Three stone slabs were found by Romanian archaeologist Nicolae Vlassa , in the mid-20th century (1961) in Tărtăria (present-day Alba county , Transylvania ), Romania , ancient land of Dacia , inhabited by Dacians, which were a population who may have been related to the Getaes and Thracians . One of the slabs contains 4 groups of pictographs divided by lines. Some of the characters are also found in Ancient Greek , as well as in Phoenician , Etruscan , Old Italic and Iberian . The origin and the timing of the writings are disputed, because there are no precise evidence in situ , the slabs cannot be carbon dated, because of the bad treatment of the Cluj museum. There are indirect carbon dates found on a skeleton discovered near the slabs, that certifies the 5300–5500 BC period.
The problem of detecting gravitational radiation is receiving considerable attention with the construction of new detectors in the United States, Europe, and Japan. The theoretical modeling of the wave forms that would be produced in particular systems will expedite the search for and analysis of detected signals. The characteristic formulation of GR is implemented to obtain an algorithm capable of evolving black holes in 3D asymptotically flat spacetimes. Using compactification techniques, future null infinity is included in the evolved region, which enables the unambiguous calculation of the radiation produced by some compact source. A module to calculate the waveforms is constructed and included in the evolution algorithm. This code is shown to be second-order convergent and to handle highly non-linear spacetimes. In particular, we have shown that the code can handle spacetimes whose radiation is equivalent to a galaxy converting its whole mass into gravitational radiation in one second. We further use the characteristic formulation to treat the region close to the singularity in black hole spacetimes. The code carefully excises a region surrounding the singularity and accurately evolves generic black hole spacetimes with apparently unlimited stability.