Some promote an infinitely (or near infinitely) old universe to avoid a creation event in the relatively recent (roughly 14-billion-year) past. So, they argue that the universe is static or semi-static-no general cosmic expansion. Others promote a very young creation (6,000-10,000 years old) to fit a particular interpretation of Genesis 1. They need the expansion to occur much more rapidly than a few billion years. Nestled in between is the established scientific-and biblical-model saying that expansion has occurred continuously over the past 13.7 billion years.
Recent measurements of Type Ia supernova eruptions, however, rule out all options except those fitting the latter model.1 To understand how, a little background is useful. Atoms of a given element absorb or emit light at unique wavelengths, so the spectrum of a particular element will show lines of specific colors instead of a rainbow of colors. When astronomers look at distant galaxies, the spectral lines from atoms in those galaxies are redshifted, or "pulled," toward the red end of the radiation spectrum.
The simplest way to explain the redshift is to say that the galaxies are moving away from us. If the universe is continuously expanding, the more distant galaxies will manifest a greater redshift-which is precisely what is measured. Through the years, some astronomers who dislike the implications of cosmic expansion have proposed other explanations for redshifts and their relation to distance.
Two static-universe alternatives are the "tired light"2 and "varying mass"3 models. The former model says that as light propagates through space it loses energy, and this loss increases its wavelength. The "varying mass" model says atomic masses increase as the universe ages. Light from more distant objects was emitted when the universe was younger and, therefore, the masses of the atoms were smaller. Smaller atomic masses mean longer wavelengths. Both of these models were developed solely to explain the redshift/distance relationship without appealing to continuous cosmic expansion from a creation event about 14 billion years ago-not because astronomers actually predicted light to lose energy in transit or atomic masses to change.
The most widely accepted young-universe model acknowledges that while the universe exhibits billions of years of development,4 due to a (hypothesized) gravitational time dilation effect, only a few thousand years have elapsed on Earth. In other words, the rates of all distant phenomena occur thousands to millions of times faster when measured from Earth. Big bang models, however, predict the opposite-that velocity time dilation effects will make very distant phenomena appear to proceed more slowly (by a few tens of percent).
Recently, a team of American astronomers developed and applied a robust new method for testing and distinguishing among the different models.5 The test involves multiple spectral measurements of Type Ia supernovae eruptions-events that last about 7 months in the absence of time dilation effects. The team looked at how the different spectral line intensities change over the supernova eruption phase and thus determined how far into the 7-month period the eruption has progressed. The time dilation factor is determined by dividing the time between observations by the change in time progressed into the eruption. Say an astronomer made two spectral observations 20 days apart and determined the time progressed into the eruption was 10 days and 26 days, respectively. The time dilation factor would be 20/(26-10) = 1.25. For static or semi-static universes, the time dilation factor will be 1. For a young universe, the time dilation factor will be near zero. For a big bang universe, the time dilation factor will be one plus the redshift of the object.
So far, the method has been accurately applied to one distant supernova, 1997ex. The results were perfectly consistent with continuous cosmic expansion from a cosmic creation event roughly 14 billion years ago. At the same time, they definitively falsified both the nonexpanding universe models and the young-universe models. As with previous tests based on a variety of methods,5 the biblically anticipated cosmic creation model has been vindicated with flying colors.
by Dr. Jeff Zweerink and Dr. Hugh Ross