Evers - Its about time: from calendars and clocks to moon cycles and light years - a history

First published in Great Britain in 2013 by
Michael OMara Books Limited
9 Lion Yard
Tremadoc Road
London SW4 7NQ

Copyright Michael OMara Books Limited 2013

All rights reserved. You may not copy, store, distribute, transmit, reproduce or otherwise make available this publication (or any part of it) in any form, or by any means (electronic, digital, optical, mechanical, photocopying, recording or otherwise), without the prior written permission of the publisher. Any person who does any unauthorized act in relation to this publication may be liable to criminal prosecution and civil claims for damages.

A CIP catalogue record for this book is available from the British Library.

ISBN: 978-1-78243-067-4 in hardback print format
ISBN: 978-1-78243-087-2 in EPub format
ISBN: 978-1-78243-088-9 in Mobipocket format

Cover design by Ana Bjezancevic
Designed and typeset by K DESIGN, Somerset
Illustrations by Greg Stevenson
Maps on by David Woodroffe

www.mombooks.com

My sincerest thanks to all at Michael OMara Books, especially to my editor Anna Marx for her support, enthusiasm and input, Ana Bjeanevi for her ever-lovely design work, and Greg Stevenson for his wonderful illustrations. Thanks also to Dan OGrady and my brother Peter Evers for all their useful suggestions. And finally the biggest thank you goes to my great friend and editor-extraordinaire, Silvia Crompton, for all the precious time she has given to me these past few years.

A few years ago some startling images were captured by Brazils Indian Affairs Department. Taken from a plane flying high above the Amazon near the border of Brazil and Peru, the images showed members of an uncontacted tribe. Some were painted red, others black, but all were looking up curiously at the metal bird cutting through the sky above.

Looking at these images felt a bit like time travel; looking at the past in the present, or two dimensions co-existing. These people do not know that its the twenty-first century. To them, we are the weird creatures from another time, possibly even another world. How long this past in the Amazon can continue is uncertain, as modern man encroaches ever more into these ancient tribal lives, sometimes violently, in the name of progress.

A few months after these images entered the public domain I came across another story, this time about a recently contacted tribe, the Amondawa in Brazil. First discovered by anthropologists in 1986, the Amondawa do not have an abstract concept of time. They have no word for time, or divisions of time such as months or years. Rather than talk about age they assign different names to each other to indicate the different stages of their lives or their status within their community. They have no time technology no calendars or clocks and only a limited numbering system.

What struck me is just how difficult this kind of life is to comprehend. And I realized how obsessed we modern people are with time especially not having enough of it and just how unique the Amondawa are in the absence of this obsession. I also realized how little I understood about time, how we capture and create it, and how our Earth and our bodies interact with it.

We each live in our own psychological time memories of the past, anticipation for the future and these time zones co-exist with our present, our now. And we experience time subjectively an hour is a long time in a doctors waiting room, but can fly by with good friends.

This book goes back to the beginning of time as we know it right back to the beginning of the universe and starts from there. It pieces together the history of time as perceived and processed by our forebears and by the great scientific minds of our current age and it also tries to have a little fun along the way.

Well journey through geological ages, meet dinosaurs and distant cousins, tell time by the Moon and the Sun, and learn about the clocks within us which dictate the rhythms of our daily lives. Well look at the evolution of time technologies, from the earliest calendars etched on the bones of eagles wings to quantum clocks. Well see how time is speeding up and how its slowing down, well travel into the future through wormholes and black holes, span light years and peek into parallel dimensions. And for aspiring time travellers, there will be tips and tricks for journeying into the past and future along the way.

Happy Birthday Planet Earth

In 1654, the Anglican Bishop of Armagh, James Usher, announced that the universe was created at six oclock on the evening of 22 October 4004 BCE . He reportedly came to this rather definitive conclusion after years of studying the Bible and world history. This theory of the Earths age was pretty popular right up to the nineteenth century, when the study of geology and Darwins theory of evolution made it clear that the world was considerably older.

It is now widely believed to be 4.54 billion years old or written out in full 4,540,000,000 years old. Thats a lot of years. The 4.54 billion figure has been reached using rather complex mathematics combined with the methods of radiometric dating which include radiocarbon dating, potassium-argon dating and uranium lead dating.

At its most basic, radiometric dating looks at radioactive decay. It compares the amount of a naturally occurring radioactive chemical component (isotope) and its decay products we know, for example, that the radioactive component uranium decays to become lead, so looking at the amount of lead left in a rock one can calculate how much uranium there would have been to start with and so how long it has taken to produce the lead.

Applying these techniques to really, really old rocks and minerals including meteorites and lunar samples the magic figure of 4.54 billion has been reached and agreed upon. For now.

The oldest known terrestrial materials are zircon crystals found in Western Australia. These have been dated as over 4.4 billion years old. The oldest known meteorite matter is 4.567 billion years old. It is believed that our solar system cant be much older than these samples.

Which brings us to the time before there was an Earth, or a solar system to house it. To when our universe was born. The prevailing theory is that of the Big Bang, when the universe started expanding from a dense and hot state and continues to expand into space, which is itself continually expanding.

The Big Bang is dated as starting 13.5 and 13.75 billion years ago

The geologic time scale

Coming back down to Earth again, something called the geologic time scale is used by earth scientists, geologists and palaeontologists to describe timings and events in our Earths past. It relates time to stratigraphy the study of layers of rocks (stratification).

There are many wonderful examples of stratification bearing testament to the Earths long history. Examples are found in chalk layers in Cyprus, the stunning Colorado Plateau in Utah, exposed strata on mountain faces in the French Alps, and the amazing Stratified Island near La Paz, Mexico, to name but a few.