Trajectories II


What if you could only move by copying yourself, leaving a string of 'you’s' behind? You could never occupy the same place again since a former you is already there.


What paths do we follow across and above the surface of the Earth? Do we have the freedom to create new routes, or are we bound to follow rivers, ocean currents, wind directions, paved roads, highways, 5G and the internet? Often, the unnoticed oddities of your own behavior become apparent when comparing it to the behavior of strangers. Like when you move to another country, and suddenly see habits you were not even aware of in a new light. Therefore, I questioned my own surface-dwelling trajectories, by comparing the paths of myself and my partner at the time, to the paths of two seagulls, aided by the GPS devises of Professor Willem Bouten (UvA-IBED). Image: Cees Camphuizen, UvA.

This story was shared at FLAM II


The two gulls make seemingly random round trips, which look like they could have been drawn with a pencil, which gives the impression that they have a lot of freedom. Sometimes, their paths are shaped by tidal currents and the wind, when they are floating on the sea.

The human beings move around differently: they spend a lot of time at one place, their homes, during the night, and then they move to another location, in this case science park, during the day, and they always take the same, shortest pre-paved routes, which seems less free.


Both the seagull and the human trajectories are influenced by some predictable boundary conditions: diurnal rhythms, paved roads, wind and sea currents. But in the end, many of the factors that shape their paths are ultimately so complex that you cannot predict them. What freedom do they have in deciding where they will go? I never found out, and probably I will never know. What I did learn from this research project however is that seagulls and human beings sometimes need to find new paths, and move across oceans to find new territories, or they need to stay behind alone to find new routes in their minds.


Walking around each others horizon

This drawing is an invitation to walk around each others horizon.

Distance to the horizon Ignoring the effect of atmospheric refraction, distance (d) to the true horizon from an observer close to the Earth's surface is about:

d = squareroot(2·h·R)

where h is height above sea level (your eye-height) and R is the Earth radius (6.371 km)

In my case, d = ~5km away.

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