Gravity in Space

About the lecture

In this mini-lecture, we discuss gravity in space, focusing in particular on: (i) a demonstration that involves wringing out a wet washcloth in the International Space Station that is orbiting around Earth (done by astronaut Chris Hadfield); (ii) Newton’s Cannon, a thought experiment that helps us understand orbits and the concept of freefall; (iii) a video of an astronaut bunny hopping on the Moon; (iv) gravity on Earth (10 N/kg) compared to gravity on the Moon (1.6 N/kg); (v) the relationship between mass and gravitational field strength; (vi) orbits, which involve an acceleration due to the change in direction of the orbiting object; and (vii) a demonstration of the relationship between radius and velocity of an object in orbit.

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.