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The Jamaican runner,
Usain Bolt has been
clocked at 23 mph – no
way he can catch a
cheetah...
The fastest human time
ever recorded is about
27 mph.
On-screen science
Jonathan Hare explains...
Animal games – scales of nature
scaling it up for the rhino beetle we
get 54 000 kg! In the programme
we see the beetle just managed to
do the lift but its smooth claw-like
legs could not provide the necessary
traction at this scale to stay upright;
it slipped over at the last minute
leading to disqualification!
ISTOCKPHOTO
The main problem with the programme
of course is that scaling-up is not
an easy calculation. The strength of
a human-sized beetle isn’t simply
obtained by multiplying the real-life
strength by a simple factor (although to
be fair there is a notice to this effect at
the start of the programme).
A cheetah can hit
speeds between
60–70 mph
Animals come in all sorts of shapes and sizes, all with
different abilities and skills. If you could somehow
make them all the same size you might then be able to
directly compare their strengths and weaknesses. This
is the idea behind the BBC TV’s Animal Games1 which
shows animals competing in their own Olympic Games.
Human-sized fleas
A rhinoceros beetle can
support things over 850
times its own weight
In the programme, each animal has a scale factor
assigned to make them all the equivalent of
human size. One of their real-life characteristics
eg strength, running speed, jumping ability etc,
was then multiplied by this factor to see how it
might fare in an Olympic-style competition. The
programme tries to answer questions such as: If a
real-life flea can jump
10 cm or so, how far
could it jump if it was
the size of a human? 2
One of the contestants
in the weightlifting
event was a rhinoceros
beetle. The human
weightlifting record
(2004) was 263 kg.
Taking this weight and
10 | The Mole | May 2012
Fair comparison?
In general, insects are strong (mechanically and in
relative muscle strength) for their size (x). As the
creature gets smaller its mass (dependent on
volume: x3) reduces more quickly than its surface
area (and the cross section of its limbs, legs etc: x 2).
Leverage effects also reduce as things get smaller.
So even if the beetle’s muscle power did scale
proportionally, the mechanical strength of the beetle’s
exo-skeleton, which would have to take this load, would
not scale in the same way. Beetles are composed of
(modified) chitin which is a very strong material. To
support such a heavy lift, the beetle would need to
be very large from a structural point of view. A human
sized beetle ‘monster’ attempting the 54 tonne weight
lift would probably crack and break-up in the process!
There is no doubt that the programme is a lot of
fun and you can hear that the professional sports
commentators also loved it too! It’s quite fascinating
as long as you don’t look too closely at the science.
References
1. Animal Games, BBC, 2004, BBC Worldwide Ltd
2. In Animal Games the human size flea was in the high
jump event. The bar was set for 622 m but we see the
flea jump thousands of metres!
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