2020-04-02_Science_Illustrated

18 | SCIENCE ILLUSTRATED

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DINO DISCOVERY
T. rex had a bite like a croc
New studies show that the skull of a T. rex had the same
structure as that of modern crocodiles. The jaw joints
were stiff and inflexible, as in birds, the descendants
of dinosaurs. Scientists from the University of Missouri
in the US have calculated that the fixed jaws provided
the T. rex with a biting strength of 7 tonnes – four times
that of a crocodile, which holds the existing record.
Ancestor was small and fast
In the US state of Utah, scientists have
found a 96-million-year-old fossil of a small
tyrannosaurus. Named Moros intrepidus, the
predator weighed only 78kg, but the small sprinter
is believed to be an ancestor of the big tyranno-
sauruses that originated 81 million years ago.
Holes cooled the head down
The T. rex had two large holes at the top of
its skull, which palaeontologists had thought
to have been full of muscles. But American scientists
have discovered similar holes in alligators, and those
are full of blood vessels that help the animals shed
heat. T. rex holes likely had the same purpose.
T. rex could not stick out its tongue
The T. rex is often portrayed with a pointed
tongue protruding from its mouth, but that is
not how it was. Scientists have compared the tongue
bones of T. rex, crocodiles and birds. The T. rex bone is
again closest to that of a crocodile, so the tongue was
probably fixed to the lower part of the mouth.
A rubber band that is alternately twisted and relaxed can cool and
heat its surroundings. The method could be used for cooling plants.
TECHNOLOGY Scientists from
Nankai University in China have
found a new way to power
refrigerators and air-conditioning,
after experimenting with an
effect that we can all test by
using an ordinary rubber band.
If you hold one against your lips
and stretch it, you will feel it
becoming warm, then cooler
again as you relax it. The Chinese
scientists studied the effect of
materials including threads made
of rubber, nylon and metal alloys,
and they discovered that the
effect intensified considerably
when they stretched and twisted
the threads at the same time.
X-radiation allowed the
scientists to see what happened
to the materials’ molecules when
the threads were twisted. The
mechanical impact forced the
molecules into organised
structures where the molecules
vibrated more to maintain the
total system order, so heating the
material. The scientists observed
the effect in all the materials,
with the temperature of a rubber
thread 15 degrees higher when
twisted, and 15 degrees lower
when untwisted. According to the
scientists, the result could be
used in cooling plants and fridges
that currently remove heat using
compressed and expanded gases.
Previously-used gases, including
CFCs, presented a major problem
for the ozone layer which
protects us against UV radiation.
Other gas types are now used,
but could still intensify the
greenhouse effect if they escape.
Twisted rubber bands could
power fridges of the future
AND TALKING OF THE T. REX...
A rubber band starting at room
temperature heats up when twisted.
After a while, the rubber band cools
back to room temperature again.
When the band is allowed to
unwind, the temperature falls.
After a while, the rubber band
returns to room temperature.
Cooling
vesselsblood
Mas observed fromodel of a T. rex head above
SCIENCE UPDATE