Carbon dating uranium
By 1904 physicist Ernest Rutherford showed how this decay process could act as a clock for dating old rocks.Meanwhile, Arthur Holmes (1890-1964) was finishing up a geology degree at the Imperial College of Science in London where he developed the technique of dating rocks using the uranium-lead method.Uranium comes in two common isotopes with atomic weights of 235 and 238 (we'll call them 235U and 238U).
In 1898, Marie Curie discovered the phenomenon of radioactivity, in which unstable atoms lose energy, or decay, by emitting radiation in the form of particles or electromagnetic waves.
With this background in the uranium-lead method, you may have a deeper appreciation of the research presented on the University of Wisconsin's "Earliest Piece of the Earth" page, including the 2001 paper in Nature that announced the record-setting date.
When asked for your age, it's likely you won't slip (with the exception of a recent birthday mistake).
Dating a rock involves uranium-lead measurements on many zircons, then assessing the quality of the data.
Some zircons are obviously disturbed and can be ignored, while other cases are harder to judge.