I have available 2 talks on cassette by myself, more are in the pipeline
for the near future:
1) The Atom - an exploration of the size, nature and our understanding of
the particles which are held to constitute everything physical. (15m)
It contains a visualisation where a grain of salt is expanded to the size of
the earth, and an atom is then the size of a room in a house.
2) Outer Space - a journey, through visualisation, out from the earth to the
outermost reaches of the known universe. It gives a strong sense of the
relative sizes and distances of the earth, the moon, the sun, the solar
system, our Milky Way galaxy and the whole visible universe. (45m)
This talk reduces, in turn, the earth, then the solar system, and then our
galaxy to a grain of salt, and at each stage compares the sizes of other
neighbouring bodies and distances to this grain. For instance if the earth
is one millimetre across, the sun is about 10 cm (the size of a football) in
diameter and is 10 metres away from it.