Last week, Steven Weinberg gave a talk in Arlington, Texas. This is the questions-and-answers part of the talk:
It's 28 minutes. At the end of the regular talk, he mentioned various indirect advantages from building a new linear collider etc. He makes a good joke when they prepare an award for his memorable talk: How did you know in advance that my talk would be memorable? I would be inclined to make exactly the same comment.
A person asked about new physics. Weinberg focused on the identity and detection of the dark matter particle. The same person and another one wanted to ask about string theory – that's what people are really excited about. Weinberg said it's extraordinarily mathematically powerful and it hasn't been possible to compare its characteristic predictions with experiments.
He says that the International Space Station was allowed to go at the same time when the Superconducting Supercollider was cancelled – even though it was 10 times more expensive and has produced no science. He strengthens the claim by saying that the astronauts have never produced any science. Of course, some people in the audience are stunned, others applaud. ;-)
The linear collider would measure the properties of the Higgs and all the things much more accurately. I have some doubts whether this information is worth $10 billion dollars, especially because it is somewhat likely (40%?) that they would exactly agree with the Standard Model, within the ILC precision. And if there were a disagreement, it would still fail to clarify where the disagreement comes from, what are actually the new particles and physical phenomena that are responsible for the deviation. Imagine that the ILC finds out that the diphoton decays of the Higgs boson are indeed 70% more frequent than the Standard Model says. Would we be fully excited and satisfied? Nope. It would only be a justification to build a collider that may actually find the new beasts that are responsible. So why wouldn't we build this collider immediately?
For those reasons, I would tend to think it's better to save a little bit more money and build a new SSC-like collider that exceeds the LHC by its superior brute force, by the energy.
Weinberg said that he was attracted to theoretical physics by reading popular books when he was at the high school. He also mentions that for a long time, he believed he had to know everything before he starts to do research, so he was reading lots of books. Then he learned better. Well, I still think that his previous "mistake" was very valuable because it gave us Weinberg who really did and does know everything about the particle physics and cosmology of his era.
Most of the time, nothing comes out of the research so it may be frustrating. Sometimes, something comes out. If you love it, do it, if you don't, then don't do it...
Weinberg's Arlington talk was a part of a broader linear collider conference (its web).