Foreword:
Ultimate questions,
ultimate answers
We’ve
come a long way. Once upon a time we thought the world rested on the back of a
turtle and the Sun was a ball of molten iron “not much bigger than Greece”. Now
we have a theory of small things like atoms – quantum theory – which not only
explains why the Sun shines and why the gound beneath our feet is solid but has
also given us lasers, nuclear reactors and Ipod nanos. In addition, we have a
theory of big things like the Universe as a whole – Einstein’s general theory
of relativity – that predicts the existence of black holes and suggests that
there was a beginning to time.
Nobody
yet knows how the theory of the small meshes with the theory of the big –
that’s a theorists’ work in progress - but, no matter. The point is that
previous generations would have killed for the kind of knowledge we now possess
about the world. It truly is a privilege to be alive today. For the first time
in history, we have a good idea of the extent of the Universe – we can see all
the way to the “light horizon” that forms the boundary of observable space -
and we have a good idea of the content of the Universe - we can count up the
building blocks of the cosmos, 100 billion or so galaxies like our Milky Way.
And not only do we have an idea of the extent and content of the Universe but
we also have a strong indication of how it came to be. The Universe burst into
being about 13.7 billion years ago in a titanic explosion called the big bang
and has been expanding and cooling ever since. Our Milky Way – along with all
the other galaxies – simply congealed out of the cooling debris of the big bang
fireball.
Admittedly,
we still do not know exactly what the big bang was, what drove it or what
happened before the big bang (or whether this is even a meaningful question!).
However, the remarkable thing is that we are the first generation with a
realistic chance of answering such “ultimate questions”. And not only these
ultimate questions but a host of others, such as:
·
What is beyond the edge
of the Universe?
·
Where does all the
complexity we see around us come from?
·
What are the limits of
what we can “know”?
·
Is the human brain
doing more than any computer?
·
Can life survive
forever in the Universe?
·
Where does the everyday
world come from?
·
Why do we experience as
past, present and future?
·
Why are loaded fridges
difficult to budge?!
·
Will we ever find ET
out in the Universe?
I
address all these questions in this book. To answer them, I have talked
to some of the most imaginative and daring scientists in the world. In
discovering their extraordinary answers, you will learn - among other things -
how the big bang may have been spawned by a collision between "island
universes"; how a single remarkable number contains the answer to every
question we could ever ask; how the most widely accepted theory of the
Universe's origin implies that Elvis is alive and well and living in another
space domain (in fact, an infinite number of other space domains!); how nobody
can rule out the possibility that the stars are technological artefacts built
by extraterrestrial intelligence; how a computer program a mere four lines long
could be generating you, me and everything we see around us; how all of us
might be resurrected in a computer simulation at the end of time.
The
last possibility inspired the title of this book. According to one
controversial physicist, when you die, you are fast-forwarded to the dying days
of the Universe where you wake up inside the ultimate cyber reality. Stretching
before you will find a subjective eternity of existence - the never-ending
days of being dead[1].
The ultimate questions I tackle are
by no means a definitive selection; they are simply ones that have intrigued me
personally. Nevertheless, there are themes which tie many together. I have
therefore grouped together the questions into convenient categories. First,
there are those whose answers shed light on the “nature of the universe” – questions
such as “What is beyond the edge of the Universe?” and “Where does the
Universe’s complexity come from?”. Secondly, there are questions whose answers illuminate
the “nature of reality” – “Where does the everyday world come from?” and “Why
do we experience a present ?”. Finally, I address questions which
address the place of life – and us - in the Universe – such “Will we ever find
ET?” and “Can life survive forever in the Universe?”.
Some of the ultimate questions I
address may at first sight seem abstract and esoteric. But it is a remarkable
feature of such questions that they invariably have significance for our
mundane everyday lives. There is no more basic question, after all, than “Where
does the everyday world come from?” And, even the most esoteric question I ask
– “Does a single number contain the secret of the Universe?” turns out to have
a bearing on the origin of human imagination and creativity and whether the
brain is doing something more than any computer. I think this is the nature of
science at the leading edge. It is ultimately about down-to-earth things we all
care about – Where did we come from? Where the Universe come from? What the
hell we are doing here?
One last thing. The answers I
present are not necessarily linked to each other. This is characteristic of
science at the frontier, where new ideas are so new they have not yet been
woven into the tapestry of accepted science. Some will stand the test of time
and some will not. Some are even mutually exclusive. All the ultimate questions
are hard questions. The hardest questions are the always the most interesting
ones. Answering them requires journeying to the very frontier of science – and,
in fact, way beyond. Have fun!