Physics theories still not playing well together
The two major theories of physics are general relativity (GR) and quantum mechanics (QM). The first views space and time as smooth, infinitely divisible, modeled as a mathematical manifold. The second insists that particles and forces are quantized. Which leaves gravity the odd man out, so far well described by GR, not yet quantized, yet necessarily interacting with everything. Some bright physicists at CEA, a French research institute, have been using gamma ray bursts to try to detect any small granularity in space. Their latest result is that if there is any granularity, it is thirteen orders of magnitude smaller than the Planck scale! That finding throws a monkey wrench at some string theories that need more granular space. The photo left shows John Wheeler. I should have kept his pennies.