What Light Can Tell Us: Spectra and Redshift

About the lecture

In this mini-lecture, we explore how to use light to help us determine what materials are out there in the Universe. In particular, we consider: (i) Newton’s prism experiment, where white light is passed through a prism and the colours that make up the white light are bent by different amounts; (ii) continuous spectra vs. emission spectra; (iii) the emission spectra of various gases; (iv) familiar examples of emission spectra, such as sodium vapour streetlights and neon signs; (v) how emissions spectra can be used to determine gases in space; (vi) the Doppler effect and how it shows up in astronomy; (vii) an example of redshift, which allows us to measure the speed and direction of an faraway object; and (viii) the Hubble Ultra Deep Field.

About the lecturer

Dr Pete Edwards is the Director of Science Outreach and the Science and Society Officer at Durham University. He is also a member of Durham University’s Astronomy and Astrophysics group. As the Director of Science Outreach at Durham University, Dr Edwards has developed a range of teaching resources aimed at primary and secondary students and teachers. He has visited one in three secondary schools in the UK, where he has provided a programme of physics demonstrations and talks. As an elected fellow of the Institute of Physics (IOP), he has contributed to the Teaching Astronomy and Space DVD (2010-2019) produced by the IOP, as well as the IOP videos How Big is the Universe? (2012) and The Expanding Universe and the Big Bang (2012). In 2005, he was chosen to deliver the 2006 IoP Schools’ and Colleges’ Lecture. This talk, Gravity, Gas and Stardust, was broadcast across the UK to over 12,000 14-16 year old students. He has also worked with TED to create the TED-Ed video, What light can teach us about the universe (2014). Dr Edwards is also a qualified secondary school teacher, who taught science and mathematics in various schools and colleges during the 1980’s before obtaining his Ph.D. and joining Durham University in 1990.