NEWS AND VIEWS

The return of cosmological creation

Without much notice, the notion that the Universe may have been through an infinite series of bouts of creation, and not just one, has been making headway in the literature.

SJR Fred Hoyle's autobiography Home is this year (267, 1007-1019; 1994). elements) synthesized in stars. The micro­ where the Wind Blows, has been well and In the large, the Universe is expanding, wave background arises, they say, from the enthusiastically reviewed, and for good rea­ but there is superposed on it an oscillation of scattering of radiation from earlier cycles of son; it is a stimulating read. Cosmologists scale with a period of 40 billion years. The matter-creation; twenty are necessary to will not be surprised to find that, among the appearance ofmatter is concentrated at those account for the present properties of the often revealing gossip, there is a modest epochs in the history of the Universe, radiation field (which implies that the bulk reiteration of Hoyle's distaste for the 'Big stretches indefinitely backwards in time, of its photons began life 800 billion years Bang' origin of the Universe, and his devo­ when the scale of the Universe is near an ago). tion to the notion ofthe continuous or at least oscillatory minimum, the most recent of And how is all this accommodated within repetitive creation of mass. But nowhere has which occurred 14 billion years ago, or not the laws of physics? By a field, of course: a it been remarked that, after a long fallow very different from the usual estimates of scalar field called C (for "creation") whose period, Hoyle appears again to be back in the age of the Big Bang. value is a function of space-time and which serious business, with a steady trickle of Among other things, this has the conse­ has the disconcerting (but not implausible) papers in the astronomy journals, the latest quence that the maximum redshift of objects effect of exerting a negative pressure on of them in this month's issue of Astronomy (such as galaxies) making their appearance matter. That idea was an essential ingredient and Astrophysics (287, 729-739; 1994). in the current oscillatory cycle will have a of the original steady-state theory. The over­ What follows is an account of what he and redshift parameter (called z) less than 4.86, all rate of creation is determined by the his colleagues now have to say. but they are no longer the only objects in the square of the time-derivative of C averaged A convenient starting-point is the article Universe that are in principle observable. over the whole Universe. by Arp et al. (Nature 357, 287; 1992), which There is no reason why galaxies from earlier The particles associated with the field was both a criticism of the Big Bang Uni­ cycles of creation should not also be found; are bosons which, the argument goes, are verse and a tentative advocacy of the view those left over from the immediately previ­ converted at places where the gravitational that the appearance of matter in the Uni­ ous cycle will have redshifts less than 5 .166, field is very large into primordial matter verse should be accommodated somehow in but will usually be three (astronomical) particles, each with a 'Planck mass' of the laws of physics. That skeleton was cov­ magnitudes fainter than objects from the 10·5 grams, which are then converted into ered with flesh just over a year ago, in an current cycle, and thus will be more difficult baryonic matter (quarks and so on) through article in The Astrophysical Journal (410, to find. But Hoyle, Burbidge and Narlikar the standard hierarchical relationship b~­ 437-457; 1993) by Hoyle and his associates argue that radiogalaxies from earlier cycles tween the fundamental particles, as in the of long-standing, Geoffrey Burbidge from should be more easily detectable at long early phase of the Big Bang. the University of California at San Diego wavelengths, which may help to explain the Whatever the critics may say, they will and J. V. Narlikar, now director of the Inter­ high frequency of very faint radiogalaxies have to allow that it is a considerable tour de University Centre for Astronomy and now found. force on the part of Hoyle, Burbidge and Astrophysics at Pune, India. In this light, the quasi-steady state cos­ Narlikar to have put so much flesh on an No longer is the objective to support the mology may be thought to include the Big awkward skeleton without more than the steady-state cosmology ofthe 1950s, Hoyle's Bang as a special case. The Universe, while most minimal institutional support, and on joint invention with Thomas Gold and expanding overall, is one in which there are the basis of occasional weeks holed up to­ Hermann Bondi, which had matter (presum­ periodic outbursts of matter-creation the gether in some hotel. ably in the form of hydrogen atoms) trick­ most recent of which was that 14 billion But what will matter, in the end, is whether ling into the Universe at such a rate that its years ago. And does it not make sense to they can make some prediction about the average density remained constant. Too suppose that the direct evidence of that is the Universe that will be arresting enough to much has happened since the 1950s for that apparent outpouring of mass from the dis­ divert the attention of others from more to be a tenable proposition, notably the tant quasars, with redshift z in excess of 3. 0 conventional trains ofthought. This month's discovery of quasars and other active galac­ or more? In the prosecution of iconoclasm, paper (in Astronomy and Astrophysics) says tic nuclei, the discovery of the microwave it always helps if the defenders of a conven­ that there should be a predominance of blue background and the recognition that the true tional view are able to retreat gracefully, by galaxies, some with their light blue-shifted, constituents of matter are quarks and lep­ arguing that their own position has merely among the faintest galaxies of all, which tons (electrons and the like). been absorbed in a more general framework. may be a beginning. The new theory is called, instead, a Nevertheless it seems improbable that What Hoyle, Burbidge and Narlikar say "quasi -steady state" cosmology. Matter does the flow of papers from Hoyle, Burbidge is that they will next tum their attention to not trickle into the Universe, but instead and Narlikar will quickly sweep away the explosive creation (in their view, in quasars appears only at places where its concentra­ Big Bang. Not that the authors have shirked and the like) and see whether quasi-steady tion is already high, in the nuclei of galaxies the task, indispensable for iconoclasts, of state cosmology has something to say about for example. What this means for the Uni­ attempting to show that the observations the distribution of galaxies as observed. verse as a whole is perhaps most easily counted as evidence for the Big Bang are However that comes out, they at least de­ gleaned from an article by the same three also compatible with their view. In this spirit serve credit for having pointed to one way in authors in the Monthly Notices ofthe Royal they deal with the synthesis of elements which the Big Bang, an event without a Astronomical Society (which now belies its such as helium, most of which, on any view, cause, might be brought within a wider title by appearing twice a month) in April must be primordial and not (like heavier framework. John Maddox

NATURE · VOL 371 · 1 SEPTEMBER 1994 11