For our purposes, we are going to look at the methods scientists use to measure the age of the earth. Most scientists seem to agree that the earth is about 4.6 billion years old.

Just how big a number is 4.6 billion??? It is difficult to visualize, but we will try to demonstrate how large the number really is.

Let's use a common land snail, the kind you see on the sidewalks, to help illustrate how huge a number 4.6 billion is. Let's say our snail can crawl one (1) foot (twelve inches) in an hour.

• That means he would travel twenty-four feet (24') in a full day -- or about the length of two mid-sized cars.

• It would take our snail a week to crawl one hundred sixty-eight feet -- or barely more the half the length of a football field.

• In a full year of crawling without ever stopping, our snail would only travel one and two-thirds miles.

• If our snail continued to crawl for one hundred years without ever stopping, he would be able to crawl from Baton Rouge, Louisiana to Jackson, Mississippi.

• If our snail started crawling on January 1, 1000 AD, on December 31, 1999, he would finally reach Boston Massachusetts -- it would take him a full millennium to go that distance -- and that's only one thousand years -- but hold on to your hat!!

• In ten thousand years, our little snail would be able to crawl from Baton Rouge, Louisiana to Cape Town, South Africa!!

• If it crawled without stopping for one hundred thousand years, he would be able to make six complete crawling trips around the earth at the equator! And remember, the circumference of the earth at the equator is about 27,000 miles!!!

• How long is a million years? Well, a million years is long enough for this slow moving snail to crawl from the earth to the moon -- and back -- THREE TIMES!!! The moon is approximately 260,000 miles from the earth.

• What about one hundred million years? How long is that? That is long enough for our snail to crawl around the earth's equator three times (27,000 miles each trip) and then travel all the way from from the earth to the sun --- 93 million (93,000,000) miles away!!

• OK, one billion years. Is that a long time? Are you ready for something really astonishing? Our snail, in 1 billion years would be able to crawl to the sun and back (a round trip of 186 million miles) NINE MILLION TIMES!! A billion years is a very long time!!!

• Thus, in 4.6 billion years, the snail would crawl from the earth to the sun and back 40,500,000 times (40.5 million times)!!

Obviously, 4.6 billiion years is a long, long, long time --- actually it's beyond our comprehension. Let's move on and find out how scientists measure earth age and how they came up with the number "4.6 billion years" as the age of the earth.