How to Describe Physical Reality?*

Because cosmology touches our ideas about what lies “beyond” as much as about what went “before”, it will always raise controversy and even cause bitterness. Although I am a classical astrophysicist, I reckon that even in the solar spectrum, some elements† indicate some general principle of the universe. At the same time, another universe than that of the astrophysicists is offered by mathematicians who conceive all sorts of objects and geometries. But there is too great a temptation to consider these constructions “real”, as soon as they are plausible. As a fellow astrophysicist, I see the universe in the same way as Professor Rees. His description of the modern progress of astronomy and cosmology cannot be more balanced, subtle and precise. I would certainly not try to contradict him on the facts, even though some astronomical observations such as “abnormal” redshifts cannot help