not lined up perpendicular to its orbit so that sometimes the Moon's North Pole tips towards the Earth, slightly, and sometimes the South Pole does so, slightly. There are no places on Earth where it would be impossible to see at least some phases of the Moon – except if local land topography were in a large crater, deep canyon or immediately adjacent to a very high mountain range. However, if explorers are located on the Moon's far side (~41% of the Moon's area) no one could ever see Earth!

Also, since the Moon's orbit is elliptical, not circular, the Moon moves slower when furthest from Earth in its orbit (apogee), and faster when closest to Earth (perigee). As a result, whilst the Moon rotates in the same period it revolves (i.e., 1/1 spin resonance), sometimes that rotation does not keep up with the revolution, for other periods it outpaces it. The result is that a laser, emitting its tightly collimated light beam vertically from a position sited at 0° E/W, would sometimes be aimed slightly to the right of Earth, sometimes slightly to the left. Seen from the Moon, Earth is ~2° wide. Christian Marchal's stellar insights on these astronomically complicated Moon movements is edifying. "Global geo-engineering" – one of the two main forms of modern-day macro-engineering, the other being terraforming – has already been bruited, and preliminarily proved efficacious, as a curative technique for unwanted or undesired Earth-atmosphere event-processes, as the granted internationally recognized USA patents of Neil M. Brice, Debra M. Udell and Bernard J. Eastlund demonstrates. Noteworthy is NASA's 2004 announcement of its proposed Earth System Science Pathfinder Missions: Orbiting Carbon Observatory, Aquarius, and Hydros – all meant to do first-of-a-kind exploratory measurement that should help to establish fundamental scientific truths about the Earth-atmosphere's event-processes.

Is it worthwhile to ponder the real-world utility of Whitehead's Sun "replacement" tarradiddle? Would there be any quantifiable advantage for Earth dwellers if humanity had a second Sun instantly available for service? In what manner could the "anti-global dimming" macro-problem be addressed if Whitehead's seemingly lunatic light bulb array – also known as the Disco Ball-Moon macroproject – was carefully scoped out, and a cursory power flow feasibility study assembled?

9. Noom

Eduoard Roche (1820-1883) demonstrated circa 1848 that a satellite ought to be physically disrupted by gravitational tidal forces if it orbited its primary at a critical distance (Roche's tidal radius). To disrupt Earth's most obvious satellite, the gravitational force on the Moon's surface has to be less than the difference between the Moon's core and its crust; for the Earth-Moon system, the Roche limit tidal radius is ~2.9 Earth's radius, or ~18,497 km from Earth. Supposing future humans build a Dyson sphere from materials derived only from our Solar System, what might be the Moon's fate? Is preservation of the Moon a worthwhile macroproject? Since the presence of the Moon near Earth poses a significant problem for macroengineers trying to demolish Earth with Freeman Dyson's postulated spin-up motor, we have opted to conserve the Moon. Accordingly, here we offer a few speculative thoughts on our present R&D problem that is concerned with constructing and guiding the movement of a finished Dyson sphere. Freeman Dyson's proposed motor, founded on the work of Sidney Drell and his colleagues, more or less replicates on a larger geographical scale a spherical motor developed only recently that permits machines a ball-based three-dimensional movement. Since the terrestrial-type planets of our Solar System spin at less than 1/10 breakup speed, Dyson's motor is required to demolish these celestial solid objects. It, literally, is a machine to make asteroids, which can later be harvested, providing a material resource for other object manufacturing. If the Moon were deliberately moved away from the Earth – it is, of course, moving so already quite naturally – before Earth were unnaturally disrupted under the influence of Dyson's motor and, by minding our "p's" and "q's" carefully, retained in a whole condition, the Moon could then become constituted as an inhabited observatory, an orb macroengineered to move about inside a completed Dyson sphere! Abbreviated, this dedicated effort could be labeled as the "Natural Observatory Orb Macroproject" (NOOM, a mirror image of the word "Moon"). The gravitational effect of a spherical distribution of attractive mass – that is, a Sun-enrobing Dyson sphere of uniform material density – on a NOOM situated anyplace within Dyson's sphere would be exactly zero!

NOOM might function as a manned science laboratory focused on the Sun (helioseismology and solar wind research especially). Even with the advanced technology available to the humans constructing a Dyson sphere, Sun-facing machines are likely to be subject to the effects of space weather and may, therefore, constitute a new kind of "cyberelectrosphere" [actually, a shell]. Humans observing the sky from a vantage place exterior to their Dyson sphere will notice, in perhaps 500,000 years' time, that passing stars affect their homeland and its energy resource, the Sun. NOOM seems to be a necessary, if not convenient, facility since the solar wind, only recently determined to naturally terminate at ~85 AU, will pressurize an anthropogenic Dyson sphere's interior surface and be somewhat absorbed as well as reflected, causing complex currents of material and energy within the Dyson sphere shell itself as well as in the space intervening between the Dyson sphere's innermost wall and its powering Sun.

Furthermore, NOOM might serve as a roving Headquarters of any concerted human effort expended towards astro-engineering the Sun. Certainly, future achievable sustained LASER intensity will be up to that task! Some power for a "swizzle stick" laser beam stirring the Sun's interior contents can be derived from using the intact Moon's precession, from solar power harvested on the rotating Moon's surface, as we have suggested above, or can be forwarded from technically special, dedicated power-plants on the Dyson sphere's inner shell surface. (The Moon's present-day libration period is ~2.86 years, while the amplitude of its forced libration is ~15 arcsec, almost undetectable; the Moon's diurnal libration is ~10.) NOOM may have the characteristic of being a directly and/or remotely controlled "Spaceship Moon" scientific laboratory and R&D command center that, initially, helped humans solve smoky environmental problems with mirrors.