How Do We Know Earth is 4.5 Billion Years Old?

Answers in Genesis, those evil people who recently opened a Creation Museum in Kentucky, have an article today on radiometric dating. Radiometric dating is they key piece of evidence supporting the contention that the earth is 4.5 billion years old.

What is radiometric dating?

The radioisotope dating clock starts when a rock cools. During the molten state it is assumed that the intense heat will force any gaseous daughter elements like argon to escape. Once the rock cools it is assumed that no more atoms can escape and any daughter element found in a rock will be the result of radioactive decay. The dating process then requires measuring how much daughter element is in a rock sample and knowing the decay rate (i.e., how long it takes the parent element to decay into the daughter element—uranium into lead or potassium into argon).

For rocks we might assume are very old, or at least there are are no recorded observations of the formation of these rocks, we have to make assumptions about how their age will be measured.

There are three critical assumptions upon which radiometric dating is based:

1. The initial conditions of the rock sample are accurately known.

2. The amount of parent or daughter elements in a sample has not been altered by processes other than radioactive decay.

3. The decay rate (or half-life) of the parent isotope has remained constant since the rock was formed.

Sounds good in theory, right? But how often do our ideas survive clashes with reality?

Here's what happened when scientist went out and radiometrically dated newly formed rock samples:

We know that radioisotope dating does not always work because we can test it on rocks of known age. In 1997, a team of eight research scientists known as the RATE group (Radioisotopes and the Age of The Earth) set out to investigate the assumptions commonly made in standard radioisotope dating practices (also referred to as single-sample radioisotope dating). Their findings were significant and directly impact the evolutionary dates of millions of years.

Steve Austin, PhD geology, and member of the RATE team, had a rock from the newly formed 1986 lava dome from Mount St. Helens dated. Using Potassium-Argon dating, the newly formed rocks gave ages between 0.5 and 2.8 million years. These dates show that significant argon (daughter element) was present when the rock solidified (assumption 1 is false).

Mount Ngauruhoe is located on the North Island of New Zealand and is one of the country’s most active volcanoes. Eleven samples were taken from solidified lava and dated. These rocks are known to have formed from eruptions in 1949, 1954, and 1975. The rock samples were sent to a respected commercial laboratory (Geochron Laboratories in Cambridge, Massachusetts). The “ages” of the rocks ranged from 0.27 to 3.5 million years old. Because these rocks are known to be less than 70 years old, it is apparent that assumption #1 is again false. When radioisotope dating fails to give accurate dates on rocks of known age, why should we trust it for rocks of unknown age? In each case the ages of the rocks were greatly inflated.

Hmmmm. If rocks that we know are only a few years old are dated at millions of years old, how can we assume rocks that we don't know the age of through observation are in fact millions of years old? Faith?

The article has more information on some different dating methods than those used in the Mt. St. Helens and New Zealand measurements. But the results are essentially the same: no scientifically reliable method for supporting a measurement of millions of years.

Apparently faith comes in pretty handy in the "scientific" world as well...