Assumed Preparation:
This lesson assumes that students are familiar with Newton’s law of gravity,
the equations for circular motion and how to calculate escape velocity. They
should already be familiar with aspects of general relativity such as gravitational
time dilation and red-shift, lensing and curved space. Some will have heard
of black holes and some will have heard of neutron stars and white dwarfs, but
this is not essential.
Subversive Physics:
This fits in well as an extension to a physics unit on orbital motion and escape
velocity.
The Activity: This lesson is structured as an
interactive lecture. The lesson can be done with or without the PowerPoint
slides. Each student will need a copy of the worksheet
and the teacher can find detailed answers here.
The lesson has two parts; theory and evidence. The theory starts with the 'dark
star' calculation done by John Michell over 200 years ago using Newton's law
of gravity. The differences between these dark stars and the black holes of
general relativity are explored in detail, conceptually and mathematically.
Finally the evidence for stellar and supermassive black holes is examined.
Other Resources:
1) Can we travel through time? http://q2cfestival.com/play.php?lecture_id=8242&talk=alice This is a short 1-minute animated cartoon from the Perimeter Institute of Theoretical Physics that looks at black holes, gravitational time dilation and the curving of light.
2) Einstein Online: http://www.einstein-online.info/ This is a fabulous website from the Max Planck Institute. It gives beginner lessons in specail and general relativity and othe parts look at the latest research - theoretical and experimental.
3) Monster of the Milky Way (Nova 2007, $20) http://www.pbs.org/wgbh/nova/blackhole/ This is a very good film about the supermassive blackhole at the centre of our galaxy.