I just returned from a vacation to the United States. It was nice to see my family and friends and get out of the CERN bubble for a little while. Of course, I got the usual questions:
- 1) Did that accelerator start yet/when will it start?
- 2) What good will it do us?
My answer to #1 was that I have no idea, hopefully in 2009.
My answer to #2 changes, probably depending on who I am talking to, or maybe just my mood. Sometimes I say something about Higgs bosons and supersymmetry (I try to avoid black holes since then I have to talk about the end-of-the-world fearmongering). Sometimes I say something about the practical benefits of past projects and that this project will also have as-yet-unknown benefits. And sometimes I say that there probably will be no direct benefit to the average person from the LHC. Each of these is partially true, but whatever answer I give, I usually feel like I could have done better. After being asked this question so many times over the years, I should have settled on an answer by now.
From now on, I think the answer should just be my personal reason and not have anything to do with the benefits to society overall. For me and I think most people that work on LHC physics, I think the answer is the same: curiosity. Humans are curious, and science is the systematic way of satisfying curiosity. And I think that anyone that takes the time to learn about LHC physics would be curious to know more. 70,000 people showed up at CERN for the open day last year which makes me sure that people are curious about the things we study here.
To really answer questions about whether the LHC is worth the cost from a practical point of view, it would probably be necessary to put a dollar amount on the knowledge and other benefits we gain from it, and on the things that we then don’t do because the money is spent on the LHC. I have no idea how to do this, it probably isn’t even possible, but if you try to say whether the LHC is worth its cost any other way, you are just guessing or justifying your own beliefs.
So I think the reason to build the LHC (and to do it now as opposed to later, after we solve the problems of world hunger and disease and all the other things some people say the money would be better spent on) is that the LHC project is right now the next logical step in a series of questions and answers that started a long time ago. Scientists asked some questions and got answers through experimentation, which raised more questions, which led to more experiments, and machines got bigger and bigger until we ended up with a 17 mile long machine. Nothing else on Earth but human civilization could express its defining trait, curiosity, as the LHC. And what other point is there to civilization than coming together to collectively do what we cannot do individually, and what is more important than our defining characteristic, curiosity?
