12. Collectanea

How the scientific community, in the absence of any observational evidence, came to a consensus that the first many hundreds of millions of years of Earth history saw a desiccated, lifeless, molten wasteland is worthy of analysis. This chapter addresses problematic aspects of our epistemology that led to this paradigm and concludes that the historical sciences can sometimes be influenced by the same existential urges for control that fueled the past four thousand years of ubiquitous creation mythology. On a more tangible level, emerging scientific views in the late 1960s provided heretofore unavailable sources of thermal energy to models of the early solar system. This occurred just prior to the return of lunar highland samples which showed that Moon had almost been globally melted almost immediately upon formation, in stark contrast to the then prevailing paradigm of cold accretion. Arguably overreacting in overthrow of that model, the community quickly adopted the view that the first many hundreds of millions of years of Earth history had been too turbulent to leave any record. Shortly thereafter, the emergence of the large radius ion microprobe provided the tool needed to first discover and then explore Hadean zircons from Western Australia. The seemingly contradictory story these results presented would take a generation to seriously challenge the orthodoxy of a protracted, hellish world. This intellectual inertia partially reflects the inevitability of the Earth and planetary sciences being more tolerant of what amounts to untestable hypotheses relative to other physical sciences. While that is understandable given the challenge that historical sciences face in attempting to understand processes operating many billions of years ago, overly elaborate models invoking speculative mechanisms that lack the basis for falsification tend to crowd out other, possibly better, models from the scientific arena.