Reversing a Negative Measurement in Process with Negative Events: A Haunted Negative Measurement and the Bifurcation of Time

Reversing an ordinary measurement in process (a haunted measurement) is noted and the steps involved in reversing a negative measurement in process (a haunted negative measurement) are described. In order to discuss in a thorough manner reversing an ordinary measurement in process, one has to account for how reversing a negative measurement in process would work for the same experimental setup. The reason it is necessary to know how a negative measurement in process is reversed is because for a given experimental setup there is no physical distinction between reversing a negative measurement in process and reversing an ordinary measurement in process. In the absence of the reversal of a negative measurement in process in the same experimental setup that supports the reversal of an ordinary measurement in process, the possibility exists of which-way information concerning the negative measurement that would render theoretically implausible reversing an ordinary measuremnt in process. The steps in reversing a negative measurement in process involve the bifurcation of time, and they shed light on the process of reversing an ordinary measurement in process. The bifurcation of time is dependent on the separation of the measurement process into two stages that is typically accomplished in one. The elimination of coherence (stage 1) usually occurs at the same time information is made available to the environment concerning these occurrences (stage 2). Restoring coherence b efore making information on the experiment available to the environment reverses a measurement in process. The bifurcation of time occurs because two processes that are mutually exclusive as far as time is concerned (i.e., whether or not a physical interaction has occurred) are presumed to both exist in the reversal of a measurement in process, whether for an ordinary measurement in process or a negative measurement in process. That is, the analysis of reversing a measurement in process presumes the existence of an event that provides which-way information (even if not revealed to the environment) while also maintaining the possibility exists that this same event is part of a process wherein which-way information is not provided. It was noted that one cannot distinguish physically between reversing an ordinary measurement in process and a negative measurement in process for a given experimental setup. There is no distinction either in terms of the process of reversal itself or the measurement result that follows the reversal. Indeed, if one type of haunted measurement did not work (a haunted ordinary measurement or a haunted negative measurement), the other type could not work as well because of the possible existence of which-way information. The present analysis indicates that it is the information available concerning expected measurement results in the experimental situation, made available through either form of analysis of the experimental situation with regard to an ordinary measurement in process or a hidden measurement in process, that is central to reversing a measurement in process. If it is the information available concerning expected measurement results in the experimental situation that is central to reversing a measurement in process, should not this finding be applicable in some sense to measurements that are not reversed? One need go no further than negative measurements to find an example of a measurement that occurs without a relevant physical interaction and consider whether it is the information available in the experimental setup that allows one to conclude that a measurement has occurred.