Because of such contamination, the less than 50-year-old lava flows at Mt.
Ngauruhoe, New Zealand (), yield a rubidium-strontium “age” of 133 million years, a samarium-neodymium “age” of 197 million years, and a uranium-lead “age” of 3.908 billion years!
8 Physicists have carefully measured the radioactive decay rates of parent radioisotopes in laboratories over the last 100 or so years and have found them to be essentially constant (within the measurement error margins).
Furthermore, they have not been able to significantly change these decay rates by heat, pressure, or electrical and magnetic fields.
Part 2 explains how scientists run into problems when they make assumptions about what happened .
An hourglass is a helpful analogy to explain how geologists calculate the ages of rocks.
Based on these observations and the known rate of radioactive decay, they estimate the time it has taken for the daughter isotope to accumulate in the rock.
However, unlike the hourglass whose accuracy can be tested by turning it upside down and comparing it to trustworthy clocks, the reliability of the radioactive “clock” is subject to three unprovable assumptions.
To make matters even worse for the claimed reliability of these radiometric dating methods, these same basalts that flowed from the top of the Canyon yield a samarium-neodymium age of about 916 million years,5 and a uranium-lead age of about 2.6 billion years!We find places on the North Rim where volcanoes erupted after the Canyon was formed, sending lavas cascading over the walls and down into the Canyon.Obviously, these eruptions took place very recently, after the Canyon’s layers were deposited ().The rate of uranium decay must have been at least 250,000 times faster than today’s measured rate! As this article has illustrated, rocks may have inherited parent and daughter isotopes from their sources, or they may have been contaminated when they moved through other rocks to their current locations.
Or inflowing water may have mixed isotopes into the rocks.
When we look at sand in an hourglass, we can estimate how much time has passed based on the amount of sand that has fallen to the bottom.