Wednesday, July 14, 2010

Unnatural Natural Navigation

My friend Tristan teaches a great course all about how to navigate naturally. Recently for example he has been posting on his blog about using lichens to find direction, in particular in a graveyard.

Natural navigation is all about finding your way by looking for signals in the natural environment around you rather than just switching on a GPS to get a fix. Its a great idea, not just because there are times when you can't get GPS but also because it enhances the experience of being out in the open air on this great planet Earth.

However I also thought there was another category, an example of which was navigation using satellite antenna. In the UK most of the residential small dishes point roughly south-south-east: indeed it is impossible for a fixed (i.e. not steerable) antenna not to be pointing somewhere south, just as in Australia they must be pointing somewhere north. In Venezuela near the equator things are very different and they must point somewhere east or west, such is the geometry of the geostationary arc.

This I decided to call unnatural natural navigation, in that you created navigational information by looking at the world around you, but in this case at something man made.

And last week out on Thames I identified another example of U-NN. As is well known the Thames in London wiggles, with downstream anything from north-north-west through east to south. This can get very confusing, and sometimes one does wonder which way one is facing, particularly on those rare (ah-hm) days when its cloudy.

The answer can be found in the sky, where the aircraft heading to London Heathrow go in a dead straight line west. So you can use that to work out which way you're heading in a trice, just by looking up. The pic above by the way is from a rather humid day when the lower pressure above the aircraft's wing was just enough to get that cloud to form.

Of course this navigational technique isn't quite up to the skills on display by the Warao people of the Orinoco Delta of Venezuela.

But then I suspect they see a lot less aircraft. If they lived under the Heathrow flight path then who knows - maybe they'd have developed this technique instead!


Tillerman said...

I must admit that whenever I am in a town on a river or lake or by the sea, I tend to use the water as a direction finder. It works in most places, even if you can only get occasional glimpses of the water. But, as you say, it can totally bamboozle you in London as I discovered when running the marathon and wrote about in

Using the satellite dishes is a clever one. Never thought of that before.

O Docker said...

There are the semi-mythical stories of people in small boats who have navigated from California to Hawaii by following the contrails in the sky as almost all southbound planes over that patch of water are headed towards the islands.

Baydog said...

Whenever I'm in bumper to bumper traffic on the Garden State Parkway at 5:00 p.m. on Sunday, I know for certain I'm heading due North!

Tristan said...

Hi John,

Thanks for the mention again.

Not sure if you spotted it, but the satellite dish method is in my book. This is a good example of a 'compass' you reset each time you arrive in a new town.

Just to add another angle to the aircraft one, high aircraft over the UK tend to be either heading southeast or northwest. Not always, but on average that is the 'prevailing' direction.



JP said...

Tristan: yes I remember! It's actually a useful pointer when you come out of the tube and know you have to go down the road but don't know which way is south/north or east/west.

O'Docker: What Tristan probably also remembers is that during the Arc there were large chunks with no planes overhead, so that particular offshore navigation technique was unavailable.

Tillerman: yup, can be very disorientating. I think as a marathon runner you probably had enough to focus on as it was.

Baydog: and it's a useful tip on public transport here too: look at the trains and the direction where they are full tells you which way is London!