If evolution is true...?

Why isn't the m spectrometer, which is a whole lot more reliable, used more than all of the other unreliable dating methods? And why, when they used this machine to date all of the earliest skeletal remains in the Western Hemisphere, were found to be only about 5,000 years old? (Brown, In the Beginning, 1989, p. 95) Hmmmm, that would throw the evolution theory out the window.