Final answer:
The age of objects or events can be determined using methods such as carbon-14 dating for organic materials and measuring the accumulation of radioactive elements in non-organic materials. These estimates tend to be consistent with the age of the universe as calculated from cosmic expansion.
Step-by-step explanation:
There are several methods of measuring the age of objects or events in absolute terms, meaning in years. The most common and widely known technique is carbon-14 dating, which is used to date organic materials based on the decay of the carbon-14 isotope. Living organisms continually take in carbon-14 through their interactions with the environment, and when they die, the carbon-14 starts to decay at a known rate. This allows scientists to determine the time elapsed since the organism's death.
An alternative method involves using other radioactive elements that have accumulated in an object. This is particularly useful in dating minerals and rocks that were heated to high temperatures in the past. By measuring the accumulated radioactive elements and their decay products, scientists can calculate the time since the heating event.
When comparing these dating methods with estimates of the age of the universe determined by its expansion, we find that they tend to be consistent. The oldest astronomical objects we can date, such as stars, are younger than the universe's estimated age of 13.8 billion years, thus affirming our models of cosmic evolution.