Many Christians consider the universe to be relatively young. But is it really? While special revelation (the Bible) does not specifically address the age issue, general revelation (the book of nature*) provides a veritable host of clues.
First, the reality that nothing travels faster than the speed of light and that billions of light-years separate us from distant galaxies leads logically to the assumption that the age of the universe is measured in billions rather than in thousands of years.
Furthermore, star life is a persuasive argument for a universe measured in billions of years. Star life depends on star mass. A star like the sun has enough fuel to burn for an estimated 9 billion years. Conversely, the fuel of a star half the size of the sun may last as long as 20 billion years. As such, the universe is presumed to be at least as old as the oldest stars within in it. While biological history may be a matter of inference, astronomical history is a function of direct observation. Put another way, star formation can be observed in all of its stages.
Finally, sequential layers in the formation of ice cores in places such as Antarctica and Greenland point to an earth much older than six thousand years. Just as arborists count tree rings to estimate the age of trees, researchers count sequential layers to date the age of ice cores. This data log seems to demonstrate that the age of the earth is at least hundreds of times older than the age presumed by young-earth creationists*.
For further study, see Guillermo Gonzalez and Jay W. Richards, The Priveleged Planet: How Our Place in the Cosmos Is Designed for Discovery (Washington, DC: Regnery, 2004).