Absolute dating for kids
We have a long record of events in absolute time but much of that occurred before humans were on Earth to write it down.
Since absolute time gives us points of reference, it helps calibrate relative time, also called chronostratic time ('strata' means 'layers').
There are some radioactive elements in rock that decay by giving off energy and turning into different, more stable elements.
This radioactive decay takes place at a constant rate for each radioactive element.
So relative to the other meals, it falls in the middle and is later than breakfast yet earlier than dinner.
This is useful in geology because you can age layers of rock relative to other layers.
They are both important in terms of Earth's history and its geological timeline, and they work together in concert to build the planet's geological record.