"resolutions" to these paradoxes are considered by many to be philosophically unsatisfying because they hinge on what is specifically meant by the measurement of an observation or what serves as an observer in the thought experiments. In a real physical sense, no matter what way either of those terms are defined, the results are the same. Any given observation of a cat will yield either one that is dead or alive; the superposition is a necessary condition for calculating what is to be expected, but will never itself be observed. Likewise, the EPR paradox yields no way of transmitting information faster than the speed of light; though there is a seemingly instantaneous conservation of the quantum-entangled observable being measured, it turns out that it is physically impossible to use this effect to transmit information. Why there is an instantaneous conservation is the subject of which is the correct interpretation of quantum mechanics. Speculative theories of quantum gravity that combine general relativity with quantum mechanics have their own associated paradoxes that are generally accepted to be artifacts of the lack of a consistent physical model that unites the two formulations. One such paradox is the black hole information paradox which points out that information associated with a particle that falls into a black hole is not conserved when the theoretical Hawking radiation causes the black hole to evaporate. In 2004, Stephen Hawking claimed to have a working resolution to this problem, but the details have yet to be published and the speculative nature of Hawking radiation means that it isn't clear whether this paradox is relevant to physical reality. Causality paradoxes A set of similar paradoxes occurs within the area of physics involving arrow of time and causality. One of these, the grandfather paradox, deals with the peculiar nature of causality in closed time-like loops. In its most crude conception, the paradox involves a person traveling back in time and murdering an ancestor who hadn't yet had a chance to procreate. The speculative nature of time travel to the past means that there is no agreed upon resolution to the paradox, nor is it even clear that there are physically possible solutions to the Einstein equations that would allow for the conditions required for the paradox to be met. Nevertheless, there are two common explanations for possible resolutions for this paradox that take on similar flavor for the explanations of quantum