Support materials only that illustrate some possible contexts for exploring Science as a Human Endeavour concepts in relation to Science Understanding content.
In the seventeenth century, Bishop James Ussher analysed historical accounts and the chronology of the Bible to deduce that the creation of Earth commenced at nightfall preceding the 23 October, 4004 BC (BCE). In the eighteenth century, the Comte du Buffon was one of the first to propose an age based on empirical evidence, suggesting that Earth was 75 000 years old, based on the rate it was cooling. In the following centuries, many scientists from many different disciplines proposed ages of Earth based on their experiments and calculations (ACSES009). The current agreed age of Earth is around 4.54 billion years. This age has been calculated from radiometric dating of meteorites and is consistent with various younger ages obtained from Earth and Moon rocks (ACSES010).
The principle of uniformitarianism, first formulated by James Hutton and later developed by Charles Lyell, suggests that change is constant and uniform. Therefore knowledge of a modern process can be used to explain similar past events or predict similar future events. For example, as part of studying the enhanced greenhouse effect, scientists have searched for possible previous geological analogues which would help them to make predictions about how the climate might change in the future (ACSES013). To achieve this, the geologic and paleoclimate scientific communities have been studying the collated data on glaciations, inter-glacial periods and atmospheric parameters to find a period in Earth’s history that can be used as an analogue for a future with an enhanced greenhouse effect (ACSES008).
As technology has not yet developed to enable direct study of Earth below a depth of about 10 km, science relies on secondary sources of data to develop models of the interior based on inference. This includes studying the propagation of seismic waves, using gravity maps developed via satellite technology, studying the composition of material ejected from volcanic eruptions and meteorites, analysing the density of rocks, and studying Earth’s magnetic field (ACSES009). The development of supercomputing has enabled the design of complex models of Earth’s interior, demonstrating, for example, the way in which changes in the dynamics of the inner and outer core cause changes in Earth’s magnetic field (ACSES010).