45. How to make electronic navigation more engaging - and rewarding

Many navigators are worried about the consequences of our increasing reliance on automatic navigation systems - especially the ‘turn-by-turn’ apps based on GPS that are now embedded in every cell phone and every vehicle.

There’s plenty of evidence (which I discuss in Incredible Journeys/Supernavigators) that the passive use of these apps impedes the development of the mental maps that enable us to find our way around most efficiently.

There are even those who think that we may endanger our overall cognitive health by using them too much. And there’s no doubt that these apps impoverish our lives by discouraging us from taking an active interest in the world around us.

But nobody seriously thinks we can turn the clock back. Navigational apps are here to stay because they make life so much easier - and sometimes (though not always) safer.

The question is whether they can be tweaked so as to reduce or eliminate some of their drawbacks.

An interesting new study (Clemenson, G.D., Maselli, A., Fiannaca, A.J. et al. Rethinking GPS navigation: creating cognitive maps through auditory clues. Sci Rep 11, 7764 (2021). https://doi.org/10.1038/s41598-021-87148-4) examines the virtues of a different kind of app - one that does seem to help people develop a better grasp of the layout of their surroundings.

Instead of relying on the usual turn-by-turn directions, some participants in the new study followed a virtual, auditory compass (based on the Soundscape app - originally designed for visually-impaired users) in order to locate various goals dotted around the Microsoft campus. The compass indicated the straight-line route to each goal, and the user then had to navigate actively around any obstacles (like buildings) that stood in the way.

The authors acknowledge that the sample size was small, but they insist that - in contrast to a standard turn-by-turn app - the Soundscape virtual compass helped participants who were new to the campus develop a better sense of its geography.

They argue that “using auditory beacons to navigate can lead to greater explorative behavior and the formation of more accurate mental maps of the surrounding environment when compared to turn-by-turn navigation. Thus, demonstrating that it is possible to use GPS technology and promote learning through active navigation.”

They conclude that an auditory beacon is “a sensory augmentation that helps us create a stronger connection with our environment.”

This is a promising development, and I hope we’ll soon see more research of this kind. But I wonder whether the mass market navigational platforms will take heed of the new findings - and whether users are ready to embrace a more active approach to navigation than they have got used to. We’ll have to wait and see.

37. The coming of GPS

When I set sail from Halifax, Nova Scotia, in late July 1973, to cross the Atlantic, there was only one reliable way to navigate a small boat across an ocean.

You had to use a sextant to measure the heights of the sun and stars above the horizon. You also needed a chronometer to determine the exact time of each sextant sight.  With these two bits of information, a Nautical Almanac and some sight reduction tables, you could plot your position on a chart. If you were skilful and the conditions were favourable, the fix might be accurate to within a few miles.  

Celestial navigation had changed little since the days of the great voyages of scientific discovery in the second half of the 18th century.

By coincidence it was also in 1973 that the US military began developing the satellite navigation system we now know as GPS.  It wasn’t the first such system but it represented a major step forward in terms of accuracy and sophistication.  And it was a really amazing technical achievement.  

At its heart is a network of satellites in precisely determined orbits each carrying their own atomic clocks.  GPS receivers pick up the faint signals from these satellites and use them to fix their positions in three dimensions.

Of course I knew nothing of these developments.  I suppose I may have been dimly aware that the US military were already using some kind of satellite navigation – as indeed they were – but the Cold War was still very much in progress and such technology was highly sensitive.  That was to change when the Iron Curtain was lifted in 1989 and the Soviet Union fell apart.  

GPS was publicly available in the 1990s and in 2000 some controls were lifted so that the public had access to even better positional information.  Anyone who could buy a GPS receiver could now fix his or her position to within a few meters anyway on the surface of the earth. It was quite incredible at first but it soon became routine and familiar.

Since 2000, as the price (and size) of GPS receivers has dropped, this astonishing navigational technology has swept the board.  It’s everywhere: in our mobile phones, our cars, in planes and of course in boats.  We can even put GPS transponders in our valuables or on our children so that we can keep track of where they are!  

And now there are other satellite navigation systems besides GPS: notably the Russian GLONASS; China’s BEIDOU; and the European Union’s GALILEO. Collectively these are known as Global Navigation Satellite Systems or GNSS.

GNSS has made life much easier and, in many ways, much safer.  But it has its shortcomings.  First of all, it’s very vulnerable to interference and can easily be jammed.  Secondly, it’s quite easy to ‘spoof’ the GNSS signals and persuade a receiver that it’s somewhere where it’s not. For these reasons – and others – robust backup systems are badly needed.  One possibility is LORAN – an old radio-based navigation system developed in World War II.

Of course the most robust alternative to GNSS is the good old sextant.  It doesn’t even need electricity. But while many offshore sailors still study the principles of celestial navigation, very few make regular use of it. For most it is only a back-up system, to be called on in the supposedly unlikely event that GNSS fails.

The trouble is that celestial navigation is a skill, and like all skills it requires practice. I wonder how many offshore sailors could actually fix their position with a sextant if they had to do so in a hurry?

But leaving aside questions of safety, one of the sad consequences of the dominance of GNSS is that few people now learn how rewarding the practice of celestial navigation can be.

As I wrote in my book Sextant:

‘It is time to rediscover the joys of celestial navigation, not merely as a safety net, but because using a sextant to find our way puts us into the closest possible touch with the natural world at its most sublime.’

That’s still true, of course, but I don’t think many people are following my advice. Pushing buttons is just too easy.

35. How do you navigate in deep space?

Earth-bound navigation mostly relies on local, terrestrial cues - like landmarks, the geomagnetic field, smells, sounds and so on. But, as we’ve seen, many animals - including us humans - also make use of the sun, moon and stars.

The history of human celestial navigation (the subject of my book, Sextant) is the story of how astronomers, mathematicians and instrument-makers down the centuries gradually improved the accuracy with which we could predict and measure the positions of heavenly bodies.

By the mid-eighteenth century their combined efforts meant that it was at last possible to determine a ship’s position on the open ocean using these techniques - to within a few miles (in good conditions).

But what if you’re trying to track the position of a space vehicle travelling at great speed across the Solar System or even beyond?

You can fix your position in space by reference to the stars - just as you can on the surface of the earth - but there is a problem.

Many of the brightest stars are close neighbours (cosmically speaking) and, though they may appear to be stationary, they actually move in complicated ways. If you want to navigate really accurately you have to factor in their motion, but that’s difficult unless you have a stable frame of reference against which to measure it.

So what you need is a set of heavenly bodies so extremely distant that they really don’t move at all.

Enter quasars. These extraordinary objects are among the most powerful sources of energy in the whole universe, and are almost certainly supermassive black holes at the hearts of other galaxies.

A single quasar can generate as much energy as the entire Milky Way - which consists of hundreds of billions of stars. In fact they are so powerful that astronomers can detect them even when they are tens of billions of light years away - on the far side of our expanding universe.

Quasars then offer the perfect solution to this navigational problem.

A new set of observations from a star-mapping satellite called Gaia now includes 1.6 million quasars, as well as a billion stars that are much, much closer to us. The quasars enable astronomers to determine with exquisite precision the velocities of the nearer stars on which super-accurate navigational calculations can then be based. (Here’s a link to a mesmerising animation showing the complex patterns of ‘proper motion’ displayed by stars in the Milky Way - based on on observations from Gaia.)

The Gaia observations furnish the most accurate celestial frame of reference yet devised.

In addition to enabling accurate deep space navigation, the Gaia observations also play a valuable role in improving the accuracy of earthbound satellite navigation systems - like GPS.

If you want to know more, read this excellent recent article in the journal Science by Joshua Sokol.