The Proceedings of the Eighth International Conference on Creationism (2018)

In the example in Figure 5, Events A and B are causally independent, which is why their relative order in time is objectively indeterminate. Events A and B are causally independent because a signal emitted at B and traveling at the speed of light, does not have enough time to reach the location of A before A takes place, and vice versa. Therefore, neither event could have in uenced the other. Stated in geometrical terms, two events A and B are causally independent if and only if the slope of the segment AB is shallower than the slope of a light beam. 4. Light cones Unlike causally independent events, the order of causally dependent events is objectively xed and does not depend on the choice of reference frame. The concept of an event’s light cone helps to illustrate the causal relationship between events (see Figure 6). In the gure, events such as D and C are within the light cone of Event E and therefore are causally related with E . Furthermore, one can see that for any possible choice of the primed reference frame, Event D remains in the future of E , while Event C remains in E ’s past. Therefore, one can objectively state that C happened before E , which happened before D . At the same time, for any choice of reference frame, events A and B remain outside E ’s light cone and are therefore causally independent from E . Moreover, in some reference frames, such as the unprimed reference frame in the gure, A appears to have happened before E , while in other reference frames, such as the primed reference frame, A appears to have happened after E . Thus, according to special relativity, our everyday notions of ‘before’, ‘after’, and ‘at the same time’, are superseded by the more objective notions of ‘past’, ‘future’, and ‘causally independent’ events. Tenev et al. ◀ Creation time coordinates solution to the starlight problem ▶ 2018 ICC 94 Figure 5 . Minkowski diagram showing events A and B measured by two observers who are moving with velocity v away from each other. The unprimed observer determines A and B to have occurred at times t A > t B , while according to the primed observer t ' A < t ' B . Consequently, the unprimed and primed observers arrive at di erent conclusions about the order of events. Figure 6. The light cone of an event E . The lines forming the boundary of the light cone correspond to all possible paths that light emitted at E can take. The top portion of the light cone, called E ’s future, consists of all events that causally depend on E . The bottom portion, E ’s past, consists of all events that are causal dependencies of E . Events outside of the light cone, are causally independent from E .