Universe from Nothing

A friend and colleague (and regular reader of Something Surprising) lent me a book last week - and I finished it in just a few days.  At the time he said that he needed to read it again to get the most out of it and I have to agree that the same applies to me.  That is not to say that I failed to learn a lot from it.

The book in question is "A Universe from Nothing" by Lawrence Krauss.

Krauss reminds us how much humanity has learned in the last century.  Just a hundred years ago we did not even know that there were other galaxies outside our own.  We had no idea that the universe was expanding and the idea of the big bang was decades away.  Much of our astronomical knowledge was not known, and controversies that now seem to be quite old were raised and argued out within much less than the last hundred years.

He takes the reader through the concepts of dark matter and dark energy.  He also explains in a coup-de-grace diagram that the abundance of light elements in the universe today is the clinching evidence for the big bang.  The amounts of hydrogen, deuterium, helium-3, helium-4 and lithium-7 are precisely as they should be if there was a big bang - and the universe is at the current estimate of 13.7 billion years old.

He tells us how the cosmic microwave background, this is the radiation that is left from the big bang itself, provides irrefutable evidence that the universe is flat - a strange concept in three dimensions - but meaning that (at least on average) light travels in straight lines right across the universe.  He also tells us the surprising estimate that there are a billion photons in the microwave background for every atom in the universe, and suggests that this is evidence to explain the mystery of the predominance of matter over anti-matter.  An imbalance of one part in a billion in the creation and subsequent annihilation of matter/anti-matter pairs would be enough to describe this unexplained fact.
One of the most interesting concepts also comes from the evidence of the cosmic microwave background's degree of lumpiness.  I was aware that people often question why the universe is not perfectly uniform - and therefore they wonder how the galaxies formed.  Part of the answer lies in the idea that the speed of light limits the degree to which different parts of the rapidly expanding universe can have any knowledge of each other.  Beyond a certain distance, the particles are simply unaware of the other side of the universe.  Krauss does not make the following analogy, but I think it demonstrates it well.  Last year I featured a set of photos of a bubble bursting - in slow motion.

Bursting bubble - an analogy to the early universe.
(Photo from here)

In this picture, the skin of the bubble on the left hand side is still spherical as if the bubble was complete.  It is blissfully unaware (to anthropomorphise a physical object) that the other side of the bubble has gone.  In the case of the bubble, that information travels at the speed of sound, and the signal has not travelled far enough to tell the bubble that it is no longer stable.  The universe therefore can become lumpy, just like the right hand side of the bubble.

I have no such graphic analogy for the predicted end of the universe - big and cold and lifeless.  I can only be glad that in 1 trillion years I will not feel very upset about it.

Nor do I fully understand the assertion that before the universe came into existence, the nothingness was unstable, and it just had to become something.  Next time I read it I might understand a little more.


As an after-thought I note a small point with a little smile.  Krauss writes in long sentences - unusually so for this century.  Some of them are the kind of sentence that I know my own editors would want to break up into several small chunks.  And yet Krauss makes them clear and comprehensible.  Take this one example (from page 56):

"Indeed as early as 1995, I wrote a heretical paper with a colleague of mine, Michael Turner, from the University of Chicago, suggesting that this conventional picture couldn't be correct, and in fact the only possibility that appeared consistent with both a flat universe (our theoretical preference at the time) and observations of the clustering of galaxies and their internal dynamics was a universe that was far more bizarre and that hearkened back to a crazy theoretical idea Albert Einstein had in 1917 to solve the apparent contradiction between the predictions of his theory and the static universe he thought we lived in and which he later abandoned."

108 clear words, and I have no problem understanding it.  Nor have the two non-technical people I read it to.  However, I thought it was funny that he (presumably) misquoted the classic and almost archetypal long opening sentence of a Tale of Two Cities, by Charles Dickens, making the first two clauses into short sentences.

"It was the best of worlds.  It was the worst of worlds."

Ironic humour I think!