14 May 2022 | New Scientist | 55Answers
Quick quiz #151
Answers1 Gamma rays
2 The kidney
3 Torpor
4 Bismuth
5 CortisolQuick crossword
#107 AnswersACROSS 1 Motile, 4 Cyberiad,
9 Dredd, 10 Sclerosis, 11 Cube,
12 Mako, 13 Hyena, 15 Residue,
16 Weir, 19 Neon, 20 Gagarin,
23 Insta, 24 Anal, 25 Wiki,
27 Cochineal, 28 Imago,
29 Protease, 30 CicelyDOWN 1 Medicare, 2 The Abyss,
3 Lode, 5 Yellow Wagtail,
6 Earthlings, 7 Instep,
8 Distal, 10 Space Invaders,
14 Adrenaline, 17 Irrigate,
18 Antimony, 21 Hiccup,
22 Psycho, 26 Kiwi#166 The week link
SolutionThe days of the week in order are
Ardik, Deldik, Curdik, Bordik, Endik,
Gandik and Fordik (ADCBEGF). The
three orders presented were (1)
ABCDEFG, (2) DBACEGF and (3)
GDCBAFE, and we know that
in each case three are correct.As nine are correct in total, but
there are only seven days in the
week, at least two days must be
correct in two lists, and since the
first guess was in alphabetical
order and we know A is the first
day, only two more days can be in
the correct alphabetical position.
This also means that each day
must have been named in the
correct position by at least one
child. The third day can’t be A,
so it has to be C. This leads to the
fourth day being B, the second D
and the rest follows.Tom Gauld
for New Scientist
Cutting it
How would prehistoric people
have cut their toenails?
John Davies
Lancaster, UK
Our nearest relatives, the great
apes, have fingernails that they
don’t cut, because these are worn
away by being used to hunt, dig
and scrape a living.
This would have also been true
of our prehistoric relatives. Only
once farming was invented did
life become less hard and so
nails needed cutting.
Stephen Arbitter
via email
Besides wear from use, prehistoric
people undoubtedly chewed
their toenails.
Albert Beale
London, UK
For much of my life so far
I have managed quite well
without needing any tool
to cut my toenails.
When soaking in the bath,
I would bite off any excess nail.
However, as I have got older, I
have become less supple – perhaps
because of doing different types or
amounts of exercise (I do no yoga
these days), or as an inevitability
of ageing – and hence have
resorted to scissors.
Maybe prehistoric people
rarely got old enough to be
unable to deal with their
toenails as I always used to.Mike Follows
Sutton Coldfield,
West Midlands, UK
Chances are that prehistoric
people didn’t need to cut
their toenails: while they were
walking around barefooted,
their nails would have been
naturally abraded by contact
with the ground. This is whytoenails continue growing
throughout our lives.
Toenails grow at half the speed
of fingernails – 1.6 millimetres
per month compared with
3.5 millimetres per month in
adults, according to a 2010 study.
This suggests that there is an
evolutionary component to
these growth rates, perhaps due
to different rates of wear and tear.
Interestingly, the growth rate
of the nail on the big toe is
significantly higher than that
of the other toes, according to
a 1937 study.
Cutting toenails was certainly
required once people started
wearing shoes and switched
to more sedentary lifestyles.
Apparently, Marie Antoinette
used a nail file made of pumice
stone, a rock that contains tiny
air bubbles and is created by
explosive volcanic eruptions.
Given that pumice is
geographically widespread,
perhaps this or something
similar would have been picked
up and used by prehistoric people
to file their nails if necessary. ❚“ Chances are that
prehistoric people
didn’t need to cut
their toenails due to
the natural abrasion
of walking barefoot”