Q&ACHEWING GUM
TAKE S SE VEN
YEARS TO DIGEST
OLD WIVES’
TA L E S...
The digestive system isn’t like an in-tray,
where everything remains until fully
processed: it’s more like a conveyor belt.
Whatever you eat moves through your
intestines at roughly the same speed, and
anything that doesn’t get broken down
and absorbed into your bloodstream
passes out the other end. This usually
takes one to three days. Chewing gum
can’t stick to the wet intestinal wall, so a
single piece of swallowed gum normally
gets swept along with everything else.
There are a few cases in the medical
literature of small children swallowing
many pieces of gum that formed a lump
too large to pass. But this quickly caused
severe constipation and pain, and needed
surgery to remove.
But supposing some gum did somehow
get trapped, would it take seven years to
digest? Chewing gum is 70 to 85 per cent
sweeteners, avourings and starch, all of
which are digestible. But the remaining 15
to 30 per cent is a blend of synthetic
polymers, o en including butyl rubber.
This rubber is also used to make the seals
on chemistry lab asks, and is rated as
suitable for storing hydrochloric acid that
is 30 times more concentrated than the
acid in your stomach. So if you could
somehow withstand the severe
constipation, the gum would likely last at
least seven years. LVEMRE YORGANCIGIL, ISTANBUL, TURKEYWe have evolved eyelids to protect our eyes from drying out or ge ing scratched. When you
are sleeping, it is dark anyway, so there’s not much point in your eyes being open. But your ears
have evolved as an important early warning mechanism, allowing you to wake up if, say,
there’s a tiger growling in the undergrowth. Some animals, including seals, o ers and hippos,
can close their ears, but this is to keep water out while swimming. LVWHY CAN’T WE CLOSE OUR EARS
LIKE WE CAN CLOSE OUR EYES?
Nerve impulses travel at about 50 to 60 metres
per second in your arm, which means they can
go from your fingertip to your brain, and back
again, in about 27 milliseconds. But in most
situations, that nerve impulse also has to be
processed by the brain so that you can decide on
the appropriate muscle movements to react to
the sensory input. This can add another 130 to
160 milliseconds to your reaction time. If your
hand is touching a hot stove, that extra delay is
enough to burn you badly. So, for certain
extreme stimuli like heat or a sharp pain, the
nerve impulses bypass your brain altogether.
The sensory nerves and the motor nerves
become short-circuited together in the spine so
that you can yank your hand out of the way
without thinking. LVTOM HAMPTON, TOWNSVILLE, AUSTRALIAHOW DO WE RE ACT SO FAST WHEN WE PUT
OUR HAND ON A HOT SURFACE?
Q&ACHEWING GUM
TAKE S SE VEN
YEARS TO DIGEST
OLD WIVES’
TA L E S...
The digestive system isn’t like an in-tray,
where everything remains until fully
processed: it’s more like a conveyor belt.
Whatever you eat moves through your
intestines at roughly the same speed, and
anything that doesn’t get broken down
and absorbed into your bloodstream
passes out the other end. This usually
takes one to three days. Chewing gum
can’t stick to the wet intestinal wall, so a
single piece of swallowed gum normally
gets swept along with everything else.
There are a few cases in the medical
literature of small children swallowing
many pieces of gum that formed a lump
too large to pass. But this quickly caused
severe constipation and pain, and needed
surgery to remove.
But supposing some gum did somehow
get trapped, would it take seven years to
digest? Chewing gum is 70 to 85 per cent
sweeteners, avourings and starch, all of
which are digestible. But the remaining 15
to 30 per cent is a blend of synthetic
polymers, o en including butyl rubber.
This rubber is also used to make the seals
on chemistry lab asks, and is rated as
suitable for storing hydrochloric acid that
is 30 times more concentrated than the
acid in your stomach. So if you could
somehow withstand the severe
constipation, the gum would likely last at
least seven years.LV
EMRE YORGANCIGIL, ISTANBUL, TURKEYWe have evolved eyelids to protect our eyes from drying out or ge ing scratched. When you
are sleeping, it is dark anyway, so there’s not much point in your eyes being open. But your ears
have evolved as an important early warning mechanism, allowing you to wake up if, say,
there’s a tiger growling in the undergrowth. Some animals, including seals, o ers and hippos,
can close their ears, but this is to keep water out while swimming.LVWHY CAN’T WE CLOSE OUR EARS
LIKE WE CAN CLOSE OUR EYES?
Nerve impulses travel at about 50 to 60 metres
per second in your arm, which means they can
go from your fingertip to your brain, and back
again, in about 27 milliseconds. But in most
situations, that nerve impulse also has to be
processed by the brain so that you can decide on
the appropriate muscle movements to react to
the sensory input. This can add another 130 to
160 milliseconds to your reaction time. If your
hand is touching a hot stove, that extra delay is
enough to burn you badly. So, for certain
extreme stimuli like heat or a sharp pain, the
nerve impulses bypass your brain altogether.
The sensory nerves and the motor nerves
become short-circuited together in the spine so
that you can yank your hand out of the way
without thinking.LVTOM HAMPTON, TOWNSVILLE, AUSTRALIAHOW DO WE RE ACT SO FAST WHEN WE PUT
OUR HAND ON A HOT SURFACE?