Where are we?

Knowing where you are is crucial, whether you're a British Royal marine patrolling the vaguely demarcated waters at the head of the Persian Gulf, or a prospector who's just discovered a mother lode.

A handheld GPS unit gives the position of a ship on the Shatt Al Arab waterway. The satellite navigation system used to be rendered deliberately imprecise by the U.S. military, for national security reasons. President Clinton ordered it unscrambled in 2000.

These days, you reach for your handheld global positioning system (GPS) device before you shout "gold" or "stand by to be boarded."

Farmers use GPS to steer combine harvesters and tractors; prison guards track escapees, and famously -or infamously - the U.S. military uses it to send "smart" bombs hurtling into their targets.

A cruise missile programmed to know where it's going can be a daunting weapon. GPS units sit on the dashboards of taxis in Europe and long-distance trucks around the world. A stricken trucker can call for help on a cellphone and tell mechanics or the police where his rig has broken down. Rescuers program GPS co-ordinates into their units and drive right to the spot.

Airlines stick to carefully predetermined routes, guided by satellite and autopiloted by computers.

False co-ordinates from space

It's chilling then, to realize that GPS technology is far from infallible. You may not be where you think you are.

Something as simple as replacing the dry-cell batteries in a GPS unit can addle the machine into reverting to false co-ordinates. Wrong locations can be plugged into perfectly functional GPS devices. Garbage in, garbage out.

In fact, the United States Defence Department, which owns the global positioning system, used to make it deliberately imprecise so that America's enemies weren't able to take advantage of U.S. technology. President Clinton ordered an end to the military's limiting of the system for civilian use in 2000. Russia, China and the European space agency are all working on their own versions of the GPS satellite network, just in case the U.S. ever goes back on Clinton's generosity.

It's not as if there wasn't any way to know where you were before GPS. In those not-too-distant days when the sky wasn't criss-crossed with direction-finding satellites, voyagers used their eyes and their mathematical abilities to make their way around the world.

Maps helped too, though early attempts at cartography left much to be desired. Mapmakers tended to cover their ignorance of distant territory by inscribing the words "here abide monsters" or positing imaginary lands.

These days, every square centimetre of Earth is intimately mapped, and if the GPS ever fails, we can fall back on maps and compasses.

Ancient grids

It was the ancient Greeks who first divided the world into grids of longitude and latitude. Methods of actually measuring these imaginary lines took a while longer.

Albert Einstein used his intellect and advanced mathematics to make radical changes to the way we perceive time, space and location. He won the Nobel Prize in Physics in 1922.

Fixing the horizontal position of a ship at sea was easy enough, using the sun and stars. But locating the vessel on a north-south axis had to wait until the British clockmaker John Harrison invented a timepiece that wasn't affected by weather or humidity — the naval chronometer.

A ship's captain would "fix" his position with an instrument called a sextant that helped compare the position of the sun at noon with Greenwich Mean Time, wherever he was in the world. This revolutionized exploration and commerce. British and other European fleets roamed ever farther.

Before that, indigenous navigation systems flourished among local people. The Vikings and Basques found Newfoundland; Polynesian islanders explored the vast reaches of the Pacific Ocean in flimsy canoes. They followed migratory birds and tested the salinity of ocean currents by tasting the water. Oral histories of the surface of the sea passed between generations of navigators from Tahiti to Hawaii. Eventually, European colonialism, and compasses, displaced traditional knowledge. Polynesians learned about latitude and longitude.

A place in time and space

Ancient mariners spent most of their time at sea level, so altitude was a given. But land exploration needed a third dimension — height. Barometers had been around since the 1600s, but it wasn't until Europeans began measuring and mapping the planet in earnest 200 years later that the surface of the Earth came to be fully measured in 3-D.

Observation of outer space and the development of theoretical physics added more complex notions to the idea of location. Einstein's theories of relativity told us that time itself was a dimension. When was an element of where; so was the perpetual motion of the Earth relative to the sun, of our solar system relative to others and so on. Time could be bent, or made to stand still. So could space. It was all relative.

There are also scientists who theorize that the deep void between the stars is home to dimensional wrinkles that render traditional notions of location utterly meaningless. Try wormholes, string theory, dark energy and loop quantum gravity. Then try to figure out where you are.

Cyberspace: data as physical reality

A little more substantial, but no less confusing, is the sense of place that comes from one's internet activity. For make no mistake, the internet has context, substance and precise locations with co-ordinates of intersecting data streams. It's a binary world of the sort imagined by the Vancouver science fiction writer, William Gibson.

He's the man who came up with the word "cyberspace." Protagonists in his early work saw the data world as a physical reality. They "jacked-in" to computer networks through wires attached to their brains. They hacked and debugged, moving as virtual beings through a matrix of light and interconnected data banks.

No surprise then, that Gibson's prescient writing inspired some of the men and women who built the internet. It's no longer science fiction to see the net and the web as physical places where users occupy locations and follow pathways in ever broadening quests for information and fulfilment.

There have been several serious attempts to map the internet. Most flag after several years, because of the exponential growth of online infrastructure, and the inadequacy of geographic terms and tools in such a multi-dimensional, virtual world.

Where you are also depends on where you're logged in. And a whole lot else besides.