Tom Hubble has taught introductory geology as well as specialist engineering and environmental geology courses to science and civil engineering students at the University of Sydney since 1988. He has been an examiner, marker and curriculum developer for the HSC. Chris Huxley has had wide experience in teaching all branches of science at the senior level. He is currently Head of Science at Blue Mountains Grammar, and has been an examiner, marker and curriculum designer. Iain Imlay- Gillespie has taught science and environmental science at all levels in NSW and overseas and is currently head of science at Nagle College, Blacktown. He has extensive experience as an examiner, marker and curriculum developer.