How much do we really understand of how our planet came to be as we know it? Five scientists tell a tantalising tale.
1: Obscure Geneses
' It's fairly certain that the Earth came into existence between 4,000- and 5.000-million years ago.
' It's when you ask how that such grave difficulties arise ' - PROFESSOR R. A. LYTTLETON , FRS, Institute of Theoretical Astronomy. Cambridge
Drifting Firmaments, by Dr Dan McKenzie : 4 March)