Page 71 - How It Works - Book Of Amazing Answers To Curious Questions, Volume 05-15

Science

Why does popping

candy pop?

Discover the science behind this
sweet’s sizzling sensation Pop Rocks candy bounces in your
mouth when high-pressure carbon
dioxide bubbles are released as it
opping candy explodes on the tip of your
melts on your tongue
tongue, a sensation either loved or loathed
P by those with a sweet tooth. The secret to
its unique fizz, crackle and pop is actually all down
to how it is made.
In fact, popping candy is created in a similar way
to traditional boiled sweets. Sugar, corn syrup,
water and flavouring are all mixed together and
then heated so that the water boils off. If the
resulting sugar syrup solution would be left to cool
at this stage, you’d end up with regular hard
sweets. But in order to give the candy its unique
popping potential, the molten mixture is exposed
to high-pressure carbon dioxide gas at about 40
times atmospheric pressure. This causes small
bubbles of gas to form within the solution. As this is
then cooled, the pressure is released, causing the
candy to shatter into small pieces of rock. However,
each piece still contains tiny high-pressure
bubbles. When you then place the candy on the tip
of your tongue, and it begins to melt, the trapped
pressurised bubbles are released, creating a
unique sizzling sound and the sensation of it
bursting and bouncing around your mouth.

What is the diving reflex?

Find out how it enables you to swim underwater

he diving reflex is a Eventually the body’s circulatory
physiological response that system will start to constrict your
T enables all mammals, capillaries, redirecting blood from
including humans, to dive the extremities, so that more is
underwater for extended periods of allocated to the vital organs such as
time on just one breath. Once the heart and brain.
triggered, it slows and shuts down At this stage you’re likely to
parts of the body in order to conserve experience cramping in your arms
energy and ensure survival. and legs, due to a lack of oxygen in
It all happens in stages. The body’s these areas. The latter stage, blood
first response, after you’ve held your shift, generally only occurs if you’re
breath or been submerged in cold free-diving at depths of a few
water, is to slow the heart rate down, hundred feet. This essentially causes
known as bradycardia. This enables the lungs to fill with plasma, helping Holding your breath
elicits the diving reflex,
more oxygen to reach the organs, as to prevent them from collapsing which enables you to © Thinkstock
conserve oxygen
less is needed in the bloodstream. under the pressure.

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