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No. 34: Jul-Aug 1984

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Does string hold the universe together?

Cosmological speculation is getting more and more bizarre. Astronomers are now postulating a kind of cosmic 'string' that is very, very thin (10-30cm), enormously massive (1022 grams per centimeter), and very taut (1042 dynes tension). This string exists only in closed loops of infinite strands. Such string in loop form could have seeded galaxies and even black holes of solar mass. But these are not the major reasons why astronomers like the string hypothesis. It turns out that this bizarre string can tie the universe together gravitationally; that is, provide the long-sought 'missing mass.'

The so-called 'missing-mass problem' is two-fold:

  • Astronomers cannot see, with eye and instrument, enough mass to keep the universe from expanding indefinitely. If the kinetic energy of cosmic expansion is to be balanced by gravitational potential energy (an apparent philosophical imperative), we have so far identified only 15% of the required mass. (2) On a smaller scale, galaxies in large galactic clusters are moving too fast. They should have flown apart long ago, but some unseen 'stuff' holds them together. Is it cosmic string?

    (Waldrop, M. Mitchell; "New Light on Dark Matter? Science, 224:971, 1984.)

    Comment. Since cosmic string weighs about 2 x 1015 tons per inch, the whole business is beginning to sound a bit silly. Actually, all action-at-a-distance forces, which we readily accept as real, are only artificial constructs of the human mind. Gluons, colored 'particles,' top quarks, cosmic string; where will it all end?

    From Science Frontiers #34, JUL-AUG 1984. 1984-2000 William R. Corliss