mlc9852: Things made in Roman times don't go back billions of years.
I think the "radioactive dating" in this case would be radiocarbon dating, which goes from near the present to about 50,000 years into the past.
It is pretty accurate, in spite of what the Creationists websites claim. I have done a bit of this, so I could try to answer any questions you might have.
Big different between 50,000 years and billions of years, right?