It is extremely evident from astronomy that our Universe is billions of light-years across, and thus that light from distant stars has taken billions of years to reach us. One method of accurately determining star distances uses Cephid variable stars, which have a known relationship between brightness and pulse rate. This relationship is explained by physics, and verified (calibrated) by measuring all Cephid variable stars whose distances are close enough to confirm by parallax. Therefore, the actual brightness of a Cephid variable star can be determined by its pulse rate, regardless of how far away it is. And, of course, if a star's actual brightness and measured (apparent) brightness are known, its distance can be calculated from a simple equation (apparent brightness decreases as one over the distance squared). This and many other methods verify Hubble's law describing the expansion of the Universe, with the beginning (Genesis 1:1) between 10 and 20 billion years ago. Attempts by young-Earth proponents to explain these facts have been unavailing. Norman and Setterfield's proposal of decay in the speed of light is easily shown to be invalid (Roberts, Ross, and Stoner all deal with this), as is Humphreys' attempt at a young-Earth cosmology (see Conner and Ross (1999) http://www.reasons.org/resources/apologetics/unravelling.html). Another explanation, that the Universe was created with "appearance of age" is both un-scientific at its core (if all the evidence that we see for age is fabricated, then why even have this debate?), as well as having theological problems with the truthfulness of God, since in that case we are constantly observing events in the cosmos which in fact never occurred (see Brain Teaser: SN1987a, http://lordibelieve.org/page16.html, for an illustrative example of this point).