Given statements emanating from some cosmologists today one could be forgiven for assuming that the solution to some of the great problems of the subject, even ``the origin of the Universe'' lie just around the corner. As an example of this triumphalist approach consider the following conclusion from Hu et al. [1] to a preview of the results they expect from spacecraft such as MAP and PLANCK designed to map the Cosmic Background Radiations: ``. . . we will establish the cosmological model as securely as the Standard Model of elementary particles. We will then know as much, or even more, about the early Universe and its contents as we do about the fundamental constituents of matter''.
We believe the most charitable thing that can be said of such statements is that they are naive in the extreme and betray a complete lack of understanding of history, of the huge difference between an observational and an experimental science, and of the peculiar limitations of cosmology as a scientific discipline. By building up expectations that cannot be realised, such statements do a disservice not only to astronomy and to particle physics but they could ultimately do harm to the wider respect in which the whole scientific approach is held. As such, they must not go unchallenged.
It is very questionable whether the study of any phenomenon that is not repeatable can call itself a science at all. It would be sad however to abandon the whole fascinating area to the priesthood. But if we are going to lend this unique subject any kind of scientific respectability we have to look at all its claims with a great circumspection and listen to its proponents with even greater scepticism than is usually necessary. This is particularly true when the gulf between observers and theoreticians is as wide as it usually is here. Either side may be more inclined to accept the claims of the other than they should. As an extra-galactic observer addressing a mostly theoretical audience I want to emphasise the very many caveats that should always be attached to the observational side of this field. I do so as a friend and admirer of George Ellis who has one of the few minds capable of bridging the gulf.