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Have Clock, Will Travel

by LiveModern Webmaster last modified Jun 29, 2019 01:08 AM
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by Geoff Manaugh (noreply@blogger.com) last modified Jun 28, 2019



 

 

[Image: From The Hunt For Red October, via Quora].

There’s a throwaway line in The Hunt For Red October where a submarine navigator jokes, “Give me a stopwatch and a map, and I’ll fly the Alps in a plane with no windows.” I was reminded of that comment by reports of a new atomic clock that will allegedly enable “futuristic navigation schemes”:
“Every single spacecraft exploring deep space today relies on navigation that’s performed back here at Earth,” said [Jill] Seubert, who’s based at NASA’s Jet Propulsion Laboratory in Pasadena, Calif. Earth-based antennas send signals to spacecraft, which the spacecraft echo back. By measuring a signal’s round-trip time within a billionth of a second, ground-based atomic clocks in the Deep Space Network help pinpoint the spacecraft’s location.

With the new Deep Space Atomic Clock, “we can transition to what we call one-way tracking,” Seubert said. A spaceship would use such a clock onboard to measure the time it takes for a tracking signal to arrive from Earth, without having to send that signal back for measurement with ground-based atomic clocks. That would allow a spacecraft to judge its own trajectory.
One might say that the ship is navigating time as much as it is traveling through space—steering through the time between things rather than simply following the lines that connect one celestial object to another.

The general problem of ship orientation and navigation in deep space is a fascinating one, and it has led to ideas like using “dead stars” as fixed directional beacons, a kind of thanato-stellar GPS. This is “the long-sought technology known as pulsar navigation,” Nature reported last year. “For decades, aerospace engineers have dreamed of using these consistently repeating signals for navigation, just as they use the regular ticking of atomic clocks on satellites for GPS.” You head toward something that’s only consistent because it’s dead.

There is something really interesting here, where human navigators and their far-flung machines are confronted with a landscape so vast it is all but devoid of local landmarks. Imagine the cognitive skills necessary for early humans to wander forth, on foot, across colossal and empty steppes, long before modern navigational tools, or picture autonomous, near-frozen hard-drives falling endlessly outward toward stars they might never reach: these scenarios lend themselves to metaphor just as much as they present real-world cartographic problems masked as an encounter with landscapes impossibly huge.

A landscape so big it becomes time, and only a clock can conquer it; or a space so empty, its only fixed points are long dead.

 

 

 
 
 
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