BBC_Earth_Singapore_2017

FALLING

UPWARDS

BY RICHARD

HOLMES

OUT NOW

FROM

ALCHEMY TO

CHEMISTRY

IN PICTURE

AND STORY

BY ARTHUR

GREENBERG

OUT NOW

BEYOND UFOS

BY JEFFREY

BENNETT

OUT NOW

AUTHOR’S

BOOKSHELF

Three books that inspired

Sam Kean while writing

Caesar’s Last Breath

“Holmes writes the best kind of

science books, capturing exactly

the wonder and awe that attract

people to science, and that help

pack museums and natural parks

around the world. This book

resurrects the miracle of flight in

the days before airplanes.”

“A fascinating book about the

painful, complicated, and

sometimes amusing transition

that turned disreputable

alchemists into the lions of

modern chemistry. Encyclopaedic

and lavishly illustrated.”

“The first signs of alien life almost

certainly won’t be hovering UFOs,

but subtle traces of gases in the

atmospheres of distant planets.

Bennett’s book captures the

magnitude of the quest for alien

life, and its incredible implications

for humanity.”

Julius Caesar has
been dead for 2,061
years, but the air he
breathed is still in
circulation

If you wanted to travel back in a time

machine to the Earth’s distant past

and take a deep breath outside, you’d

only be able to go back a few hundred

million years – it’s only very recently in

our planet’s history that there’s been

enough oxygen to sustain us.

How is the air we breathe

changing?

The atmosphere is like a living thing

• it’s constantly evolving. The rates of
  carbon dioxide and other greenhouse
  gases are increasing, and the air is
  more radioactive now because we’re
  still dealing with fallout from 1950s
  nuclear weapons tests.
  We also see a lot more complex,
  human-made molecules in the air
  today. If aliens were to look at our
  planet’s atmosphere, the presence of
  these gases would be a good sign that
  the Earth harbours life. Likewise, the
  next generation of telescopes should
  allow us to start looking for these
  complicated gases in the atmospheres
  of distant exoplanets, helping us

to search for the best candidates for

extraterrestrial life.

I think it’s also inevitable that we’ll find

an exoplanet with a great mix of gases

for us to survive on. The hard part will be

figuring out how to get there.

What other interesting stories did

you uncover about the air?

One of my favourites involves Charles

Dickens. In his 1853 novel Bleak House,

a character called Krook appears to

spontaneously combust, turning into

a pile of ash. At the time, scientists

were beginning to figure out how

breathing works, and they were also

starting to make connections between

burning and the oxygen in air. So some

people thought that if we have a lot of

oxygen in our bodies, maybe we could

spontaneously ignite. It’s possible that

these ideas influenced Dickens, along

with eyewitness accounts. But now, of

course, we know it’s not possible. The

body is up to 75 per cent water, and

even the worst fever doesn’t get us hot

enough to start a fire.