For 198 pages, A Brief History of Time is aptly a brief book, but in some ways we can also say that it is one of the densest text out there written to whom I believe is the layman. The big question of this book is not whether it answers the questions of the universe at all, but instead if you understand it at all. Or if you claim you do, how much of it do you understand? This is a hard question for me, because I just need to swallow a humble pie on this one and say that I only understood some of it. I’ve been trying to explain the concepts of the book to the missus and I quickly admitted that I don’t understand the subtle and not-so-subtle nuances between the general theory of relativity and quantum mechanics — one attempting to explain how things as large as the universe works and the latter how things smaller than an atom works.
The other important part of the title is “A”. Hawking admitted that a theory where the universe lays on top of a tortoise proposed by a lady in a university lecture may seem totally absurd but not implausible — who is to say that she is not wrong? Who is to say that any of these theories are wrong? The indefinite article concedes that this is a theory among many, and a modest attempt from mankind to make sense of the universe. It is a humble beginning of a book from a man whose reputation is the most intelligent man, and perhaps it is impossible to be this intelligent without this kind of humility. Hawking is also generous on sharing the credits where the theories go, even conflicting theories which have proved him wrong.
Time is ever-present in this book, but the concepts of time, space and gravity are complementary though different theorists explain them in different ways. The general theory of relativity conjectures that space is a horizontal fabric which is the horizon of the galaxy. A star such as the sun sits right in the middle, which gives the fabric its curvature, which in the end warps the rest of the planets towards its centre in a circular motion we call the orbit, perpetually falling into the centre of the fabric where the sun is, but not really.
Scientists can agree that the universe is expanding at least, that our visible space no matter what point are moving away from us overtime, and we may speculate that we too, are part of this expansion. Thus, the universe may have started in an infinite state where the matter is infinitely small and energy infinitely high, what we know now as the big bang. Unfortunately, mathematics fail when infinity is at hand, as many calculations involving the universe often are (no surprises here). But where do we go from here if we are still part of this expansion? Will the universe keep expanding in a linear fashion to infinity, or eventually peters out to a stable state where it will just stay as such. The other end of the extreme is where the universe will eventually contract again — the big crunch.
Things do get interesting when we try to insert quantum theory into the universe, where such things as antimatters are created. Quarks, the units which make up protons and neutrons also create antiquarks, which often destroy each other when they come into contact with each other. When quarks survive and the antiquarks die off, then the matter becomes stable. Thus, all known matter in space could be made of the surviving quarks which did not touch each other. This also give us the speculative theory that there may be parallel universes where there is a version of you and me, and if we touch our clone we bot will cancel each out. Which begs the question — are you the quark or the antiquark?
Hawking’s life was dedicated to the research of black holes and their implications in the universe. It is also the most speculative but the most interesting part of the book. Collapsing and dying stars will also suck in everything around them as their mass becomes larger and larger. Anything contributed into the black hole will just be converted into mass. It is a depressing thought, but we really don’t know what happens inside a black hole as our visibility is clouded by the event horizon — as light also gets sucked into the black hole.
You’re even smaller than you think
I think A Brief History of Time merits a re-read unless your major is astrophysics. There are concepts here that I have to accept that I won’t grasp for some time to come: why people in lower attitudes will age faster than those in higher altitudes and those travelling in space (this is the famous twin paradox), the concept of particle spin which annoyed the crap out of me for many many many pages, and everything to do with string theory, which at the time of Hawking’s writing, still is. But in a bigger picture, who are we to try to even attempt describing the infinite? Perhaps one day we will come across a theory which consolidates our thoughts in the universe and makes us fully understand the essence of our existence, but we are light years away from that, to put it mildly.
Carl Sagan, in the introduction of this book points out Hawking’s wrestling the idea of God. God is present (or not present) in all the pages of this book, but there are times when Hawking wonders why the universe is so systematic — so beautiful. Though Hawking is a self-proclaimed atheist, and that he believes that the the book does not reject that the universe is created by accident. There are underlying laws of the universe that exists and we still cannot answer why. Perhaps this was beyond the scope of this book.
No other book had succeeded in making me feel as humble and small. Our distance to the stars are too far for us to reach and fathom; our knowledge of how the universe works is still largely unanswered and will continue to be though we make baby steps in it; the universe is too large in magnitude for us even to understand what infinity is. But it comforted me some that someone with the physical limitations of Hawking can flex his astrophysical minds larger than any of us had possibly done before, except perhaps for Einstein. You don’t need to be smart to read this book. Not at all, but accept that you may not grasp all the ideas here, and what you’d be able to understand will blow your mind.
