I did not publish anything here within the last few months, as the review I am writing took up much more time than expected. A lot of interesting project developments happened also during this time. I will write on them as well later, so that nobody will miss out on the insights we gained and the fun we had with them.
But now, I want to write about how the review comes along. It has now grown into a veritable almost 120 page document. And actually most of it is texts and formulas, and only very few figures. This makes for a lot of content. Right now, it has reached the status of a release candidate 2. This means I have distributed it to many of my colleagues to comment on it. I also used the draft as lecture notes for a lecture on its contents at a winter school in Odense/Denmark (where I actually wrote this blog entry). Why? Because I wanted to have feedback. What can be understood, and what may I have misunderstood? After all, this review not only looks at my own research. Rather, it compiles knowledge from more than a hundred scientists over 45 years. In fact, some of the results I write about have been obtained before I was born. Especially, I could have overlooked results. With by now dozens of new papers per day, this can easily happen. I have collected more than 330 relevant articles, which I refer to in the review.
And, of course, I could have misunderstood other people’s results or made mistakes. This needs to be avoided in a review as good as possible.
Indeed, I had many discussions by now on various aspects of the research I review. I got comments and was challenged. In the end, there was always either a conclusion or the insight that some points, believed to be clear, are not as entirely clear as it seemed. There are always more loopholes, more subtleties, than one anticipates. By this, the review became better, and could collect more insights from many brilliant scientists. And likewise I myself learned a lot.
In the end, I learned two very important lessons about the physics I review.
The first is that many more things are connected than I expected. Some issues, which looked to my like a parenthetical remark in the beginning became first remarks at more than one place and ultimately became an issue of their on.
The second is that the standard modelof particle physics is even more special and more balanced than I thought. I was never really thinking that the standard model is so terrible special. Just one theory among many which happen to fit experiments. But really it is an extremely finely adjusted machinery. Every cog in it is important, and even slight changes will make everything fall apart. All the elements are in constant connection with each other, and influence each other.
Does this mean anything? Good question. Perhaps it is a sign of an underlying ordering principle. But if it is, I cannot see it (yet?). Perhaps this is just an expression of how a law of nature must be – perfectly balanced. At any rate, it gave me a new perspective of what the standard model is.
So, as I anticipated writing this review gave me a whole new perspective and a lot of insights. Partly by formulating questions and answers more precisely. But, and probably more importantly, I had to explain it to others, and to either successfully defend or adapt it or even correct it.
In addition, two of the most important lessons about understanding physics I learned were the following:
One: Take your theory seriously. Do not take a shortcut or use some experience. Literally understand what it means and only then start to interpret.
Two: Pose your questions (and answers) clearly. Every statement should have a well-defined meaning. Never be vague when you want to make a scientific statement. Be always able to back up a question of “what do you mean by this?” by a precise definition. This seems obvious, but is something you tend to be cavalier about. Don’t.
So, writing a review not only helps in summarizing knowledge. It also helps to understand this knowledge and realize its implications. And, probably fortunately, it poses new questions. What they are, and what we do about, this is something I will write about in the future.
So, how does it proceed now? In two weeks I have to deliver the review to the journal which mandated it. At the same time (watch my twitteraccount) it will become available on the preprint server arxiv.org, the standard repository of all elementary particle physics knowledge. Then you can see for yourself what I wrote, and wrote about