BookendsThe word

Incredible journeysNatural History Museum Atlas of Bird Migration edited by Jonathan Elphick, Natural History Museum (UK)/Firefly Books (US), £19.99/$35, ISBN 9780565092184/ 9781554072484 Reviewed by Debora MacKenzie

BIRD migrations

are among the

marvels of the

natural world.

This newest

incarnation of the

Atlas of Bird Migration, which

now includes results from

satellite tracking, is a graphic

overview of them all, from auks

to warblers and from Alaska to

Australia. An abundance of

maps, diagrams and photos

showing which birds go where

are accompanied by snippets on

conservation or how particular

migrations evolved, for example.

A good book for browsing, or for

when the kids ask, “Where does

that bird go in winter?”

Look up in wonderWhy the Sky is Blueby Götz Hoeppe, Princeton University Press, £18.95/$29.95, ISBN 9780691124537 Reviewed by Jon Richfield

DELIVERING far

more than the

title promises,

Hoeppe’s book

describes an

intellectual quest

that began with

the ancients. He details our

growing understanding of the

sky’s light, and the insights and

experiments that brought

it about. After the mid-19th

century, abstract studies of sky

light fostered advances in

climatology, physiology, ozone,

astronomy, electromagnetism

and more. A well-illustrated,

rewarding read that answers

one of the most frequently

asked questions addressed to

New Scientist’s The Last Word.

Enigma

IT IS very hot, very flat, and very bare.

You might also consider it very ugly.

Explorer Edward John Eyre, the first

European to cross it in 1841, reportedly

described it as “a hideous anomaly, a

blot on the face of nature”. Others

find its bleakness perversely

beautiful. At first glance, it may look

like a whole lot of nothing, but there

is far more to the Nullarbor than

meets the eye.

The name comes from the Latin

“null” for “nothing” and “arbor” for

“tree” – an appropriate name for the

1200-kilometre-wide swathe of

desolation straddling the border

between South and Western Australia.

Still, the Nullarbor has become a

magnet for tourists, scientists and

potholers, not to mention 32 Postie

bike riders, who on 7 May will begin

an attempt to cross this inhospitable

plain on second-hand Hondas bought

from the Australia Post.

What is the big attraction? For a

start, it’s the world’s largest slab of

limestone, deposited by marine

organisms 15 to 25 million years ago

when the Nullarbor was still sea floor.

Today its surface is littered with

meteorites that have accumulated over

the past 35,000 years or so. The

meteorites are preserved by the arid

conditions. Usually dark coloured, they

are easy to spot against the pale,

featureless plain, making the Nullarbor

a prime locale for planetary scientists.

The limestone is responsible for

some impressive sights. Because

limestone is partially soluble, any

water that has visited Nullarbor

has left its mark. In some coastal

regions the Southern Ocean flows

inland for several hundred metres,

creating spectacular blowholes and

underground rivers. Rain run-off from

a wet phase of the plain’s history

roughly 6 million years ago has riddled

the region with hundreds of caves.

Nullarbor’s caves have harboured

more than their fair share of

palaeontological treasures. The most

recent find, which was described in

detail for the first time this January

(Nature, vol 445, p 422), is a cache of

fossils representing 69 different

species of prehistoric mammals, birds

and reptiles, including the first

complete skeleton of a marsupial lion.

There were also several species of tree-

climbing kangaroo, suggesting that

the Nullarbor once hosted more

vegetation than today’s sad display of

drought and salt-tolerant shrubs.

Sure it’s got some strange scenery,

but who dares to try to cross the

Nullarbor? Backpackers in clapped-out

cars, retirees on trains and

engineering students in solar-

powered vehicles feel compelled to

make the journey, often in the height

of summer. Food, water and petrol are

in short supply, though a tarmacked

road, the Eyre Highway, now runs

along its southernmost edge.

Not that those Postie bike riders

will bother with the modern road in

their upcoming trek. They will ride

straight through the hostile terrain

next week to raise money for the Royal

Flying Doctor Service of Australia. ●

Nullarbor

“Today its surface is littered with meteorites”

The missing linkNo. 1441 Susan Denham

I SENT in the Enigma on the right, and it was

accepted for publication.

Unfortunately in the meantime the

digit that should have been printed in the

shaded square has become smudged and

is illegible. However, that should not stop

you doing the puzzle. Please send in the

intended answer to the original puzzle.

AER

OPI

X/A

LAM

Y

56 | NewScientist | 5 May 2007 www.newscientist.com

£15 will be awarded to the sender of the

first correct answer opened on Wednesday

6 June. The Editor’s decision is final. Please

send entries to Enigma 1441, New Scientist,

Lacon House, 84 Theobald’s Road, London

WC1X 8NS, or to enigma@newscientist.com

(please include your postal address). The

winner of Enigma 1435 is John Wilby of

Belmont, Queensland, Australia.

Answer to 1435 A good sign

8, 8, 7, 7, 9, 7.

“Fill in each of the empty spaces with a

non-zero digit so that the rows, columns and

main diagonals add up to the total shown:

Please send in the completed grid.”

1

7

3

20

20 22 15 15

15

8

20

29

9

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