The actual underlying assumption is that, if those requirements have not been met, there is no reason for the data points to fall on a line.The resulting plot has data points for each of five meteorites that contain varying levels of uranium, a single data point for all meteorites that do not, and one (solid circle) data point for modern terrestrial sediments.

radiometric isochron dating-64radiometric isochron dating-74radiometric isochron dating-29

Helium is not light enough to escape the Earth's gravity (unlike hydrogen), and it will therefore accumulate over time.

The current level of helium in the atmosphere would accumulate in less than two hundred thousand years, therefore the Earth is young.

A young-Earther would object to all of the "assumptions" listed above.

However, the test for these assumptions is the plot of the data itself.

For example: Also note that the meteorite ages (both when dated mainly by Rb-Sr dating in groups, and by multiple means individually) are in exact agreement with the solar system "model lead age" produced earlier.

Young-Earthers have several methods which they claim to give "upper limits" to the age of the Earth, much lower than the age calculated above (usually in the thousands of years).While these values do not compute an age for the Earth, they do establish a lower limit (the Earth must be at least as old as any formation on it).This lower limit is at least concordant with the independently derived figure of 4.55 billion years for the Earth's actual age.For example, Henry Morris says: He lead to similar results, i.e., a rate virtually identical to the estimated production flux.Another possible escape mechanism is direct interaction of the solar wind with the upper atmosphere during the short periods of lower magnetic-field intensity while the field is reversing.he generally accepted age for the Earth and the rest of the solar system is about 4.55 billion years (plus or minus about 1%).