  I consider the question posed to me by the scientific organisers of the
conference, "Are the modern computer simulations a substitute for physical
models? The SKA case." I briefly consider the current knowledge of computer
simulations and of physical prototypes in the context of understanding
interferometric radio telescopes. My conclusion is that, "no, computer
simulations are not a substitute for physical models when it comes to
understanding the SKA.....furthermore, physical models are not much help
either." This conclusion is intentionally provocative, designed to promote some
discussion at the conference, which it did. However, the conclusion reflects my
belief that we do not have a deep enough understanding, theoretical or
practical, of how interferometry works, to determine if the SKA will meet the
stated specifications or not. I conclude that we need to adopt a qualitatively
different approach to dealing with interferometric data. I note that some good
work is being done on this front, but it is likely a bigger effort is needed in
the SKA era. This is exactly the type of innovation that projects such as the
SKA should encourage.
