What is it?
In keeping with the theme of this blog, and as elaborated on below, Steady State theory has few advocates today. However, it has evolved somewhat, and survives thanks to a few staunch supporters in the form of the Quasi-Steady State Cosmology (QSSC hereafter). QSSC is named as such as its model of matter creation is not as ‘steady’ as that of its predecessor. In this more recent version of the theory, proposed in the early ‘90s, the Universe undergoes alternating phases in which small and large amounts of matter creation take place. Increased creation boosts the acceleration of the Universe as the matter is repelled. This in turn causes the strength of the repulsive c-field to diminish, slowing the acceleration until the next large creation phase takes place. It is this coupling of steady exponential expansion with short-term oscillations in matter creation that give the QSSC its name.
QSSC also provided a more detailed mechanism for the creation of matter. On a small scale, QSSC describes the creation of a ‘Planck particle’ in the c-field, the mass of which depends on the speed of light, Planck’s constant and the Gravitational constant. This particle then decays into a family of eight baryons; a proton, a neutron and six other short-lived particles which further decay to form six more protons. This process therefore creates the basic matter required to form stars, which in turn (according to Steady State theory) produce all the heavier elements.
Some proponents of the QSSC claim that the creation of matter on the larger scale is actually observed today in the form of matter ejection from the centre of active galactic nuclei (AGN). According to traditional Big Bang cosmology, the centre of such a system is inhabited by a black hole, around which in-falling matter is pulled into a whirling, energy radiating accretion disc and matter is violently ejected in jets along its axis. Conversely, it is proposed in QSSC that the central nucleus of an active galaxy is not a point from which matter cannot escape, but rather a point at which energy is created. In fact, QSSC does not allow the existence of singularities, the theoretical infinitely dense point that lies at the centre of a black hole in standard Big Bang cosmology. Purported observational evidence of matter ejection from the centre of AGN comes in the form of quasi-stellar objects, or ‘quasars’, extremely bright objects which appear as star-like points in the sky, but themselves appear to be a type of AGN. These are sometimes found to be clustered around larger active galaxies, sometimes even displaying a ‘bridge’ of faintly luminous matter apparently connecting the two objects.
What happened to it?
The first major challenge to the Steady State theory came as a result of advances in radio astronomy in the late 1950s. It was observed that there was a surplus of faint, distant radio sources. Both Steady State and Big Bang cosmologies originally assumed that the production of radio sources is conserved, so that there would be the same number of radio sources everywhere in the Universe at any given time. Since Steady State cosmology tells us that the density of the Universe and the rate of creation of matter have always remained constant, it was impossible for the surplus of distant radio sources to be explained. Big Bang cosmology had already predicted a greater density of radio sources in the early Universe – since the same number of radio sources existed in a smaller volume – but even so its prediction still fell short of the observation. Since SS had based its predictions upon assumptions crucial to the foundations of the theory itself, adjustments could not be made to fit this data. BB cosmologists however, were able to discard the principle of conservation of radio sources, and instead postulate that an excess of radio sources were produced at a given time after the Big Bang, hence producing a good fit to the observations.
In the previous section we briefly reviewed the process by which the lightest nuclei are created in the Steady State theory. Since there is no initial creation event in this cosmology, it was originally proposed that all the heavier elements could be synthesised in stars. However, although heavy element abundances are generally proportional to each other (relative to the amount of hydrogen present) observations show that the abundance of helium does not fall to zero along with other heavier elements. Advocates of Steady State theory accepted that the observed abundance of helium could not be produced in stars alone. Indeed, Fred Hoyle himself – one of the theory’s originators – published an article in 1964 entitled ‘The Mystery of the Cosmic Helium Abundance’, in which he stated as much. The paper was published shortly before a scientific discovery that, for most scientists, provided undeniable validation for the Big Bang theory and solved the puzzle for good.
The discovery in 1965 that a microwave-frequency radiation permeates the Universe is considered by many to be the biggest triumph of Big Bang theory and the final blow for Steady State cosmology. The cosmic microwave background radiation has an average temperature of about 3 degrees Kelvin, and displays a smooth spectrum characteristic of an ideal black body – a body through which no light passes and none is reflected. Big Bang cosmology holds that up until 380,000 years after the Big Bang, the temperature was so high that radiation and matter were coupled and the Universe was opaque. A major prediction of the theory was that a radiation such as the CMB would be produced after the Universe had cooled sufficiently for matter and radiation to decouple. Upon the observational discovery of this radiation, the Big Bang was hailed by many as a success. Steady State cosmologists attempted to reconcile this data with their cosmology by attributing the radiation to the scattering of ancient starlight by galactic dust. Such a mechanism is however at odds with the extreme black-body nature of the radiation, as well as the fact that the light shows little evidence of polarisation and other phenomena associated with scattering. Recent attempts by Quasi Steady State cosmologists to model the CMB spectrum as a result of absorption and thermal re-emission of energy by metallic needle-like dust known as ‘whiskers’ have produced a better fit to data, but still are unable to produce a result as convincing as that of the Big Bang theory.
In what might be considered damning with faint praise, it is sometimes said of the Steady State theory that its biggest strength as a cosmological model was that it made useful, testable predictions. Unfortunately for the theory, the tests did not yield the desired results. At the very least, in Steady State theory we have an alternative model of the Universe that has been formulated, tested and assessed alongside the Big Bang theory according to the basic principals of the scientific method. It is important to bear in mind that the current standard cosmology has not been arbitrarily awarded such a status, but has provided us with predictions that have been validated, and a useful description of observational information. Conversely, we should consider the fact that Steady State theory once seemed a perfectly reasonable model of the Universe, and there may yet be experimental or observational evidence that leads us to question the deep-seated beliefs that are currently seen as elementary to our understanding of the Universe.
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