New Scientist - USA (2019-11-09)

(Antfer) #1

54 | New Scientist | 9 November 2019


Different minds


Why do some people become
interested in science and
some don’t?

Steve Gisselbrecht
Boston, Massachusetts, US
People are incredibly complicated
and a lot of factors affect what we
like. In this case, one person might
have had more inspiring science
teachers early on in life. Or
perhaps they saw more science-
oriented TV shows growing up,
or had a book read to them with
a scientific fact that answered
a question they had just been
wondering about. Since our brains
grow and change in response to
our thoughts, this kind of accident
can contribute a lot to how we
think in the future.
But people are also just
different. Scientists who study
personality have mostly settled
on five major traits, or axes, that
people differ along. They have
been given different names,
but we can call them curiosity,
friendliness, conscientiousness,
outgoingness and nervousness.
There is evidence that these traits
are fairly heritable, meaning that
outgoing parents tend to have
outgoing children more often
than introverted parents do,
and so on.
These traits could affect a
person’s reaction to science – a
more conscientious person might
work harder to get answers, say,
while a more nervous person
could be unhappy about ideas
that aren’t really settled – but
curiosity seems like the strongest
driver of a scientific mindset.
Curious people tend to seek
out new things and more cautious
people prefer the tried and true. I
suspect that both exist as a result
of natural selection. A group in
which no one is willing to try new
things will fail when conditions
change or familiar foodstuffs
become unavailable. But on
the other hand, a group in which
no one values familiarity and
tradition will lose the knowledge
of what is edible and what is

useful, and waste a lot of time and
energy reinventing the wheel.

Marilyn Lott
Front Royal, Virginia, US
Sixty-five years ago, girls were
told, “don’t take these subjects:
mechanical drawing, motor
mechanics, advanced
mathematics”. That rubric
became far less common by
the 1970s.

Terry McDonald (graduate of
Mirboo North high school,
Australia, 50 years ago)
Maidstone, Kent, UK
A high level of curiosity about
the world around them.

It is also worth pointing out
that science encompasses a
vast array of subjects. A person
who is interested in analysing
fossils might be as different
from someone who models
fluid dynamics in pipes as they
are from someone who studies
languages – Ed

Coil conversion


If I compress a metal spring, tie it
with an acid-proof binding then
submerge it in acid and dissolve
the spring, what happens to the
energy that was used to compress
it? I think the acid must warm up,
but how is the stored energy
converted to heat?

Eric Kvaalen
Les Essarts-le-Roi, France
The acid solution will warm up
even if the spring isn’t compressed,
due to the heat of reaction as the
acid dissolves the metal. If the
spring is compressed, it will warm
up slightly more. As each atom or
ion is released from the crystals of
metal, it will leave with a slightly
higher energy because it is being
released from a slightly higher

energy state. However, the
amount of energy needed to
compress the spring is quite small,
so the difference in temperature
would be hard to detect.

Ron Dippold
San Diego, California, US
When you compress a spring,
the potential energy is stored in
the mechanical bonds between
atoms, which you can think of
as little springs. The spring as a
whole can’t decompress – until
it breaks – but little chunks can
decompress as they come off.
Most of the stored energy goes
into decompressing each small
part. It isn’t 100 per cent efficient,
so the fragments heat up a tiny bit
from friction. The bits also stir the
acid slightly as they come off.
This is where the spring energy
goes. But stirring is a terrible way
to heat a liquid – try stirring a cup
of water with a spoon.
The heat from the chemical
reaction between the metal and
the acid will be much greater
than that released by the spring’s
decompression, but it will still
be a very small amount.

David Muir
Edinburgh, UK
The reaction between a metal and
an acid is exothermic, releasing
energy to the solution and raising
its temperature. A steel spring
weighing 5.6 grams gives out
around 8800 joules of energy
when dissolved in acid.
If the spring is compressed
10 centimetres with a force of
10 newtons, then the spring is
stressed by 1 joule of energy.
This increases the solution’s
temperature by 1/8800 more
than an unstressed spring,
a piffling 0.01 per cent.  ❚

This week’s new questions


Burning hot Are all flames the same temperature? If
not, what causes them to have different temperatures?
Stefan Badham, Portsmouth, Hampshire, UK

Number games My bank has given me a new PIN,
advising me that I can change the number for one that
is “more memorable”. Anything I chose, say based on my
birthday, would surely be easier for a fraudster to discover.
So should I keep the randomly generated PIN I was issued?
Martin Frearson, St Albans, Hertfordshire, UK

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Are some flames hotter than
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