“Moreover, as we saw in Problems with string theory,‡ while each string theory is internally consistent, Smolin presents a strong case against external consistency with evidence, concluding that “all the versions we can study in any detail disagree with observation”. He also maintains that it is externally inconsistent with the scientific tenet of relativity theory: “Einstein’s discovery that the geometry of space and time is dynamical has not been incorporated into string theory.” Without more positive results from these tests of reasonableness for a scientific (as distinct from a mathematical) conjecture, it is difficult to see how the speculated existence of other dimensions is any more tenable than the belief of many Buddhist schools that there are 31 distinct realms of existence. Furthermore, the so far untestable idea that the matter of the universe reduces not to fundamental particles but to strings of energy seems no more or less reasonable than the Upanishadic insight that prana (vital energy) is the essential substrate of all forms of energy and, in many interpretations, of all matter.”