Plato’s Ghost

Abstract

Every year, at the beginning of a lecture course I teach at Cardiff University on cosmology, I ask the students to come up with a list of all the questions they have ever had about life, the Universe and everything. With some prompting from me, they usually come up with a list of between ten and twenty (Figure 9.1 shows the list from earlier this year with a few additions from me). Just as the class is getting excited by a lecture course that for once is going to address all the big issues of life, I dash their hopes by ticking the one question my course on the Big Bang theory is actually going to answer. The point of this exercise is to show both the power and limitations of the theory. The theory is powerful because it only tries to address a narrow range of questions. However, a philosopher from an earlier more ambitious era, such as Plato who invented his own cosmological theory, would never have been satisfied with it. In the second half of this chapter, in deference to Plato, I am going to discuss whether it is possible to broaden the scope of our modern scientific theory of cosmology to address more of these big questions. During the first half of this chapter, however, I am going to continue the observational slant of this book and consider what nitty-gritty facts we can possibly discover about the first moments after the Big Bang.