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Redshift Without Expansion at All

Molecular Hydrogen: The Invisible Energy-Absorber

The steady-state and Kleine's antimatter theories both accepted the conventional interpretation of the redshift but sought causes for it other than the Big Bang. But what if it has nothing to do with expansion of the universe at all? We already saw that Finlay-Freundlich's derivation of the background temperature in the early fifties considered a "tired light" explanation that Born analyzed in terms of photon-photon interactions. More recently, the concept has found a more substantial grounding in the work of Paul Marmet, a former physicist at the University of Ottawa, and before that, senior researcher at the Herzberg Institute of Astrophysics of the National Research Council of Canada.

It has long been known that space is permeated by hydrogen, readily detectable by its 21-centimeter emission line, or absorption at that wavelength from the background radiation. This signal arises from the spin of the hydrogen atom. Monatomic hydrogen, however, is extremely unstable and reacts promptly to form diatomic hydrogen molecules, H2. Molecular hydrogen is very stable, and once formed does not easily dissociate again. Hence, if space is pervaded by large amounts of atomic hydrogen, then molecular hydrogen should exist there too—according to the calculations of Marmet and his colleagues, building up to far greater amounts than the atomic kind. 56 Molecular hydrogen, however, is extraordinarily difficult to detect—in fact, it is the most transparent of diatomic molecules. But in what seems a peculiar omission, estimates of the amount of hydrogen in the universe have traditionally failed to distinguish between the two kinds and reported only the immediately detectable atomic variety.

Using the European Space Agency's Infrared Space Observatory, E. A. Valentijn and P. P. van der Werf recently confirmed the existence of huge amounts of molecular hydrogen in NGC891, a galaxy seen edge-on, 30 million light-years away. 57 This discovery was based on new techniques capable of detecting the radiation from rotational state transitions that occur in hydrogen molecules excited to relatively hot conditions. Cold molecular hydrogen is still undetectable, but predictions from observed data put it at five to fifteen times the amount of atomic hydrogen that has long been confirmed. This amount of hitherto invisible hydrogen in the universe would have a crucial effect on the behavior of light passing through it.

Most people having a familiarity with physics have seen the demonstration of momentum transfer performed with two pendulums, each consisting of a rod weighted by a ball, suspended adjacently such that when both are at rest the balls just touch. When one pendulum is moved away and released, it stops dead on striking the other, which absorbs the momentum and flies away in the same direction as the first was moving. The collision is never perfectly "elastic," meaning that some of the impact energy is lost as heat, and the return swing of the second pendulum will not quite reverse the process totally, bringing the system eventually to rest.

Something similar happens when a photon of light collides with a molecule of a transparent medium. The energy is absorbed and reemitted in the same, forward direction, but with a slight energy loss—about 10-13 of the energy of the incoming photon. 58 (Note this is not the same as the transverse "Rayleigh scattering" that produces angular dispersion and produces the blueness of the sky, which is far less frequent. The refractive index of a transparent medium is a measure of light's being slowed down by successive forward re-emissions. In the case of air it is 1.0003, indicating that photons traveling 100 meters are delayed 3 centimeters, corresponding to about a billion collisions. But there is no noticeable fuzziness in images at such distances.)

What this means is that light traveling across thousands, or millions, or billions of light-years of space experiences innumerable such collisions, losing a small fraction of its energy at each one and hence undergoing a minute reddening. The spectrum of the light will thus be shifted progressively toward the red by an amount that increases with distance—a result indistinguishable from the distance relationship derived from an assumed Doppler effect. So no expansion of the universe is inferred, and hence there's no call for any Big Bang to have caused it.

Two further observations that have been known for a long time lend support to this interpretation. The Sun has a redshift not attributable to gravity, which is greater at the edges of the disk than in the center. This could be explained by sunlight from the edge having to pass through a greater thickness of lower solar atmosphere, where more electrons are concentrated. (It's the electrons in H2 molecules that do the absorbing and reemitting.) Second, it has been known since 1911 that the spectra of hot, bright blue OB-type stars—blue-white stars at the hot end of the range that stars come in—in our galaxy show a slight but significant redshift. No satisfactory explanation has ever been agreed. But it was not concluded that we are located in the center of an expanding shell of OB stars.

So the redshift doesn't have to imply an expansion of the universe. An infinite, static universe is compatible with other interpretations—and ones, at that, based on solid bodies of observational data rather than deduction from assumptions. However, none of the models we've looked at so far questions the original Hubble relationship relating the amount of the shift to distance (although the value of the number relating it has been reappraised several times). But what if the redshifts are not indicators of distance at all?

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