
Is the Universe of infinite extent, or is it a finite system? Will it expand forever, or will it reach some maximum size before turning and collapsing upon itself like an inverse Big Bang? Just a few years ago, models of the conventional Friedman types were showing consistent, albeit tentative, evidence for an open, ever-expanding Universe. Since then, further data and theory have inevitably conspired to blur the appealing simplicity of that picture. In this article I will show how the Friedman models fare in the light of new developments—particularly the recognition of a whole new class of evolutionary corrections to the properties of distant galaxies (see figure 1), and a proposed reinstatement of Einstein's disinherited cosmological constant. We shall see that the basic questions, posed above, are still unanswered.
| selected citations These citations are derived from selected sources. This is an alternative to the "Influence" indicator, which also reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically). | 19 | |
| popularity This indicator reflects the "current" impact/attention (the "hype") of an article in the research community at large, based on the underlying citation network. | Average | |
| influence This indicator reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically). | Top 10% | |
| impulse This indicator reflects the initial momentum of an article directly after its publication, based on the underlying citation network. | Top 10% |
