Light
(tabletop interactives)
Designed and produced for Rutherford Appleton and Daresbury Laboratories
1999
The first three items are completely original concepts. Apart from
the final one, these interactives were not designed merely to teach specific
principles. Better than that, the aim was to provide an exploratory, investigative
experience, with a certain amount of adult supervision likely to be available.
Bouncing
light off things
An intense beam comes from a safe, cool, fibre-optic light source with
a focusing lens. Various different materials are available for testing.
Their colour varies and so does their roughness or 'shiny-ness'. The colour
and scattering of the reflected patch of light can be examined on the
translucent, hanging screen.
These simple, but non-standard experiments provide plenty of scope for
systematic recording and the results can be surprisingly thought-provoking.
For example, why DOES shiny red plastic produce a white patch on the screen,
while rough red plastic reflects a much greater proportion of red light?
Shining
light through things
A similar set-up, elegantly juxtaposed for investigation of a range of
samples using transmitted light. The samples vary in their colour, in
the amount of light they transmit and in the extent to which they scatter
transmitted light.
Juxtaposition of such closely related activities is an important experience
in itself.
Ball
gun
Table tennis balls are loaded into the top of the 'gun' then fired at
the mirror using the spring-loaded plunger. Firstly, the gun is aimed
until the torch beam illuminates one of the coloured targets. Then the
ball is shot to hit the same target.
I learned something interesting while developing this one: balls DON'T
usually reflect in the same way as light beams. The spin of a ball is
sufficiently affected by an angled bounce to absorb energy and change
the ball's angle of reflection. Notice the special pad on the lower part
of the mirror. The pad has to be just soft enough, and just shiny enough
for this experiment to 'work'.
Infinite
reflections?
This is not an original idea, but provides plenty of scope for enjoyable
experimentation. there is another black bead on a post between the two
facing mirrors. The nearest mirror has a central peep-hole giving an 'infinity
tunnel' effect. Moving either mirror couses the 'tunnel' to 'bend'.
Kaleidoscope
What is the relationship between the angle between the two hinged mirrors
and the number of bead-reflections that can be seen?
Shaped pieces of coloured paper can also be laid out between the mirrors
to explore patterns and symmetry reversals.
Angles
This circular platform, together with its mirror and a angle-measuring
scale, rotates smoothly on a concealed bearing.
A bright, narrow streak of light is shone across it so that angles of
incidence and reflection can be measured, recorded and considered.
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