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Making Bubbles
What do I need?
-
Straws
- String
- Pipe cleaners
- Washing
up liquid
- Water
pistol
- Washing
up bowl
- Scissors
- Glycerine
What
do need to do
-
Make a soap solution with washing up liquid
(10%), water (89%) and glycerine (1%). Mix
carefully – and don’t whisk it or you’ll get
lots of small bubbles appearing that make
blowing larger ones difficult
-
Make a hoop out of wire to test that the soap
solution works.
-
Use the water pistol to moisten the air
-
You can design different shapes and sizes with
hoops to make different bubbles.
-
Drinking straws also act as good ‘bubble blowers’.
They will hold more bubble juice if 4 short
slits around 5cm are cut on the end.
-
Pipe cleaner is also a good method for making
a basic loop. Dip it into the bubble solution
and blow!
Explanations
The Shape: As you lift your frame out of the solution,
the soap film flows into a state of minimum energy.
The soap film is in this state of minimum energy
when it's covering the least possible amount of
surface area. The intricate shapes you see inside
the frame represent the minimum area the soap
film can cover. You may notice that a soap film
will sometimes take on different shapes when you
dip the frame into the solution again and again.
That's because there may be more than one way
for the soap film to form a minimum surface area.
The rainbow: Bubbles consist of two thin films
of soap with water in between. When white light
(which contains all the colours of the rainbow)
hits the soap films, it will be reflected back,
but is sometimes spread out into a spectrum (or
rainbow). When two sets of reflected waves meet,
they can add together, cancel or partially cancel
each other out depending on the thickness of the
film and the initial colour of the light. When
light waves of a particular colour meet and cancel
each other, then that colour is subtracted from
white light. For example, if the red light waves
cancel, then you see white light minus red light,
which you perceive as blue-green light.
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