Title: Quantum Time – Exactly What Is Time?
Headings: Quantum Time
Quantum Time
Quanta
Copenhagen Interpretation
Many Worlds Interpretation
Quantum Gravity
Imaginary Time

Content: This view of quantum mechanics (developed by two of the originators of quantum theory, Niels Bohr and Werner Heisenberg ), is sometimes referred to the Copenhagen interpretation of quantum mechanics. Because the collapse of the wave function cannot be undone, and because all the information associated with the initial possible positions of the particle contained in the wave function is essentially lost as soon as it is observed and collapsed, the process is considered to be time-irreversible, which has implications for the so-called “arrow of time”, the one way direction of time that we observe in daily life (see the section on The Arrow of Time ). Some quantum physicists (e.g. Don Page and William Wootters) have developed a theory that time is actually an emergent phenomenon resulting from a strange quantum concept known as entanglement, in which different quantum particles effectively share an existence, even though physically separated, so that the quantum state of each particle can only be described relative to the other entangled particles. The theory even claims to have experimental proof recently, from experiments by Ekaterina Moreva which show that observers do not detect any change in quantum particles (i.e. time foes not “emerge”) until becoming entangled with another particle. Many Worlds Interpretation
The Copenhagen interpretation of quantum mechanics, mentioned above, is not however the only way of looking at it. Frustrated by the apparent failure of the Copenhagen interpretation to deal with questions like what counts as an observation, and what is the dividing line between the microscopic quantum world and the macroscopic classical world, other alternative viewpoints have been suggested. One of the leading alternatives is the many worlds interpretation, first put forward by Hugh Everett III back in the late 1950s. According to the many worlds view, there is no difference between a particle or system before and after it has been observed, and no separate way of evolving. In fact, the observer himself is a quantum system, which interacts with other quantum systems, with different possible versions seeing the particle or object in different positions, for example. These different versions exist concurrently in different alternative or parallel universes.