A Universe From Nothing
Why There is Something Rather Than Nothing

Lawrence Krauss, 2013

I've seen Krauss give the talk that became this book twice before, once as a public lecture (he gives great public lectures), and once with far more technical detail as a guest lecturer in my cosmology class. That was actually the last lecture of my undergrad, and I enjoyed it so much that I wanted to read more. At this point I should probably mention that one of my degrees is in theoretical physics. A lot of physicists look down on pop physics books like this, and I think that's a real shame for two reasons.

The first is that those people miss out on the absolute joy of explaining things to people, and seeing their reaction when it actually clicks. If you hadn't figured it out from the fact that I spend my evenings writing non fiction summaries for strangers on the internet, I really enjoy explaining things. Problem is, modern physics is really goddamn hard to explain. I've read the actual papers behind this book, and I know for sure that I wouldn't have a hope in hell of explaining them to you if I hadn't seen how Krauss managed it.

The second is that, no matter what they were saying by the time they graduated, I know that every single person in my physics lectures absolutely devoured pop physics books in high school, and I know that they made the degree so much more bearable. Some people may disagree with me, but I know that, in order to really grok a concept, I need to see the high level conceptual picture, as well as the nuts and bolts of the equations, and preferably in that order. I remember solving the Friedmann equations in class and being palpably excited, not because of the raw calculation, but because after decades of hearing the romantic creation story of the big bang, now I could see it playing out in front of my very eyes. Almost like a composer who sits at the piano to tap away at keys without hearing the melody in her head beforehand, I think the significance of those equations would have been wholly lost on me if I had no idea where they were taking me.

Now, on to the actual book. A Universe from Nothing breaks down roughly into two sections. The first is a brief review of the accepted facts of modern cosmology.

![WMAP Ka band](http://map.gsfc.nasa.gov/media/101082/101082_ka_7yr_WMAP_2048.png)

If you've seen this picture, but never understood what it means, the first part of the book is for you. For those who just can't wait that long, this is a composite map of the of the sky taken from the WMAP satellite. Without going into too much detail, what it's showing is that the background temperature of the Universe is really consistent (it doesn't look it, but that's a *very* fine scale on that graph). Too consistent. In fact, the only way that the temperature could be so balanced is if the whole Universe was really close together in the past, so that heat could move around and balance out easily. This was one of the earliest pieces of evidence for the Big Bang.

The second part, and main purpose, of the book is an introduction to inflationary cosmology. Broadly speaking, inflationary cosmology deals with the question of 'but what was happening immediately after (in some extensions, even before) the Big Bang?' As it turns out, there are a number of open questions about the Universe that the 'basic' Big Bang theory can't answer. Questions like: Why does that picture up there look like it does? Not outright contradictions or errors; but things that can't be explained are usually an indication that there's a more fundamental explanation out there. In this, Krauss mostly summarises the work of the Alan Guth, Andrei Linde, and Alexander Vilenkin, and I recommend that anyone who is interested (and technically capable!) read their original papers on the subject, because I'm not quite ready to explain inflationary cosmology for you here.

As for the final verdict, and suggestions for further reading, I'd probably skip this one if I were to do the year again. No doubt that this is good introduction to cosmology for the mathematical laity, but I think that Max Tegmark's Our Mathematical Universe (my review #40 for 2015) hits all of those points plus more. Also, as I mentioned at the top, Krauss is a great speaker on this topic, and it's definitely worth an hour of your day to watch one of the public lectures that tie in nicely with A Universe from Nothing.

The cover image is a famous image of the Hubble Ultra Deep Field, and is the most distant (in both time and space) visual spectrum image ever taken by humans, showing tens of thousands of galaxies as much as 13 billion years old.