I took a poll in my class the other day asking the students to rate their "belief" in certain aspects of modern physics. To get them started and to normalize the 0..10 scale, I basically asked them the probability they felt described the chance that a given theory/idea would still be around in 100 years. I put up the following (roughly in order of how I would rank them):
- Special Relativity (SR)
- Quantum Mechanics (QM)
- General Relativity (GR)
- The Big Bang (BB)
SR finds itself at the top because it's hard to see how any new theory wouldn't conform to it. Likewise w/ QM, but to perhaps a somewhat lesser extent with hidden variables, non-locality, and interpretations. GR, despite its success, will surely come up for some modification, if only to fit into quantum gravity. But of course, there could be higher order curvature terms, other couplings, etc. Even more far out, maybe gravity is emergent. As for BB, depending on how one limits the theory, will surely be around, but to what extent? How changed will it be? And then there's inflation, and to this, one could add the anthropic principle. I'm not sure how much I want to say here, but I suspect we're getting pretty controversial. Of course, I wisely left off any theories-which-must-not-be-named, I think I'd rather go off and name a Teddy bear "Mohamed," than open that can of worms.