BBC Knowledge April 2017

(Jeff_L) #1
As our planet bulges at the equator, its gravitational pull there is lower
than in the UK. Better still, the effect of the spin of the Earth at the
equator also helps offset the force of gravity. The bad news is that even
the combined effect would reduce your weight by less than 1 per cent –
so it’s probably easier, all told, just to cut back on the beer and pies. RM

Will I weigh less if I move


to the equator?


WHAT CONNECTS...

...BANANAS AND


PROSTHETIC LIMBS?






A discarded banana peel
is extremely slippery. The friction
between the peel and a smooth
floor is six times lower than
between the floor and your shoe.

2.
The slipperiness comes from
the follicle cells on the inside
of the peel. When they are
crushed underfoot, they
release a polysaccharide gel
between the floor and the peel.

3.
This gel is so
slippery, it is
actually a better
lubricant than
the oil used in metal
bearings. It’s only
slightly less slippery than
a ski on snow!

4.
Polysaccharide gels are also found in
the membranes covering our bones at
the joints. Research into banana peel
slip-ups is helping to improve the design
of joints in prosthetic limbs.

How long
before
extra
calories
show on
the
scales?

If you step on the scales as soon as you have eaten a jam doughnut
for lunch, you will weigh an extra 70g, because this is the mass of
the doughnut itself. But 22g of this is water, which you’ll lose over the
next few hours in your breath and urine. You’ll lose another 2g sometime
tomorrow, when you poop out the small amount of dietary fibre.
The other 46g is digested and, if your body doesn’t immediately need it
to grow or for energy, it is stored as fat. A 2012 study at Oxford University
found that the fat in your food ends up on your waistline in less than four
hours. Carb and protein take a little longer, because they need to be
converted into fat in the liver first and it takes nine calories of protein or
carbohydrate to make 1g of fat. Altogether, that doughnut has about 225
calories. Around 100 of those come from the 11g of fat in the doughnut,
which will be on your waistline by teatime. Then the 125 calories of carbs
and protein will be converted into another 14g of body fat sometime
tomorrow, unless you hit the gym after work and burn it off again. LV


April 2017 15
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