DK Findout! Science - Dorling Kindersley

Earth, wind, and fire

Some plants have more dramatic or unusual
ways of spreading their seeds. Fire may kill
the parent plants, but it leaves behind fertile
ash for their seeds to grow in.

Sticky seeds Heat treatment
Jack pine cones are glued shut with resin.
tspSpAheatleanairdctnitkmsssty,tsoaciscflwasekltielhctetdahodesnoitrbwuhcubtaierolrelsadrv,anyyhet,itnsamwaevrceaehehdlial’lssitletioftazsulwideonriam.hfgyfoeeifotrr.keosnmt When a fire sweeps through the trees, the
resin melts and the seeds are released.

Desert rover
Tumbleweed is
the dried-up top
part of some
plants. It rolls
around the
desert whenever
the wind blows,
scattering its
seed as it goes.

Exploding pods Pop!

ps2sttaswc2phpahTsaorheslfohtatemdtetolneresni(t.snt.7rHi-TtngTkbthmihghehmyueee.e)etnyaphsaesslaseweaxeuryeippssaetadpleoysornsee,dissdcopusbeitosfepeaeitn,ndolxetsgsunpocaatlimonnodfe

49

Moth Insects
toise
Tor All insects have six legs and a pair
of feelers on their heads, like this
moth. Most of them have wings
and can fly.

Reptiles

Reptiles are covered in hard,
dry scales, or a shell, like this
tortoise. They have either four
legs or no legs at all.

Giraffe

Mammals

Mammals have fur
or hair on their bodies,
and feed their babies milk.
Humans are a type of mammal.

Animals

There are millions of different types of
animal on Earth, so scientists have divided
them into groups, based on features
that they share. For example, is
their body covered in fur, feathers,
or scales? The amazing imaginary animal
shown here combines key parts of
animals from six well-known groups.

50

Birds

Birds have wings,

and they are the

Par akeet only animals that
have feathers, which

keep them warm and

help them to fly.

Fish Manda

All fish live in water and use rinfish
their tails to help them
swim. Their bodies are
covered in scales, and
they have gills for
breathing underwater.

Frog

Amphibians

Amphibians live both on land
and in water. Most of them
have four legs, which they use
for walking and swimming.

51

Heart
ain

52
Thinking Br

The brain controls the body, The jaw and teeth
sorting out information from are used to bite
and chew food.
the world around you and
sending out instructions. It

also stores memories.

Lungs Pumping

Breathing With each beat, the heart
pumps blood around
Lungs bring air into the body the body, delivering
through breathing. This air nutrients and
contains oxygen, which is oxygen to
needed to keep the body alive. every part.

Eating Digestive system The ribs form a
cage that protects
The body needs the heart and
food to survive. lungs.

The digestive Hands can grip
system breaks food and hold objects
such as tools
down, keeping the and pens.
nutrients and getting

rid of the waste.

Being human Strong muscles

Like all vertebrate animals, humans Muscles are like elastic
have bony skeletons underneath their straps that can stretch
skin and muscles. It is a framework to or squeeze. Many
hold up the body, help it move, and muscles move the body
protect what is inside. The amazing by pulling on the bones.
brain makes humans the smartest of
all the animals. That includes you! Strong legs help
humans to run,
4 Body facts climb, and swim.

1 Human skeletons contain more Standing tall
than 200 bones. The smallest
bone is inside the ear and is only Unlike most animals,
1⁄8 in (3 mm) long. humans walk upright
on two legs. This allows
2 The thighbone is the strongest the arms to be used for
bone in the body. It is about four other activities, such as
times stronger than concrete. making things.

3 A human heart beats more than
100,000 times in a day. That is
over 35 million times in a year.

4 In one day, blood travels about
12,000 miles (19,000 km) around
the body.

53

Darwin, 1809–188 Moth

Charles 52, UKComputers
Ada
n, 1847–1931, US Ada Lovelace wrote the
2, UK Lightbulb
Beetle Great first published computer
scientists program. She also
Evolution
Life is full of problems, and predicted that a computer
Charles Darwin figured would be able to make
out how animals, such music and images, not
as moths and beetles, just do math problems.
can change over
many generations Lovelace, 1815–18
to become new

species. This scientists are always trying to find
process is called new ways to solve them. There are
evolution.

hundreds of great scientists who

have changed our lives for the better,

through their discoveries and their

inventions. Here are seven of them. 011010101000101000100

110000101010111100101

Lightbulb Thomas Ediso 00101000100100101000101
11110010101 01101010100010
Thomas Edison is best 100010111000010101011110010
known for inventing 00010100010010010100010111000010
the first lightbulb that 101 0110101010001010001001001010001011
could be made in large 1110010101 011010101000101000100100101
numbers. He also invented 10101011110010101 01101010100010100010
a sound recorder and a 111000010101011110010101 0110101010001
moving-image projector, 0100010111000010101011110010101 011010
which helped to start the 1001001010001011100001010101111001010
age of movies. 0101000100100101000101110000101010111

A 010 0110101010001010001001001010001011

“To invent, you need Modern computer
a good imagination
and a pile of junk.”

54

Isaac Newto n, 1642–1727, UK Gravity

Isaac Newton is said to have
discovered how gravity works
when he saw an apple fall
from a tree. He realized that
there must be a similar force
that keeps the Earth moving
around the Sun.

Radioactivity Marie Curie’s work also helped with
the development of X-rays for use
Marie Curie discovered two
substances, called radium and in operations in hospitals.
polonium, that give off
invisible rays that can pass
through materials. She called
these rays radioactivity. 7–1934, Poland
Marie Curie, 186
“Nothing in life is to
0100101000101 be feared. It is only bert Einstein, 1879–1955, Germany Relativity
101 0110101010 to be understood.”
1110000101010 Albert Einstein’s theories
0100010010010 ander Fleming, 18 of relativity, along with his
0101 011010101 Alex 81–1955, UK groundbreaking E=mc2
0101011110010 equation, helped scientists to
1100001010101 understand the universe, and
1000101110000 how energy, mass, space, and
0010010100010 time are all related.
1010001001001
0101000101000 Al
01 01101010100
1100101001111 Antibiotics
1100001010101
Alexander Fleming discovered
Antibiotics penicillin, which led to the
creation of a group of medicines
called antibiotics. They kill the
bacteria that cause many
infections in humans and other
animals, and so have saved
millions of lives.

Einstein’s famous equation

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Science in action

Science is all around us. From the moment we wake up to the moment
we go to bed, almost everything that we do or that happens to us can
be explained by science. Here are a few examples of the ways that
science helps us to understand what goes on in our daily lives.

Rise and shine! Light the way

Science explains Science explains how
how a rooster could flicking a switch turns
wake us up in the
morning. Sound on our lights, by
waves travel through allowing electricity to
the air from the
rooster’s mouth to flow around an
our ears. electrical circuit.

dCooocdkl-ea--do!

Keeping warm Eat up!

Science explains how our clothes keep Science explains why we need to eat food
us warm. Wool and cotton are poor every day. Food contains stored energy
conductors of heat energy, so they that we need in order to move, grow, and
stop our body heat from escaping. keep warm.

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Woosh!

On the Sun power

move Science explains why a plant grows when we
put it on a windowsill. Plants use energy
Science explains how from sunlight to produce food, which gives
we can use a bicycle to the plant energy to grow.
travel quickly. The grip of the
tires produces friction between
the wheel and the road, which helps
to push the bike along.

Time for bed

Science explains why the Moon stays in the sky.
The force of gravity from the Earth pulls on the
Moon, keeping it in orbit around our planet.

Boing!

Ball games

Science explains why a ball moves when we
kick, throw, or hit it. Our arms and legs
produce a force that propels the ball forward.

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Science facts 42 quarts
and figures
(40 liters) is the
The world of science is full of amazing total amount of
things. Here are some weird and water in the body
wonderful facts and figures that of an adult man of
you may not know. average weight.

This is enough c A humpback whale’s song
can travel more than
ement to make 5,000 of Eg4½ billion 1,600 miles (2,600 km)
through water.
tons (4 billion metric
tons) of cement are Giza.
made in the world

every year.

ypt’s Great Pyramid of

23 186,283
miles per second (299,792 kilometers per
English scientist second) is the speed at which light travels.
Isaac Newton was only If you could move this fast, you could go
23 years old when he around the Earth 7.5 times in one second.
first described the
force of gravity.

58

(1T5hcemE)ififnelsuTomwmeerriwnhPeanritsh,eFirraonnciet,is“grmoadwes”ofbeyx6p iannds.The number of times l ar.
nd in the US every ye
97.2% 25
million
of all water
on Earth is ightning hits the grou
undrinkable
because it is 600 volts
saltwater.
is the shocking amount of
electricity an electric eel can
produce. That is enough to kill

any other fish nearby.

352,000 ½ in (10 mm) is the distance a
maglev (magnetic levitation)
train is lifted above the
track using magnets.

different species of flowering plant are alive
in the world today, and there may be many
more that are yet to be discovered.

59

Glossary gas State of matter with
no fixed shape, such as
Here are the meanings of some words that air, that fills any space
are useful for you to know when learning it is in
about science.
gravity Invisible force that
pulls objects toward each
other

attract When two things conductor Substance that groundwater Water found
pull toward each other allows heat or electricity to beneath the Earth’s surface
pass through it easily
bacteria Tiny creatures that herbivore Animal that eats
live everywhere on Earth, echo Sound that has only plants
such as inside food, soil, bounced off a surface
or even in the human body and been sent back invertebrate Animal that
in the direction it does not have a backbone
boil When a liquid is started from
heated to a temperature insulator Substance that
at which it bubbles and electricity Type of energy does not allow heat or
turns into a gas or vapor that can be used to power electricity to pass easily
called steam household items through it

brittle Easily snapped evaporation When a liquid The force of the
is heated and changes tennis racket hitting
carnivore Animal that eats into a gas or vapor the ball causes the
only meat ball to change
evolution Process where direction.
characteristics Certain living things change, over
qualities or features that many generations, to become
things, animals, plants, or new species
objects have
force Push or pull that
circuit Loop that an electric causes things to start
current travels around moving, move faster,
change direction, slow down,
condensation When a gas or stop moving
cools and becomes a liquid.
Often seen as droplets of friction Force created when
water that form on cold two surfaces rub or slide
surfaces, such as windows against each other

60

irreversible Change that omnivore Animal that eats Steel paper clips
cannot be undone both plants and meat that have been
attracted to
laboratory Place where organ Body part that has a horseshoe
scientists conduct a certain job, for example, magnet.
experiments the heart

light Type of energy that organism Living thing spectrum Range of
allows humans and other something—for example,
animals to see reflect When light or sound the range of colors in a
is bounced off a surface rainbow
liquid State of matter that
flows and takes the shape of repel When two objects temperature Measure of
any container it is in push away from each other how hot or cold things are

magnetism Invisible force reproduce To have young
that is created by magnets,
which then pull certain reversible Change that can
metals toward them be undone

mass Amount of matter rust Reddish-brown vertebrate Animal that has
that is in an object crystals that form on iron a backbone
and steel when they come
material Substance that into contact with water weight Amount of the force
can be used to make things. and oxygen of gravity that acts on an
It can be natural or made object, making it feel heavy.
by humans shadow Formed when light The more mass something
rays are blocked by a solid has, the larger the force of
matter Stuff that all things object gravity on the object, and
are made of the heavier it feels
solid State of matter that
melt When a solid is heated holds its shape
and becomes a liquid
solution Mixture that
mixture Combination of is created when a solid
more than one type of thing dissolves in a liquid and
disappears
nutrients Food or substance
that gives a living thing the sound Form of energy that
energy or chemicals that it is produced when objects
needs to live, grow, and move vibrate, or shake

61

Index

A E H

air resistance 17, 19 Earth 22, 55, 57, 58 heart 52, 53
amphibians 51 echoes 31 heat 27, 28–29, 56
animals 4, 44, 47, 48, 49, Edison, Thomas 54 human body 29, 52–53, 58
Einstein, Albert 55 hydroelectric power 36
50–51 electrical circuits 38–39, 56 hydrogen 42, 43
antibiotics 55 electricity 4, 26, 36–37,
attraction 40, 41 I
axles 25 38–39, 59
energy 26–27, 28, 31, 32 42, ice 7
B insects 50
55, 56, 57 insulation/insulators 39
bacteria 55 evaporation 11, 12, 14 inventions 54–55
batteries 38 evolution 54 iron 8, 40, 59
berries 46, 48 excretion 44, 48 irreversible changes 13
birds 51
blood 53 F J
boiling 7, 29
bones 53 filtering 11 jumping 22–23
brain 52, 53 fire 29, 49
bricks 9 fish 51 L
Fleming, Alexander 55
C flowers 46 Laws of Motion 18–19
food 26, 44, 46, 47, leaves 13, 47
changes 7, 12–13 levers 24
chemical energy 26 52, 56 lifting 24–25
cloth 9 forces 16–17, 18, 19, light 27, 32–33, 34–35, 56
clouds 14, 15
color spectrum 35 20, 24, 25, 40, 57 bulbs 39, 54
comets 43 freezing 12, 29 speed of 58
computers 54 friction 20–1, 57 lightning 37, 59
condensation 13, 14 fruits 46, 48 liquids 5, 6–7, 10, 11, 12
conduction/conductors 28, fuel 36, 45 living things 4, 44–45
fulcrums 24 loads 24–25
39, 56 funguses 45 Lovelace, Ada 54
convection 28 lungs 52
Curie, Marie 55 G
M
D gases 5, 7, 10, 11
gears 24 machines 24–25
Darwin, Charles 54 glass 9, 29 magnets/magnetism 5, 16,
deserts 15, 49 gravity 22–23, 55, 57, 58
digestive system 52 groundwater 15 40–41, 59
growth 44 mammals 50

62

mass 55 reflection surfaces 20–21
materials 8–9 light 32, 34 switches 38, 56
matter 5, 6–7 sound 31
medicine 55 T
melting 12, 15, 29 relativity 55
metals 8, 28 repelling 41 temperature 29
mixtures 10–11 reproduction 44, 46
molds 45 reptiles 50 U
Moon 22, 23, 57 resistance 17
movement 16–17, 18–19, 26, respiration 44, 52 universe 55
reversible changes 12, 13
44, 57 rock 9 V
muscles 53 rockets 23, 31
roots 47 vertebrates 53
N rotting 13 vibrations 27, 30, 31
rust 13
Newton, Isaac 18–19, 55, W
58 S
water 7, 11, 14–15, 29, 47,
non-magnetic materials 41 scientists 54–55, 42–43, 58, 59
nutrition 44, 56 54–55
water cycle 14–15
O screws 25 water molecules 42
seeds, spreading 48–49 water resistance 17
oxygen 42, 52 sensitivity 44 waves, sound 30–31, 56
shadows 5, 32–33 wedges 24
P sieving 11 wheels 24, 25
sight 32 wind 16, 48, 49
plants 44, 45, 46–47, 48–49, skeletons 53 wind turbines 36
57, 59 sliding 20–21 wires 37, 38, 39
snow 15, 29 wood 9, 47
poles, magnetic 41 solar energy 36
pollination 46 solids 5, 6–7, 10, 11, 12 X
potential energy 27 solutions 10, 11
power plants 36–37 sound 27, 30–31 X-rays 55
properties 8 space 19, 23, 29, 31, 43, 55
pulleys 25 state, changing 7
pulling 5, 17, 19, 24, static electricity 37
steam 7, 13
40, 41 steel 40
pushing 5, 16, 19, 24, stems 47
stored energy 27
40, 41 Sun 14, 27, 28, 29, 32, 33, 34,

R 42, 57
sunlight 16, 34, 57
radiation 28
radioactivity 55
rain 15, 34–35
rainbows 34–35
rays, light 32–33, 34

63

Acknowledgments

The publisher would like to thank the following people for their assistance in the preparation
of this book: Kathleen Teece, editorial assistant; Lucy Sims, designer; Emma Hobson, designer;
Surya Sarangi, picture research; Alexandra Beeden, proofreader; Helen Peters, indexer; Dan Crisp,
illustrator; and Lorraine Johnson for photography. The publishers would also like to thank
Dr. Suze Kundu of Imperial College London, UK, for the Meet the Expert interview.

The publisher would like to thank the Alamy Images: Leo Kanaka (fbr). Dorling Canada Photos (tl). Corbis: Leander Baerenz
following for their kind permission to Kindersley: The National Music Museum / Westend61 (br). 62 Alamy Images: David
reproduce their photographs: (crb). Getty Images: Nash Photos / Wall (tl).
Photographer's Choice RF (tr). 42 Ed
(Key: a-above; b-below/bottom; c-center; Prosser: (tr). 42-43 123RF.com: Ekasit Cover images: Front: Corbis: Dave Michaels
f-far; l-left; r-right; t-top) Wangprasert / bankerwin (b). 44-45 br; Dreamstime.com: Jakub Gojda / Jagcz
Dreamstime.com: Geert Weggen / clb; Back: 123RF.com: Dimitar Marinov /
2 Alamy Images: Kim Karpeles (bl). Corbis: Geertweggen. 45 Dreamstime.com: oorka tl; Alamy Images: Everett Collection
Hank Grebe / Purestock / SuperStock (bc). 3 Yauheni Krasnaok / krasnaok (tr). 46 Alamy Historical cra; Corbis: 145 / Steven Puetzer /
Alamy Images: Olga Khomyakova (bl). 4 Images: Zoonar GmbH / Peter Ocean cr, AgStock Images tr; Spine: Getty
Dorling Kindersley: Natural History Himmelhuber (tc). Corbis: Robert Pickett (tl). Images: Nash Photos / Photographer's
Museum, London (clb, fclb). 6 Corbis: 46-47 Alamy Images: Olga Khomyakova. Choice RF; Front Flap: 123RF.com: Ekasit
Momatiuk - Eastcott (tr); Dave Reede / All 47 Corbis: AgStock Images (r); Houin / BSIP Wangprasert / bankerwin bl/ (back); Alamy
Canada Photos (b). 7 Corbis: (tl). 8 Corbis: 2 (tr). 48 Corbis: Dave Michaels (cl); Thijs van Images: Kim Karpeles c/ (front); Corbis: 145
/ Travelif / Ocean (cb). 8-9 Dreamstime. den Burg / NIS / Minden Pictures (cr). 49 / Ocean cla/ (back), Hank Grebe / Purestock /
com: Juhku. 10 Alamy Images: Alamy Images: Don Johnston_PL (tr); SuperStock br/ (back); Dorling Kindersley:
Fotograferen.net (br). Corbis: 167 / Stacy Nurlan Kalchinov (cr). Corbis: (tl). Science The National Music Museum cr/ (back);
Gold / Ocean (tl); India Picture (tr). 13 Photo Library: Dr. Keith Wheeler (br). 50 Fotolia: Tujian cra/ (back); Getty Images:
Corbis: Chris Clor / Blend Images (crb/rusty). Corbis: 145 / Ocean (c); Nature Picture Nash Photos / Photographer's Choice RF tr/
Getty Images: Fahim Shafayat Rahman / Library (br). Dorling Kindersley: Natural (back); naturepl.com: David Pattyn tc/
Moment Open (cra). 15 Corbis: EPA (tr). History Museum, London (tl, tc). Fotolia: (front); Back Flap: Dorling Kindersley: Gary
Dorling Kindersley: Tim Draper / Rough StarJumper (cl); Tujian (ca). 50-51 Fotolia: Ombler / The University of Aberdeen cl/
Guides (tc). 16-17 Corbis: Andrea Francolini. Tujian. 51 Corbis: Nature Picture Library (bc, (front), Tim Parmenter / Natural History
17 Alamy Images: Leroy Francis / hemis.fr br). 52-53 Corbis: Hank Grebe / Purestock / Museum, London crb/ (front); NASA: JSC
(tr). 19 NASA: JSC (tr). 20-21 Alamy SuperStock. 54 Alamy Images: Pictorial clb/ (front).
Images: David Wall (t). 22 naturepl.com: Press Ltd (cr). Corbis: Bettmann (clb, ftl).
David Pattyn (crb, bl). 23 Corbis: Kirk Dorling Kindersley: Natural History Endpapers: Front: Alamy Images:
Norbury / incamerastock (cla/squirrel); Roger Museum, London (tl). 55 123RF.com: Georgios Kollidas (gravity); Kumar Sriskandan
Ressmeyer (tr). NASA: Joel Kowsky (cra). Narongsak Yaisumlee / studio306 (ftr). (columns). Dorling Kindersley: Museo de
naturepl.com: David Pattyn (br, clb). 24 Alamy Images: Everett Collection Historical Sitio Huaca Pucllana (bricks); The Science
Corbis: 145 / Steven Puetzer / Ocean (tr). 25 (cb). Corbis: (tl); Oscar White (clb); Museum, London (wheel). Back: Alamy
Alamy Images: Kim Karpeles (clb). Corbis: Underwood & Underwood (c). Fotolia: Images: Everett Collection Historical
Missen / RooM the Agency (tr). 27 Corbis: Dario Sabljak (tr). 56 Corbis: Monkey (penicillin); GL Archive (lovelace); Pictorial
Brett Stevens (bl). 29 Corbis: robertharding Business Images (cr); Ian Nolan / cultura (bl). Press Ltd (einstein). Corbis: Bettmann
(bl). Dorling Kindersley: NASA (tr). 30 57 Corbis: 2 / Mark Lund / Ocean (tr); (darwin, heart transplant); Najlah Feanny /
Alamy Images: matthiasengelien.com (tl). Leander Baerenz / Westend61 (cl). Dorling Corbis Saba (cloning). Dorling Kindersley:
31 NASA: (cb). 34-35 Alamy Images: Mike Kindersley: Getty Images / Photographer's Gary Ombler / Whipple Museum of History
Grandmaison / All Canada Photos. 36 Choice RF (bl). Dreamstime.com: Gregsi of Science, Cambridge (battery); The Science
123RF.com: Steve Allen / steveallenuk (br); (br). 58 Getty Images: M Sweet / Moment Museum, London (lightbulb). Getty
Dimitar Marinov / oorka (bl); skylightpictures (cr); ScPhotographie / Photographer's Images: CBS Photo Archive / CBS (goodall).
(tl); scalatore1959 (tr). 37 Dreamstime.com: Choice (b). iStockphoto.com: mstay (cl). 59
Monkey Business Images / Alamy Images: Bernd Mellmann (br). All other images © Dorling Kindersley
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Robbie George / National Geographic (r). 39 Alamy Images: Mike Grandmaison / All www.dkimages.com

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