http://en.wikipedia.org/wiki/Doubly_special_relativityIf Special Relativity is to hold up exactly to this scale, different observers would observe Quantum Gravity effects at different scales, due to the Lorentz-FitzGerald contraction, in contradiction to the principle that all inertial observers should be able to describe phenomena by the same physical laws...A drawback of the usual doubly special relativity models is that they are valid only at the energy scales where ordinary special relativity is supposed to break down, giving rise to a patchwork relativity...
Doubly Special Relativity (DSR) is a modified version of Einstein's theory of Special Relativity that accounts for both the speed of light being constant and the existence of a maximum energy scale in the universe. It proposes that there is a fundamental length scale in the universe, in addition to the speed of light being the same in all reference frames.
In Special Relativity, the speed of light is the same in all reference frames, and there is no maximum energy scale. In DSR, the speed of light is still constant, but there is also a maximum energy scale that can be observed. Additionally, DSR proposes that the Planck length (the smallest possible length in the universe) is a fundamental constant, similar to the speed of light.
The main motivation behind DSR is to reconcile the principles of Special Relativity with the discrete nature of quantum mechanics. It aims to provide a more complete understanding of the universe by incorporating both theories into one framework.
DSR has implications for our understanding of spacetime and the behavior of particles at high energies. It also has potential implications for cosmology and the study of the early universe.
Currently, there is no direct experimental evidence for DSR. However, there are ongoing experiments that aim to test its predictions, such as the Large Hadron Collider. Some observations in astrophysics have also been interpreted as supporting DSR, but more research is needed to confirm its validity.