In earlier chapters, I noted that the acceptance of new scientific views was usually determined by a loosely defined leadership, which Ludwik Fleck had called the community's thought collective. A clearer picture of how this acceptance comes about has gradually emerged through an improved understanding of the ebb and flow of influence within the scientific community. When the weight of mounting influence triggers a cascade, widespread acceptance becomes inevitable. Once set in motion, however, cascades are almost impossible to control; misinformation can spread as readily as more reliably documented data. High priority thus needs to be assigned to containing the spread of error.

Transforming Belief

The inflationary theory of cosmology envisioned by Alan Guth, and extended most persistently by Andrei Linde, proposed that at the birth of time the Universe comprised a high-density vacuum permeated by chaotic fluctuations on all scales. Almost at once, the vacuum explosively expanded at a rate that exponentially increased. During this inflationary phase, which may have lasted no more than 10-33 seconds, distances across the Universe separating individual fluctuations dramatically increased by factors of order ˜3 × 1027 or more. This left the fluctuations isolated, able to seed the formation of clumps of radiation and matter as the inflationary phase subsided.

This astonishing theory was widely adopted almost as soon as it was proposed. It accounted for the homogeneous and isotropic appearance of the Universe; explained why space is seemingly flat, meaning that light propagates along straight lines rather than curved paths as it traverses the Universe; and also suggested why the Cosmos appeared to be devoid of magnetic monopoles.

Given the unruly onset of cascades described in the last chapter, how can we ever be sure whether our investigations are yielding a credible picture of the Universe? What warning signs should we look for to determine whether our pursuit may merely lead to a construct, potentially accounting for all available observations but nonetheless a mere caricature of the Cosmos – rather than a true portrait?

Language and Its Role in Persuasion

Astrophysics progresses through persuasion. Astronomers need to convince each other of the reality of a new finding. A discovery that fails to persuade colleagues goes nowhere. Once the astronomical community is convinced, it has to also persuade funding agencies of the discovery's importance.

Neither step is easy. Researchers investigating planetary systems, the structure and evolution of stars, the chemistry of interstellar dust and gases, the formation of galaxies, and the birth and evolution of the Cosmos all express themselves using slightly, but nevertheless significantly differing vocabularies. A clear exchange of ideas among the members of different disciplines, however, requires those vocabularies to be well defined and mutually understood. In practice this is rare. Words assume new meanings as novel findings in a discipline enrich a concept. The connotations of identical expressions used in different disciplines then gradually diverge, so that misunderstandings easily arise and dialogue suffers.

In the course of the twentieth century science gained insights on the nature of the Cosmos that might have seemed unimaginable even as late as the year 1900. New words and concepts, novel ways of conceiving space and time, and massive efforts to understand the structure of matter were needed to describe the world we were encountering. I embarked on writing this book to gain clearer insight on the factors that had most effectively contributed to all these advances.

Astronomy is a small field whose tools were largely imported from physics and engineering. Early in the century, theoretical physicists provided us with new perspectives for devising and interpreting novel observations.

Then, in mid-century the United States adopted a deliberate policy of coupling basic research to practical national priorities. Other countries followed suit, leading to an explosive expansion of all of the sciences and engineering. Scientific progress led to novel engineering ventures. These, in turn, offered the sciences increasingly powerful research tools. The coupling could not have been more fruitful. For astronomy the benefits were immense.

Today, we may be entering a new era, in which this bond may loosen between astronomy and engineering. Astronomers are turning their efforts to studies of dark matter and dark energy, whose potential utility to society is not at all apparent. In view of competing national priorities governments may find themselves unable to support the development of the novel tools required for conducting such esoteric cosmological searches. Astronomers may then have to find alternative ways of extending their investigations of the true Universe.