Facts about radiometric dating
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%).
This value is derived from several different lines of evidence.
You could talk about the tiny quartz crystal and the piezoelectric effect used to provide a stable time base for the electronic movement.
You could describe the atomic workings of the quartz oscillator and how it resonates at a specific and highly stable frequency, and how this is used to accurately pace a timekeeping mechanism.
Over time, the amounts of Pb-206 and Pb-207 will change in some samples, as these isotopes are decay end-products of uranium decay (U-238 decays to Pb-206, and U-235 decays to Pb-207).
This causes the data points to separate from each other.
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).
You can only establish the time for the race if it was timed by two or more qualified eyewitnesses who observed the start, the progress and the finish.When I have asked an audience this question they have looked at me incredulously and said, “Starting time?” You cannot know how long the swimmer took unless you knew the time on the wristwatch when the race started.This illustrates the whole problem with the radioactive dating of geological events.