12.09.2007 17:54

People often claim that the situation in physics nowadays is very similar to then back in the golden days at the beginning of the 20th century when Einstein cooked up all his marvelous theories and quantum mechanics peered around the corner and physics was full of genius' like Planck, Bohr, Heisenberg, Pauli, Schroedinger and Dirac... Is this really true?
The reason why they claim so is that nowadays there are some known fundamental questions which go to the very heart of what we know and believe: For instance what happens to general relativity at very small length scales? It cannot be quantized along the way as you quantize the other field theories. What about the hierarchy problem? Is it a real problem? What is all this so called dark stuff out there made off? Is there something behind the standard model of particle physics and what is it?
Though these question are there, aren't they purely theoretical? It is just aesthetical uneasiness of theoretical physicists, this conviction that there must be some kind of inherent beauty in final theory which makes it clear that it could not have been different. Or two theories that are not consistent somewhere at a scale where we, honestly, don't know anything about. There is no experimental indication so far for these problems, (with the exception of dark matter, afaik). In particle physics for instance, all data we have support the standard model to a very good accuracy. We have not seen anything contradicting it (of course we might do so very soon at the LHC).
100 years ago it was different: People were not hunting for a fancy theory, rather they were looking for something that could explain data. Known facts that contradicted what were the theories of the time like for instance the black body radiation, the photo electric effect, the stability of atoms.