The Big Book of Why

116 Pages·2016·25.28 MB·English

FROM THE MAKERS OF BBC MAGAZINE
THE BIG
BOOK OF
LIFE, THE UNIVERSE AND EVERYTHING - SOLVED!
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WELCOME
WELCOME...
THE EXPERTS
SUSAN BLACKMORE
Susan is Visiting Professor
Our minds seemingly have an infinite ability to question. at the University of Plymouth.
Her books include The Meme
Some of these ponderings seem daft at first, but once you Machine and Ten Zen Questions
start to think about it, you realise there really is no such
thing as a stupid question.
For example, outside our offices is a beautiful horse
DR ALASTAIR GUNN
chestnut tree. While writing this, I’m watching some
Alastair is a radio astronomer
birds hopping through their branches. But why do some at the Jodrell Bank Centre for
Astrophysics at the University
birds hop, while others run? Find out on page 56. Or of Manchester
maybe you’re reading this as you stand in the magazine aisle at the supermarket.
Is there a delicious smell wafting from the bakery? So how does your brain know
it’s delicious? All is revealed on page 12. Or maybe you’ve bought the magazine
already and are now enjoying it with a glass of cola. But could you enjoy the ROBERT MATTHEWS
Ater studying physics at Oxford,
same fizzy drink in space? Check out page 28. Robert became a science writer.
Children often have incredibly enquiring minds, and their supply of ‘But He is also Visiting Professor
in Science at Aston University
whys?!’ is inexhaustible. So if you find yourself struggling to come up with
satisfactory explanation for all their questions, then we’re sure you can find
the answers in The Big Book Of Why?, brought to you by BBC Focus.
But even if you don’t have kids, there are oodles of facts here to feed the GARETH MITCHELL
Starting out as a broadcast
curious mind. We’ve covered all the bases, including animals, the environment,
engineer, Gareth now writes
space, the human body, and much more. So get ready to start impressing your and presents Click on the
BBC World Service
friends and family, and maybe you’ll even win your next pub quiz!
Enjoy!
LUIS VILLAZON
Luis has a BSc in computing
and an MSc in zoology from
Oxford. His works include
How Cows Reach The Ground
Alice Lipscombe-Southwell, Managing Editor
EDITORIAL PRODUCTION BBC WORLDWIDE, © Immediate Media Co Bristol Ltd 2016. All rights
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While every atempt has been made to ensure that the content of The Big Book Of Why? was as accurate as possible at time of press, we acknowledge
that some information contained herein may have since become out of date. Also, the content of certain sections is occasionally subject to
interpretation; in these cases, we have favoured the most respected source.
THE BIG BOOK OF WHY? 3
CONTENTS
Pop: the
question
What’s best for you –
cola or diet cola?
C O N T E N T S See p37
8 20 32

The World
Around Us
Human Body
Does puting a wet
Space
Why do people get mobile phone in rice
migraines? Why do we What caused the Big Bang? dry it out? Is it safer to
have wisdom teeth? Can lightning occur in space? sit backwards on a plane?
Do fingerprints change? What’s the biggest known star? How does a whistling ketle whistle?
44 52 64

A
S
A
N
Y,
T
T
E
Energy and Environment Animals Technology O, G
T
R
What would happen if all the glaciers melted? Which fish can jump highest out of water? How precise is robotic surgery? BU
A
Do trees have to be used to make paper? Why do dogs and cats enjoy being stroked? How do governments prevent cyber atacks? O
VI
Should we move polar bears to Antarctica? Why don’t buterlies ly in straight lines? What is the world’s smallest camera? TA
C
O
S,
S
E
76 84 96 PR
A
R
ME
A
Y, C
R
A
R
B
O LI
T
O
H
P
E
C
N
E
CI
3, S
X
K
C
O
T
S
Genetics and Evolution Planet Earth Maths and Physics MY, I
A
L
Is the rate of human evolution increasing Has Earth ever had more than one moon? Does time exist in space? S: A
with population growth? Is talent genetic or Is there a limit to human population? What’s the most amazing result in maths? TO
O
learned? What’s the earliest writen language? Is every snowlake really unique in shape? Are coin tosses really random? PH
4 THE BIG BOOK OF WHY?
CONTENTS
6 18 30

The Big
Picture
N 42 50 62 74
O
T
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E
W
UL
A
P
Y,
M
A
L
A
M,
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A
U
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A
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D
SI
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/
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OO 82 94 104 112
Y B
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N
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N, F
O
CIATI 106
O
S
S
A
S
S
E
R
P
TH, How It Works
R
O
W
R
E
T
UT OFormula E electric race cars
B
ON OMind-controlled robotic exoskeletons
M
Y, SI OHow geckos can cling to anything 
T
GET O The non-stop, solar-powered plane
L,
EL O The ‘smart’ cap for milk cartons
N
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X C
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A
2,
X
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P
THE BIG BOOK OF WHY? 5
THE BIG PICTURE
HOW GREEN
IS MY VALLEY?
The buildings of Gouqi Island are slowly being consumed by
a thick blanket of green. The island is located a few hours east
of Hangzhou Bay in eastern China and was once home to a
thriving fishing community. But as the shipbuilding and
tourism industries grew, the village became deserted. With
nobody left to maintain them, the buildings were soon
reclaimed by the natural world.
“These buildings are covered with Parthenocissus
tricuspidata, a relative of the grape vine and Virginia
creeper,” explains Dr Alastair Culham, Curator of the
University of Reading’s herbarium. ‘It’s native to China but is
also widely cultivated as an ornamental climber for its red
autumn foliage and was probably already planted there to
decorate the houses. It’s equivalent to ivy in the UK, which
will soon cover a building if left alone.”
Y
T
T
E
G
O:
T
O
H
P
6 THE BIG BOOK OF WHY?
THE BIG BOOK OF WHY? 7
THE HUMAN BODY
T H E H U M A N
B O DY
Organ transplants, wisdom teeth, suncream protection, fingerprints,
sense of smell, heart rate and music, phobias, embarrassment...
WHY DO SOME
PEOPLE GET
MIGRAINES?
Amazingly, the precise cause of migraines
is still unknown. These intense headaches –
often on one side and accompanied by nausea
and sometimes visions of zigzag lines and
extreme sensitivity to light and noise – must
be caused by abnormal brain activity. But we
just don’t know what kind or whether there
are many different causes.
Hormonal fluctuations, especially
in oestrogen, can trigger migraines,
so some women suffer more during
menstruation, pregnancy or menopause.
Certain foods and additives can also
cause migraines, while people who
diet, skip meals or consume a lot of
caffeine can suffer. Disturbed sleep
and jetlag can also cause them.
One rare inherited type called
familial hemiplegic migraine is
caused by four specific gene
mutations. More common types are also
associated with many different genes that
affect brain function. The simplest answer
lies in the family. Up to 90 per cent of
sufferers have a family history of migraines.
8 THE BIG BOOK OF WHY?
WHY ARE SOME PEOPLE
PERFECTIONISTS?
This is because of the way that leading to high achievement,
genes and experience work satisfaction and self-esteem,
together. Genetic effects are seen it can also be negative with harsh
even in newborn babies, whose self-criticism, procrastination,
different temperaments show the disappointment and depression.
beginnings of their personality. Both are related to the ‘Big
Recent twin studies suggest Five’ personality traits that sum
that personality is more heritable up our relatively stable adult
than previously thought. personalities. These traits are
Identical twins are twice as openness, conscientiousness,
likely as non-identical twins to extraversion, agreeableness
share particular qualities, such and neuroticism. Yet all these
as determination, self-control traits are subject to the effect
and a sense of purpose. While of life’s encouraging or
perfectionism can be positive, dispiriting experiences. How does
suncream protect
you from sunburn?
Opaque sunblocks are, effectively, paint: inorganic

particles of white t itanium dioxide or zinc oxide
suspended in a heavy oil. The oxide particles form
an opaque barrier that reflects visible light and
ultraviolet. Clear suncreams use organic
compounds, such as phenylbenzimidazole sulfonic
acid, which protects from UVB and lets visible
light through. Many creams blend inorganic and
organic particles to offer good protection.
Why do we go red
in the face when
embarrassed?
4
X
CK Humans seem to be the only animals to show
O
ST embarrassment, leading Charles Darwin to describe
Y, I
R blushing as “the most peculiar and most human of all
A
R
B expressions”. Blushing makes it harder to lie, which
TO LI seems like a disadvantage. However, a 2009 study by
O
PH Dutch psychologists found that we are more likely to
E
NC give people a second chance if they blush when they
E
S: SCI betray us. The ability to blush acts as a signal that you
O are sensitive to the social rule you have just broken.
T
O
H Psychopaths, on the other hand, do not blush at all.
P
THE BIG BOOK OF WHY? 9
THE HUMAN BODY
TOP TEN
Can an organ
HUMAN PHOBIAS
be transplanted
SUFFERED FROM IN THE UK
more than once?
=1. Arachnophobia
Yes. Sometimes patients will receive
Fear of spiders
Proportion of population heart or liver transplants but die
afected: 33 per cent anyway within a few weeks and, in
very rare cases, the donated organ
was still healthy enough to be worth
=1. Ophidiophobia re-transplanting to a new patient.
Fear of snakes In 2012, a 27-year old man from the
Proportion of population
US received a kidney transplant
afected: 33 per cent
but then had it removed again two
weeks later because the disease he
was suffering from was damaging
3. Astraphobia
the kidney. Doctors rescued it in
Fear of thunder/lightning
Proportion of population time and gave it to a 67-year old man
afected: 15 per cent instead, returning the first patient
to dialysis treatment.
=4. Trypanophobia
Fear of needles
Proportion of population
afected: 10 per cent
ARE WOMEN
=4. Claustrophobia REALLY BETTER AT
Fear of enclosed spaces
Proportion of population MULTI-TASKING?
afected: 10 per cent
Maybe, but the brain cannot
handle two complex tasks at
6. Odontophobia once, so what looks like clever
Fear of dentists multi-tasking is more often
Proportion of population
afected: 9 per cent switching quickly between two
or more tasks. This is an
inefficient way of working
7. Aviophobia because the brain has to
Fear of lying both decide when to switch
Proportion of population
afected: 7 per cent and remember each task.
In many laboratory tests, men
and women do equally well. In
8. Acrophobia a more realistic study, men and
Fear of heights women under time pressure had
Proportion of population
to juggle simple mathematics
afected: 5 per cent
problems, answer the phone and
decide how to find something
9. Cynophobia lost in a field. During the study,
Fear of dogs the women were found to be 0
Proportion of population calmer and better organised K X1
afected: 3 per cent OC
than the men. But even if this T
S
difference is real, we still don’t TY, I
T
know whether it is biological GE
10. Agoraphobia S:
or culturally imposed. O
Fear of public spaces OT
H
Proportion of population P
afected: 2 per cent
10 THE BIG BOOK OF WHY?