By using synchronized atomic clocks located around the globe, scientists can establish a common time scale.
Local Clocks and Time Transfer: To measure time locally within specific regions of the universe, scientists rely on highly accurate atomic clocks. These clocks are designed to be as precise and stable as possible. Time transfer techniques, such as satellite-based signals or optical fibers, can be used to synchronize clocks across long distances, compensating for relativistic effects during the transfer.
Gravitational Time Dilation Compensation: Clocks located in different gravitational fields experience different rates of time due to gravitational time dilation. To compensate for this effect, scientists can apply correction factors based on the known gravitational field strength at each location. This allows for the comparison of time measurements across different regions with varying gravitational influences.
Time Delays in Observations: When observing distant objects in the universe, there can be time delays in receiving their signals due to the finite speed of light. This means that the information we receive from those objects is already "outdated" by the time it reaches us. Scientists take these time delays into account when studying remote events and adjusting their measurements accordingly.
Despite these measures, achieving truly consistent timekeeping across the entire universe is currently not feasible. The vast distances, variations in gravitational fields, and the expansion of the universe itself all contribute to significant challenges in establishing a universal time scale. However, within local or regional contexts, precise timekeeping methods and synchronization techniques help maintain a consistent measure of time to support scientific observations and calculations.