Very basic: for any kind of map making we need a stable reference. Some point that we are sure of where exactly it is, so we can relate other positions and measurements to this reference.
Come to think of it, we all need a stable reference.
For daily routines, just getting up and around.
Being social. Living.
And in academia, where I also spend some time, we use references to back up a position and make sure our aim is right
This project has taught me something about how difficult it can be to attain a stable and precise reference, and how much work it is to maintain it
The reference attained by VLBI is used to calibrate all satellite navigation systems, and so is the basis for the commonly used GPS system. Furthermore it is used for environmental monitoring and as such can be seen as one of the things that may help us sustain human life on planet earth into the future. If we take the signals from nature seriously, that is.