GREAT
EXPLORATIONS - Moving air | Forming
images | Reflecting light | Electricity
and magnetism | Spinning things | Making
sense | Changing colours | Making
sounds and waves | Moving to and fro
| Thinking about shapes
This is an old set of proven ideas, for reference. My latest designs are
far better!
Spinning
things
Rolling
wheels
TEXT:
Have a race with a friend. Try
rolling one wheel each down the tracks.
Which wheel reaches the bottom first? Does
the other wheel catch up as they climb uphill?
Look at the four heavy weights in each wheel.
Can you see what is making the two wheels behave differently, even though
they both weigh exactly the same?
Both wheels are fitted with an identical set of weights. In one of the
wheels the weights are close to the centre. In the other wheel the weights
are close to the rim.
Vortex
TEXT:
Press the button to make a vortex.
You are switching on an electric motor that
stirs the water.
What other examples of this kind of vortex have
you seen in everyday life?
Slow
and fast
TEXT:
Make the ball swing round the pole,
then pull the cord.
Does this make the ball go faster or slower?
What happens if you let go of the cord while the ball is still moving?
A spinning ice skater can speed up in just the
same way, by pulling in outstretched arms and legs.
Another 'Ian Russell original', first built in 1988, this a neat demonstration
of angular momentum which is also very appealing to 'play' (experiment)
with. I once saw a middle-aged professional astrophysicist and an unrelated
seven-year-old boy taking turns at it without speaking to each other,
each deeply engrossed at his own level. When correctly set up, it needs
remarkably little maintenance.
Chaos
pendulum
(Sorry, no picture.)
TEXT:
Spin the bars using the knob in
the middle.
See them go crazy. As you watch, can you
guess what will happen in the next few seconds?
Things that look quite simple can sometimes
behave in such a complicated, "chaotic" way that nobody can
possibly predict what will happen next.
I designed most of these exhibits, but not this one, supplied by Experimentarium,
Copenhagen, Denmark. This was one of the very few 'bought-in' exhibits
that passed my stringent criteria for robustness and low maintenance combined
with "child-appeal". It is one of the best versions of Rott's
Pendulum I have seen, as well as being another 'zero-maintenance' exhibit.
Free-standing and completely transparent, it is big, standing higher than
most children, yet the central knob is so small that it is impossible
for the strongest person to damage it. (My most memorable encounter
with this exhibit was the massive electric shock I received on unpacking
it, after enthusiastically ripping the protective plastic film off the
large acrylic window then immediately grabbing hold of the knob to try
it out!)
Gyroscope
TEXT:
Hold the red handle, lift up the
wheel, spin it with your other hand and let go.
What is surprising about the behaviour of
the wheel?
Does the wheel continue to "defy gravity"
if you hold out a hand to stop the red handle from moving round?
GREAT
EXPLORATIONS - Moving air | Forming
images | Reflecting light | Electricity
and magnetism | Spinning things | Making
sense | Changing colours | Making
sounds and waves | Moving to and fro
| Thinking about shapes
This is an old set of proven ideas, for reference. My latest designs are
far better!
|
