Problems in Quantum Cosmology

l Observer based - who is the observer?
l The universe represents a very long quantum "moment"

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According to quantum physics virtual particles can pop into existence from nothingness through quantum tunneling. Some cosmologists have suggested that the entire universe could have emerged in this way as a giant quantum particle. However, quantum theory states that quantum systems possess dynamic properties such as position, momentum, and spin orientation only when these properties are measured by some device or observer. The physical measuring devices themselves can be given a quantum physical description. Therefore, for the universe, there is the problem that there is nothing beyond quantum physics to make the measurement that is a necessary condition of the reality of the properties of the universe. It might be argued that God is the observer. However, this is the implication that quantum cosmology attempts to avoid. It has been suggested that the collapse of the wave function associated with a quantum system might function as the observer. However, the measuring device itself, also lacks any intrinsic dynamic properties (such as precise location or velocity). So if the measuring device itself is indeterminate then it cannot collapse the wave function of the quantum system being measured. If one hypothesizes other devices that collapse the wave function, we are left with the problem of infinite regression.

The second problem with quantum cosmology is that quantum mechanics states that quantum events occur according to finite probabilities within finite time intervals. The larger the time interval, the greater the probability that a quantum event will occur. Outside of time, however, no quantum event is possible. Since time originated at the moment of the creation of the universe, quantum tunneling could not be its "creator." In addition, quantum events are extremely short-lived. As a quantum event, the existence of the universe is many orders of magnitude longer than any described quantum event. Therefore, cosmologists who propose such theories must appeal to unknown laws of physics to describe the reality of the universe.
Last Modified October 4, 2004


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