26 | New Scientist | 16 November 2019
Editor’s pick
Let’s confront some causes
of domestic violence
19 October, p 20
From Bonita Ely, Sydney, Australia
Alice Klein discusses the prevalence
and prevention of domestic violence
and the treatment of victims and
perpetrators. Another aspect
worth mentioning is the effect
of post-traumatic stress disorder
(PTSD) on behaviour.
As Joshua Goldstein writes in
War and Gender, PTSD typically
leads to emotional numbing,
recurrent nightmares, substance
abuse and, most frighteningly,
delusional outbursts of violence.
Think of the preponderance
in any nation of those who have
felt the trauma of war, racism,
rape, colonisation, persecution,
dispossession – refugees,
Indigenous peoples and members of
minorities – and domestic violence.
Some may later traumatise others.
As a child of a veteran of the
second world war who clearly
suffered from PTSD, I attest that
his irrational, unprovoked rages
and physical abuse, often under
the influence of “self-medicating”
alcohol, belied his evident love
for us, adding to our insecurity
and hyper-vigilance. To address
domestic violence, PTSD has to be
central to research into it and the
treatment of its causes and effects.A few solutions to the
minimoon conundrum
26 October, p 23
From Brian Horton, West
Launceston, Tasmania, Australia
Leah Crane argues that 214 moons
is too many for a solar system
because some are just rocks.
She suggests we only include
satellites that are large enough
to be roughly spherical: 400 to
600 kilometres in diameter.
This limit would remove Phobos
and Deimos, at 22 km and 13 km
in diameter respectively. I spent
so much effort learning about
them when young that I insist
we find a way to include them.Phobos is so close to Mars that
to a person standing on the planet,
it would appear to be one-third the
width of our own moon seen from
Earth. This is clearly big enough
to be called a moon. So how to
include it, while excluding rocks?
The largest single rock on
Earth is Uluru in the Northern
Territory of Australia, which is
9.4 km in circumference.
A moon should be at least 10 km
in circumference. This eliminates
the tiny rocks that Crane objects
to and the minimoons that
sometimes orbit Earth without
being permanently captured.From Bryn Glover, Kirkby Malzeard,
North Yorkshire, UK
Things are getting out of hand
with the number of moons in our
solar system, says Crane. Perhaps
she could go one step further than
redefining moons and consider
the well-established example of
binary stars as a model. Why not
binary planets?
The moons Ganymede and
Titan are bigger than Mercury.
If they occupied independent
solar orbits, they would have no
difficulty in qualifying as planets.
The Jupiter/Ganymede andSaturn/Titan combinations, and
even that of Earth/moon, are pairs
of planet-sized bodies orbiting
around their common centres of
gravity. The centre of gravity of the
dwarf planet Pluto and its moon
Charon lies outside both. Let’s
reclassify such pairs as binary
planets, or binary dwarf planets.Our examples of thinking
without language
Letters, 26 October
From Brian Josephson,
Cambridge, UK
According to David Werdegar,
“a composer may internally hear
a melody, hum the tune and have
a second person hum it too. But
developing it for an instrument
or an entire orchestra requires
much thought, and that thought
requires language.” That contrasts
with my own experience
composing Sweet and Sour
Harmony, which I would
characterise not as involving
“much thought”, but rather as
a cumulative process of step-by-
step advance, each step involving
an idea such as “change to a minor
key here”, or “find a good way
to end it”. What was principallyinvolved was acting upon
feelings deriving from one’s past
experience of music, rather than
logical analysis or language. It
was only at the final stage, when
transitioning from use of a single
instrument to a kind of dialogue
between two, that language-based
reasoning might have been
involved to a significant degree.From Philip Stewart, Oxford, UK
Meaning seems to be partially
independent of language.
Bilingual people can often
remember what was said without
knowing in which language it was
said. Within as little as a minute,
my children may have forgotten
which language they spoke in,
but still be capable of recalling
the meaning of what was said.From Paul Whiteley,
Bittaford, Devon, UK
When my son was about
14 months old, we let him sit on
the doorstep of our house in the
Canary Islands with another child
of a similar age, eating ice cream.
Then, we heard a cry. We found
him on one side of the mosquito
net door with his friend on the
other. He had bite marks on hisViews You r le t te r s