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8 - Energy extracted from black holes

Published online by Cambridge University Press:  04 May 2010

Igor D. Novikov
Translated by
Vitaly Kisin
Igor D. Novikov
Affiliation:
University of Copenhagen
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Summary

Our story of holes in space and time would not be complete if we failed to mention their wonderful property of continuously releasing energy. This feature is one of the manifestations of the as yet undeciphered relationship between time and energy. This relationship manifests itself clearly when quantum properties of matter begin to dominate.

However, I should start very briefly with empty space and its quantum properties.

According to current notions, the vacuum is not absolute emptiness, the ‘perfect nothingness’. It is a sea of so-called virtual particles and antiparticles which do not emerge as real particles. However, the vacuum is the place where pairs of virtual particles and antiparticles are constantly created for a very short moment, only to disappear immediately. They cannot transform into real particles because this would mean the creation of real energy from emptiness. The so-called uncertainty relation of quantum physics allows these particles to appear for a fleeting moment; this relation states that the product of the lifetime of a pair of virtual particles and their energy is of the order of Planck's constant. Real particles can always be removed from a volume while virtual particles cannot be removed - in principle.

Such are the properties of the vacuum. If some strong field is applied to the vacuum, then some virtual particles may ‘pick up’ sufficient energy in this field to become real; they extract the energy for that from the external field.

Type
Chapter
Information
The River of Time , pp. 139 - 150
Publisher: Cambridge University Press
Print publication year: 2001

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