To read the time on this radioactive clock, scientists use a device called a mass spectrometer to measure the number of parent and daughter atoms.
The ratio of parents to daughters can tell the researcher how old the specimen is.
So if scientists believe that a creature lived millions of years ago, then they would need to date it another way. They assume dinosaurs lived millions of years ago (instead of thousands of years ago like the bible says).
The same is true if you take a block away from one of the pyramid's sides, making the rest unstable.
Eventually, some of the blocks can fall away, leaving a smaller, more stable structure.
Radiometric dating relies on the properties of isotopes.
These are chemical elements, like carbon or uranium, that are identical except for one key feature -- the number of neutrons in their nucleus.