Lost in Space?

Super-Navigational Charts

Physicists often speculate about the possibility of instantaneous travel through space––in effect faster than light travel, creating the kind of galaxy loved by science fiction writers. But achieving that by itself will avail us little. For there will be a need, if they succeed, for an entirely kind of chart of the skies. All of today's charts of the night sky, including NASA's super-charts consisting of many CD-roms, would be almost useless for interstellar travel. For they are all two-dimensional. The charts only tell you what the sky looks like from Earth. Because no one has been into deep space to take photographs, they can give no hint of what one part of space would look like from another part of space.

An electron star chart allows one to 'zoom in'

With an electronic star chart, one can of course ``zoom in'' to get a detailed view of any desired part of the sky. But one cannot, from this vantage point, ``turn around'' and look back at the Solar System from afar. The view is always outward-facing and two-dimensional. Isaac Asimov, in his fifties novel Second Foundation, presented the idea of a three-dimensional star chart called the Lens that faster-than-light starship captains used for navigation before and after making their `jumps' through hyperspace. ``This is how Pellot's Nebula looks from Trantor," says a space captain, demonstrating the ``newest feature of the interstellar cruisers of the day.'' The Lens would of course consist of computer software, since no conceivable printed atlas could handle such gigantic quantities of information. With up to 400 billion stars in our galaxy, the software would need to know what the night sky looked like from the vicinity of each star––and any point between any of them–– and how far every star was from every other. The Lens would solve the problem which has both plagued and fascinated many serious science fiction writers: what should a ship's captain do when he is lost in space? Instead of waiting to die, he simply says to the Lens computer: ``This is the view from my forward window. Where am I?'' The Lens would respond like the picture books that yachtsmen used before the days of global positioning satellites, where you discover what shore you had approached by checking countless images of coastline mountain ranges against what could be seen. It would search through its huge database and announce: ``There is a 98 percent probability that your galactic coordinates are such-and-such.'' The coordinates themselves present quite another problem. For in a three-dimensional galaxy, points of direction like north and south (or right ascension and celestial longitude) are quite useless. Something of the nature of ``up'' and ``down'' will have to be added. But what if no means of instantaneous travel is ever found, and speeds must be less than that of light? Then, at high speeds through normal space, the effects of special relativity would distort the entirety of space, making the Lens useless at the very moment when it was most needed. So don't let's start writing that complicated software just yet.