Light – BLDGBLOG

Looming Matter With Light

“When light collides with other light, it can transform into particles of matter,” science writer Corey S. Powell posted on Twitter the other day. He was referring to recent evidence from the Relativistic Heavy Ion Collider that “pairs of electrons and positrons—particles of matter and antimatter—can be created directly by colliding very energetic photons.” In other words, the “conversion of energetic light into matter” might be physically achievable: you can create matter with light.

I am in no position to comment on the science of this beyond the sheer poetry of the description; if you want to learn more about the actual experiment, I’d strongly advise going to the source material, not to BLDGBLOG. But so many metaphors come to mind here—precipitation and snow; depositional 3D printing; shining looms of light, bringing matter into the cosmos.

Imagine an industrial printing facility of the far future whose only input is light. Factories of weird mirrored rooms where objects flash into existence one at a time, in a new manufacturing process extruding matter from illumination.

In any case, I was also reminded of a piece published in Nature back in 2011: “Moving mirrors make light from nothing.”

The hypothesis there was that a single mirror “moving through a vacuum at nearly the speed of light” could, through something called the Casimir force, actually generate photons—the mirror could create light. This was apparently given experimental support when “a shower of microwave photons [was] shaken loose from the vacuum” by a highly sensitive superconducting device known as a SQUID.

The scientist behind that experiment now “hopes to see a moving piece of metal generate detectable light from the vacuum,” as if farming light from nothingness, coaxing photons into appearing like seeds, shaking them loose from the void.

Mirrors moving through darkness at the speed of light can create light—the sheer poetry of this is astonishing to me, like a statement from the Gnostic Gospels.

Anyway, now put these two experiments together: use a moving mirror to pull light from darkness, then collide that light back into itself to generate matter. You could design a kind of internal combustion engine made of moving mirrors, turning darkness into light into matter.

Again, though, read the original articles if you prefer science over speculation.

Ghosts Only Cars Can Perceive

[Image: An otherwise unrelated image of car-based LiDAR navigation, via Singularity Hub].

There was a lot of design interest a few years back in a product that allowed cyclists to project their own bike lanes, an idea that is still being honed today.

Transportation infrastructure that only exists in the form of a projection is a great analogy for the state of cycling in the U.S. today, but what we might call projected infrastructure—road signs, bike lanes, and crosswalks that aren’t really there—can apparently also be weaponized, turned against the machine-sensing systems that navigate and steer driverless vehicles.

Researchers at Ben-Gurion University, for example, have shown that fake, drone-projected street signs can spoof driverless cars. Amazingly, these fake street signs can apparently exist for only 100 milliseconds and still be read as “real” by a car’s sensing package. They are like flickering ghosts only cars can perceive, navigational dazzle imperceptible to humans.

As if pitching a scene for the next Mission: Impossible film, Ars Technica explains that “a drone might acquire and shadow a target car, then wait for an optimal time to spoof a sign in a place and at an angle most likely to affect the target with minimal ‘collateral damage’ in the form of other nearby cars also reading the fake sign.” One car out of twenty suddenly takes an unexpected turn.

Although this spoof is, for now, entirely visual, “a more advanced attacker might combine GNSS [Global Navigation Satellite System] spoofing and perhaps even active radar countermeasures in a very serious bid at confusing its target,” Ars Technica adds. Cars, lost in their own technical hallucinations, being steered to unknown destinations, unaware that they’ve even strayed.

The Mirror War and the Light Brigade

MirrorFire-sm [Image: A cosmetically touched-up view of villages being set alight by mirrors; view slightly larger. From Deliciae physico (1636) by Daniel Schwenter].

Perhaps you remember the Austrian village of Rattenberg, so thoroughly hidden in the mountain shadows every winter that it installed a huge system of mirrors to bring the sun back in. The town of Rjukan, Norway, recently experimented with the same thing.

“High on the mountain opposite,” the Guardian reported back in 2013, “450 metres above the town, three large, solar-powered, computer-controlled mirrors steadily track the movement of the sun across the sky, reflecting its rays down on to the square and bathing it in bright sunlight.”

A far more sinister version of this exact sort of system was illustrated in a German book called Deliciae physico, published back in 1636, by Daniel Schwenter.

There, a woodcut shows a kind of reflective super-weapon mounted atop pillars, made of concave mirrors and magnifying lenses, setting fire to two distant buildings simultaneously the way a bumbling child might torture ants.

MirrorFire-big [Image: The full original page; view larger. From Deliciae physico (1636) by Daniel Schwenter].

Interestingly, this Apollonian death ray—a frighteningly literal light brigade—is presented in the book’s much larger context of telescopes, astronomy, and other optical devices, including distorting mirrors and cameras obscura.

Check out all 650 pages of the book here, courtesy of the U.S. Library of Congress, including some very cool images.

(Originally spotted via the excellent Twitter feed, @HistAstro).

Nocturnes

merrell4 [Image: Screen grab from Nocturnes].

Filmmaker Alec Earnest—who we last saw here for his short film about the death of a mysterious map collector in Los Angeles—is back with a mini-documentary about landscape painter Eric Merrell.

Merrell, we read, “might be best known for his rigorous approach to landscape painting. For several years Merrell has been working on Nocturnes, a series of abstract desert works that he has painted all over Southern California, each solely by the light of the moon.”

merrell6 [Image: Screen grab from Nocturnes].

Earnest’s film follows Merrell into Joshua Tree National Park, “where night falls and the desert takes on a surreal and mysterious beauty, where edges blur and shapes transform, and solitude takes on a whole new meaning.”

The small crew used a new Sony A7S camera “that basically allowed us to shoot completely in the dark,” Earnest explained to me over email.

The film is embedded, below:

Of course, as the video makes clear, this is a slight—but only slight—exaggeration, in that Merrell uses a headlamp and small clip lights on his painting box to help illuminate the scene.

merrell11 merrell2 [Image: Screen grab from Nocturnes].

When those lights are switched off, however, the landscape takes on a silvered, almost semi-metallic lunar glow, as if bathed in ambient light.

merrell8 merrell7 [Image: Screen grab from Nocturnes].

Standing there in the darkness, Merrell comments on how working at night also comes with a peculiar kind of audio enhancement, with distant sounds riding the breeze with a peculiar clarity; and at one point a fortuitous lightning storm rolls by in the distance, as if to prove Merrell’s point with the atmospheric sonar of a thunder crash echoing over the otherworldly rocks of the National Park.

merrell12 merrell13 [Images: Paintings by Eric Merrell; screen grabs from Nocturnes].

Read a bit more at the L.A. Review of Books, and don’t miss Earnest’s earlier film here on BLDGBLOG.

Islands at the Speed of Light

A recent paper published in the Physical Review has some astonishing suggestions for the geographic future of financial markets. Its authors, Alexander Wissner-Gross and Cameron Freer, discuss the spatial implications of speed-of-light trading.

Trades now occur so rapidly, they explain, and in such fantastic quantity, that the speed of light itself presents limits to the efficiency of global computerized trading networks.

These limits are described as “light propagation delays.”

[Image: Global map of “optimal intermediate locations between trading centers,” based on the earth’s geometry and the speed of light, by Alexander Wissner-Gross and Cameron Freer].

It is thus in traders’ direct financial interest, they suggest, to install themselves at specific points on the Earth’s surface—a kind of light-speed financial acupuncture—to take advantage both of the planet’s geometry and of the networks along which trades are ordered and filled. They conclude that “the construction of relativistic statistical arbitrage trading nodes across the Earth’s surface” is thus economically justified, if not required.

Amazingly, their analysis—seen in the map, above—suggests that many of these financially strategic points are actually out in the middle of nowhere: hundreds of miles offshore in the Indian Ocean, for instance, on the shores of Antarctica, and scattered throughout the South Pacific (though, of course, most of Europe, Japan, and the U.S. Bos-Wash corridor also make the cut).

These nodes exist in what the authors refer to as “the past light cones” of distant trading centers—thus the paper’s multiple references to relativity. Astonishingly, this thus seems to elide financial trading networks with the laws of physics, implying the eventual emergence of what we might call quantum financial products. Quantum derivatives! (This also seems to push us ever closer to the artificially intelligent financial instruments described in Charles Stross’s novel Accelerando). Erwin Schrödinger meets the Dow.

It’s financial science fiction: when the dollar value of a given product depends on its position in a planet’s light-cone.

[Image: Diagrammatic explanation of a “light cone,” courtesy of Wikipedia].

These points scattered along the earth’s surface are described as “optimal intermediate locations between trading centers,” each site “maximiz[ing] profit potential in a locally auditable manner.”

Wissner-Gross and Freer then suggest that trading centers themselves could be moved to these nodal points: “we show that if such intermediate coordination nodes are themselves promoted to trading centers that can utilize local information, a novel econophysical effect arises wherein the propagation of security pricing information through a chain of such nodes is effectively slowed or stopped.” An econophysical effect.

In the end, then, they more or less explicitly argue for the economic viability of building artificial islands and inhabitable seasteads—i.e. the “construction of relativistic statistical arbitrage trading nodes”—out in the middle of the ocean somewhere as a way to profit from speed-of-light trades. Imagine, for a moment, the New York Stock Exchange moving out into the mid-Atlantic, somewhere near the Azores, onto a series of New Babylon-like platforms, run not by human traders but by Watson-esque artificially intelligent supercomputers housed in waterproof tombs, all calculating money at the speed of light.

[Image: An otherwise unrelated image from NOAA featuring a geodetic satellite triangulation network].

“In summary,” the authors write, “we have demonstrated that light propagation delays present new opportunities for statistical arbitrage at the planetary scale, and have calculated a representative map of locations from which to coordinate such relativistic statistical arbitrage among the world’s major securities exchanges. We furthermore have shown that for chains of trading centers along geodesics, the propagation of tradable information is effectively slowed or stopped by such arbitrage.”

Historically, technologies for transportation and communication have resulted in the consolidation of financial markets. For example, in the nineteenth century, more than 200 stock exchanges were formed in the United States, but most were eliminated as the telegraph spread. The growth of electronic markets has led to further consolidation in recent years. Although there are advantages to centralization for many types of transactions, we have described a type of arbitrage that is just beginning to become relevant, and for which the trend is, surprisingly, in the direction of decentralization. In fact, our calculations suggest that this type of arbitrage may already be technologically feasible for the most distant pairs of exchanges, and may soon be feasible at the fastest relevant time scales for closer pairs.

Our results are both scientifically relevant because they identify an econo-physical mechanism by which the propagation of tradable information can be slowed or stopped, and technologically significant, because they motivate the construction of relativistic statistical arbitrage trading nodes across the Earth’s surface.

For more, read the original paper: PDF.

(Thanks to Nicola Twilley for the tip!)

Shining Path

One of many things that we’ll be looking at tonight in the Blackout seminar that I’ve been teaching over at Pratt in Brooklyn is organically generated electricity—things like virus batteries, biogeobatteries, sediment batteries, and more.

[Image: From Christopher Nolan’s film The Prestige (2006)].

By way of getting there, though, we’ll be taking a very brief look at Christopher Nolan’s under-rated film The Prestige—specifically the scene in which we see a hillside covered in giant incandescent light bulbs, none of which appear to be plugged into anything but soil and all of which are powered wirelessly by a generator located over 12 miles away.

The geological form of the mountain plateau becomes a shining grid framing our two featured characters.

[Image: From Christopher Nolan’s film The Prestige (2006)].

Although The Prestige does not suggest that this is what’s happening in this scene, what if the soil itself was powering these light bulbs? What if soil could be turned into a landscape-scale, distributed electrical device?

Awesomely, as Nature reported just two months ago, there is growing evidence to back up “a suggestion within the geophysics and microbiology communities that bacteria can grow tiny ‘wires’ and hook up to form a biogeobattery—a giant natural battery that generates electrical currents.”

[Image: From Popular Science].

Then Popular Science picked up on the story:

Scientists have known that bacteria can create electricity when mixed with mud and seawater, and have even built microbial fuel cells around the little buggers. Now they have begun figuring out just how bacteria create electrical networks that serve as long-distance communication, at least on the microbial scale—the distances ranged up to 2 centimeters. Yet those few centimeters equal roughly 20,000 times the body size of individual bacteria.

Imagining soil itself—the ground all around us—as a giant electrical transmission network is astonishing. And, again, while there is no mention of anything like biogeobatteries and their ilk in The Prestige, the very idea that perhaps someday we could plug light bulbs directly into the soil—an organic battery coextensive with the living surface of the earth—amazes me.

[Images: From The Prestige (2006)].

And biogeobatteries are not even the only option here; there are also virus batteries.

MIT reported back in 2006 that a team of researchers had “harnessed the construction talents of tiny viruses to build ultra-small ‘nanowire’ structures for use in very thin lithium-ion batteries. By manipulating a few genes inside these viruses, the team was able to coax the organisms to grow and self-assemble into a functional electronic device.” The resulting virus batteries are tiny, but they could vary in scale “from the size of a grain of rice up to the size of existing hearing aid batteries.”

The future design possibilities are bewildering. Could deposits of virus-impregnated soil be used as electricity-storage devices in rural, off-the-grid areas?

[Image: From Nature].

After all, bacteria might already be “wiring up the soil,” Nature suggested three years ago. Indeed, “bacteria can sprout webs of electrical wiring that transform the soil into a geological battery,” meaning that “the earth beneath our feet might act as a gigantic circuit built by microbes to power their metabolic systems.” And you can build a soil battery yourself:

The researchers filled plastic columns with wet sand infiltrated with a nutrient compound (lactate), and allowed S. oneidensis to grow in this “fake soil.” Only the top of the column was in contact with air. Electrodes inserted at various heights up the columns revealed that, after about ten days, electrical charge was coursing up the column… threaded by a web of filaments between the bacterial cells.

I’m reminded here of the work of Philip Beesley, which often uses self-fertilizing yeast-packs, gels, and seeds to create living geotextiles. In fact, a Beesley Battery doesn’t seem at all very off: a living mat woven through the soil, generating and storing electricity based on pre-existing bacterial activity in the ground.

You infect the soil with a genetically-modified virus patented by MIT and electrical currents start to flow…

[Image: From Christopher Nolan’s The Prestige (2006)].

Perhaps someday, then, we could simply show up somewhere, in the middle of the night, surrounded by pine forests and hills, and just crouch down, push a light bulb two or three inches into the earth—

[Image: From The Prestige (2006)].

—and watch as everything around us starts to glow.

The Bioluminescent Metropolis

[Image: “Lightning Bugs in York, PA,” by tom.arthur, courtesy of a Creative Commons license].

While traveling last week, I managed to re-read W.G. Sebald’s book The Rings of Saturn.
At one point, Sebald describes two entrepreneurial scientists from the 19th century, who he names Herrington and Lightbown; together, we’re told, they had wanted to capture the bioluminescent properties of dead herring and use that as a means of artificially illuminating the nighttime streets of Victorian London.
Sebald writes:

An idiosyncrasy peculiar to the herring is that, when dead, it begins to glow; this property, which resembles phosphorescence and is yet altogether different, peaks a few days after death and then ebbs away as the fish decays. For a long time no one could account for this glowing of the lifeless herring, and indeed I believe that it still remains unexplained. Around 1870, when projects for the total illumination of our cities were everywhere afoot, two English scientists with the apt names of Herrington and Lightbown investigated the unusual phenomenon in the hope that the luminous substance exuded by dead herrings would lead to a formula for an organic source of light that had the capacity to regenerate itself. The failure of this eccentric undertaking, as I read some time ago in a history of artificial light, constituted no more than a negligible setback in the relentless conquest of darkness.

Sebald goes on to write, elsewhere in the book, that, “From the earliest times, human civilization has been no more than a strange luminescence growing more intense by the hour, of which no one can say when it will begin to wane and when it will fade away.”
But it’s the idea that we could use the bioluminescent properties of animals as a technique of urban illumination that absolutely fascinates me.
In fact, I’m instantly reminded of at least three things:

1) Last month I had the pleasure of stopping by the Architectural Association’s year-end exhibition of student work. As part of a recent studio taught by Liam Young and Kate Davies, a student named Octave Augustin Marie Perrault illustrated the idea of a “bioluminescent bacterial billboard.”
From the project text: “A bioluminescent bacterial billboard glows across the harbour… We are constantly reminded of the condition of the surrounding environment as the bio indicators becomes an expressive occupiable ecology.”

[Image: Bioluminescent billboards on one of the Galapagos Islands, by Octave Perrault].

In many ways, Perrault’s billboards would be a bit like the River Glow project by The Living… only it would, in fact, be illuminated by the living. These bioluminescent bacteria would literally be a living window onto a site’s environmental conditions (or, of course, they could simply be used to display ads).
Liam Young, the studio’s instructor, has also designed a version of these bioluminescent displays, casting them more fantastically as little creatures that wander, squirrel-like, throughout the city. They pop up here and there, displaying information on organic screens of light.

[Image: Bioluminescent billboards by Liam Young].

I’m genuinely stunned, though, by the idea that you might someday walk into Times Square, or through Canary Wharf, and see stock prices ticking past on an LED screen… only to realize that it isn’t an LED screen at all, it is a collection of specially domesticated bioluminescent bacteria. They are switching on and off, displaying financial information.
Or you’re watching a film one night down at the cinema when you realize that there is no light coming through from the projector room behind you – because you are actually looking at bacteria, changing their colors, like living pixels, as they display the film for all to see.
Or: that’s not an iPod screen you’re watching, it’s a petri dish hooked up to YouTube.
This is what I imagine the world of screen displays might look like if Jonathan Ive had first studied microbiology, or if he were someday to team up with eXistenZ-era David Cronenberg and produce a series of home electronic devices.
Our screens are living organisms, we’ll someday say, and the images that we watch are their behavior.

2) As I mentioned in an earlier post, down in the Blue Mountains of New South Wales is a tunnel called the Newnes Glow Worm Tunnel. It is a disused railway tunnel, bored through mountain sandstone 102 years ago, that has since become the home for a colony of glow worms.
As that latter link explains: “If you want to see the glow worms, turn off your torch, keep quiet and wait a few minutes. The larvae will gradually ‘turn on’ their bioluminescence and be visible as tiny spots of light on the damp walls of the tunnel.”

[Image: A map of the Glow Worm Tunnel Walk, New South Wales].

Incorporate this sort of thing into an architectural design, and it’s like something out of the work of Jeff VanderMeer – whose 2006 interview here is still definitely worth a read.
I’m picturing elaborate ballrooms lit from above by chandeliers – in which there are no lightbulbs, only countless tens of thousands of glow worms trapped inside faceted glass bowls, lighting up the faces of people slow-dancing below.
Or suburban houses surviving off-grid, because all of their electrical illumination needs are met by specially bred glow worms. Light factories!
Or, unbeknownst to a small town in rural California, those nearby hills are actually full of caves populated only by glow worms… and when a midsummer earthquake results in a series of cave-ins and sinkholes, they are amazed to see one night that the earth outside is glowing: little windows pierced by seismic activity into caverns of light below.

3) Several years ago in Philadelphia, my wife and I went out for a long evening walk, and we sat down on a bench in Washington Square Park – and everything around us was lit by an almost unbelievable density of fireflies, little spots of moving illumination passing by each other and overlapping over concrete paths, as they weaved in and out of aerial formations between the trees.
But what if a city, particularly well-populated with fireflies (so much more poetically known by their American nickname of lightning bugs) simply got rid of its public streetlights altogether, being so thoroughly drenched in a shining golden haze of insects that it didn’t need them anymore?
You don’t cultivate honeybees, you build vast lightning bug farms.
How absolutely extraordinary it would be to light your city using genetically-modified species of bioluminescent nocturnal birds, for instance, trained to nest at certain visually strategic points – a murmuration of bioluminescent starlings flies by your bedroom window, and your whole house fills with light – or to breed glowing moths, or to fill the city with new crops lit from within with chemical light. An agricultural lightsource takes root inside the city.
Using bioluminescent homing pigeons, you trace out paths in the air, like GPS drawing via Alfred Hitchcock’s The Birds.
An office lobby lit only by vast aquariums full of bioluminescent fish!
Bioluminescent organisms are the future of architectural ornament.

[Image: A bioluminescent tobacco plant, via Wikivisual].

On the other hand, I don’t want to strain for moments of poetry here, when this might actually be a practical idea.
After all, how might architects, landscape architects, and industrial designers incorporate bioluminescence into their work?
Perhaps there really will be a way to using glowing vines on the sides of buildings as a non-electrical means of urban illumination.
Perhaps glowing tides of bioluminescent algae really could be cultivated in the Thames – and you could win the Turner Prize for doing so. Kids would sit on the edges of bridges all night, as serpentine forms of living light snake by in the waters below.
Perhaps there really will be glowing birds nesting in the canopies of Central Park, sound asleep above the heads of passing joggers.
Perhaps the computer screen you’re reading this on really will someday be an organism, not much different from a rare tropical fish – a kind of living browser – that simply camouflages new images into existence.
Perhaps going off-grid will mean turning on the lifeforms around us.

Dark Sky Park

[Image: The dark skies above Galloway Forest Park, Scotland, via the Guardian].

Note: This is a guest post by Nicola Twilley.

2009 has been designated by the United Nations as the International Year of Astronomy (IYA), marking the 400th anniversary of Galileo’s telescope. The excitement is starting early, with Galloway Forest Park in Scotland announcing its plans to become Europe’s first “dark sky park.”

The forest, which covers 300 square miles and includes the foothills of the Awful Hand Range, rates as a 3 on the Bortle scale. The scale, created by John Bortle in 2001, measures night sky darkness based on the observability of astronomical objects. It ranges from Class 9 – Inner City Sky – where “the only celestial objects that really provide pleasing telescopic views are the Moon, the planets, and a few of the brightest star clusters (if you can find them),” to Class 1 – Excellent Dark-Sky Site – where “the galaxy M33 is an obvious naked-eye object” and “airglow… is readily apparent.” Class 3 is merely “Rural Sky,” meaning that while “the Milky Way still appears complex… M33 is only visible with averted vision.”

[Image: The Pleiades, photographed by Thackeray’s Globules, photographed by Hubble].

Nonetheless, Galloway Forest Park contains the darkest skies in Europe, and Steve Owens, co-coordinator of the IYA plans in the UK, is determined to gain recognition from the International Dark-Sky Association (IDA) as a lasting legacy for the 2009 celebrations.

The certification process is challenging. According to the Guardian, “to earn dark sky park status, officials in Galloway will submit digital photographs of the night sky taken through a fisheye lens. Their application must be supported by readings from light meters at different points in the park, and a list of measures that are being taken within the forest to prevent lights in and around the handful of farm buildings from spilling upwards into the sky and ruining the view.”

The IDA website itself contains everything that “locations with exceptional nightscapes” need to know to submit their application to be certified as “International Dark Sky Communities (IDSC), International Dark Sky Parks (IDSP), and International Dark Sky Reserves (IDSR).” Currently, there is only one dark-sky community in the world (Flagstaff, AZ), and just two dark-sky parks (the first, Natural Bridges National Monument in Utah, and the slightly less well-known Cherry Springs State Park in northern Pennsylvania). There are no actual reserves yet; indeed, the concept is still being thrashed out in partnership with UNESCO (who issued their own Starlight Reserve framework in 2007).

[Images: The “center of the Milky Way,” photographed by the European Southern Observatory at al.; the galaxy NGC 281, photographed by Ken Crawford of the Rancho Del Sol Observatory; and the Pleiades, photographed by Philip L. Jones].

The idea of a human-created dark sky park is fascinating, of course, as are the architectural and landscape modifications that must be undertaken by town councils and park management services in order to secure a qualifying Bortle score. For example, Observatory Park in Montville Township, Ohio, has been awarded provisional IDSP status (Silver Tier), contingent on “the completion of the park’s outdoor lighting scheme, visitor’s center, and enactment of outdoor lighting ordinances in surrounding townships.” The Geauga Park District submitted their 34-page Lighting Management Plan (read the PDF) in August 2008, detailing various proposals for the reduction of local skyglow (as opposed to natural airglow), light trespass, and glare. These include full shading for all light installations and lighting curfews, as well as strategic tree planting.

The concept of shaping the ground to frame and enhance the sky is not new (for instance, James Turrell’s Skyscapes are an architectural attempt to achieve “light effects and perceptual events” centered on a complex reframing of the sky). Nonetheless, the idea of rebuilding and landscaping an entire community specifically for the purposes of experiencing darkness is an exciting one – as is the idea of UNESCO, official protector of World Heritage Sites, attempting to safeguard dark skies as a “natural and cultural property.”

Scotland, with its northerly latitude and constant rain (which cleans the atmosphere of dust), has perhaps discovered its global tourist niche: A spokesman for VisitScotland, which is working closely with Dark Sky Scotland, ventured that “the night sky could be as important for tourism as the landscape.”

The light/surface fold: advertisements, Steven Holl, et cetera

I noticed several years ago that the pine forests outside Chapel Hill, NC, fill with a strange white light in winter, and not for the obvious reasons that, yes, it’s winter, so the leaves are all gone: ergo more light.
Nope: it’s because the angle that the earth takes in relation to the sun has changed, as it does every winter, and so the forests have literally begun to glow: the sun has begun hitting them at a different angle.
Winter, in this regard, is really a question of spherical geometry, angles, and trigonometric effects at long distances: sun–>earth/angle of incidence (or whatever). One of winter’s more interesting side effects, then, is the way that it transforms shadows – making them longer and thinner – while simultaneously illuminating objects from the side. This brings out details that go unremarked – and unlit – in other seasons.
All of these written reflections having been inspired by this photograph:

What’s interesting here is how the billboard enlists sun/earth trigonometry in the selling of suntan lotion. Who’da guessed?
But so I got to thinking about what would happen if you did more of that with architecture, if you learned a spatio-architectural lesson from however brief a glance at that billboard.
The deliberate shadow-machining effects of different times of day, say, in the vein of Steven Holl: entire hallways and galleries and courtyards and milled surface details could become visible only at specific hours, perhaps in pre-patterned ways.
Like an inhabitable sundial, you would always know it was 3 o’clock in the afternoon because the little grilled incisions in the plaster of the upstairs walls just appeared. They were invisible before that, and will be invisible again: but now is their moment in the light…
Or you know it’s noon because there are suddenly no shadows of any kind in your courtyard: you’ve angled everything perfectly for that moment. The space folds in on itself, reboots back to undisturbed white, and at 12:01pm the shadows reappear.
I just mean to point out the connection, here, between architecture and astronomy – via spherical, planetary trigonometrics – not because I’m the first to do so or even because it’s ultimately all that interesting, but because every little mundane trace – mere shadows – can be seen as an indication of literally superior, astro-stellar relationships.
Every shadow, if you do the math right, if you know the angles and the trig and the spherical velocity of objects in space, is actually an indication of the time of day – in a calendar that precedes Swatch and Swiss Army and electricity and even biological organisms as such.
And every kid with a flashlight – every person with a match or candle – every architect, even – can participate. Everything you build can be – and is automatically – an astronomical event.