GPS – Page 2 – BLDGBLOG

Glitches in Spacetime, Frozen into the Built Environment

Back in the summer of 2012, Nicola Twilley and I got to visit the headquarters of GPS, out at Schriever Air Force Base in Colorado.

[Image: Artist’s rendering of a GPS satellite, via Wikipedia].

“Masters of Space”

Over the course of a roughly two-hour visit, we toured, among other things, the highly secure, windowless office room out of which the satellites that control GPS are monitored and operated. Of course, GPS–the Global Positioning System—is a constellation of 32 satellites, and it supplies vital navigational information for everything from smartphones, cars, and construction equipment to intercontinental missiles.

It is “the world’s largest military satellite constellation,” Schriever Air Force Base justifiably boasts.

For somewhat obvious reasons, Nicola and I were not allowed to bring any audio or video recording devices into the facility (although I was able to take notes), and we had to pass through secure checkpoint after secure checkpoint on our way to the actual room. Most memorable was the final door that led to the actual control room: it was on a 15-second emergency response, meaning that, if the door stayed open for more than 15 seconds, an armed SWAT team would arrive to see what was wrong.

When we got inside the actual office space, the lights were quite low and at least one flashing red light reminded everyone inside that civilians were now present; this meant that nothing classified could be discussed. Indeed, if anyone needed to hop on the telephone, they first needed to shout, “Open line!” to make sure that everyone knew not to discuss classified information, lest someone on the other end of the phonecall might hear.

Someone had even made a little JPG for us, welcoming “Geoff Manaugh and Nicola Twilley” to the GPS HQ, and it remained on all the TV monitors while we were there inside the space.

[Image: Transferring control over the GPS constellation. Photo courtesy U.S. Air Force/no photographer given].

Surreally, in a room without windows, a group of soldiers who, on the day we visited, were all-male and looked no more than 23 or 24 years old, wore full military camouflage, despite the absence of vegetation to blend into, as they controlled the satellites.

At one point, a soldier began uploading new instructions to the satellites, and we watched and listened as one of those artificial stars assumed its new place in the firmament. What would Giordano Bruno have made of such a place?

This was the room behind the curtain, so to speak, a secure office out of which our nation’s surrogate astronomy is maintained and guided.

Appropriately, they call themselves “Masters of Space.”

[Image: A “Master of Space” badge from Schriever Air Force Base].

In any case, I mention all this for at least two reasons:

A 50,000km-Wide Dark Matter Detector

Edge to edge, the GPS constellation can apparently be considered something of a single device, a massive super-detector whose “time glitches” could be analyzed for signs of dark matter.

As New Scientist explained last month, “The network of satellites is about 50,000 kilometers in diameter, and is traveling through space—along with the entire solar system—at about 300 kilometers a second. So any time shift when the solar system passes through a cosmic kink will take a maximum of 170 seconds to move across network.”

The temporal distortion—a kind of spacetime wave—would propagate across the constellation, taking as long as 170 seconds to pass from one side to the other, leaving forensically visible traces in GPS’s navigational timestamps.

The very idea of a 50,000-kilometer wide super-device barreling through “cosmic kinks” in spacetime is already mind-bogglingly awesome, but add to this the fact that the “device” is actually an artificial constellation run by the U.S. military, and it’s as if we are all living inside an immersive, semi-weaponized, three-dimensional spacetime instrument, sloshing back and forth with 170-second-long tides of darkness, the black ropes of spacetime being strummed by the edges of a 32-point star.

Even better, those same cosmic kinks could theoretically show up as otherwise imperceptible moments of locational error on your own smartphone. This would thus enlist you, against your knowledge, as a minor relay point in a dark matter detector larger than the planet Earth.

The Architectural Effects of Space Weather

While Nicola and I were out at the GPS headquarters in Colorado, one of the custodians of the constellation took us aside to talk about all the various uses of the navigational information being generated by the satellites—including, he pointed out, how they worked to mitigate or avoid errors.

Here, he specifically mentioned the risk of space weather affecting the accuracy of GPS—that is, things like solar flares and other solar magnetic events. These can throw-off the artificial stars of the GPS constellation, leading to temporarily inaccurate location data—which can then mislead our construction equipment here on Earth, even if only by a factor of millimeters.

What’s so interesting and provocative about this is that these tiny errors created by space weather risk becoming permanently inscribed into the built environment—or fossilized there, in a sense, due to the reliance of today’s construction equipment on these fragile signals from space.

That 5mm shift in height from one pillar to the next would thus be no mere construction error: it would be architectural evidence for a magnetic storm on the sun.

Take the Millau Viaduct—just one random example about which I happen to have seen a construction documentary. That’s the massive and quite beautiful bridge designed by Foster + Partners, constructed in France.

[Image: The Millau Viaduct, courtesy of Foster + Partners].

The precision required by the bridge made GPS-based location data indispensable to the construction process: “Altimetric checks by GPS ensured a precision of the order of 5mm in both X and Y directions,” we read in this PDF.

But even—or perhaps especially—this level of precision was vulnerable to the distorting effects of space weather.

Evidence of the Universe

I have always loved this quotation from Earth’s Magnetism in the Age of Sail, by A.R.T. Jonkers:

In 1904 a young American named Andrew Ellicott Douglass started to collect tree specimens. He was not seeking a pastime to fill his hours of leisure; his motivation was purely professional. Yet he was not employed by any forestry department or timber company, and he was neither a gardener not a botanist. For decades he continued to amass chunks of wood, all because of a lingering suspicion that a tree’s bark was shielding more than sap and cellulose. He was not interested in termites, or fungal parasites, or extracting new medicine from plants. Douglass was an astronomer, and he was searching for evidence of sunspots.

Imagine doing the same thing as Andrew Ellicott Douglass, but, instead of collecting tree rings, you perform an ultra-precise analysis of modern megastructures that were built using machines guided by GPS.

You’re not looking for lost details of architectural history. You’re looking for evidence of space weather inadvertently preserved in titanic structures such as the Millau Viaduct.

[Image: The Millau Viaduct, courtesy of Foster + Partners].

Fossils of Spacetime

If you take all of this to its logical conclusion, you could argue that, hidden in the tiniest spatial glitches of the built environment, there is evidence not only of space weather but even potentially of the solar system’s passage through “kinks” and other “topological defects” of dark matter, brief stutters of the universe now fossilized in the steel and concrete of super-projects like bridges and dams.

New Scientist points out that a physicist named Andrei Derevianko, from the University of Nevada at Reno, is “already mining 15 years’ worth of GPS timing data for dark matter’s fingerprints,” hoping to prove that GPS errors do, indeed, reveal a deeper, invisible layer of the universe—but how incredibly interesting would it be if, somehow, this same data could be lifted from the built environment itself, secretly found there, inscribed in the imprecisions of construction equipment, perhaps detectable even in the locational drift as revealed by art projects like the Satellite Lamps of Einar Sneve Martinussen, Jørn Knutsen, and Timo Arnall?

The bigger the project, the more likely its GPS errors could be read or made visible—where unexpected curves, glitches, changes in height, or other minor inaccuracies are not just frustrating imperfections caused by inattentive construction engineers, but are actually evidence of spacetime itself, of all the bulging defects and distortions through which our planet must constantly pass now frozen into the built environment all around us.

(Very vaguely related: One of my personal favorite stories here, The Planetary Super-Surface of San Bernardino County).

Drive-By Archaeology

[Image: From a patent filed by MIT, courtesy U.S. Patent and Trademark Office].

The technical systems by which autonomous, self-driving vehicles will safely navigate city streets are usually presented as some combination of real-time scanning and detailed mnemonic map or virtual reference model created for that vehicle.

As Alexis Madrigal has written for The Atlantic, autonomous vehicles are, in essence, always driving within a virtual world—like Freudian machines, they are forever unable to venture outside a sphere of their own projections:

The key to Google’s success has been that these cars aren’t forced to process an entire scene from scratch. Instead, their teams travel and map each road that the car will travel. And these are not any old maps. They are not even the rich, road-logic-filled maps of consumer-grade Google Maps.
They’re probably best thought of as ultra-precise digitizations of the physical world, all the way down to tiny details like the position and height of every single curb. A normal digital map would show a road intersection; these maps would have a precision measured in inches.

The vehicle can thus respond to the city insofar as its own spatial expectations are never sufficiently contradicted by the evidence at hand: if the city, as scanned by the vehicle’s array of sensors and instruments, corresponds to the vehicle’s own internal expectations, then it can make the next rational decision (to turn a corner, stop at an intersection, wait for a passing train, etc.).

However, I was very interested to see that an MIT research team led by Byron Stanley had applied for a patent last autumn that would allow autonomous vehicles to guide themselves using ground-penetrating radar. It is the subterranean realm that they would thus be peering into, in addition to the plein air universe of curb heights and Yield signs, reading the underworld for its own peculiar landmarks.

[Image: From a patent filed by MIT, courtesy U.S. Patent and Trademark Office].

How would it work? Imagine, the MIT team suggests, that your autonomous vehicle is either in a landscape blanketed in snow. It is volumetrically deformed by all that extra mass and thus robbed not only of accurate points of measurement but also of any, if not all, computer-recognizable landmarks. Or, he adds, imagine that you have passed into a “GPS-denied area.”

In either case, you and your self-driving vehicle run the very real risk of falling off the map altogether, stuck in a machine that cannot find its way forward and, for all intents and purposes, can no longer even tell road from landscape.

[Image: From a patent filed by MIT, courtesy U.S. Patent and Trademark Office].

Stanley’s group has thus come up with the interesting suggestion that you could simply give autonomous vehicles the ability to see through the earth’s surface and scan for recognizable systems of pipework or other urban infrastructure down below. Your vehicle could then just follow those systems through the obscuring layers of rain, snow, or even tumbleweed to its eventual destination.

These would be cars attuned to the “subsurface region,” as the patent describes it, falling somewhere between urban archaeology and speleo-cartography.

In fact, with only the slightest tweaking of this technology and you could easily imagine a scenario in which your vehicle would more or less seek out and follow archaeological features in the ground. Picture something like an enormous basement in Rome or central London—or perhaps a strange variation on the city built entirely for autonomous vehicles at the University of Michigan. It is a vast expanse of concrete built—with great controversy—over an ancient site of incredible archaeological richness.

Climbing into a small autonomous vehicle, however, and avidly referring to the interactive menu presented on a touchscreen dashboard, you feel the vehicle begin to move, inching forward into the empty room. The trick is that it is navigating according to the remnant outlines of lost foundations and buried structures hidden in the ground around you, like a boat passing over shipwrecks hidden in the still but murky water.

The vehicle shifts and turns, hovers and circles back again, outlining where buildings once stood. It is acting out a kind of invisible architecture of the city, where its routes are not roads at all but the floor plans of old buildings and, rather than streets or parking lots, you circulate through and pause within forgotten rooms buried in the ground somewhere below.

In this “subsurface region” that only your vehicle’s radar eyes can see, your car finds navigational clarity, calmly poking along the secret forms of the city.

In any case, for more on the MIT patent, check out the U.S. Patent and Trademark Office.

(Via New Scientist).

Loop Geography as Defensive Tactic

In a fascinating detail from a long series of articles published two years ago in the Washington Post, recently expanded as a stand-alone book called Top Secret America, we learn about one way to hide classified government infrastructure in plain sight.

[Image: Photo by Michael S. Williamson, courtesy of The Washington Post].

“[J]ust outside Washington,” authors Dana Priest and William Arkin explain, in the exurbs of depopulated office parks and “huge buildings with row after row of opaque, blast-resistant windows,” there can be found what the authors describe as “the capital of an alternative geography of the United States, one defined by the concentration of top-secret government organizations and the companies that do work for them.”

One such complex, called Fort Meade, “is the largest of a dozen such clusters across the United States.”

And it is cleverly camouflaged:

The existence of these clusters is so little known that most people don’t realize when they’re nearing the epicenter of Fort Meade’s, even when the GPS on their car dashboard suddenly begins giving incorrect directions, trapping the driver in a series of U-turns, because the government is jamming all nearby signals.

It’s an experiential trap street—an infinite loop—a deliberate cartographic error introduced into the mapping of the world so as to sow detour and digression. A kind of digital baffling, or recursive geography as state defensive tactic.

I’m also curious when we might see this privatized and domesticated—gated communities, for instance, blocking the GPS navigation of their streets in the misguided belief that this will help protect them from future burglary, effectively delisting themselves from public cartographic records. Perhaps the future of neighborhood security lies in the privatized repurposing of advanced signal-jamming technology, the misleading lamination of other, false maps onto the streets as they really exist.

(Detail spotted via @doingitwrong and [thisisaaronland]).