This blog was started a little bit over ten years ago, and I’ve been intending for a while to write something marking the occasion and commenting on what has changed over the past ten years. I’ve found this mostly a rather discouraging topic to think about and whatever I have to say about it is going to be pretty repetitive for anyone who regularly reads this blog, so I’ll keep this fairly short.
Re-reading some of the early postings I’m struck mainly by how little has changed in ten years. Back in March 2004 I was writing about a David Gross talk promoting string theory, about whether CMB measurements would give information about GUT scale physics, about how string cosmology seemed to be an empty subject, and about new twistor-based methods for computing gauge theory amplitudes. There’s been a lot of progress on the last topic since then, but little change for the others.
One big change over the past ten years is that the argument that string-theory based unification is a failed project is no longer a particularly controversial one, with most physicists now leaning to this conclusion. Last night even Sheldon of The Big Bang Theory acknowledged that this isn’t working out and he needs to find something else to work on (see here). Maybe even Sheldon’s real life model will soon reach this conclusion. Ten years ago the argument one often heard was that string theory was the winner in the marketplace of ideas, with skeptics just sore losers. These days, it’s string theorists who are more often complaining about the unfairness of this marketplace.
One development that is just starting to have a major impact is the failure of the LHC to find any evidence of SUSY, leading to increased skepticism about SUSY extensions of the standard model. This is a developing story, with results over the next couple years from the LHC likely to make this a textbook example of what scientists do in the face of experimental disconfirmation of their most cherished ideas.
The discovery of the Higgs has been a wonderful vindication of the ideas and techniques of high energy physics, both experimental and theoretical. As we learn more about the Higgs the lesson seems to be that this sector of the Standard Model behaves in the simplest way possible. This is a significant new piece of information about nature, although a frustrating one since it doesn’t provide a hint of how to improve the Standard Model.
On the whole though, I fear that thinking about changes over the last ten years mostly puts me in a not very good mood. Some of the depressing developments and trends of the last ten years are:
- One reaction to string theory’s failures in the marketplace of ideas has been a Russian billionaire’s decision to try and manipulate that marketplace by injecting tens of millions of dollars into it on one side. The largest financial prize in science now is devoted to each year rewarding people for work on a failed project. This is corrupting the marketplace in a significant way.
- Some of my earliest postings back in 2004 were about KKLT, the string landscape and the multiverse. At the time I was sure that if the landscape proposal being pushed by the Stanford group became widely accepted as an implication of string theory unification, that would be the end of it. Surely no sensible person would try and argue for an extremely complicated, inherently unpredictive theoretical framework. Boy, was I wrong. As I’ve gone on about far too often here, the current multiverse mania is a disastrous and shameful episode for fundamental theoretical physics, threatening its essential nature as a science.
- Most physics departments have reacted to the failure of string theory by at least partly blaming this failure on the over-emphasis of mathematics, instead of the fact that this was just a wrong idea about physics. An interesting document I recently ran across is this one about the connections of particle physics with other disciplines, written by my advisor Curtis Callan and Shamit Kachru. Mathematics is mentioned in a section discussing past successes in cross-fertilization with other fields, but it appears not at all in the rest of the document discussing opportunities for the future.
I’m quite surprised that I’ve continued to find topics worth blogging about ten years down the road, this is something I never expected when this started. Right now I’m hoping for something unexpected in coming years, that I’ll be writing about something different and much more interesting ten years from now!