Last week I was up in Lancashire for the Mobilities Futures conference at Lancaster University. Mobilities has been brewing in the periphery of my awareness for a couple of years now, so it was great to get a chance to immerse myself in so many interesting streams of thinking.
The session was based around a small group of people wearing the sashes walking in a loose group, in silence, around the campus for about an hour. Naturally it started to chuck it down with rain just as the workshop started…
A quick redux for those that weren’t there: the sashes are connected by a mesh radio network, all receiving broadcasts from a central node. This central node is monitoring GPS data to get a measure of inaccuracies. These inaccuracies can be caused by many different things, but typically multipath error is the main candidate:
The multipath effect is caused by reflection of satellite signals (radio waves) on objects. It was the same effect that caused ghost images on television when antennae on the roof were still more common instead of today’s satellite dishes.
For GPS signals this effect mainly appears in the neighbourhood of large buildings or other elevations. The reflected signal takes more time to reach the receiver than the direct signal. The resulting error typically lies in the range of a few meters.http://www.kowoma.de/en/gps/errors.htm
Once it has a value for the degree of error, the central node then broadcasts instructions for the sashes to vibrate in a particular pattern. Thus the general pattern is that the more built up or undercover an area is, the greater the extent of error induced into the GPS data and the more the sashes vibrate.
In open areas people wearing a sash would typically feel a gentle pulse every 30 seconds or so. In areas where there is not such a clear view of open sky, the sashes vibrate for longer and more intensely.
Being a fairly miserable Friday morning outside of term time, there weren’t many people out and about on campus as we drifted around. We were smiled at a few times and some of us were asked either for directions or if we needed directions.
The latter points to something interesting. Most of our sashes were covered up by coats in order to protect the electronics: in the absence of this signifier, the way in which we were moving slowly marked us out as being slightly different.
Afterwards, one of the participants – someone who works on the campus – commented on this change of speed and the opportunity it gave for reflective thought.
A few others too reported on how their thoughts wandered at different times. The vibrations from the sashes come through every 20 to 30 seconds and they’re pitched at a moderate level so that they’re there as a sense to tune into if you wish, but they also fade into the background if not.
At the end of the session we were able to take a quick look at a chunk of data rendered visually. After trying to relate the lines back to the landscape and the journey we’d made I then transferred the data to Google Earth. Ah! That’s where that happened!
I’ve made an A4 poster of all of the data from that day (the workshop and a test walk I did earlier in the morning) for you to download and print.
You can also download this .kml file for viewing in Google Earth if you’d like to see the data superimposed over imagery of the landscape.
My (somewhat grey and dingy) photos from the workshop are in this Flickr set.
Many thanks to the conference organisers, the workshop participants and everyone else at Mobilities Futures for a very interesting few days.